JP2607292C - - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film image scanner for optically reading an image on a light-transmitting film. 2. Description of the Related Art Conventionally, there is a film image scanner for reading an image on a film, and an example thereof is shown in FIG. 10 to FIG. Reference numeral 50 denotes a slide holding the periphery of the film 51 by a thick paper frame 52. As shown in FIG. 12, the slide 50 is detachably held by a holder 101 provided on a carrier 100.
In the process of moving the carrier 100 along the carrier shaft 102, the light from the light source 103 is diffused by the diffusion plate 104 and transmitted through the film 51, and the transmitted light is imaged on the line type image sensor 106 by the lens 105. By doing so, the image on the film 51 is read. FIG. 10 and FIG. 11 are perspective views showing the scanner case 107 in different viewing directions. The case 107 has projections 109 and 110 formed with a concave portion 108 interposed therebetween. Inside one of the protrusions 109, a carrier 100 and a driving unit (not shown) for driving the carrier 100 are provided.
, The diffusion plate 104 and the light source 103 are housed, and the other projection 110 holds the lens 105 and houses the image sensor 106. A guide groove 111 for movably holding a connecting portion of the holder 101 to the carrier 100 is formed on a wall surface of the protrusion 109. Problems to be Solved by the Invention The case 107 requires a concave portion 108 for attaching and detaching the slide 50 to and from the holder 101 on the front surface of the lens 105, and the protrusions 109 and 110 are provided with the concave portion 108 interposed therebetween.
In this case, the size of the case 107 increases. Therefore, when the case 107 is incorporated in an electronic device, a large space is required, and it is difficult to determine the arrangement. In addition, since the slide 50 is inserted and removed from above the case 107, when the case 107 is incorporated in an electronic device, other devices or the like cannot be installed on the electronic device. Further, since the holder 101 and the lens 105 are exposed to the outside,
Outside light as well as light from the light source 103 passing through the image enters the lens 105, the outside light affects reading accuracy, and the lens 105 is easily damaged. Before reading, the light of the lamp 103 is passed through the image sensor 10.
6 and shading correction is performed based on the output of the image sensor 106 at this time. For this reason, the slide 50 must be taken in and out each time shading correction is performed, which is troublesome. In addition, the time from when the shading correction is performed to when the actual reading is performed cannot be specified by the operation of the user, and if the time is long, the time between the lamp 103 and the surrounding temperature changes. Therefore, the light amount of the lamp 103 and the sensitivity of the image sensor 106 may change, and the desired correction value may change. In addition, before the manufacturer ships the scanner,
The shading correction is performed in advance, the correction data is written to the RAM in the scanner body, and the correction data is called from the RAM before the reading, and the shading correction is also performed. Due to changes with time from use to use, the light amount of the lamp 103, the sensitivity of the image sensor 106, the reflectance of the mirror in the optical path, and the like may change, so that high-precision shading correction cannot be performed. Means for Solving the Problems A movable body having a holding portion for detachably holding the film is reciprocated toward the back from the film insertion port on a support having a film insertion port into which a film is inserted formed on the surface. An optical reading means movably provided, having a light source fixed on an optical axis orthogonal to a conveying direction of the movable body and an image sensor for receiving light of the light source is provided on the support, A light transmitting window penetrating the film is formed at a position deeper than the film, and an output change of the image sensor when the light transmitting window crosses an optical axis of the light source.
A reading start time setting means for setting a reading start time on the basis of image formation, and a shading correction means using the output of the image sensor corresponding to the light amount of the light source passing through the light transmitting window as a correction reference. Action The film inserted from the film insertion slot is held and transported by the movable body, and the image of the film can be read by receiving the light transmitted through the film from the light source by the image sensor in the transport process. Since the insertion slot is formed on the surface of the support, it is possible to insert and remove the film using a large external space, thereby making it possible to reduce the space inside the film insertion slot, and the system When it is incorporated in an electronic device, it can be placed in a small space, and all the components of the optical reading means can be hidden and protected inside the support, and the influence of external light on the reading accuracy can be reduced. Can be removed. Further, when the movable body moves, shading correction can be performed using the output of the image sensor corresponding to the light amount of the light source passing through the light transmitting window as a correction reference, whereby the light amount of the light source, the reflectance of the optical system, Under various conditions such as the sensitivity of the image sensor,
Shading correction can always be performed accurately immediately before the start of reading. Also possible
When the moving object moves, the output of the image sensor changes when the edge of the light transmission window crosses the optical axis of the light source.
By setting the reading start time by the reading start time setting means on the basis of
Precise reading start timing without any influence of power transmission loss of moving body drive system
The return position of the movable body can be set accordingly, and the hysteresis is low and expensive.
Such accuracy is not necessary to define a limit switch or the like, moreover, there is no need to define the mounting position such that limit switch Strictly, therefore, Fig costs
Can be Embodiment An embodiment of the present invention will be described with reference to FIGS. The same reference numerals are used for the slide 50 as in the conventional example, and the description is omitted. FIG. 5 is an exploded perspective view. In the figure, reference numeral 1 denotes a support, and the support 1 comprises a base 2 having an open front surface and an upper surface, and a front panel 3 covering the front surface of the base 2. 3, a film insertion port 4 is formed. A cover 5 covers both sides and the upper surface of the base 2. The casing 6 is formed by connecting the base 2, the front panel 3, and the cover 5 together. A carrier frame 7 is fixed to the bottom surface of the base 2 by a plurality of screws 8. Support portions 10 for supporting a carrier shaft 9 are formed on both sides of the carrier frame 7. A fixing member 11 for pressing the shaft 9 is attached by a screw 12. Thus, there is provided a transport means 13 for transporting the slide 50 reciprocally toward the inside of the film insertion slot 4. The transport means 13 includes a carrier 14, which is a movable body slidably held on the carrier shaft 9, a step motor 15, and a gear 17 connected to the step motor 15 via a speed reduction mechanism 16.
And a rack (not shown) formed on one side of the carrier 14 and meshed with the gear 17
And The step motor 15, the speed reduction mechanism 16, and the gear 17 are mounted on one side of the carrier frame 7. Further, an optical reading unit 22 having a lamp (fluorescent lamp) 18, a mirror 19, a converging lens 20, and an image sensor 21 is provided. The lamp 18 and the mirror 19 are arranged on an optical axis orthogonal to the transport direction of the carrier 14, and the converging lens 20 and the image sensor 21 are arranged on an optical axis refracted at right angles by the mirror 19. Then, the converging lens 20 is attached to the carrier frame 7 via the attachment plate 24 so that the position of the convergent lens 20 can be adjusted freely on the opt frame 23 attached to the carrier frame 7 in the optical axis direction. The lamp 18 is attached to the carrier frame 7 via a lamp holder 25. Reference numeral 26 denotes a printed wiring board mounted on the carrier frame 7. Further, as shown in FIG. 6, the frame 14 of the slide 50 is provided on the carrier 14.
A U-shaped receiving portion 27 that supports three sides around 2 is formed, and a pressing member 28 that presses both sides of the frame 52 is provided on the receiving portion 27. The receiving portion 27, the pressing member 28, Serves as a holding portion for detachably holding the slide 50. The length B in the depth direction of the receiving portion 27 is set to be shorter than the length A of the frame 52. The pressing member 28 includes a leaf spring 30 attached to the carrier 14 by screws 29, and a leaf spring 31 fixed to both sides of the leaf spring 30. The leaf spring 31 is formed of a material that is thinner than the plate thickness of the leaf spring 30, and has an elastic portion 32 that is curved in a U-shape, and is bent from one end of the elastic portion 32 to press the frame 52 over a predetermined length. It has a pressing surface 33 and an inclined surface 34 inclined upward at an angle of approximately 45 degrees from the tip of the pressing surface 33. Further, the carrier 1
4, a pair of left and right slide detection holes 35 formed in a portion of the receiving portion 27 that supports the front edge of the frame 52, and a horizontally long light transmission window 36 located on the back side of the slide detection holes 35. Are formed. Next, FIG. 8 shows an electronic circuit. The CPU 37 has a ROM 38 in which a program is written, a RAM 39 for storing variable data, an inverter circuit 40 for driving the lamp 18, and a motor control circuit 4 for driving the step motor 15.
1, a limit switch 42 located near the film insertion slot 4 for detecting the return operation of the carrier 14, and a sensor drive circuit 43 for driving the image sensor 21 are connected. Further, an amplifier 44, an A / D converter 45, an image processing circuit 46, a RAM 47 for temporarily storing read data, and an I / F circuit 48
Are sequentially connected to the output side of the image sensor 21 and are also connected to the CPU 37. The output side of the I / F circuit 48 is connected to a host computer. In such a configuration, the slide 50 is inserted from the film insertion slot 4, supported by the receiving portion 27 of the carrier 14, and pressed by the leaf spring 31 of the pressing member 28. Hereinafter, the reading operation will be described with reference to the flowchart shown in FIG. When the power is turned on or a scan command is received, the lamp 18 is turned on after confirming that the limit switch 42 is ON. Limit switch 42 is OFF
In this case, the step motor 15 is rotated in the reverse direction to return the carrier 14 to the film insertion port 4 side. As shown in FIG. 1, the light from the lamp 18 passes through the light transmission window 36, is reflected by the mirror 19, is formed on the image sensor 21 by the converging lens 20, and the output of the image sensor 21 at this time is set as a reference. In step 4, shading correction and magnification correction are performed. This step 4 is the shading correction means. During this time, since the carrier 14 travels forward away from the film insertion port 4, the light of the lamp 18 passes through the edge of the light transmission window 36, and immediately thereafter, the light from the lamp 18 to the mirror 19, as shown in FIG. Is shielded by the carrier 14. At this moment, the output of the image sensor 21 changes from H to L, and the step counter is set to 0 based on this change. The carrier 14 still advances forward, and the slide detection hole 35 passes below the lamp 18. At this time, slide 5 against carrier 14
Whether 0 is inserted or not is detected. That is, as shown in FIG. 3, when the light of the lamp 18 passes through both the left and right slide detection holes 35, the slide 50 is detected as not inserted by the output of the image sensor 21, and only one of the slide detection holes 35 is detected. When the light from the lamp 18 is transmitted through the slide 50, the slide 50 is detected as being inserted obliquely by the output of the image sensor 21. In this case, the step motor 15 is rotated in reverse by the detection signal to return the carrier 14. If the left and right slide detection holes 35 are closed by the frame 52 of the slide 50, the output of the image sensor 21 becomes L
, The slide insertion is determined to be appropriate, and the reading of the image on the film 51 is started when the count of the carrier counter reaches a certain value. That is, step 10 in the flowchart of FIG. 9 is reading start timing setting means for setting the reading start timing. At this time, the count number of the step counter is determined when the output of the image sensor 21 changes from H to L when the edge of the light transmission window 36 passes through the optical axis of the lamp 18 in Step 6 (0 is set to 0 in Step 7). Is set as a reference). Further, when reading is completed when the count number of the step counter reaches a certain value, the lamp 18 is turned off.
F, the stepping motor 15 is reversed, and the carrier 14 is
The carrier 14 is returned until it is turned ON by interfering with the other actuator. In this case, light passing through the light transmission window 36 for shading correction and magnification correction is transmitted to the carrier 1.
Since the reading start time is set on the basis of the point at which the light is shielded by 4, the return position of the carrier 14 does not need to be accurately determined. Therefore, the limit switch 42
Only serves to prevent the carrier 14 from overrunning, uses a limit switch 42 having a rough hysteresis characteristic, and does not need to strictly determine the mounting position. Thereby, cost reduction can be achieved. As described above, since the film insertion opening 4 is formed on the front surface of the support 1, the slide 50 can be inserted and removed using a wide external space, and as a result,
The space inside the film insertion slot 4 can be reduced, and when the system is incorporated in an electronic device, it can be arranged in a small space. Further, the lamp 18 and the mirror 19 are arranged to face each other with the conveyance direction of the carrier 14 therebetween,
Moreover, by shortening the depth B of the receiving portion 27 of the carrier 14 from the length A of the frame 52 of the slide 50, the moving distance of the carrier 14 and the depth of the support 1 can be effectively reduced. it can. Furthermore, since the film insertion slot 4 is formed on the front surface of the casing 6, when the casing 6 is incorporated into an electronic device, another electronic device or another object may be placed on the upper surface of the electronic device. Therefore, a narrow installation space can be effectively used. Further, all the components of the optical reading means 22 can be hidden and protected inside the support 1, and the influence of external light on the reading accuracy can be eliminated. Further, since the leaf spring 30 of the pressing member 28 is formed of a thick material,
The pressing force of the slide 50 can be increased. Further, on both sides of the leaf spring 30, leaf springs 31 made of a thin material are fixed, and these leaf springs 31 have a U-shaped elastic portion 32 and a flat pressing surface 33. Thus, the entire pressing surface 33 can be brought into close contact with the frame 52 by bending the elastic portion 32. Thus, the slide 50 can be reliably held even though the depth dimension B of the receiving portion 27 is short. Furthermore, since the inclined surface 34 is formed at the distal end of the leaf spring 31, the slide 50 can be easily inserted into the carrier 14, and the distal end edge of the frame 52 can be prevented from being bent or broken. Next, the shading correction will be described. Even if the film 51 is a transparent portion, the light amount of the lamp 18 is reduced by about 50 to 60%. Image sensor 2 at this time
If the gain of 1 is an appropriate value, the output of the image sensor 21 is saturated at the time of shading correction because the amount of light of the lamp 18 passing through the transmission window 36 is high, and the correction standard becomes ambiguous. For this reason, at the time of the shading correction, the light amount of the lamp 18 is reduced to about 50 to 60% of the reading amount. Thereby, a correct output can be obtained by obtaining a high output from the image sensor 21 without being saturated at the time of shading correction, and a high output can be obtained from the image sensor 21 even at the time of reading, thereby increasing the SN ratio. At the same time, the image on the film 51 can be read with the gradation accuracy increased. Of course, the same object can be achieved even if the light amount of the lamp 18 is kept constant and the gain of the image sensor 21 at the time of shading correction is reduced to about 50 to 60% of that at the time of reading. In particular, when the carrier 14 moves, the shading correction can be performed using the output of the image sensor 21 corresponding to the light amount of the lamp 18 passing through the light transmission window 36 as a correction reference, whereby the light amount of the lamp 18 and the mirror Based on various conditions such as the reflectivity of the image sensor 19 and the sensitivity of the image sensor 21, the shading correction can always be accurately performed immediately before the start of reading. Moreover, the shading correction and the reading can be continuously performed only by once attaching the slide 50 to the carrier 14 from the film insertion slot 4 for the reading, so that the operation is easy. Next, the determination of the magnification correction coefficient will be described. Since the width of the light from the lamp 18 corresponds to the length in the width direction of the light transmission window 36 of the carrier 14, as shown in FIG. 7, the output distribution of the image sensor 21 is higher at the center and gradually lower toward both ends. It is a kamaboko distribution. Here, since the width of the light transmission window 36 and the imaging magnification of the optical system are known, the output at both ends of the image sensor 21 extends from the boundary between L and H to the boundary between H and L. The number of power pixels can be calculated as follows. That is, if the width of the light transmitting window 36 is W, the imaging magnification of the optical system is B, and the pixel pitch of the image sensor 21 is d, the number of pixels to be obtained is W × B / d. However, since there is a limit in adjusting the accuracy of the imaging magnification of the optical system, there is a difference between the actual number of pixels and the calculated number of pixels. Thus, the actual number of pixels is determined by performing magnification correction by signal processing such as linear interpolation and determining a correction coefficient. In the above-described embodiment, the description has been made in a state where the periphery of the film 51 is held by the frame 52. However, the film 51 may be directly mounted on the carrier 14. In addition, a belt may be used as a movable body that holds and conveys the slide 50, and a holding unit that holds the slide 50 may be provided on the belt. Advantageous Effects of the Invention As described above, the present invention moves a movable body having a holding portion for detachably holding the film on a support having a film insertion opening into which a film is inserted on the surface thereof, from the film insertion opening. Optical support means is provided on the support body, the optical reading means having a light source fixed on an optical axis orthogonal to the transport direction of the movable body and an image sensor for receiving light from the light source. Forming a light transmission window that penetrates a position on the back side of the film of the movable body, the light transmission window when the light transmission window crosses the optical axis of the light source
Reading start time setting that sets the reading start time based on the output change of the image sensor
Setting means, and shading correction means using the output of the image sensor corresponding to the amount of light of the light source passing through the light transmitting window as a correction reference to hold the film inserted from the film insertion port by the movable body. The image of the film can be read by receiving the light transmitted through the film from the light source by the image sensor in the conveyance process, and the film insertion port is formed on the surface of the support, so that an external A large space can be used to insert and remove the film, which can reduce the space inside the film insertion slot, and can be placed in a small space when incorporated into an electronic device as a system. Also, all the components of the optical reading means can be hidden and protected inside the support,
Further, the influence of external light on the reading accuracy can be removed, and further, the shading correction can be performed using the output of the image sensor corresponding to the light amount of the light source passing through the light transmitting window when the movable body moves, as a correction reference. Based on various conditions such as the amount of light from the light source at that time, the reflectivity of the optical system, and the sensitivity of the image sensor, the shading correction can always be accurately performed immediately before the start of reading. The shading correction and reading can be performed continuously only once by attaching the camera to the holder of the movable body from the film insertion port, so that the operation can be facilitated and light can be transmitted when the movable body moves. setting the read start timing at a start timing setting means reading based on the change in the output of the image sensors when the edge of the window crosses the optical axis of the light source
Read without being affected by the power transmission loss of the drive system of the movable body
The start time can be set accurately, and accordingly, the return position of the movable
There is no need to set accurately with expensive limit switches with low lysis, and
, There is no need to strictly determine the mounting position of the limit switch, etc.,
This has the effect of reducing costs .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 to FIG. 9 show an embodiment of the present invention. FIG. 1 is a longitudinal side view showing a state of shading correction and magnification correction, and FIG. 2 is a reading start position. FIG. 3 is a longitudinal side view showing a slide insertion detection state, FIG. 4 is a perspective view showing an appearance, FIG. 5 is an exploded perspective view showing an internal structure, and FIG. FIG. 7 is an exploded perspective view showing the slide holding structure in an enlarged manner, FIG. 7 is a graph showing an output distribution of the image sensor corresponding to the width of the light transmitting window, FIG. 8 is a block diagram showing an electronic circuit, and FIG.
10 is a flowchart showing a reading operation, FIGS. 10 to 12 show a conventional example, FIGS. 10 and 11 are perspective views showing the appearance, and FIG. 12 is an exploded perspective view showing the internal structure. . DESCRIPTION OF SYMBOLS 1 ... Support body, 4 ... Film insertion port, 14 ... Movable body, 18 ... Light source, 21 ... Image sensor, 22 ... Optical reading means, 27, 28 ... Holding part, 36 ... Light transmission window, 51 ...
the film

Claims (1)

Claims: There is provided a support having a film insertion opening formed on a surface into which a film is inserted, and a holding portion for detachably holding the film, and is reciprocally movable from the film insertion opening to the back. An optical reading means having a movable body mounted on the support, a light source fixed on an optical axis orthogonal to a transport direction of the movable body, and an image sensor for receiving light from the light source; A light transmission window penetrated to a position deeper than the film, and an output change of the image sensor when the light transmission window crosses an optical axis of the light source.
Reading start time setting means for setting a reading start time on the basis of a reference value, and shading correction means using the output of the image sensor corresponding to the light amount of the light source passing through the light transmitting window as a correction reference. Image scanner for film.