JPH04104637U - Camera diopter correction device - Google Patents

Abstract

(57) [Summary] [Objective] The object is to provide a diopter correction device for a camera that can easily correct the diopter of a finder optical system during macro photography without any mechanical stress. [Structure] When the finder optical system driving mechanism 20 sets the finder optical system 10 to a state for macro photography, the reflection mirror 18 is moved by the operation of the finder optical system driving mechanism 20 to change the optical path length of the finder optical system 10. Along with changing the viewfinder optical system 1
Reflection mirror driving means 24 and 37 are provided to change the direction of the reflection mirror 18 so as to correct the deviation of the optical axis of the optical axis.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This idea was developed to compensate for changes in the diopter of the finder optical system during macro photography. The present invention relates to a diopter correction device for a camera.

0002

[Conventional technology]

For cameras other than single-lens reflex cameras, the facsimile is Since the diopter of the inner optical system changes, it is necessary to correct it.

0003 Conventionally, the lens in the finder optical system was moved in the direction of the optical axis during macro photography. The diopter was corrected by moving the lens.

0004

[Problem that the idea aims to solve]

However, with cameras equipped with a zoom mechanism, the zoom movement is required in the viewfinder optical system. The cam that performs the image movement only moves slightly between the telephoto and macro positions. . Therefore, in order to correct the diopter during macro photography, it is necessary to adjust the lens by a small amount of cam movement. The cam has to be driven by the lens, which creates strain on the cam mechanism and prevents smooth operation. There were drawbacks such as loss of performance.

[0005] Therefore, this invention aims to correct the diopter of the finder optical system during macro photography, which is mechanically impossible. Our aim is to provide a diopter correction device for cameras that can be easily performed without target

[0006]

[Means to solve the problem]

In order to achieve the above purpose, the camera diopter correction device of the present invention The focal length of the finder optical system can be changed in conjunction with the operation of changing the focal length. a finder optical system drive mechanism that moves the lens in the finder optical system forward and backward; A reflecting mirror arranged to change the direction of the optical axis of the finder optical system and the above-mentioned frame are The finder optical system drive mechanism puts the finder optical system into the state for macro photography. When the viewfinder optical system drive mechanism moves, the reflecting mirror is moved. The optical path length of the finder optical system is changed by moving the optical path, and the above-mentioned Change the direction of the above reflecting mirror to correct the misalignment of the optical axis of the finder optical system. The present invention is characterized in that a reflecting mirror driving means is provided.

[0007]

【Example】

Examples will be described with reference to the drawings.

[0008] Figure 2 schematically shows a so-called 35mm compact camera, and 1 is the camera body. , 2 is a photographing lens. Photographing lens 2 is a so-called autofocus zoom tie. The focus adjustment for the subject is done using autofocus (not shown). This is automatically done by the zooming device, and the zoom Zooming (stepless adjustment of focal length) is performed by operating switching switch 3. be exposed. Also, by setting zooming switch 3 to the "macro" position, The photographing lens 2 is set to a so-called macro photography state for extremely close-up photography.

[0009] The finder optical system 10 includes first and second lenses that are movable forward and backward only in the optical axis direction. movable lenses 11, 12 and first and second fixed lenses 14, 15 on the eyepiece side. It is composed of four groups. Also, between the first and second fixed lenses 14 and 15, A Porro prism 16 is fixedly installed, and a second fixed lens 15 and a second movable lens 1 A plane reflection mirror 18 is arranged between the two.

0010 FIG. 1 shows the area around the finder optical system. 4 performs various automatic controls. It is a control unit for zooming by the signal input from the zooming switch 3. A control signal is output to the drive circuit of the motor 5.

[0011] The zooming motor 5 drives the photographing optical system for zooming the photographing lens 1. At the same time as driving the mechanism 6, the movable lenses 11 and 12 of the finder optical system 10 are driven. The finder optical system drive mechanism 20 for driving is driven. Below, finder light The academic drive mechanism 20 will be explained.

0012 21 is a flat cam plate provided movably in the left and right direction in FIG. , an arcuate first cam groove 22 and a linear second cam groove 23 are formed. A first pin 11b connected to the lens frame 11a of the first movable lens 11 is engaged with the first cam groove 22 and connected to the lens frame 12a of the second movable lens 12. The second pin 12b is engaged with the second cam groove 23.

[0013] Further, on the back side of the lower end of the cam plate 21, there is a rack parallel to the movable direction of the cam plate 21. A rack 25 is formed, and an intermediate gear group 26 is connected to the rack 25 and the zooming motor. The output gear 5a of the motor 5 meshes with the output gear 5a of the motor 5.

[0014] Therefore, when the zooming motor 5 rotates, the photographing lens 2 At the same time as the focal length of advance and retreat. Then, the pins 11b and 12b are moved by the movement of the cam grooves 22 and 23. Move the moving lenses 11 and 12 back and forth in the optical axis direction (vertical direction in Figure 1) The focal length of the optical system 10 changes in conjunction with the change in the focal length of the photographic lens 2.

[0015] The reflecting mirror 18 bends the direction of the optical axis Z of the finder optical system 10 by 90 degrees. It is located in Further, the Porro prism 16 is arranged along the optical axis Z of the finder optical system 10. The direction of the image is bent again by 90 degrees, and the observed image is made into a correct erect image.

[0016] The photographing range of the photographic lens 2 is determined through the viewfinder optical system 10 configured as described above. Although it is possible to obtain a viewfinder field of view that almost matches the It is not possible to correct changes in diopter during shooting.

[0017] Therefore, in this embodiment, as shown in FIG. A pair of pins 31 and 32 are coaxially protruded from the top and bottom of the mirror frame 18a to be held. It is rotatably supported on a slide frame 33. The axes of this pair of pins 31 and 32 are It is on the reflective surface of the reflective mirror 18 and also reflects the optical axis Z of the finder optical system 10. It passes through the point.

[0018] Therefore, the reflecting mirror 18 can be rotated around the pins 31 and 32 as the central axis. Also, the reflection point on the optical axis Z does not move when rotated.

[0019] There is a relatively large diameter space between the center part of the back surface of the mirror frame 18a and the slide frame 33. A large compression coil spring 35 is tightly attached, and its urging force causes the mirror frame 18 to a is stably maintained parallel to the slide frame 33.

[0020] The slide frame 33 has a protrusion that engages with a linear guide groove formed on the camera body 1 side. A raised part 33a is provided protrudingly, and the slide frame 33 is arranged in the optical axis direction of the movable lenses 11 and 12. It can move forward and backward only (in the vertical direction in FIG. 1).

[0021] Then, a pin 33b connected to the slide frame 33 is bored into the cam plate 21. It is engaged with the third cam groove 24, and as the cam plate 21 moves, the slide frame 33 is driven forward and backward in the optical axis direction of the movable lenses 11 and 12.

[0022] However, the third cam groove 24 is located on the cam plate 21 in the normal distance zoom range. Since it is formed parallel to the moving direction, the slide frame 33 does not move and the reflecting mirror 18 doesn't move.

[0023] However, at the macro observation position 24a corresponding to macro photography, the third cam groove 2 4 is bent in the direction away from the movable lenses 11 and 12, and at that time The stopper pin 37 is attached to the cam plate 3 so that it comes into contact with the left front end surface of the mirror frame 18a. It protrudes from 7. The left front end portion of the slide frame 33 is attached to the stopper pin 37. It is cut out to prevent collisions.

[0024] FIG. 4 shows the state during macro photography, where the cam plate 21 is connected to the zooming motor. 5 to move all the way to the left in the direction of arrow A.

[0025] As a result, the pin 33b directly connected to the slide frame 33 is inserted into the third cam groove 24. The slide frame 33 moves away from the movable lenses 11 and 12 by engaging with the b position 24a. .

[0026] At the same time, the stopper pin 37 comes into contact with the left front end surface of the mirror frame 18a. Then, the mirror frame 18a, which had been kept in balance by the spring force of the coil spring 35, was pushed. The reflecting mirror 18 fixed to the mirror frame 18a is centered around the pins 31 and 32. Rotate by a small angle in the direction of arrow B. This rotation angle is reversed along with the slide frame 33. Movable lens of finder optical system 10 caused by movement of projection mirror 18 11, 12 and the fixed lenses 14, 15 to correct the deviation of the optical axis. It is set as follows.

[0027] In this way, by moving the slide frame 33, the finder optical system The optical path length of 10 is extended inside the optical system, and the diopter of the finder optical system 10 during macro photography Changes are corrected.

[0028] However, if the reflecting mirror 18 only moves together with the slide frame 33, the fine There is an optical axis misalignment between the movable lenses 11, 12 and the fixed lenses 14, 15 of the optical system 10. Misalignment (misalignment) occurs. Therefore, by rotating the mirror frame 18a, the reflecting mirror 18 The path of the optical axis Z is changed by rotating the This prevents misalignment between the lenses 14 and 15.

[0029] Note that this invention is not limited to zoom cameras, but can also be used to change the focal length in multiple stages. It can also be applied to cameras that can do this.

[0030]

[Effect of the idea] According to the camera diopter correction device of the present invention, the viewfinder optical system can be used for macro photography. The drive mechanism for moving the lens in the finder optical system forward and backward when the The reflection mirror in the finder optics can be moved depending on the design, making it easy to By changing the optical path length, the diopter correction of the finder optical system can be performed smoothly without mechanical strain. It can be done at any time.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment.

FIG. 2 is a schematic illustration of an example camera.

FIG. 3 is a partial perspective view of the embodiment.

FIG. 4 is a sectional view of the embodiment in a state for macro photography.

[Explanation of symbols]

2 Photographic lens 10 Finder optical system 11,12 Movable lens 14,15 Fixed lens 18 Reflection mirror 18a Mirror frame 20 Finder optical system drive mechanism 21 Cam plate 24 Cam groove 31,32 pin 33 Slide frame 35 Coil spring 37 Stopper pin

Claims (1)

[Scope of utility model registration request] 1. A finder optical system drive mechanism that moves a lens in the finder optical system back and forth so as to change the focal length of the finder optical system in conjunction with an operation that changes the focal length of a photographic lens; When the finder optical system is set to a state for macro photography by a reflecting mirror arranged to change the direction of its axis and the finder optical system driving mechanism, the reflecting mirror is moved by the operation of the finder optical system driving mechanism. The camera is characterized in that it is provided with a reflection mirror drive means that changes the direction of the reflection mirror so as to change the optical path length of the finder optical system and correct the deviation of the optical axis of the finder optical system caused thereby. Diopter correction device.