JP4439245B2 - Electronic endoscope device - Google Patents

Description

  The present invention relates to an electronic endoscope apparatus, and more particularly to an electronic endoscope apparatus capable of capturing a freeze image with less blur.

  In an electronic endoscope apparatus that observes and examines a body cavity, capturing a subject image, that is, a still image (freeze image) of the affected part in the body cavity, also enables the operator to periodically grasp the healing state of the affected part. It is a necessary function. However, when capturing a freeze image, it is necessary to capture a moving image of the subject in parallel. In addition, when capturing a fast-moving subject, capturing a freeze image with less blur is a function necessary for obtaining a clear image of the affected part in the body cavity.

Patent Document 1 discloses an apparatus that displays a less blurred image by shortening the charge accumulation and readout period by thinning out and reading out one field image when capturing a fast-moving subject image.
JP 2002-209838 A

  However, this device is suitable for capturing a moving image that is difficult to recognize that the image quality has deteriorated even if the image of one field is thinned out and read out. Is not suitable because it causes a significant decrease in image quality.

  Accordingly, an object of the present invention is to provide an electronic endoscope apparatus that can capture a freeze image with less blur while performing moving image capturing in parallel.

  The electronic endoscope apparatus according to the present invention is different in size from a scope having an electronic shutter and a field storage type imaging device that outputs an image signal for generating a predetermined video signal. Consists of a light transmission part and a light blocking part, and the first and second light transmission parts sequentially pass on the light beam emitted from the light source device by rotation, and the light quantity is controlled by the first light transmission part. The first light transmission part passage period passing above is shorter than one field period of the video signal, and the first light transmission part passage period during which the second light transmission part passes over the luminous flux is one frame period of the video signal. A shorter shutter, a first luminance of the subject imaged during the first light transmission portion passage period, a luminance detection means for detecting a second luminance of the subject imaged during the second light transmission portion passage period, 1. Brightness control hand that controls the second brightness to the same level The rotation is performed at the first rotation timing when the first field of the frame is switched from the first field to the second field at the end of half of the first light transmission part passage period, and at the start time of the second light transmission part passage period. Switching from the second field to the first field of the next frame is performed in accordance with the second rotation timing at which the second light transmission part passage period ends after the end of the second field of the next frame.

  Preferably, in the second rotation timing, the second light transmission portion passage period ends at the end of the second field of the next frame.

  Preferably, in the rotary shutter, the first and second light transmission parts are configured continuously, and the second rotation timing is after the end of the second field of the next frame and the first light transmission part passage period. The second light transmission part passage period ends at the start time of the first, and the electric charge accumulated between the end time of the second field of the next frame and the start time of the first light transmission part passage period is swept out by the electronic shutter. In addition, the light beam is blocked by the light blocking unit from the end point of the first light transmitting unit passing period to the start point of the second transmitting unit passing period.

  Preferably, the luminance control unit controls at least one of a light amount emitted from the light source device during a first light transmission unit passage period and an amplification degree for amplifying an output signal from the imaging element. This makes it possible to control the brightness of the subject image captured during the first light transmission portion passage period.

  Preferably, the luminance control means includes at least one of a light amount emitted from the light source device during the second light transmission unit passage period, an amplification factor for amplifying an output signal from the image sensor, and a dimming period of the electronic shutter. To control. This makes it possible to control the brightness of the subject image captured during the second light transmission portion passage period.

  Preferably, when the first and second luminances do not become the same level due to the luminance control, the charges accumulated during the first light transmission portion passing period are swept out as unnecessary charges and written as image signals in the image memory. Write stop means for stopping is provided. As a result, it is possible to eliminate the difficulty of viewing the moving image that is caused by the difference in brightness between the subject images captured during the first and second light transmission section passage periods.

  Preferably, when capturing a freeze image, there is provided freeze image capturing means for reading out an image signal based on the electric charges of the first and second fields accumulated during the first light transmission section passage period and storing it in the image memory. Thereby, it is possible to capture a freeze image captured in a short exposure period, and it is possible to capture a freeze image with less blur for a subject image that moves quickly.

  Preferably, when the freeze image is captured when the first and second luminances are not at the same level due to the luminance control, the charge of the first field or the second field accumulated during the second light transmission portion passage period is acquired. Freeze image capturing means for storing an image signal based on only one of the charges in the image memory.

  Preferably, a switching unit that switches between and uses either a rotary shutter or a dimming blade that controls the amount of light from the light source device when capturing a moving image is provided. As a result, when a freeze image is not required, it is possible to capture a moving image that is brighter than when a rotary shutter is used.

  An electronic endoscope apparatus for outputting an image signal for generating a predetermined video signal according to the present invention includes an electronic shutter and a scope having a field storage type and a frame storage type switchable image sensor. And the first and second light transmitting portions and the light blocking portions having different sizes, and the first and second light transmitting portions sequentially pass on the light beam emitted from the light source device by rotating. The first light transmission part passing period in which the light amount is controlled and the first light transmission part passes over the light beam is shorter than one field period of the video signal, and the second light transmission part passes through the light beam. The part passing period includes a rotary shutter shorter than one frame period of the video signal, the first luminance of the subject imaged during the first light transmitting part passing period, and the first brightness of the subject imaged during the second light transmitting part passing period. A luminance detecting means for detecting two luminances; And a luminance control means for controlling the luminance to the same level. In the frame including the first light transmission portion passing period, the charge accumulated in the frame accumulation type is read out, and in the other frames, the charge is accumulated in the field accumulation type. The charge is read out and the rotation is performed at the end of the first field of the frame at the third rotation timing at which the first light transmission part passage period ends and at the start of the second light transmission part passage period. The first field is switched to the fourth rotation timing at which the second light transmission part passage period ends after the end of the second field of the next frame. As a result, when a freeze image is captured, the timing at which charge accumulation starts and ends in the first and second fields can be matched, and a freeze image with less blur can be captured.

  Preferably, in the fourth rotation timing, the second light transmission part passage period ends at the end time of the second field of the next frame.

  Preferably, in the rotary shutter, the first and second light transmission portions are configured continuously, and the fourth rotation timing is after the end of the second field of the next frame and the first light transmission portion passage period. The second light transmission part passage period ends at the start time of the first, and the electric charge accumulated between the end time of the second field of the next frame and the start time of the first light transmission part passage period is swept out by the electronic shutter. In addition, the light beam is blocked by the light blocking unit from the end point of the first light transmitting unit passing period to the start point of the second transmitting unit passing period.

  Preferably, the luminance control unit controls at least one of a light amount emitted from the light source device during the first light transmission unit passage period and an amplification degree for amplifying an output signal from the imaging element. This makes it possible to control the brightness of the subject image captured during the first light transmission portion passage period.

  Preferably, the luminance control means includes at least one of a light amount emitted from the light source device during the second light transmission unit passage period, an amplification factor for amplifying an output signal from the image sensor, and a dimming period of the electronic shutter. To control. This makes it possible to control the brightness of the subject image captured during the second light transmission portion passage period.

  Preferably, when the first and second luminances do not become the same level due to the luminance control, the charges accumulated during the first light transmission portion passing period are swept out as unnecessary charges and written as image signals in the image memory. Write stop means for stopping is provided. As a result, it is possible to eliminate the difficulty of viewing the moving image that is caused by the difference in brightness between the subject images captured during the first and second light transmission section passage periods.

  Preferably, when capturing a freeze image, there is provided freeze image capturing means for reading out an image signal based on the electric charges of the first and second fields accumulated during the first light transmission section passage period and storing it in the image memory. Thereby, it is possible to capture a freeze image captured in a short exposure period, and it is possible to capture a freeze image with less blur for a subject image that moves quickly.

  Preferably, when the freeze image is captured when the first and second luminances are not at the same level due to the luminance control, the charge of the first field or the second field accumulated during the second light transmission portion passage period is acquired. Freeze image capturing means for storing an image signal based on only one of the charges in the image memory.

  Preferably, a switching unit that switches between and uses either a rotary shutter or a dimming blade that controls the amount of light from the light source device when capturing a moving image is provided.

  As described above, according to the present invention, it is possible to provide an electronic endoscope apparatus capable of capturing a freeze image with less blur while performing moving image capturing in parallel.

  Hereinafter, an embodiment of the present invention will be described first with reference to FIGS. FIG. 1 is an overall configuration diagram of an electronic endoscope apparatus. The endoscope apparatus according to this embodiment includes a color scope 10, a color processor 20, and a color monitor 40. The color scope 10 is controlled by the color processor 20 and images a subject. The image signal obtained by imaging is converted by the color processor 20 into a video signal that can be output by the color monitor 40. The converted video signal is transmitted to the color monitor 40 as an analog signal. The transmitted video signal is output (screen display) by the color monitor 40. The user can observe the subject image captured by the color scope based on the output result from the color monitor 40.

  The color scope 10 includes an imaging unit 11, an illumination unit 12, an operation unit 13, and a connector unit 14. The imaging unit 11 captures an image of the subject while the illumination unit 12 gives an appropriate amount of illumination light to the subject.

  The imaging unit 11 includes an imaging element 11a such as a CCD, a driver 11c that drives the imaging element 11a, and a ROM 11d in which data related to the characteristics of the color scope 10 are stored in advance. The driver 11c is controlled by the system control unit 24 according to a clock pulse output from the ROM 11d and a timing unit 25 described later. The charges accumulated in the image sensor 11a by imaging the subject are color-separated into R, G, and B image signals as electric signals and transferred to the first-stage image signal processing unit 21.

  The illumination unit 12 supplies light from a light source device 26 (described later) to the subject as illumination light. The operation unit 13 includes a switch 13a for switching the imaging mode and a switch 13b for instructing to capture a freeze image. The color scope 10 and the color processor 20 are optically and electrically connected by a connector unit 14.

  The color processor 20 includes a first-stage image signal processing unit 21, an image memory unit 22, a rear-stage image signal processing unit 23, a system control unit 24, a timing unit 25, a light source device 26, an operation switch unit 27, and a dimming unit unit 30. The image signal captured by the color scope 10 and generated based on the accumulated charge is converted into a video signal that can be output by the color monitor 40.

  The color monitor 40 is a commercially available color monitor that can capture and display an image signal, and outputs (displays on the screen) the video signal captured by the color scope 10 and converted by the color processor 20.

  The configuration of the color processor 20 will be described in detail with reference to FIG. The first-stage image signal processing unit 21 amplifies the transferred image signal by the RGB amplification degree setting unit 21 a and sequentially stores it in the image memory unit 22. The first-stage image signal processing unit 21 generates a luminance signal from the transferred image signal, and detects the luminance. The generation of the luminance signal is performed by the RGB / Y block 21b. Luminance detection is performed by the first brightness detection unit 21c and the second brightness detection unit 21d. The first brightness detection unit 21c performs luminance detection when a dimming blade 31 described later is used, and the second brightness detection unit 21d performs luminance detection when a rotary shutter 32 described later is used. Do. The luminance values detected by the first and second brightness detection units 21c and 21d are transferred to the system control unit 24, and the light control period of the electronic shutter, the amplification degree of the RGB amplification degree setting unit 21a, and the lamp unit 26b. Is used to control the amount of light.

  The image memory unit 22 stores the image signal amplified by the RGB amplification degree setting unit 21a for each RGB and for each field. The image signal stored in the image memory unit 22 is transferred to the subsequent image signal processing unit 23. 1 and 2 show that among the amplified image signals, the R image signal accumulated in the first field is accumulated in R1, the G image signal is accumulated in G1, the B image signal is accumulated in B1, and the second field. The R image signal is stored in R2, the G image signal is stored in G2, and the B image signal is stored in B2.

  The post-stage image signal processing unit 23 converts the transferred image signal into a video signal such as a composite signal or a Y / C separation signal and outputs it to the color monitor 40 or the like.

  The system control unit 24 includes a CPU and a RAM (not shown), and controls each part of the endoscope apparatus and temporarily stores signals.

  The timing unit 25 adjusts the processing timing by outputting a clock pulse, a synchronization signal, or the like to each unit under the control of the system control unit 24.

  The light source device 26 includes a lamp power supply unit 26 a, a lamp unit 26 b, and a condenser lens 26 c, and gives a light amount to the subject via the light control unit unit 30 and the illumination unit 12. The lamp unit 26b emits light by the electric power supplied from the lamp power supply 26a, the light beam is collected by the condenser lens 26c, and the collected light is illuminated by a light guiding member (not shown) such as an optical fiber. Is transmitted to the unit 12.

  The operation switch unit 27 includes a switch that sets the amount of light given through the dimming unit 30 and the illumination unit 12 to an arbitrary reference value of the user.

  The dimming unit 30 is a dimming blade 31 that adjusts the amount of light when capturing a normal moving image, and a rotary shutter 32 that adjusts the amount of light and the exposure period when capturing a freeze image in parallel with the capturing of a moving image. And having. The dimming unit 30 includes a first motor 33 that drives the dimming blade 31, a second motor 34 that drives the rotary shutter 32, and a first motor 33 that moves the dimming blade 31 and the rotary shutter 32 together to switch between them. 3 motors 35. Switching between the light control blade 31 and the rotary shutter 32 is performed by depressing the switch 13 a for switching the imaging mode of the operation unit 13 of the color scope 10. FIG. 2 shows a case where the third motor 35 is driven and the rotary shutter 32 is on the light beam, and FIG. 3 shows a case where the third motor 35 is driven and the dimming blade 31 is on the light beam. Further, in the present embodiment, as shown in FIG. 2, when the light beam from the lamp unit 26b is parallel light, the light beam is blocked by the rotary shutter 32 in a timely manner, but the light beam is collected by the condenser lens 26c or the like. The rotary shutter 32 may be disposed at a position after the operation.

  FIG. 4 is a perspective view of the rotary shutter 32 as seen from the lamp portion 26b side. FIG. 5 is a perspective view of the rotary shutter 32 as viewed from the side opposite to the lamp portion 26b. FIG. 6 is a plan view of the rotary shutter 32 as seen from the lamp portion 26b side. As shown in FIGS. 4 to 6, the rotary shutter 32 includes first and second light transmission parts 32a and 32b, and a light blocking part 32c. The second light transmission parts 32 a and 32 b sequentially pass on the light beam emitted from the light source device 26. The rotation direction is clockwise when viewed from the lamp portion 26b side. The first and second light transmission parts 32a and 32b are transparent members or holes that allow light from the lamp part 26b to pass through without being blocked. The light blocking portion 32c is an opaque member that blocks light from the lamp portion 26b.

  The period and timing when the first and second light transmission parts 32a and 32b pass over the light beam will be described in detail with reference to FIGS. First, timings such as charge accumulation at the time of normal moving image capturing will be described with reference to FIGS. Then, referring to FIG. 10, the period and timing when the first and second light transmission parts 32a and 32b pass over the light beam will be described.

  FIG. 7 shows a timing chart when a moving image is picked up by a normal field storage type image pickup device. FIG. 8 is a schematic diagram of transfer of charges accumulated in the first field in the field accumulation type imaging device. FIG. 9 is a schematic diagram of transfer of charges accumulated in the second field in the field accumulation type imaging device.

FIG. 7 shows the timing at which charges are accumulated in the first and second fields, and the timing at which image signals are output, that is, the accumulated charges are output as electrical signals, with the time axis t on the horizontal axis. The time lengths of the first and second fields are each 1/60 seconds, and the combined length of one frame is 1/30 seconds. Accordingly, the lengths of T _{10 to} T ₂₀ , T _{20 to} T ₃₀ ,..., T _{70 to} T ₈₀ are the same, and each is 1/60 second.

From the time of T _10, at time T ₂₀ that has elapsed 1/60 seconds, when the first field is completed, the odd-numbered pixels from the pixels close to the horizontal transfer register 11hr shown in FIG. _{8 (P 11, P 13,} P 21 , P ₂₃ , P ₃₁ , P ₃₃ ) and the charges of the next even-numbered pixels (P ₁₂ , P ₁₄ , P ₂₂ , P ₂₄ , P ₃₂ , P ₃₄ ) are simultaneously added and read out. The read charges are separated into RGB as an image signal and output to the color processor 20 through the vertical transfer register 11vr and the horizontal transfer register 11hr.

Meanwhile, have been made to accumulate a next charge, at the time T ₃₀ the first field has elapsed 1/60 seconds from the time T ₂₀ ended, the second field ends in an imaging device. Upon completion, as shown in FIG. 9, the combination of addition is changed, and the charges of the even-numbered pixels (P ₁₂ , P ₁₄ , P ₂₂ , P ₂₄ , P ₃₂ , P ₃₄ ) from the pixels close to the horizontal transfer register 11hr are changed. The charges of the next odd-numbered pixels (P ₁₃ , P ₁₅ , P ₂₃ , P ₂₅ , P ₃₃ , P ₃₅ ) are simultaneously added and read out. The read charges are separated into RGB as an image signal and output to the color processor 20 through the vertical transfer register 11vr and the horizontal transfer register 11hr.

Since the freeze image is formed by superimposing the image signals of the first and second fields, the charge accumulation start time is not the same time as the time point T ₁₀ for the first field and the time point T ₂₀ for the second field. Since the charge accumulation period is 1/60 second, blurring occurs when a moving subject image is captured. However, in the moving image, charge accumulation and charge reading are continuously performed for each of these fields, and it appears to the human eye that the image moves smoothly without blurring compared to the freeze image.

  FIG. 10 is a timing chart for capturing a freeze image according to the first embodiment. In FIG. 10, the horizontal axis represents the time axis t, and the charge accumulation timing in the first and second fields, the output timing of the image signal, the release of the electronic shutter, the timing of the dimming period, and the light amount of the lamp unit 26b are increased. The timing of the period to be performed is shown.

The flow in which the charge accumulated for each field is read out and output as an image signal to the color processor 20 through the vertical transfer register 11vr and the horizontal transfer register 11hr is the same as that shown in FIGS. Period in which the first light transmitting portion 32a passes over the light beam is between A period, namely from the time of T ₁₁ up to the point of T _21. From the time of T ₁₁ after which the first field has begun (T _10), beginning the first light transmitting portion 32a passes over the light beam, when the first field starts the second field of the same frame ends (T ₂₀ in), the first light transmitting portion 32a passes half on the optical beam at the time of T _21, passing on the light flux of the first light transmitting portion 32a is completed. T ₁₁ is the time point between the time of T ₁₀ up to the point of T _20, the shorter the T ₁₁ to T _20, the exposure period is short. In the present embodiment, as the time closer between a and T ₂₀ of the T ₁₁ T ₁₀ and T _20, and shorter than one field the length of the T ₁₁ ~T ₂₁ (1/60 seconds). For example, the period of A is 1/500 second. The length from time T ₂₀ to time T ₂₁ is the same as the length from time T ₁₁ to time T ₂₀ . That is, when the first light transmission part 32a passes through the light beam, the first light transmission part 32a passes over the light beam at the timing when the first field and the second field are switched. FIG. 6 shows the position of the rotary shutter 32 and the light beam at the half time point (T ₂₀ ) when the first light transmission part 32a passes over the light beam. Between _{T 10 ~T 11, T 21 ~T} 30 , the light blocking portion 32c passes over the light beam.

Between _{T 10 ~T 20, T 20 ~T} 30, the electronic shutter is released. Charge accumulation is performed every 1/60 seconds as usual, but light from the light source device 26 does not reach the subject and is not exposed while the light blocking portion 32c of the rotary shutter 32 passes over the light flux. The light from the light source device 26 is delivered to the subject and exposed only while the first light transmission part 32a passes over the light beam. Since the exposure period (T _{11 to} T ₂₁ ) is shorter than one field (1/60 second), there is a possibility that the amount of light is not sufficient. Therefore, only during this period, the light amount of the lamp unit 26b is increased or the amplification degree is adjusted by the RGB amplification degree setting unit 21a. The adjustment of the light amount and amplification will be described later.

Period in which the second light transmitting portion 32b passes over the light beam is between B period, namely from the time of T ₃₀ up to the point of T _50. When the first field starts (T ₃₀ ), the second light transmission part 32b starts to pass over the light beam, and when the second field of the same frame ends (T ₅₀ ), the light beam of the second light transmission part 32b. The upper pass ends.

Since the amount of light in the A period is smaller than the amount of light in the B period, the period of dimming for each field in the B period is shortened compared to 1 field (1/60 seconds), thereby suppressing the exposure amount. The brightness of the subject imaged in the A period and the brightness of the subject imaged in the B period are adjusted to the same level. This adjustment is performed not only by adjusting the light control period by the electronic shutter but also by adjusting the amplification degree of the RGB amplification degree setting unit 21a and the light amount of the lamp unit 26b. FIG. 10 shows the adjustment of the length of the light control period, the length of the light control period T _{31 to} T ₄₀ , T _{41 to} T ₅₀ , and the light control period (T ₇₁ to T the length of the T _80, T ₈₁ ~T ₉₀₎ show different states.

  The shape and rotation period of the rotary shutter 32 are set so as to satisfy the timing condition and the period during which the light passes through the first and second light transmission portions 32a and 32b as described above. Therefore, in the first embodiment, as shown in FIG. 6, the first light transmission part 32a is configured in a sector shape smaller than a semicircle, and the second light transmission part 32b is configured in a semicircle. The rotation period is 1/15 seconds including the first and second fields twice.

  Next, imaging of a moving image of a subject and capture of a freeze image in the first embodiment will be described.

  When a normal moving image is captured without requiring a freeze image, the switch 13a for switching the imaging mode of the operation unit 13 of the color scope 10 is pressed to select the normal imaging mode. When the normal imaging mode is selected, the third motor 35 of the dimming unit 30 of the color processor 20 is driven, and the dimming blade 31 is disposed at a position on the light beam emitted from the lamp unit 26b. The

  The amount of light emitted from the lamp unit 26 b is controlled by the light diaphragm (not shown) of the light control blade 31. The controlled light is collected by the condenser lens 26c, and the light is transmitted to the illumination unit 12 by the light guiding member. The transmitted light illuminates the subject by the illumination unit 12. The imaging unit 11 images a subject illuminated with light. Charges are accumulated in the image sensor 11a by imaging, and the accumulated charges are divided into RGB as image signals for each field and transferred to the first-stage image signal processing unit 21 of the color processor 20, that is, output as image signals. The first-stage image signal processing unit 21 amplifies the RGB image signals by the RGB amplification degree setting unit 21a, and stores them in the image memory unit 22 for each RGB and for each field. The stored image signal is transferred to the subsequent image signal processing unit 23, converted into a video signal by the subsequent image signal processing unit 23, and output to the color monitor 40 or the like. By repeating this flow for each field, a moving image is output.

  The first-stage image signal processing unit 21 generates a luminance signal from the image signals for each RGB in the RGB / Y block 21b, and the first brightness detection unit 21c detects the luminance of the generated luminance signal. The detected value is transferred to the system control unit 24. The system control unit 24 determines whether or not it matches the reference value of brightness set in advance by the operator using the operation switch unit 27. If they do not match and it is determined that the brightness is insufficient, the light aperture of the light control blade 31 is adjusted in the opening direction, that is, the direction in which the light from the light source device 26 is not blocked. On the other hand, when it is determined that the light is too bright, the light adjustment degree of the light control blade 31 is adjusted to a further direction, that is, a direction in which light from the light source device 26 is blocked. If it is determined that they match, the aperture of the light control blade 31 is not changed. Accordingly, it is possible to capture a moving image of the subject and observe it on the color monitor 40 while maintaining the brightness reference value set in advance by the operator using the operation switch unit 27.

  The dimming blade 31 can reduce the ratio of blocking light compared to the rotary shutter 32. Therefore, when the distance to the subject is long and a frozen image cannot be captured with satisfactory brightness by the rotary shutter 32 described later, it is effective for capturing a moving image with moderate brightness.

  When a freeze image is required, the switch 13a for switching the imaging mode of the operation unit 13 of the color scope 10 is pressed to select the freeze image capture mode. When the freeze image capturing mode is selected, the third motor 35 of the dimming unit 30 of the color processor 20 is driven, and the rotary shutter 32 is disposed at a position on the light beam emitted from the lamp unit 26b. The

  The amount of light emitted from the lamp unit 26b is controlled by the first and second light transmitting units 32a and 32b and the light blocking unit 32c of the rotary shutter 32 passing through the light flux. The controlled light is collected by the condenser lens 26c, and the light is transmitted to the illumination unit 12 by the light guiding member. The transmitted light illuminates the subject by the illumination unit 12. The imaging unit 11 images a subject illuminated with light. Charges are accumulated in the image sensor 11a by imaging, and the accumulated charges are divided into RGB as image signals for each field and transferred to the first-stage image signal processing unit 21 of the color processor 20. The first-stage image signal processing unit 21 amplifies RGB image signals by the RGB amplification degree setting unit 21a, and stores them in the image memory unit 22 for each RGB signal for each field. The stored signal is transferred to the subsequent image signal processing unit 23, converted into a video signal by the subsequent image signal processing unit 23, and output to the color monitor 40 or the like. This flow is repeated for each field in the same manner as when the light control blade 31 is used.

  In the first-stage image signal processing unit 21, a luminance signal is generated from the image signal for each RGB in the RGB / Y block 21b, and the luminance of the generated luminance signal is detected in the second brightness detection unit 21d.

  The detected luminance value is transferred to the system control unit 24. The system control unit 24 determines whether or not it matches the reference value of brightness set in advance by the operator using the operation switch unit 27. If they do not match and it is determined that the brightness is insufficient, the gain adjustment by the RGB gain setting unit 21a in the A period, the light amount adjustment of the lamp unit 26b, and the light control period by the electronic shutter in the B period Adjustment, amplification adjustment by the RGB amplification setting unit 21a, and light amount adjustment of the lamp unit 26b are performed. Increasing the degree of amplification by the RGB amplification setting unit 21a, increasing the light amount of the lamp 26b, and lengthening the dimming period by the electronic shutter all have the effect of increasing the brightness of the captured subject image. However, if only one of them is biased and adjusted, the S / N ratio may be remarkably deteriorated and image quality may be deteriorated. Therefore, these three are adjusted in a balanced manner.

  In addition, the system control unit 24 performs adjustment for maintaining the brightness of the subject image captured in the A period and the brightness of the subject image captured in the B period at the same level. That is, since the A period is shorter than the B period, in order to eliminate the decrease in the exposure amount in the A period compared to the exposure amount in the B period, the degree of amplification by the RGB amplification degree setting unit 21a in the A period, In addition, the light amount of the lamp unit 26b is increased, the light control period of the electronic shutter in the B period is shortened, the amplification degree by the RGB amplification degree setting unit 21a, and the light amount of the lamp unit 26b is decreased. By this adjustment, the brightness of the moving image is lower than when the dimming blade 31 is used, but the brightness of the subject imaged in the A period and the subject imaged in the B period are the same level. Can be maintained. Imaging and output are repeated alternately in the A period and the B period, but it is possible to comfortably observe a moving image.

In the freeze image capture mode using the rotary shutter 32, a freeze image can be captured at an arbitrary timing while capturing a moving image in parallel. When the switch 13b for instructing to capture a freeze image of the operation unit 13 of the color scope 10 is pressed, the first light transmission unit 32a is accumulated in the first and second fields in the period A in which the first light transmission unit 32a passes over the light flux immediately after the pressing. Charge is captured and output as a freeze image. Specifically, the time series will be described with reference to FIG. Between T ₁₀ through T ₁₁ time of the first field containing A period, the light because it is blocked by the light blocking portion 32c, albeit at the charge accumulation ready charge is not accumulated. The first light transmitting portion 32a starts the exposure from T ₁₁ time of starting passes over the light beam, the first field in the T ₂₀ time ends. The accumulated charges are transferred as image signals to the first stage image signal processing unit 21 of the color processor 20 and further stored in R1, G1, and B1 of the image memory unit 22. Next, a second field containing the A period, the charge accumulation is started from the T ₂₀ time of the intermediate time of the first light transmitting portion 32a passes over the light beam. During the period from T _{20 to} T ₂₁ , since the first light transmission part 32a passes over the light beam, exposure is also performed. Exposure at the time of T ₂₁ is completed. Between T ₂₁ through T _30, since the light blocking portion 32c terminates passage of the optical beam of the first light transmitting portion 32a passes over the light beam, the light is blocked, the charge accumulation albeit at ready, Charge is not accumulated. The second field at the time of T ₃₀ is completed. The accumulated charge is transferred as an image signal to the first-stage image signal processing unit 21 of the color processor 20 and further stored in R2, G2, and B2 of the image memory unit 22. These image signals are superimposed and output to the color monitor 40 as a freeze image.

The temporal shift between the first and second fields is 1/60 seconds, but the temporal shift at which exposure is started by the passage of the first light transmitting portion 32a of the rotary shutter 32 on the light beam is T _11. it is between ~T _20. Accordingly, the amount of blur in the superposition of the image signals with respect to the first and second fields is reduced by reducing the temporal deviation. Further, since the exposure period is also shorter than 1/60 seconds, the amount of blur due to the length of the exposure period when capturing a fast-moving subject image is reduced. Furthermore, during the exposure period, the amplification degree of the RGB amplification setting unit 21a and the light amount of the lamp unit 26b are adjusted, so that a small exposure amount is compensated.

  If the brightness of the subject image captured during the A period and the brightness of the subject image captured during the B period cannot be sufficiently adjusted, such as when the lamp unit 26b deteriorates, the system control The unit 24 sweeps out charges accumulated during the first and second fields including the A period as unnecessary charges and does not store them in the image memory unit 22 as image signals. Further, in this case, when the switch 13b for instructing to capture the freeze image is pressed, the charge accumulated during the first field including the B period passing through the second light transmission part 32b immediately after being pressed. Alternatively, an image signal based on only one of the charges accumulated during the second field is captured and output as a freeze image.

Specifically, the time series will be described with reference to FIG. Between T ₃₀ through T ₃₁ time of the first field containing a B period, but the charge accumulation is conducted charge accumulated so far in the time of T ₃₁ are swept out as unnecessary charges. Unwanted charges that have been swept out are not read out as image signals and are not stored in the image memory unit 22. T ₃₁ point by dimming the electronic shutter is started from the newly charge storage and exposure is started. The first field in the T ₄₀ time ends. The accumulated charge is transferred as an image signal to the first stage image signal processing unit 21 of the color processor 20. Charge accumulation is performed between T _{40 and} T _{41 in} the second field, but the charges accumulated so far at T ₄₁ are swept out as unnecessary charges. The unnecessary charges that have been swept out are not read out as image signals and are not stored in the image memory 22. From time T ₄₁ , dimming is started by the electronic shutter, and charge accumulation and exposure are newly started. The second field at time T ₅₀ is completed. The electric charge accumulated between T _{41 and} T ₅₀ is transferred to the first stage image signal processing unit 21 of the color processor 20 as an image signal. One of the image signal based on the charge accumulated in the first field including the B period or the image signal based on the charge accumulated in the second field during the synchronization is stored in R1, G1, and B1 of the image memory unit 22. Further, R2, G2, and B2 of the image memory unit 22 store image data generated by performing processing such as interpolation on the image data stored in R1, G1, and B1 of the image memory unit 22. These image signals are superimposed and output to the color monitor 40 as a freeze image.

  As described above, by using the rotary shutter 32 of the first embodiment, it is possible to capture a freeze image in a short exposure period in parallel while capturing a moving image that can be observed comfortably. In addition, in the case of a subject in which the amount of light cannot be sufficiently secured by using the rotary shutter 32, the optical unit 30 is moved by the third motor 35, and a moving image that can be comfortably observed can be captured by the light control blade 31. Become.

  Next, a second embodiment will be described. The second embodiment is different from the first embodiment in the shape of the rotary shutter 32. Further, the release period of the electronic shutter varies with the change in the shape of the rotary shutter 32. These differences will be mainly described.

  The configuration of the electronic endoscope device other than the rotary shutter 32 and the electronic shutter is the same as that of the first embodiment. Unlike the first embodiment, the shape of the rotary shutter 32 is shown in FIG. The first and second light transmission portions 32a and 32b are continuous transmission members, and a boundary line 32e between the first and second light transmission portions 32a and 32b is indicated by a dotted line. In the first embodiment, the light blocking section 32c blocks light while switching from the second light transmitting section 32b to the first light transmitting section 32a. In the second embodiment, the second light transmitting section 32b is blocked during that time. Is exposed on the light beam, and thus is exposed. However, the charge accumulated so far at the time of switching to the passage of the first light transmission part 32a is swept out as an unnecessary charge by the electronic shutter. This will be described with reference to the timing chart of FIG. In FIG. 13, the horizontal axis represents the time axis t, the charge accumulation timing in the first and second fields, the timing for outputting the accumulated charge as an electric signal, the timing of the dimming period of the electronic shutter, and the lamp unit 26b. The timing of the period during which the amount of light is increased is shown.

The period during which the first light transmission part 32a passes over the light beam is the same as in the first embodiment. That is, the period A is from the time point T _{11 to} the time point T ₂₁ . FIG. 12 shows the position of the rotary shutter 32 and the light beam at the half time point (T ₂₀ ) when the first light transmission part 32a passes over the light beam.

Unlike the first embodiment, the release period of the electronic shutter is between T _{11 to} T ₂₀ and T _{20 to} T ₃₀ . Accordingly, charge accumulation and exposure are performed from the time point T _{10 to} the time point T ₁₁ , but the accumulated charge is swept out as an unnecessary charge at the time point T ₁₁ . The unnecessary charges that are swept out are not stored in the image memory unit 22 as image signals. Between T _{21 and} T ₃₀ , the light is blocked by the light blocking unit 32 c, so that charge accumulation is possible but no charge is accumulated. The period during which the light amount of the lamp unit 26b is increased is the same as that in the first embodiment. In addition to the increase in the light amount of the lamp unit 26b, the amplification adjustment performed by the RGB amplification setting unit 21a is the same. As a result, in the first field, only the charges accumulated between T _{11 and} T ₂₀ are stored in the image memory unit 22 as image signals. The second field is the same as in the first embodiment.

Period in which the second light transmitting portion 32b passes over the light beam is longer than B period, it is between the time of the T ₃₀ time points T _51. That is, unlike the first embodiment, the second light transmission part 32b is extended to the boundary line 32e of the first light transmission part 32a, and therefore the passage end point on the light flux of the second light transmission part 32b is different. .

  The light control period by the electronic shutter in period B is the same as that in the first embodiment. The same applies to the light amount adjustment of the lamp unit 26b and the amplification degree adjustment of the RGB amplification setting unit 21a.

  The shape, rotation period, and rotation direction of the rotary shutter 32 are set so as to satisfy the timing condition and the period during which the light passes through the first and second light transmission portions 32a and 32b as described above. Therefore, in the second embodiment, as shown in FIG. 12, the first light transmission part 32a is a sector smaller than the semicircle, and the second light transmission part 32b is a semicircle continuous with the sector of the first light transmission part 32a. Each is configured with a larger fan shape. Further, the rotation cycle and the rotation direction are the same as those in the first embodiment.

  The subject moving image capturing and freeze image capturing in the second embodiment are the same as the subject moving image capturing and freeze image capturing in the first embodiment. Therefore, the effect is also the same.

  Next, a third embodiment will be described. The third embodiment is different from the first embodiment in that the charge accumulation method of the image sensor is changed from the field accumulation type to the frame accumulation type for a certain period. Accordingly, the position of the first light transmission part 32a and the passage timing on the light beam are different. Description will be made centering on differences from the first embodiment.

14 and 15 show a charge accumulation method of a frame accumulation type imaging device. In the frame storage type image pickup device charge storage method, when a freeze image of a subject is captured, in the first field, odd-numbered pixels (P ₁₁ , P ₁₃ , P ₂₁ , P ₂₃ , The charges of P ₃₁ and P ₃₃ ) are read out. The read charges are separated into RGB as an image signal and output to the color processor 20 through the vertical transfer register 11vr and the horizontal transfer register 11hr (see FIG. 14). Next, in the second field, the pixel to be read is changed, and the charges of the even-numbered pixels (P ₁₂ , P ₁₄ , P ₂₂ , P ₂₄ , P ₃₂ , P ₃₄ ) are read from the pixels close to the horizontal transfer register 11 hr. The read charges are separated into RGB as an image signal and output to the color processor 20 through the vertical transfer register 11vr and the horizontal transfer register 11hr (see FIG. 15). The image signals read in the first and second fields are superimposed to form one freeze image.

  The configuration of the electronic endoscope apparatus is the same as that of the first embodiment. However, the charge storage method of the image sensor 11a can be switched to the frame storage type in addition to the field storage type. The shape of the rotary shutter 32 is shown in FIG. The positional relationship between the first and second light transmission parts 32a and 32b is different from that of the first embodiment. This positional relationship will be described with reference to the timing chart of FIG. FIG. 17 shows the time axis t on the horizontal axis, the charge accumulation timing in the first and second fields, the timing to output the accumulated charge as an image signal, the release by the electronic shutter, and the timing of the dimming period. The timing of the period which increases the light quantity of the lamp part 26b is shown.

The period during which the first light transmission part 32a passes on the light beam is an A ′ period different from that of the first embodiment, that is, from the time point T _{11 ′ to} the time point T ₂₀ . In a frame including this interval, the charge accumulation method of the image sensor 11a is switched from the field accumulation type to the frame accumulation type. Among the charges accumulated in the imaging device 11a during this period, in the first field, the charges of the odd-numbered pixels are read from the pixels close to the horizontal transfer register 11hr, and in the second field, close to the horizontal transfer register 11hr. The charge of the even-numbered pixel is read from the pixel. As a result, the timing at which reading, that is, the output of the accumulated charge starts as an image signal is shifted by 1/60 seconds, but the exposure and charge accumulation are performed during the same period. Therefore, it is possible to capture a freeze image that is not temporally shifted and is exposed between fields. FIG. 16 shows the position of the rotary shutter 32 and the light beam at the time (T ₂₀ ) when the first light transmission part 32a finishes passing over the light beam.

  As the first light transmission part 32a passes over the light flux and the timing changes to the A 'period, the light quantity increase period of the lamp part 26b also changes. In other words, the period A is matched with the period A ′ in the first embodiment. The electronic shutter release period is the same as that in the first embodiment.

  The period and timing when the second light transmission part 32b passes over the light beam are the same as those in the first embodiment. The unnecessary charge sweeping and light control period by the electronic shutter in the period B are the same as those in the first embodiment. The same applies to the light amount adjustment of the lamp unit 26b and the amplification degree adjustment of the RGB amplification setting unit 21a.

  In the third embodiment, the shape and rotation period of the rotary shutter 32 are set so as to satisfy the timing and timing conditions for passing the light beams of the first and second light transmission parts 32a and 32b as described above. The As shown in FIG. 16, the first light transmission part 32a is configured in a fan shape smaller than a semicircle, and the second light transmission part 32b is configured in a fan shape larger than a semicircle continuous with the fan shape of the first light transmission part 32a. However, the position is different in accordance with the light beam passage timing of the first light transmission part 32a. Further, the rotation cycle and the rotation direction are the same as those in the first embodiment.

  From these configurations, a description will be given of capturing a moving image of a subject and capturing a freeze image in the third embodiment. When a normal moving image is captured without requiring a freeze image, it is the same as in the first embodiment. Accordingly, the normal imaging mode is selected by pressing the switch 13a, the light amount is controlled by the light diaphragm condition of the light control blade 31, and the flow from when the image is picked up by the image sensor 11a until the moving image is output to the color monitor 40 is This is the same as the embodiment.

  When a freeze image is required, the switch 13a for switching the imaging mode of the operation unit 13 of the color scope 10 is pressed to select the freeze image capture mode. When the freeze image capturing mode is selected, the third motor 35 of the light control unit 30 of the color processor 20 is driven, and the rotary shutter 32 is disposed on the light beam emitted from the light source device 26. This point is not different from the first embodiment. However, when the freeze image capturing mode is selected, the charge accumulation method of the image sensor 11a is switched from the field accumulation type to the frame accumulation type for a certain period.

  Although the shape of the rotary shutter 32 is different from that of the first embodiment, the light emitted from the lamp unit 26b is transmitted on the light beam by the first and second light transmitting units 32a and 32b and the light blocking unit 32c of the rotary shutter 32. The point that the amount of light is controlled by passing through is the same as in the first embodiment. The flow of the controlled light transferred to the illumination unit 12 and the illumination unit 12 irradiating the subject with the light is the same as in the first embodiment. The flow in which the imaging unit 11 captures a subject, the image signal obtained by the imaging is converted into a video signal by the color processor 20, and the image is output by the color monitor 40 is the same as in the first embodiment. However, the flow in which charges accumulated in the image sensor 11a of the imaging unit 11 are transferred to the first-stage image signal processing unit 21 is different from that in the first embodiment. This will be described later in conjunction with the electronic shutter release period, the light amount increase of the lamp unit 26b, and the timing of the first and second light transmission units 32a and 32b of the rotary shutter 32 to pass through the light flux.

  The RGB / Y block 21b of the first stage image signal processing unit 21 generates a luminance signal from the image signal, and the luminance of the luminance signal generated by the second brightness detection unit 21d is detected as in the first embodiment. It is the same.

  The detected value is transferred to the system control unit 24. The system control unit 24 determines whether or not it matches the reference value of brightness set in advance by the operator using the operation switch unit 27. If they do not match and it is determined that the brightness is insufficient, the gain adjustment by the RGB amplification setting unit 21a in the A ′ period, the adjustment of the light quantity of the lamp unit 26b, and the light control by the electronic shutter in the B period The period adjustment, the amplification degree adjustment by the RGB amplification degree setting unit 21a, and the light amount adjustment of the lamp unit 26b are performed. Increasing the degree of amplification by the RGB amplification setting unit 21a, increasing the light amount of the lamp 26b, and lengthening the dimming period by the electronic shutter all have the effect of increasing the brightness of the captured subject image. However, if only one of them is biased and adjusted, the S / N ratio may be remarkably deteriorated and image quality may be deteriorated. Therefore, these three are adjusted in a balanced manner.

  In addition, the system control unit 24 performs adjustment to maintain the brightness of the subject image captured during the A ′ period and the brightness of the subject image captured during the B period at the same level. That is, since the A ′ period is shorter than the B period, the RGB amplification degree setting unit 21a in the A ′ period eliminates that the exposure amount in the A ′ period is smaller than the exposure amount in the B period. The amplification degree and the light amount of the lamp unit 26b are increased, the light control period by the electronic shutter in the B period is shortened, the amplification degree by the RGB amplification degree setting unit 21a, and the light amount of the lamp unit 26b are decreased. By this adjustment, the brightness of the subject is lower than when the dimming blade 31 is used, but the brightness of the subject imaged in the A ′ period and the subject imaged in the B period are the same level. Can be maintained. Imaging and output are alternately repeated in the A ′ period and the B period, but it is possible to comfortably observe a moving image.

  In the freeze image capture mode using the rotary shutter 32, a freeze image can be captured at an arbitrary timing while capturing a moving image in parallel. When the switch 13b for instructing to capture the freeze image of the operation unit 13 of the color scope 10 is pressed, the first and second fields are accumulated in the first and second fields in the A ′ period in which the first light transmitting unit 32a passes over the light flux immediately after the pressing. The captured charge is captured and output as a freeze image.

Specifically, the time series will be described with reference to FIG. In the frame period including the A ′ period, the charge accumulation of the image sensor 11a is performed in the frame accumulation type. During and T ₂₀ through T ₃₀ time 'T ₁₀ through T ₁₁ of the frame containing the _period' A, the light because it is blocked by the light blocking portion 32c, albeit at the charge accumulation ready charge is accumulated Not. The first light transmitting portion 32a starts the exposure from T _{11 'the} time of starting to pass over the light beam, in other words the electric charge accumulation first at T ₂₀ time, the second field is terminated. In the first field, charge of odd-numbered pixels from the pixels close to the horizontal transfer register 11hr is, between the T ₂₀ of the T _30, is read. The read charges are transferred as image signals to the first-stage image signal processing unit 21 of the color processor 20 for each of RGB. The image signals for each RGB are transferred to the first-stage image signal processing unit 21 and then stored in R1, G1, and B1 of the image memory unit 22. In the second field, among the charges accumulated in the image sensor 11a during the same T _{11 ′ to} T ₂₀ , the charges of the even-numbered pixels from the pixels close to the horizontal transfer register 11hr are between T ₃₀ and T ₄₀ . Read out. The read charges are transferred as image signals to the first-stage image signal processing unit 21 of the color processor 20 for each of RGB. The RGB image signals are transferred to the first-stage image signal processing unit 21 and then stored in R2, G2, and B2 of the image memory unit 22. These image signals are superimposed and output to the color monitor 40 as a freeze image.

The period during which charges are accumulated in the first and second fields is the same as T _{11 ′ to} T _20, and there is no time lag in exposure. Therefore, the blurring of the superimposition of the image signals with respect to the first and second fields due to the exposure time shift is eliminated. Further, since the exposure period is also shorter than 1/60 seconds, the amount of blur due to the length of the exposure period when capturing a fast-moving subject image is reduced.

  If the brightness of the subject image captured during the period A ′ and the brightness of the subject image captured during the period B cannot be sufficiently adjusted, such as when the lamp unit 26b deteriorates, the system The control unit 24 sweeps out the accumulated charges in the first and second fields including the A ′ period as unnecessary charges and does not store them in the image memory unit 22 as image signals. Further, in this case, when the switch 13b for instructing to capture the freeze image is pressed, the charge accumulated during the first field including the B period passing through the second light transmission part 32b immediately after being pressed. Alternatively, an image signal based on only one of the charges accumulated during the second field is captured and output as a freeze image. The charge storage method of the image sensor 11a at this time is a conventional field storage type.

Specifically, the time series will be described with reference to FIG. Between T ₃₀ through T ₃₁ time of the first field containing a B period, but the charge accumulation is conducted charge accumulated so far in the time of T ₃₁ are swept out as unnecessary charges. Unwanted charges that have been swept out are not read out as image signals and are not stored in the image memory unit 22. T ₃₁ point by dimming the electronic shutter is started from the newly charge storage and exposure is started. The first field in the T ₄₀ time ends. The charges accumulated at T _{31 to} T ₄₀ are transferred to the first stage image signal processing unit 21 of the color processor 20 as an image signal. Charge accumulation is performed between T _{40 and} T _{41 in} the second field, but the charges accumulated so far at T ₄₁ are swept out as unnecessary charges. Unwanted charges that have been swept out are not read out as image signals and are not stored in the image memory unit 22. Dimming from the time of T ₄₁ by the electronic shutter is started, a new charge storage and exposure is started. The second field at time T ₅₀ is completed. The electric charge accumulated between T _{41 and} T ₅₀ is transferred to the first stage image signal processing unit 21 of the color processor 20 as an image signal. One of the image signal based on the charge accumulated in the first field including the B period or the image signal based on the charge accumulated in the second field during the synchronization is stored in R1, G1, and B1 of the image memory unit 22. Further, R2, G2, and B2 of the image memory unit 22 store image data generated by performing processing such as interpolation on the image data stored in R1, G1, and B1 of the image memory unit 22. These image signals are superimposed and output to the color monitor 40 as a freeze image.

  As described above, by using the rotary shutter 32 of the third embodiment, it is possible to capture a freeze image in a short exposure period in parallel while capturing a moving image that can be comfortably observed. In addition, in the case of a subject in which the amount of light cannot be sufficiently secured by using the rotary shutter 32, the optical unit 30 is moved by the third motor 35, and a moving image that can be comfortably observed can be captured by the light control blade 31. Become.

  Next, a fourth embodiment will be described. The fourth embodiment is different from the third embodiment in the shape of the rotary shutter 32. Further, the release period of the electronic shutter varies with the change in the shape of the rotary shutter 32. Description will be made centering on differences from the third embodiment.

  The configuration other than the points related to the invention of the electronic endoscope apparatus is the same as that of the third embodiment. The shape of the rotary shutter 32 is shown in FIG. The first and second light transmission portions 32a and 32b are continuous transmission members, and a boundary line 32e between the first and second light transmission portions 32a and 32b is indicated by a dotted line. In the third embodiment, the light blocking unit 32c blocks light while switching from the second light transmitting unit 32b to the first light transmitting unit 32a. In the fourth embodiment, the second light transmitting unit is in the meantime. 32b is exposed because it passes over the light beam. However, unnecessary charges accumulated up to that point when switching to the passage of the first light transmission part 32a is swept out by the electronic shutter. This will be described with reference to the timing chart of FIG. In FIG. 20, the horizontal axis represents the time axis t, the charge accumulation timing in the first and second fields, the timing for outputting the accumulated charge as an image signal, the release of the electronic shutter and the timing of the dimming period, and the lamp The timing of the period which increases the light quantity of the part 26b is shown.

The period during which the first light transmission part 32a passes over the light beam is the same as in the third embodiment. That is, it is between the time point T _{11 ′ and} the time point T ₂₀ . FIG. 19 shows the positional relationship between the rotary shutter 32 and the light beam when the first transmission part 32a finishes passing on the light beam (T ₂₀ ).

Unlike the third embodiment, the release period of the electronic shutter is between T _{11 ′ to} T ₂₀ and T _{20 to} T ₃₀ . Charge accumulation and exposure are performed from the time point T _{10 to} the time point T _{11 ′} , but unnecessary charges accumulated so far at the time point T _{11 ′} are swept out by the electronic shutter. The unnecessary charges that are swept out are not stored in the image memory unit 22 as image signals. Between T ₂₀ through T ₃₀ are light because it is blocked by the light blocking portion 32c, albeit at the charge accumulation ready charge is not accumulated. The period in which the light amount of the lamp unit 26b is increased is the same as that in the third embodiment (T _{11 ′ to} T ₂₀ ). In addition to the increase in the light amount of the lamp unit 26b, the amplification adjustment performed by the RGB amplification setting unit 21a is the same. Thus, first, the second field both only charges accumulated between the T _{11 'through} T ₂₀ is transferred to the color processor 20 as an image signal.

Period in which the second light transmitting portion 32b passes over the light beam is longer than B period, is between the time of the T ₃₀ time points T _{51 '.} That is, unlike the third embodiment, since the second light transmission part 32b is extended to the boundary line 32e of the first light transmission part 32a, the passage end point on the light flux of the second light transmission part 32b is different. .

  The light control period by the electronic shutter in period B is the same as that in the first embodiment. The same applies to the light amount adjustment of the lamp unit 26b and the amplification degree adjustment of the RGB amplification setting unit 21a.

  The shape and rotation period of the rotary shutter 32 are set so as to satisfy the timing condition and the period during which the light passes through the first and second light transmission portions 32a and 32b as described above. In the fourth embodiment, as shown in FIG. 19, the first light transmission part 32a is smaller than a semicircle, and the second light transmission part 32b is smaller than a semicircle continuous with the fan shape of the first light transmission part 32a. Each is composed of a large sector. Further, the rotation period and the rotation direction are the same as those in the third embodiment.

  The subject moving image capturing and freeze image capturing in the fourth embodiment are the same as the subject moving image capturing and freeze image capturing in the third embodiment. Therefore, the effect is also the same.

  In any of the embodiments, the shape of the first and second light transmission portions 32a and 32b of the rotary shutter 32 is not limited to a sector shape. This is because the same effect can be obtained if the shape satisfies the requirements of the timing chart of FIG. For the same reason, the rotation period of the rotary shutter 32 is not limited to 1/15 seconds.

In the first and third embodiments, the light beam passage end point of the second light transmission part 32b is described as being the same as the end point (T ₅₀ ) of the B period, but it may be later. . That is, it may be from the end point (T ₅₀ ) of the B period to the start point (T ₅₁ (or T _{51 ′} )) of the next A period (or A ′ period). In this case, the light is not blocked by the rotary shutter 32 from the end point (T ₅₀ ) of the B period to the end point of the light beam passage of the second light transmission part 32b, but unnecessary charges are removed by the electronic shutter. This is because the same effect can be obtained by changing the timing of sweeping and releasing.

The block diagram of an electronic endoscope apparatus is shown. The block diagram of the electronic endoscope apparatus shows the details of the color processor. The light control unit part shows the state where the light control blade is arranged on the light beam from the light source device. The perspective view which looked at the rotary shutter from the lamp part side is shown. The perspective view which looked at the rotary shutter from the opposite side to the lamp part is shown. The top view which looked at the rotary shutter of 1st Embodiment from the lamp | ramp part side is shown. 2 shows a charge transfer of the image sensor, that is, a timing chart for outputting an image signal. The charge transfer of the 1st field of a field storage type image sensor is shown. The charge transfer of the 2nd field of a field storage type image sensor is shown. 4 is a timing chart when a freeze image is captured by a first light transmission unit according to the first embodiment. 4 is a timing chart when a freeze image is captured by a second light transmission unit according to the first embodiment. The top view which looked at the rotary shutter of 2nd Embodiment from the lamp | ramp part side is shown. The timing chart at the time of freeze image taking in by the 1st light transmission part of a 2nd embodiment is shown. The charge transfer of the 1st field of a frame storage type image sensor is shown. The charge transfer of the 2nd field of a frame storage type image sensor is shown. The top view which looked at the rotary shutter of 3rd Embodiment from the lamp | ramp part side is shown. The timing chart at the time of freeze image taking in by the 1st light transmission part of a 3rd embodiment is shown. 9 shows a timing chart when a freeze image is captured by a second light transmission unit of the third embodiment. The top view which looked at the rotary shutter of 4th Embodiment from the lamp | ramp part side is shown. The timing chart at the time of freeze image taking in by the 1st light transmission part of a 4th embodiment is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Colorscope 11 Imaging part 12 Illumination part 20 Color processor 21 First stage image signal processing part 22 Image memory part 23 Later stage image signal processing part 24 System control part 25 Timing part 26 Light source device 27 Operation switch part 30 Light control unit part 31 Light control Blade 32 Rotary shutter 32a First light transmitting portion 32b Second light transmitting portion 32c Light blocking portion 40 Color monitor

Claims (18)

A scope having an electronic shutter and a field storage type imaging device that outputs an image signal for generating a predetermined video signal;
The first and second light transmitting portions and the light blocking portions are different in size, and the first and second light transmitting portions are sequentially passed through the light beam emitted from the light source device by rotation, thereby reducing the light amount. And the first light transmission part passing period in which the first light transmission part passes over the light flux is shorter than one field period of the video signal, and the second light transmission part passes through the light flux. One light transmission part passage period is a rotary shutter shorter than one frame period of the video signal;
Luminance detection means for detecting a first luminance of the subject imaged during the first light transmission portion passage period and a second luminance of the subject imaged during the second light transmission portion passage period;
Brightness control means for controlling the first and second brightness to the same level,
The rotation is performed at the first rotation timing when the first field of the frame is switched from the first field to the second field at the end of half of the first light transmission part passage period, and at the start time of the second light transmission part passage period. Switching from the second field to the first field of the next frame, and in accordance with a second rotation timing at which the second light transmission part passage period ends after the end of the second field of the next frame. Endoscopic device.   2. The electronic endoscope apparatus according to claim 1, wherein the second rotation timing is such that the second light transmission unit passage period ends at the end of the second field of the next frame.   In the rotary shutter, the first and second light transmission parts are configured continuously, and the second rotation timing is after the end of the second field of the next frame and the first light transmission part passage period. The second light transmission part passage period ends at the start time of the first frame, and the charge accumulated between the end time of the second field of the next frame and the start time of the first light transmission part passage period is the electrons. The light beam is blocked by the light blocking section from the end of the first light transmission section passage period to the start time of the second transmission section passage period. The electronic endoscope apparatus according to 1.   The brightness control unit controls at least one of a light amount emitted from the light source device during a passage period of the first light transmission unit and an amplification degree for amplifying an output signal from the imaging element. The electronic endoscope apparatus according to claim 1.   The brightness control means includes at least one of a light amount emitted from the light source device during a passage period of the second light transmission unit, an amplification factor for amplifying an output signal from the imaging element, and a dimming period of the electronic shutter. The electronic endoscope apparatus according to claim 1, wherein the electronic endoscope apparatus is controlled.   If the first and second luminances do not become the same level due to the luminance control, the charge accumulated during the first light transmission unit passing period is swept out as unnecessary charges, and writing to the image memory as an image signal is stopped. The electronic endoscope apparatus according to claim 1, further comprising a writing stop unit.   When a freeze image is captured, a freeze image capturing unit is provided that reads out an image signal based on the charges of the first and second fields accumulated during the first light transmission portion passage period and stores the image signal in an image memory. The electronic endoscope apparatus according to claim 1.   When the frozen image is captured when the first and second luminances do not become the same level due to the luminance control, the charge of the first field or the second field accumulated during the second light transmission unit passage period is acquired. 2. The electronic endoscope apparatus according to claim 1, further comprising freeze image capturing means for storing an image signal based on only one in an image memory.   The electronic endoscope according to claim 1, further comprising: a switching unit that switches between and uses the rotary shutter and a dimming blade that controls a light amount from the light source device when capturing a moving image. apparatus. A scope having an electronic shutter and a field storage type and a frame storage type switchable image sensor that outputs an image signal for generating a predetermined video signal;
The first and second light transmitting portions and the light blocking portions are different in size, and the first and second light transmitting portions are sequentially passed through the light beam emitted from the light source device by rotation, thereby reducing the light amount. And the first light transmission part passing period in which the first light transmission part passes over the light flux is shorter than one field period of the video signal, and the second light transmission part passes through the light flux. The two light transmission part passage period is a rotary shutter shorter than one frame period of the video signal;
Luminance detection means for detecting a first luminance of the subject imaged during the first light transmission portion passage period and a second luminance of the subject imaged during the second light transmission portion passage period;
Luminance control means for controlling the first and second luminances to the same level, in the frame period including the first light transmission part passing period, the charge accumulated in the frame accumulation type is read, and in other frames Read out the charge accumulated in the field storage type,
The rotation includes a third rotation timing at which the first light transmission part passage period ends at the end of the first field of the frame and a second frame at the start of the second light transmission part passage period. The electronic endoscope apparatus is switched to one field and is performed according to a fourth rotation timing at which the second light transmission part passage period ends after the end of the second field of the next frame.   11. The electronic endoscope apparatus according to claim 10, wherein in the fourth rotation timing, the second light transmission unit passage period ends at the end of the second field of the next frame.   In the rotary shutter, the first and second light transmission parts are configured continuously, and the fourth rotation timing is after the end of the second field of the next frame and the first light transmission part passage period. The second light transmission part passage period ends at the start time of the first frame, and the charge accumulated between the end time of the second field of the next frame and the start time of the first light transmission part passage period is the electrons. The light beam is blocked by the light blocking section from the end of the first light transmission section passage period to the start time of the second transmission section passage period. The electronic endoscope apparatus according to 10.   The brightness control unit controls at least one of a light amount emitted from the light source device during a passage period of the first light transmission unit and an amplification degree for amplifying an output signal from the imaging element. The electronic endoscope apparatus according to claim 10.   The brightness control means includes at least one of a light amount emitted from the light source device during a passage period of the second light transmission unit, an amplification factor for amplifying an output signal from the imaging element, and a dimming period of the electronic shutter. The electronic endoscope apparatus according to claim 10, wherein the electronic endoscope apparatus is controlled.   If the first and second luminances do not become the same level due to the luminance control, the charge accumulated during the first light transmission unit passing period is swept out as unnecessary charges, and writing to the image memory as an image signal is stopped. The electronic endoscope apparatus according to claim 10, further comprising a writing stop unit.   When a freeze image is captured, a freeze image capturing unit is provided that reads out an image signal based on the charges of the first and second fields accumulated during the first light transmission portion passage period and stores the image signal in an image memory. The electronic endoscope apparatus according to claim 10.   When the frozen image is captured when the first and second luminances do not become the same level due to the luminance control, the charge of the first field or the second field accumulated during the second light transmission unit passage period is acquired. The electronic endoscope apparatus according to claim 10, further comprising a freeze image capturing unit that reads an image signal based on only one of the charges and stores the image signal in an image memory. The electronic endoscope according to claim 10, further comprising a switching unit that switches between and uses the rotary shutter and a dimming blade that controls a light amount from the light source device when capturing a moving image. apparatus.

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