JP2736782B2 - Variable magnification finder device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION (a) Technical Field The present invention relates to a variable magnification finder device, and more particularly, to an improvement of a variable magnification finder device in which an observation field of view is changed in conjunction with a variable magnification photographing lens. Things.

(B) Prior Art In general, a finder optical system is formed by a plurality of lenses, and a finder as a finder variable magnification drive lens among the plurality of lenses is interlocked with zoom driving of a zoom photographing lens as a variable magnification photographing lens. In a zoom finder device as a variable magnification finder device in which a view angle is changed by moving a zoom driving lens, a large parallax occurs because a photographing angle of view changes greatly.

If such a parallax is indicated by a display frame such as a bright frame arranged inside the observation field of view 1 as shown in FIG. Although the frame range formed by the display frames indicated by a2, b1, and b2 does not substantially change between the tele side (telephoto side) and the wide side (wide angle side), the subject distance is a medium distance, for example,
In the case of a distance of about 1 m, the frame range is formed by display frames indicated by reference numerals a1 ', a2', b1 ', and b2', and greatly changes between the tele side and the wide side.

Further, when the subject distance is a short distance, for example, 0.5 m to 1 m, the frame range is formed by display frames indicated by reference symbols a1 ", a2", b1 ", and b2". It will change significantly more than in the case of the medium distance described above.

In other words, the closer the subject distance is, the more the displacement of the photographing range and the viewfinder view range occurs. The direction of this displacement is closer to the photographing lens side when the photographing range is viewed through the viewfinder, and the amount of this displacement is wide. Larger on the tele side than on the side.

Therefore, it is almost impossible to display the photographing range without parallax with a display frame that greatly changes between the tele side and the wide side and that greatly changes from infinity to a very close distance of the subject.

By the way, in order to reduce parallax, a specific lens among a plurality of lenses constituting a finder optical system is shifted in a direction orthogonal to the optical axis to be corrected in conjunction with a focusing drive of a photographing lens. There is something. However, in the zoom finder optical system, if such parallax correction is adjusted based on the wide side, the correction on the tele side becomes insufficient. Conversely, if the correction is adjusted based on the tele side, the correction on the wide side becomes excessive. A new problem arises.

If parallax is corrected by partially shifting some of the lenses constituting the zoom finder optical system other than the finder zoom drive lens in a direction perpendicular to the optical axis, the finder optical system may be damaged. Field adjustment is likely to be difficult.

In view of the above circumstances, it is desirable that the lenses other than the finder zoom drive lens among the plurality of lenses constituting the zoom finder optical system be fixed, and that this is also desirable from the viewpoint of cost.

(C) Object The present invention has been made in view of the above-described circumstances, and an object of the present invention is to eliminate parallax caused by a change in subject distance without causing a complicated configuration and complicated man-hours for adjustment. Another object of the present invention is to provide a zoom finder device that can always perform parallax correction regardless of whether the zoom position is set to the tele side or the wide side.

(D) Configuration According to the present invention, in order to achieve the above object, the finder variable magnification driving lens moves among the plurality of lenses forming the finder optical system in conjunction with the variable magnification driving of the variable magnification photographing lens. In a variable magnification finder device in which an angle is changed, a first finder zoom driving lever for guiding movement of a frame holding the finder variable magnification driving lens in an optical axis direction, and variable magnification driving of the variable magnification photographing lens First finder variable-magnification driving means for moving the frame body in the optical axis direction via the first finder zoom driving lever in conjunction with the camera; and manual setting or distance measuring means for photographing at least a subject at a short distance The first finder zoom drive lever is tilted in the direction perpendicular to the optical axis direction in accordance with the distance measurement result, and the amount of movement in the direction perpendicular to the optical axis direction is wide-angle and telephoto. And a second finder variable-power driving means for moving the frame so as to have different movement amounts in the finder optical axis of the finder variable-power driving lens. It is characterized in that the correction is made by moving in a direction substantially orthogonal to the direction.

Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS.

FIG. 1 is an exploded perspective view showing a main part of an embodiment of a zoom finder device according to the present invention, and FIG. 2 is a view showing a part of the configuration of FIG. In the sectional view shown,
FIG. 3 is a view conceptually showing a finder optical system.
This embodiment is an example in which the view angle of the finder optical system is changed in conjunction with the zoom driving of the photographing lens, and the parallax is corrected only when the distance to the subject is short.

That is, a zoom photographing lens barrel 2 is provided in the camera body, and the zoom photographing lens barrel 2 is provided with a zoom pin 2a that moves in parallel with the optical axis in conjunction with zoom driving. The zoom pin 2a is provided with a tip of the first arm 4 of a zoom interlock lever composed of a first arm 4 and a second arm 5 rotatably supported by a support shaft 3 supported by a stationary member. The drilled guide slot 4a fits, while the transmission pin 4b implanted at the other end of the first arm 4 has a guide slot 5b drilled at one end of the second arm 5. Are fitted. The first arm 4 is linked to the zoom drive of the zoom lens barrel 2.
When the zoom shooting lens barrel 2 is driven to the wide side, the zoom pin 2a moves rearward in parallel with the optical axis, and the telephoto side. The zoom pin 2a is moved in the opposite direction (forward), and the second arm 5 of the zoom interlock lever composed of the first arm 4 and the second arm 5 The lens barrel 2 rotates clockwise when the zoom drive of the lens barrel 2 is on the retracted side, and rotates counterclockwise when it is on the wide side.

A drive pin 5a is fixed to the distal end of the second arm 5, and the drive pin 5a is connected to a support shaft 7b fixed to a stationary member 7a (see FIG. 2) at one end by a guide slot 6b. A supported plate-like first finder zoom drive lever (hereinafter referred to as a “first
A fork part 6a bent and extended below the lever 6 is fitted.

The zoom finder optical system is composed of four groups of lenses, namely, a positive lens 8, a negative lens 9, a negative lens 10, and a positive lens 11, and the second lens 9 disposed as a finder variable magnification driving lens. The zoom lens is a finder zoom drive lens, and the finder viewing angle is driven according to the zoom drive of the zoom photographing lens barrel 2.

The negative lens 9 is formed in a substantially square shape, and the whole is supported by a frame 9a, and a tip of a driven pin 17 described later is fixed to a side surface of the frame 9a.

The frame 9a for fixedly supporting the negative lens 9 is
A vertically long guide slot 14 is provided in a frame 14 that is longer in the vertical direction than 9a.
The driven pin 17 is supported movably in the vertical direction by engaging the driven pin 17 with b. A guide pin 14a, which is an elliptical protrusion long in the optical axis direction for stopping rotation, is fixed to the upper side surface of such a frame 14, and the guide pin 14a is a guide length formed in an immovable member. It is movably fitted in the hole 15. Therefore, when the driven pin 17 is driven in the optical axis direction, the negative lens 9 moves in the optical axis direction together with the frames 9a and 14 using the guide elongated hole 15 as a guide, while the driven pin 17 moves in the optical axis direction. When driven in the orthogonal direction, the negative lens 9 is moved together with the frame 9a in a direction orthogonal to the optical axis direction with the guide elongated hole 14b of the frame 14 as a guide.

Now, the above-mentioned first lever 6 has a horizontally long guide slot formed so as to be movable with respect to the above-mentioned support shaft 7b.
In addition to the guide slot 6b, a guide slot 6c is further formed on an extension of the guide slot 6b. And this guide slot 6c
A drive pin 16 standing upright on a side surface of a second finder zoom drive lever (hereinafter abbreviated as “second lever”) 12 rotatably supported on the support shaft 7b linearly moves. Freely engaged.

The distal end (the right end in FIG. 1) of the second lever 12 is engaged with a guide arc hole 12b that can freely move in an arc with respect to a support shaft 12a fixed to an immovable member.

The second lever 12 is given a clockwise rotation behavior about the support shaft 7b by a tension spring 13.

Further, a straight-moving member 18 for moving the second lever 12 in accordance with the subject distance is arranged in an orthogonal state at the bottom on the distal end side of the second lever 12. The rectilinear member 18 is formed in a strip shape, and a slope 18a for pushing up the second lever 12 from the lower surface is formed at one end (the right end in the figure) at one end thereof, and at the other end thereof. Is a distance button 18b which moves in two steps: normal shooting from infinity to 1m, and close-up shooting (macro shooting) from about 1m to 0.5m in this case, for example. ing. Close distance (macro) on the bottom of this distance button 18b
A click groove 18c corresponding to the infinite distance and a click groove 18d corresponding to the infinite distance are formed, and a click spring 19 made of a leaf spring is disposed on a surface on which the click grooves 18c and 18d are formed. The click grooves 18c and 18d are selectively engaged to give a click motion. The illustrated state in which the click groove 18d and the click spring 19 are engaged corresponds to an infinite distance. Further, the zoom lens barrel 2 is located at the telephoto end.

Here, a zoom interlocking lever that moves a negative lens (finder zoom driving lens as a finder variable magnification driving lens) 9 in a first direction (optical axis direction in this example) in conjunction with the zoom driving of the zoom photographing lens. 4, 5, the first lever 6 and the like are referred to as first finder variable magnification driving means.

A straight lever 18 for moving the negative lens 9 in a second direction (in this example, a direction orthogonal to the optical axis);
The drive pins 16 and the like are referred to as second finder variable magnification drive means.

The zoom finder device of the present embodiment configured as described above operates as follows. That is, during normal shooting from a subject distance of about 1 m to infinity, the click groove 18d formed in the rectilinear member 18 is held in a state of being engaged with the click spring 19, so that the slope 18a of the rectilinear member 18 There is a gap between the lower surface of the second lever 12 and no contact, and the second lever 12 is biased clockwise around the support shaft 7 by the biasing force of the tension spring 13. ing.

When the zoom driving of the zoom lens barrel 2 is performed in this state, the zoom pin 2a is moved in the direction of the photographing optical axis accordingly, and the first arm 4 is driven to rotate via the guide slot 4a. With the transmission pin 4b and the guide slot 5b,
The second arm 5 is rotated clockwise around the support shaft 5c in the case of driving on the telephoto side and counterclockwise in the case of driving on the wide side.

For this purpose, the fork portion 6a is driven by the drive pin 5a of the second arm portion 5, and the first lever 6 is straight forward when the first lever 6 is driven on the tele side, and forward when the first lever 6 is driven on the wide side. Since the driven pin 17 moves straight in the same direction as described above, the frame 14 and the frame 9a
The negative lens 9 is moved in the direction of the optical axis as shown in FIG. 3 while being regulated by 14a, that is, the negative lens 9 is moved backward in the case of driving on the telephoto side, and forward in the case of driving on the wide side. Respectively.

Therefore, the viewing angle of the finder optical system is changed according to the focal length of the zoom photographing lens barrel 2.
In this case, by forming a parallax having a subject distance of infinity to 1 m in a complex manner with a bright frame or the like, it is possible to accurately know the actual visual field of view.

On the other hand, when performing macro photography from a subject distance of about 1 m to about 0.5 m, the distance button 18b is manually pushed in the direction of the arrow (rightward in the figure), and clicked instead of the click groove 18d formed in the linear member 18. The groove 18c is engaged with the click spring 19. Then, the second surface is inclined by the slope 18a of the linear member 18.
The lower surface of the lever 12 is pushed up.

For this purpose, the second lever is rotated counterclockwise about the support shaft 7b against the spring force of the tension spring 13, and the drive pin 16 pushes up the guide slot 6c of the first lever 6. . Along with this, the driven pin 17 fixed to the first lever 6 is moved on an arc centered on the support shaft 7b. For this purpose, the guide slot 6c of the first lever 6 is pushed up by the drive pin 16, the first lever 6 rotates counterclockwise around the support shaft 7b, and the driven pin 17
The negative lens 9 moves upward along the area 14b via the frame 9a by an amount corresponding to the zoom position (focal length). Therefore, the field of view in the finder optical system moves upward. Therefore, at the time of close-up shooting, it is the same as moving the frame range upward, and downward movement of the frame range, which occurs greatly at close-up shooting, is corrected.

On the other hand, when the zoom lens barrel 2 is driven by zooming,
Guide long hole inclined as shown by the two-dot chain line in FIG.
Guided by 6b and 6c, the negative lens 9 is driven to zoom. During such a zoom drive, the frame range corrected as described above is displayed, and parallax at the time of close-up photographing is practically used. It is reduced to an unmanageable level.

It should be noted that the zoom finder device according to the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention.

For example, a finder zoom drive lens (negative lens 9)
When moving in a direction substantially orthogonal to the finder optical axis direction by the rectilinear movement of the rectilinear lever 18, the shape of the slope 18a is formed so as to have a different moving amount depending on the subject distance,
The setting position of the straight-ahead lever 18 may be set in multiple steps or steplessly, and continuous parallax correction may be performed according to the distance of the subject.
In this case, the straight advancing lever 18 is driven by a servo motor, a stepping motor, or the like that rotates based on the subject distance information from the distance measuring device, and automatically and continuously performs parallax according to the magnitude of the subject distance. Correction may be performed. Further, the distance button 18b may be switched not by manual operation but by a plunger controlled by a switch.

Further, as described above, the present invention is applied to a zoom finder device in which the observation field magnification (or field angle) continuously changes in conjunction with a zoom photographing lens in which the image plane position does not change even when the focal length is changed. I gave an example,
Applicable to a variable-magnification finder device in which the observation field magnification continuously changes in conjunction with a variable-magnification photographing lens (or a variable-focus (varifocal) lens) in which the image plane position changes with a change in focal length. It goes without saying that you can do it.
Further, the present invention can be applied to a variable magnification finder of a bifocal lens in which a photographing lens capable of switching between tele (telephoto) and wide (wide angle) is incorporated.

(E) Effect As described above in detail, according to the present invention, the first finder zoom drive lever for guiding the movement of the frame holding the finder variable power drive lens in the optical axis direction. First finder variable-power driving means for moving the frame in the optical axis direction via the first finder zoom driving lever in conjunction with variable-power driving of the variable-power photographing lens; When photographing a subject, the first finder zoom drive lever is tilted in the direction perpendicular to the optical axis direction according to the manual setting or the distance measurement result of the distance measuring means, and the amount of movement in the direction perpendicular to the optical axis direction Is provided with second finder variable-magnification driving means for moving the frame so that the amount of movement is different between the wide-angle side and the telephoto side. Since the correction is performed by moving the finder variable power drive lens in a direction substantially perpendicular to the finder optical axis, it is difficult to perform correction only by parallax only according to the subject distance as in the related art. In the double viewfinder, parallax that greatly changes depending on the focal length could not be corrected. However, according to the present invention, even if there is a change in the subject distance and a change in the zooming position, especially when the subject and the subject A variable magnification finder that can correct large parallax that occurs when shooting an object with the focal length set to a level that does not hinder practical use, and that can achieve the correction without complicating the configuration and adjustment. An apparatus can be provided.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a main configuration of an embodiment of a zoom finder device according to the present invention, and FIG. 2 is a diagram showing a part of the configuration in the embodiment along a line AA in FIG. 3 is a view conceptually showing a finder optical system, and FIG. 4 is a view for explaining the subject distance and the amount of parallax generated by zoom driving. is there. 2 ... Zoom lens barrel, 3,5c, 7b ... Support shaft, 4 ...
1st arm, 5 2nd arm, 6 1st lever (1st finder zoom drive lever), 8,11 ... positive lens, 9,10 ... negative lens, 9a, 14 ...... frame, 12 ... second lever (second finder zoom drive lever), 13 ...
Tension spring, 16 ... Drive pin, 17 ... Driven pin, 18 ...
Straight member, 18a ... slope.

Claims (1)

(57) [Claims] 1. A variable magnification finder device in which a finder variable magnification driving lens among a plurality of lenses forming a finder optical system moves to change a viewing angle in conjunction with a variable magnification driving of a variable magnification photographing lens. A first finder zoom drive lever for guiding the movement of the frame holding the finder variable magnification drive lens in the optical axis direction; and the first finder zoom drive lever interlocking with the variable magnification drive of the variable magnification photographing lens. A first finder variable-magnification driving means for moving in the direction of the optical axis via a finder zoom driving lever of the first type; The finder zoom drive lever is tilted in the direction orthogonal to the optical axis direction, and the frame is moved so that the amount of movement in the direction orthogonal to the optical axis direction is different between the wide-angle side and the telephoto side. A second finder variable magnification driving means for moving the finder, the parallax which varies depending on the object distance and the variable magnification position is corrected by moving the finder variable magnification driving lens in a direction substantially orthogonal to the finder optical axis. A variable magnification finder device characterized by comprising.