JP3218781B2 - Optical finder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical finder,
In particular, the present invention relates to an optical finder which is provided separately from a photographic lens and can change a finder magnification in accordance with a photographic magnification of the photographic lens.

[0002]

2. Description of the Related Art An inverted Galilean finder is known as a conventional optical finder of this type. The inverted Galileo finder has a feature that a large actual field of view can be obtained with a relatively small outer diameter, and that it can be manufactured at a low cost because of its simple configuration, and is used in compact cameras and the like. Since the reverse Galileo finder does not have a real image plane and cannot place a field stop, the field of view is unclear and the field of view changes depending on the position of the eyes. Therefore, a method of arranging a field frame and superimposing the image of the field frame on the subject image has been adopted.

The inverted Galileo finder is also applied to a camera using a bifocal lens capable of switching between telephoto (telephoto) and wide-angle (wide) as a photographing lens, and a low-magnification zoom lens. When the photographing lens is a variable magnification system, it is desirable for photographing to use a variable magnification finder in which the finder magnification changes with the magnification of the photographing lens. On the other hand, a video camera generally uses a small CRT display or an electronic finder using a liquid crystal display, but there is also one in which an optical finder is applied to a video camera. The optical viewfinder has the advantage that the color and details of the subject are easier to see than the electronic viewfinder, and that the subject can be confirmed without turning on the power.

[0004]

In the case of photographing using an optical finder, the larger the telephoto-to-wide ratio, the smaller the subject at the time of widening. Also, in the video camera, it is necessary to display during recording, or battery warning, warning of the tape end, and warning at the time of abnormality due to condensation or some trouble, but when applying the optical finder to the video camera, There is a limit to the display in the optical viewfinder. Therefore, it is important how to efficiently perform various displays in a narrow space in the optical viewfinder.

Further, unlike the electronic viewfinder, the optical viewfinder allows the user to check the subject even when the power is not turned on. Therefore, it is necessary to check the power ON / OFF and the recording standby state based on the presence or absence of the display in the viewfinder. There is a problem that can not be. The present invention has been made in view of such circumstances, and its object is to prevent a subject from becoming too small when wide.
It is to provide an optical viewfinder that is easy to see.

[0006]

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a finder optical system capable of switching a finder magnification stepwise in accordance with a photographic magnification of a photographic lens in which a photographic magnification is switched stepwise. A plurality of field frame plates having field frames of different sizes corresponding to the photographing magnification of the photographing lens, and switching the finder magnification of the finder optical system in accordance with the photographing magnification of the photographing lens, When the photographing magnification is switched to a high value, the finder magnification of the finder optical system is switched to a finder magnification higher than the finder magnification before switching and lower than the photographing magnification, and the switching is performed. Switching means for switching to a field frame plate having a field frame smaller than the field frame of the previous field frame plate; It is characterized in that to obtain a visual field range corresponding to the imaging magnification of the imaging lens and the viewfinder magnification academic system by the size of the field frame.

[0008]

[0009]

[0010]

According to the present invention, by combining the optical magnification in the finder optical system in which the finder magnification can be switched stepwise and the size of the field frame in the field frame plate appropriately selected from a plurality of field frame plates, A desired visual field range is obtained. That is, a large field frame is used at the time of widening so that the finder magnification (subject) does not become too small.

[0011]

[0012]

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the optical finder according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a perspective view showing an embodiment of a video camera to which the optical finder according to the present invention is applied.

As shown in FIG.
0 is thin in the front-back direction of the camera (the direction of arrow AB in FIG. 1),
It has a flat and substantially rectangular parallelepiped appearance. The taking lens 110 and the optical viewfinder 120 are provided above the camera, and the stereo microphone 130 is provided at the top of the camera. Reference numeral 140 denotes a VTR deck unit, 150 denotes a side grip unit, 152 denotes a shooting button, and 154 denotes a tele / wide switching button.

The taking lens 110 is tele / wide (about,
This is a bifocal lens that can be electrically switched to one of focal lengths for (2 × zoom), and the focal length is alternately switched between the two focal lengths each time the tele / wide switching button 154 is pressed once. It is supposed to be. The photographing lens 110 has a large depth of field, and is designed so that, even when the focal length is switched to any one of the focal lengths, focusing can be performed from the closest to infinity depending on the depth of field. The tele / wide switching time of the taking lens 110 is about 0.3 seconds.

The optical viewfinder 120 switches the field of view according to switching of the focal length of the photographing lens 110, that is, according to the operation of the tele / wide switch button 154 so that the field of view and the field of view match. Is configured. The optical viewfinder 120 is configured to switch the field of view by using both the switching of the viewfinder magnification by the lens and the switching of the size of the field frame, the details of which will be described later.

The VTR deck section 140 includes a rotary head drum, a tape loading mechanism, a tape feeding mechanism, and the like (not shown), and outputs a video signal indicating a subject photographed by the photographing lens 110 and an audio signal detected by the stereo microphone 130. Magnetic recording and reproduction on video tape of milli-cassette. Reference numeral 142 denotes a cassette lid which is opened and closed when inserting and removing a cassette, and 144 denotes a cassette eject button.

The side grip portion 150 is formed with a bulge, and a finger hook 151 is formed on the front surface of the camera. The shooting button 152 is provided on the front of the camera, and is operated by the right forefinger holding the side grip 150. Also, the tele / wide switching button 154 is disposed at a position where it can be operated by the index finger of the right hand. Reference numeral 156 denotes a grip belt.

Next, the internal configuration of the video camera 100 will be described. The video camera 100 includes a camera block, a VTR block, and a system control block. FIG. 2 mainly shows the camera block. The camera block mainly includes a photographing lens 110, an optical finder 120, a solid-state imaging device (CCD) 200, a digital signal processing circuit 210,
It is composed of a camera microcomputer 220 and the like. The system microcomputer 230 and the key switch 232 belong to a system control block.

The subject image is formed on the light receiving surface of the CCD 200 via the photographing lens 110. The CCD 200 is driven by a CCD driver 234 that outputs a CCD drive signal, photoelectrically converts an incident subject image, and outputs a signal indicating the subject image to the correlated double sample hold circuit and the AGC circuit 202. The timing pulse generator 23
6 outputs a timing pulse for driving the CCD driver 234 at a predetermined timing, and outputs a signal for controlling the charge accumulation time in the CCD 200 based on an electronic shutter control signal applied from the camera microcomputer 220. I do.

Correlated double sample hold circuit and AGC
The circuit 202 samples and holds the signal from the CCD 200, automatically adjusts the gain of the sampled and held signal, and outputs the signal to the A / D converter 204.
A / D converter 204 converts an input signal into a digital signal, and converts the input signal into a digital signal.
8 is output. The integrating circuit 238 integrates the input digital signal for each field, and the integrated data is output to the camera microcomputer 220 for aperture control and white balance control.

The digital signal processing circuit 210 includes a white balance circuit, a gamma correction circuit, an encoder circuit, etc., processes a digital signal input from the A / D conversion circuit 16, and outputs a luminance signal (Y signal) and a chroma signal (C signal). Signal), and outputs these Y signal and C signal to a recording signal processing circuit for generating a recording signal suitable for magnetic recording via a low-pass filter 242 and a band-pass filter 244, respectively. The digital signal processing circuit 21
To 0, a timing pulse and a synchronization signal are added from the timing pulse generator 236 and the synchronization signal generator 240, respectively, and a control signal is added from the camera microcomputer 220.

The system microcomputer 230 has a shooting button 1
52, controls the functions and specifications of the camera based on control signals input from a key switch 232 including a tele / wide switching button 154, a power switch, etc., and transmits and receives signals to and from the camera microcomputer 220 and the like. The lighting control of the light emitting diode (LED) in the optical finder 120 is performed. The lighting control of this LED will be described later.

The camera microcomputer 220 is supplied with integrated data from the integrating circuit 238 and with a Hall voltage from a Hall element (not shown) for detecting the opening of the iris through a Hall amplifier 246. , The camera microcomputer 220 outputs a control signal for controlling white balance and the like to the digital signal processing circuit 210, and outputs a signal for controlling iris to the adjustment circuit 2.
48 and an iris driver 250, and outputs a lens drive signal to a lens drive motor via a lens driver 252 in response to an operation of a tele / wide switching button 154 or the like. The adjustment circuit 248
And 254 are appropriately written with adjustment data, thereby adjusting circuit variations and the like.

Next, the optical finder according to the present invention will be described in detail. FIG. 3 is a perspective view of the photographing lens 110 and the optical finder 120 shown in FIG. 1, and FIG. 4 is an exploded perspective view of the optical finder 120 of FIG. In FIG. 3, reference numeral 112 denotes a motor for driving the photographing lens 110, and reference numeral 114 denotes a gear for transmitting a driving force from the motor 112 to the optical finder 120. That is, the gear 114 meshes with the gear 34 provided on the cylindrical cam 32 (FIG. 4) of the optical viewfinder 120.

As shown in FIG. 4, this optical finder 1
The optical system 20 includes a concave lens 12 on the objective side fixed to the finder frame 10 and a lens frame 14 movable in the optical axis direction.
Lens group 16 composed of two convex lenses held at
And the concave lens 1 on the eyepiece side fixed to the finder frame 10
8 (see FIG. 6). Incidentally, reference numeral 20 denotes a cover glass. The concave lens 18 and the cover glass 2
Between 0 and 0, the field frame holder 22 is rotatably housed in a range of approximately 90 °.

The field frame holder 22 has a field frame 2 for tele.
Field frame plate 24 having 4A and wide field frame 26A
And a field frame plate 26 having the following. The details of these field frames 24A and 26A will be described later.
The lens frame 14 is integrally formed with a drive arm 30. The drive arm 30 has two cam pins 30A,
30B is formed, and an engagement hole 30 for engaging with a pin 22A provided in the field frame holder 22 is formed at the tip of the arm.
C is formed.

On the other hand, the cylindrical cam 32 is rotatably provided on a cam holder 36, and the cam holder 36 is fixed to a side surface of the finder frame 10 by a screw 38 or the like. At this time, a pair of cam pins 30 provided on the drive arm 30 are provided.
A and 30B are assembled so as to sandwich the ridge 32A spirally formed on the cylindrical cam 32. FIG. 5 is a view showing a state in which the cam holder 36 is attached to the side surface of the finder frame 10. As shown in FIG.
Between the pin and the pin 22A of the field frame holder 22
0 is provided. The torsion spring 40 always acts to urge the pin 22A of the field frame holder 22 downward. The pin 22A of the field frame holder 22 is guided by an arc-shaped guide hole 10A formed in the finder frame 10, whereby the rotation range of the field frame holder 22 is regulated. The pins 22A are spring-biased at both ends of the movement range.

When the rotational driving force is transmitted from the lens driving motor 112 of the photographing lens 110 to the cylindrical cam 32 via the gears 114 and 34, the convex ridge 32A of the cylindrical cam 32 and the cam pin of the driving arm 30 are transmitted. 30A, 30B
The driving force is transmitted to the drive arm 30 via the drive arm 30, and the drive arm 30 is moved in the finder optical axis direction. Accordingly, the lens frame 14 integrally formed with the drive arm 30 also moves in the optical axis direction, and the field frame holder 22 in which the pin 22A is engaged with the engagement hole 30C of the drive arm 30.
Is rotated.

FIGS. 6A and 6B show the driving arm 3.
FIG. 4 is an internal perspective view of the optical finder 120 that has been switched to a tele state and a wide state by movement of 0, respectively. As shown in the figure, the field frame holder 22 rotates approximately 90 ° when switching between tele / wide, and the torsion spring 40
(See FIG. 5), the pin 22A of the field frame holder 22 is spring-biased so as to contact the end of the guide hole 10A.

The convex lens group 16 moves to a predetermined tele position and a wide position at the time of tele / wide switching, and is spring-biased in a tele direction and a wide direction with an intermediate point of the moving range as a boundary. It has become. That is, FIG.
As shown in FIG. 3, a pin 14A is implanted on the upper surface of the lens frame 14, and this pin 14A engages with an engaging portion 44A of a lever 44 rotatably disposed on the finder cover 42 shown in FIG. are doing. The engaging portion 44A has a concave portion formed therein for engaging with the pin 14A. Further, a torsion spring 46 is provided between the finder cover 42 and the lever 44.

FIG. 3 shows a case in which the convex lens group 16 is substantially at the middle, and the lever 44 is rotated clockwise (CW direction) in conjunction with the movement of the lens frame 14 from this state.
, The lever 44 is moved CW by the torsion spring 46.
When the lever 44 is rotated in the counterclockwise direction (CCW), the lever 44 is biased in the CCW direction by the torsion spring 46. That is, the lever 44 is moved in the CW direction and CC
By being urged in the W direction, the engaging portion 4 of the lever 44
4A, the lens frame 14 via the pin 14A of the lens frame 14
The (convex lens group 16) is biased in the wide direction or the tele direction.

Next, the field of view of the optical viewfinder 120 when switching between the telephoto state and the wide state will be described. 7 and 8 show the optical system of the optical viewfinder 120 switched to the telephoto state and the wide state, respectively. As shown in these drawings, the rotation of the field frame holder 22 causes the field frame plate 24 for telephoto during telephoto.
Is inserted on the optical axis, and at the time of widening, the wide viewing frame plate 26 is inserted on the optical axis. These field frame plates 24, 2
6, the field frames 24A and 26A are vapor-deposited, respectively, and the reflection film 19 is vapor-deposited on the surface on the eyepiece side of the concave lens 18 so as to form a translucent concave mirror.

That is, this optical finder 120 is an Albada finder, and the field frame 24A or 26A is illuminated with the light entering from the concave lens 18 and is reflected by the reflection film 19 deposited on the concave lens 18 to be reflected in the field frame 24A or 26A.
Are connected at a distance. Then, the virtual image of the field frame 24A or 26A and the image of the subject are simultaneously observed. FIG. 15B shows the optical viewfinder 12.
0 shows a virtual image 24A 'of the field frame 24A observed, and FIG. 15 (A) shows a virtual image 26A' of the field frame 26A. As shown in FIG.
A differs from the size of the wide viewing frame 26A, and the size ratio is 1: √2.

On the other hand, by moving the convex lens group 16 in the optical axis direction, the ratio of the finder magnification at the time of widening to the finder magnification at the time of telephoto is designed to be 1: √2.
Therefore, when the optical finder 120 is switched from tele to wide, the size of the field frame becomes √2 times by switching the field frame, and the size of the finder image at the time of tele is changed by switching the finder magnification. 1 / √
As a result, the viewing range at the time of widening is twice as large as the viewing range at the time of telephoto. That is, it is possible to observe the visual field range corresponding to the photographing lens 110 having the zoom ratio of 2 as described above.

Next, a description will be given of a display for displaying the operation state and the like of the video camera 100 in the optical viewfinder 120. As shown in FIGS. 3 and 9, the display mainly includes a prism frame 52 on which a prism 50 is integrally formed, a mask 54, and an LED substrate 6 on which LEDs 56 and 58 are mounted.
0. Then, the optical finder 12
The prism frame 52 integrally formed with the prism 50, the mask 54, and the LED substrate 60 are sequentially inserted into the side portion of the finder frame 1.
Fixed to 0. Reference numeral 64 denotes a light shielding plate, and the prism 5
0 is inserted into the back of the prism frame 52 so that external light does not enter.

Now, as shown in FIGS. 10A and 10B, an LED 56 that emits green light
And an LED 58 that emits red light. still,
The LEDs 56 and 58 are soldered on the LED board 60, and are arranged at regular intervals so that the solder of the adjacent LEDs 56 and 58 does not contact each other. LED5
The size of 6, 58 is about 1 mm ² .

On the other hand, the mask 54 comprises a diffusion plate 54A and a light shielding material 55B having a circular window 55A. The light shielding material 55B is provided on the surface of the diffusion plate 54A. The mask 54 is disposed on the light emitting surface side of the LEDs 56 and 58 at a small interval, and the window 56A
A part of the light-emitting surface 58 faces each.

According to the above configuration, when one of the LEDs 56 and 58 is turned on, the light passes through the window 55A of the mask 54 and is diffused by the diffusion plate 54A. Even at the position deviated by the deviation, the light intensity distribution is made uniform and emitted. This light is reflected by the prism 50 and expanded at the same time as shown in FIG. 9, and is guided into the finder.
Then, it is displayed at a predetermined position 65 in the viewfinder as shown in FIG.

By the way, the LEDs 56 and 58 of this display device
Is controlled by the system microcomputer 2 as shown in FIG.
30. The following table shows examples of display types and their contents. As described above, according to this display, various colors can be displayed at one place in the viewfinder, and display suitable for a narrow space in the viewfinder becomes possible. Note that FIG.
Shows another embodiment of the mask. The mask 66 is provided with a long window 66A. FIG. 12 shows another embodiment of the number and arrangement of LEDs, in which three LEDs 67, 68, and 69 are provided.
The light-emitting surfaces 68 and 69 are arranged so that a part of them faces the circular window 55A.

Next, a description will be given of a display mechanism for displaying whether or not recording is possible in the optical viewfinder 120. FIG.
3 is a perspective view of a main part of a driving part provided with the cylindrical cam 32 and the like shown in FIG. As shown in the figure, the display mechanism mainly includes a recording prohibition bar 70, a torsion spring 72, and a plate cam 7
And 2. The recording prohibition bar 70 is formed of a red transparent member, and is rotatably disposed on the cam holder 36 by a support shaft 71. One end of a torsion spring 72 is engaged with the rear end 70A of the recording prohibition bar 70, and the recording prohibition bar 70 is constantly urged in the CCW direction by the torsion spring 72.

The plate cam 74 is fixed on the axis of the cylindrical cam 32 and rotates together with the cylindrical cam 32. And when it rotates in the CCW direction beyond a predetermined rotation position described later,
The plate cam 74 transmits the driving force to the rear end portion 70A of the recording prohibition bar 70, and rotates the recording prohibition bar 70 in the CW direction against the urging force of the torsion spring 72. 76 is a plate cam 74
The stopper.

The distal end of the recording prohibition bar 70 has a hole 10 formed in the side of the finder frame 10 as shown in FIG.
Inserted from B. Then, when the recording prohibition bar 70 is rotated in the CW direction by the plate cam 74, FIG.
As shown in (C), it enters the finder field of view, while
When it is returned in the CCW direction by the torsion spring 72, it retracts from the finder field of view.

Next, the advance / retreat control of the recording prohibition bar 70 will be described in detail with reference to a timing chart shown in FIG. When the power of the video camera 100 is off, the barrier (not shown) of the taking lens 110 is closed as shown in FIG. 14, and the recording prohibition bar 70 is inserted in the viewfinder field (FIG. 15C). reference). Although the optical viewfinder 120 can see the subject even when the power is off, the photographer can easily recognize whether or not recording is possible based on the presence or absence of the recording prohibition bar 70.

Now, when the power is turned on (FIG. 14)
(A)), the camera microcomputer 220 (FIG. 2) rotates the lens driving motor 112 of the photographing lens 110 forward (FIG. 2B). When the barrier open / close position is detected by a photo interrupter (not shown) that detects the barrier open / close position, the tele position, and the wide position according to the rotational position of the motor 112, the motor 112 is braked and stopped (see FIG. Figures (B) and (C)).

As a result, the barrier is opened and the recording prohibition bar 70 is lowered (FIGS. 3C and 3D).
Also, the video camera 100 enters a recording standby state.
The finder is in a telephoto state as shown in FIG. Here, when the tele / wide switching button 154 is pushed once, the camera microcomputer 220
When the wide position (W) is detected by the photointerrupter, the motor 112 is braked and stopped. Also, a tele / wide switching button 154
Is pushed once again, the camera microcomputer 220
When the motor 112 is rotated in the reverse direction and the tele-interrupter detects the tele position (T), the motor 112 is braked and stopped.

On the other hand, when the power is turned off, the camera microcomputer 220 further reverses the motor 112 from the telephoto state, and when the barrier position is detected by the photo interrupter, the motor 112 is braked and stopped. As a result, the barrier is closed and the recording prohibition bar 70 is raised (FIGS. (C) and (D)), and the recording prohibition bar 70 is displayed in the viewfinder as shown in FIG.
Will be visible.

Note that the video camera 100 is provided with a mode switching button for switching between a camera mode and a VTR mode. Even when the power is on, the camera is switched to the VTR mode by the mode switching button. The microcomputer 220 controls the motor 112 to close the barrier and raise the recording prohibition bar 70.

[0049]

As described above, according to the optical finder according to the present invention, the optical magnification in the finder optical system in which the finder magnification can be switched stepwise and the field frame plate appropriately selected from a plurality of field frame plates. By combining with the size of the visual field frame, a desired visual field range is obtained, so that the subject can be prevented from becoming too small when wide, and the subject becomes easy to see. Also,
The ratio of the finder magnification at the time of tele / wide can be reduced, whereby the amount of movement of the variable power lens can be reduced, and the design of the finder optical system becomes easy.

[0050]

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a video camera to which an optical finder according to the present invention is applied.

FIG. 2 is a main block diagram showing an internal configuration of the video camera shown in FIG.

FIG. 3 is a perspective view of a photographing lens and an optical finder shown in FIG. 1;

FIG. 4 is an exploded perspective view of the optical finder of FIG. 3 as viewed from the direction of arrow A.

FIG. 5 is a side view of the optical finder according to the present invention.

FIGS. 6A and 6B are internal perspective views of the optical viewfinder switched to a tele state and a wide state, respectively.

FIG. 7 is a schematic diagram showing the optical system of the optical finder switched to the telephoto state.

FIG. 8 is a schematic diagram showing an optical system of an optical finder switched to a wide state.

FIG. 9 is a diagram showing a positional relationship of a display for displaying an operation state and the like of a video camera in an optical finder.

10 (A) is an LED of the display shown in FIG. 9;
FIG. 3 is a side view showing the relationship between the mask and the mask, and FIG. 2 (B) is a plan view.

FIG. 11 is a plan view showing another embodiment of the mask.

FIG. 12 is a plan view showing another embodiment of the number and arrangement of LEDs.

FIG. 13 is a perspective view of a main part of a driving portion provided with the cylindrical cam and the like shown in FIG. 4;

FIG. 14 is a timing chart used to explain the advance / retreat of the recording prohibition bar.

FIGS. 15A, 15B and 15C are views showing displays in each operation state of the optical viewfinder according to the present invention.

[Explanation of symbols]

 12, 18 ... concave lens 14 ... lens frame 16 ... convex lens group 22 ... field frame holder 24, 26 ... field frame 30 ... drive arm 30A, 30B ... cam pin 30C ... engagement hole 32 ... cylindrical cam 40, 46, 71 ... torsion spring 44 Lever 50 Prism 54, 66 Mask 56, 58, 67, 68, 69 LED 54A Diffusion plate 55A, 66A Window 55B Light shielding material 60 LED board 70 Recording prohibition bar 74 Plate cam 100 … Video camera 110… photographing lens 120… optical finder 220… camera microcomputer 230… system microcomputer

Continuation of the front page (56) References JP-A-4-113341 (JP, A) JP-A-3-287217 (JP, A) JP-A-2-193132 (JP, A) JP-A-2-158707 (JP) JP-A-5-2209 (JP, A) JP-A-5-45700 (JP, A) JP-A-4-163536 (JP, A) JP-A-7-253611 (JP, A) 7-175122 (JP, A) JP-A-5-88238 (JP, A) JP-A-6-73747 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03B 13/00 -13/16

Claims (7)

(57) [Claims] 1. A finder optical system capable of switching a finder magnification stepwise according to a photographic magnification of a photographic lens in which a photographic magnification is switched stepwise, and having a different size corresponding to a photographic magnification of the photographic lens. A plurality of field frame plates having a field frame, and switching means for switching the finder magnification of the finder optical system in accordance with the photographic magnification of the photographic lens and switching the field frame plate , wherein the photographic magnification is increased.
When switching, the fine finder optical system
The magnification is higher than the viewfinder magnification before switching and the shooting magnification
Switch to the viewfinder magnification lower than the magnification
Has a field frame smaller than the field frame of the field frame plate before switching.
Switching means for switching to a field frame plate to be set, and a field of view corresponding to a photographing magnification of the photographing lens is obtained by a finder magnification of the finder optical system and a size of the field frame. finder. 2. The optical finder according to claim 1, wherein the optical finder is an inverted Galilean finder. 3. The optical finder according to claim 1, wherein said optical finder is an Albada finder. 4. A finder optical system capable of switching a finder magnification to tele / wide corresponding to a photographing lens which can be switched to one of tele / wide photographing magnification, wherein By holding the double lens group, the wide position in the optical axis direction and the finder magnification at the wide position are determined.
Viewfinder magnification higher than telephoto magnification
A finder optical system and a lens frame that moves in the telephoto position becomes different Te of corresponding to the photographing magnification size of the photographic lens
Two field frame plate der with Les and for field frame for the wide
Therefore, the field of view for tele is smaller than the field of view for wide
Two field frame plates , a field frame holder provided with the two field frame plates, and rotating one of the field frame plates on the finder optical axis by rotating by a predetermined angle; and the finder optical system. When the variable magnification lens group is moved to the wide position by being connected to the lens frame and engaging with the field frame holder and moving in the optical axis direction,
The wide field of view frame is located on the finder optical axis.
Rotate the field frame holder at the predetermined angle so that
Or, when the zoom lens group is moved to the telephoto position,
The telescopic field frame is located on the finder optical axis.
Wherein a drive member for said field frame holder is the predetermined angle rotation, and a drive means for moving said drive member in response to shooting magnification of the imaging lens, wherein the finder optical system finder magnification and so An optical finder, wherein a field of view corresponding to a photographing magnification of the photographing lens is obtained depending on a size of a field frame. 5. The optical finder according to claim 4, wherein said optical finder is an inverted Galilean finder. 6. The optical finder according to claim 4, wherein the optical finder is an Albada finder. 7. The finder optical system according to claim 1, wherein the first finder optical system includes
7. The optical finder according to claim 4, further comprising a concave lens group, a second concave lens group on the eyepiece side, and the variable power lens group including a convex lens group between the first and second concave lens groups.