JPS61129630A - Variable magnification finder - Google Patents

Abstract

PURPOSE:To make a finder system small in size while keeping the observation of a finder image well by varying the magnification of the finder system and changing the size of a finder visual field frame in accordance with magnification varying of a photographing system. CONSTITUTION:Not only one of a front group 1 and a rear group 2 of, for example, an object lens is moved at least to vary the magnification of the finder system but also the size of a finder visual field frame 6 of the finder system is changed in accordance with magnification varying of the photographing system.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a variable magnification finder, and particularly relates to variable magnification finding, which is suitable for lens-shutter cameras, etc., by changing the magnification of a photographing system, changing the magnification of the finder system, and changing the size of the viewfinder field frame. It is something.

Conventionally, a nine-variable magnification finder has been proposed which attempts to increase the magnification of the finder itself by moving some of the lens groups of the finder system together with changing the magnification of the photographing system. Among these, for example, Japanese Patent Publication No. 27-3024 and Japanese Patent Application Laid-Open No. 53-63014 consist of an objective lens with a negative refractive power and an eyepiece lens with a positive refractive power. We have proposed a system in which the lens is divided into lens groups with different refractive powers, and among these, the lens group with negative refractive power is moved to change the magnification in response to the change in magnification of the photographing system [1]. In this method, a variable magnification ratio equivalent to that of the photographing system must be obtained only with the finder system, and the amount of movement of the lens detail increases, leading to a tendency for the finder system to become larger.

Furthermore, Japanese Patent Application Laid-Open No. 54-161931 proposes a daylight type finder in which the viewfinder field frame is continuously changed in accordance with the change in magnification of the ftm shadow system. This method has a tendency that as the zoom ratio of the photographing system increases, the viewfinder field frame becomes smaller and it becomes difficult to observe the 7-inder image.

SUMMARY OF THE INVENTION An object of the present invention is to provide a simple variable magnification finder that allows the finder system to be downsized while maintaining good observation of the finder image.

The main feature of the variable magnification finder for achieving all the objects of the present invention is that the magnification of the finder system is changed in conjunction with the variable magnification of the photographing system, and the size of the viewfinder field frame of the finder system is changed. Ruru.

In this way, in the present invention, by dispersing the amount equivalent to the zoom ratio of the photographing system into the zoom ratio of the viewfinder system and the zoom ratio of the viewfinder field frame, it is possible to observe a compact yet excellent viewfinder image. A variable magnification viewfinder has been achieved.

Next button An embodiment of the present invention will be explained together with each tooth.

FIG. 1 is a schematic diagram of an optical system applied to a full daylight finder according to the present invention. In the figure, 1.2 are the front and rear groups of the objective lens, 3 is the eyepiece, and 4 is the half mirror 1.
5 is a mirror, 6 is a variable viewfinder field frame near the lighting window, and 16° 17tZL is a photographing system that can zoom.

The finder system consists of the front group, rear groups 1 and 2 of the objective lens, and the eyepiece lens 3. The eyepiece lens 3 is fixed, and at least -1 lens group t- of the front group and rear groups 1 and 2 of the objective lens is fixed.
Can you change the magnification by moving it in conjunction with the magnification of the m shadow system? ing.

The eyepiece lens 3t is fixed and the diopter up to the viewfinder field frame 6 is constant.

In this embodiment, the size of the viewfinder field frame 6 is changed along with the magnification of the finder system to correspond to the change in the photographic screen due to the magnification of the photographing system.

It's set.

The viewfinder field frame is changed mechanically or electrically, for example by using a liquid crystal display.

Now, when the zoom ratio of the shooting system ZL is 2, conventionally the zoom ratio zt- is achieved by the -) of the finder system.As a result, the amount of movement of the lens group increases and the finder system tends to become larger. If you change the viewfinder field frame fic to make it as large as the zoom ratio 2, even if the finder field frame is an appropriate size at the wide-angle end, it will become too small at the telephoto end, making it difficult to observe. 6 friends have the disadvantage of being difficult.

In this example, in addition to changing the magnification of about 1 lens in the viewfinder system, the size of the viewfinder field frame is reduced by an amount corresponding to 29 magnification ratio f lens, and the overall appearance is changed. The entire magnification ratio is 2x.

In this way, this embodiment uses the synergistic effect of the change in magnification of the finder system and the change in the viewfinder field frame to correspond to the change in magnification of the photographing system. Therefore, the movement of the lens group of the finder system due to zooming can be reduced, and the finder system can be made more compact. Also, the size of the viewfinder field frame does not have to be very small, so it does not make it difficult to observe the finder image.

FIG. 2 is a schematic diagram of an embodiment of the present invention in which the size of the finder field frame is changed along with the magnification of the finder system of the present invention. In the figure, the rear group 2t of the objective lens is moved to change the magnification. At this time, the position of the rear group 2, that is, the variable magnification position, is detected digitally by the position sensor 8, or when detected analogously, it is then converted to a digital signal by the Ω converter 9, and the output signal is Then, the finder field frame control means 10 displays a predetermined finder field frame made of, for example, a liquid crystal.

FIG. 3 is an explanatory diagram of an embodiment in which the viewfinder field frame according to the present invention is composed of liquid crystal.

In the figure, 6 □ is a finder field of view frame 1.6 □ is a finder field frame that becomes opaque when energized, and broken line 7 is a finder field frame that is transparent when not energized.

In this embodiment, the size of the finder afF frame 7 is configured to change with the magnification of the finder system by a finder field frame control means (not shown). For example, when the viewfinder system increases magnification, the size of the viewfinder field frame decreases.

FIG. 4 is an explanatory diagram of another embodiment of the finder field frame according to the present invention. In the embodiment shown in the figure, the opaque fAA portion of the viewfinder field frame 7 is selected and displayed so that the viewfinder parallax (balarax) t-mNIE is taken into consideration by the magnification change position information and object distance information of the photographing system. It's a friend.

In this way, by configuring the finder field frame with a plurality of sizes t using a plurality of liquid crystal elements and appropriately selecting and displaying them, it is possible to correct the distortion as well as the parallax of the finder.

In the present invention, the magnification ratio of the photographing system is tz1f7 (the magnification ratio of the 7-dar system is t-z, and when the amount of change in the magnitude corresponding to the magnification ratio of the viewfinder field frame is t-22, z-zl) If the configuration is such that the formula z2 is approximately satisfied, it is not necessarily necessary to make the variable magnification ratios of the finder system and the finder field frame the same, and they may each be set to z1 or Z21ft depending on the purpose.

As described above, according to the present invention, the magnification of the finder system is changed in conjunction with the magnification change of the photographing system, and the size of the viewfinder field frame is also changed, while maintaining good observation of the finder image. By changing either the magnification of the finder system or the dimensions of the viewfinder field frame, it is possible to achieve a variable magnification finder that is much more compact than usual.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of an embodiment of the present invention when applied to the Qll lighting type finder, and Fig. 2 is a view through the finder with variable magnification of the finder system of the present invention. FIGS. 3 and 4 are explanatory diagrams of an embodiment in which the size of the field frame is changed, and FIGS. 3 and 4 are explanatory diagrams of a finder field frame made of a liquid crystal according to the present invention, respectively. In the figure, 1 and 2 are the front and rear groups of the objective lens, respectively, and 3 is the Jil
lt lens, 6 a finder field frame, 7 a liquid crystal display piece, 8 a position sensor, 9 an AE converter, and 10 a finder field frame control means.

Claims (3)

[Claims] (1) A variable magnification finder characterized in that the magnification of the finder system is changed in conjunction with the magnification change of the photographing system, and the size of the viewfinder field frame of the finder system is changed. (2) The variable magnification finder according to claim 1, wherein the finder magnification of the finder system is increased and the size of the finder field frame is reduced. (3) The variable magnification finder according to claim 2, wherein the variable magnification finder is constructed of a daylight type finder.