JPH01183624A - Liquid crystal shutter camera - Google Patents

Abstract

PURPOSE:To eliminate turning of a mirror at the time of operating a shutter and to reduce the vibration by using a half mirror as a mirror, providing as one body a liquid crystal plate on its film face side, and making the liquid crystal plate transparent by interlocking with the shutter operation. CONSTITUTION:When a shutter is operated, a liquid crystal plate 11 is made transparent by synchronizing with opening of a mechanical shutter 9, a light beam which has transmitted through a half mirror 10 of light beam which is transmitted through photographic lenses 1, 2 transmits through the plate 11, as well, made incident on the film 4 surface and an image is recorded. On the other hand, when photographing is not executed, the plate 11 goes to opaque, and the light beams which is transmitted through the lenses 1, 2 are reflected by the mirror 10 and made incident on a finder 7. In such a way, the transmission and reflection of a light beam are controlled by varying the fixed plate 11 without turning the large-sized and heavy mirror 10. In such a way, the vibration at the time of operating the shutter is reduced and a satisfactory photographing image is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION <Public Expenses for Industrial Use> The present invention relates to a camera equipped with a liquid crystal shutter that utilizes transparency and opacity of a liquid crystal plate.

<Prior Art> A conventional single-lens reflex camera had a structure as shown in FIGS. 4 and 5. As shown in the figure, - an eye reflex camera has a total reflection mirror 3 which is vertically rotatable behind the photographic lenses 1 and 2;
is provided, and a film surface 4 is provided behind the mirror 3, while
It had a structure in which a finder consisting of a focusing plate 5, a pentaprism 6, and an eyepiece 7 was provided above the mirror 3. still,
In the figure, 8 is an aperture provided in the photographic lens system, and 9 is a focal-brain type mechanical shutter provided just in front of the film surface 4.

Therefore, as shown in FIG. 4, under normal conditions when the mirror 3 is located at the bottom, the light that has passed through the photographic lenses 1 and 2 is transmitted to the mirror 3.
The light is reflected upward to form an image on the focusing plate 5, and this image can be observed through the prism 6 and the eyepiece lens 7.

Also, by operating the shutter, the mirror 3
During photographing when the camera is rotated upward, the light transmitted through the photographic lenses 1 and 2 enters the film surface 4 and is recorded. In addition, when shooting, the mechanical shutter 9 is activated in conjunction with the rotation of the mirror 3.
will also be held.

<Problem to be solved by the invention> In recent years, cameras are required to have fairly high shutter speeds, but mechanical shutter mechanisms that open and close by moving parts have their own limitations. In order to meet the above requirements, it is necessary to reduce the number of constituent parts as much as possible.

In the conventional example described above, the mirror 3, which is large and heavy, is provided as a shutter mechanism and is rotated by shutter operation, so there is a problem that the above requirements cannot be satisfied.

The present invention has been made in view of the above-mentioned conventional circumstances, and it is an object of the present invention to provide a liquid crystal shutter camera in which the mechanical components of the shutter mechanism are largely omitted.

Means for Solving the Problems〉 The liquid crystal shutter camera of the present invention transmits light through a photographing lens.
In a camera equipped with a mirror that switches light between the viewfinder side and the film surface side, the mirror is a half mirror, a finder is provided at a position where the reflected light from the half mirror is incident, and the transmitted light of the half mirror is incident. A liquid crystal plate is integrally provided on the film side of the half mirror, and a drive circuit is provided for making the liquid crystal plate transparent by shutter operation.

Function> When observing a subject through the finder, the liquid crystal panel provided on the rear side of the half mirror is in an opaque state such as black or gray. Therefore, the light that passes through the photographic lens does not reach the film surface.
The light reflected by the half mirror enters the finder side.

On the other hand, when photographing to record an image of a subject on a film surface, the liquid crystal panel is made transparent by operating a shutter. Therefore, part of the light that has passed through the photographic lens that has passed through the half mirror also passes through this liquid crystal plate, reaches the film surface, and is recorded.

Embodiments The liquid crystal shutter camera of the present invention will be specifically described based on embodiments. Incidentally, the same parts as those in the conventional example described above are given the same reference numerals and redundant explanations will be omitted.

1 and 2 are schematic configuration diagrams of the camera of this embodiment, and FIG. 3 is a sectional view showing a portion of the liquid crystal shutter.

As shown in the figure, a half mirror 10 is provided behind the photographic lenses 1 and 2 in place of the conventional total reflection mirror 3.
When the film plane 4 and reticle 5 are hidden by 90 degrees, the λ-fmirror 10 is fixed at an angle of 45 degrees between them. Therefore, the reflected light from the half mirror 10 can be incident on the focus plate 5, and the transmitted light from the half mirror 10 can be incident on the film surface 4. This half mirror
The reflectance and transmittance of 10 are determined by how much light i is required on the film surface 4 and how much light is required for viewfinder observation.For example, the reflectance and transmittance are set to be about 50% each.

A liquid crystal plate 11 is provided on the rear surface of the half mirror 10, that is, on the film surface 4 side. A transparent electrode 12 is provided on the rear surface of the liquid crystal plate 11, and a transparent glass plate 13 is placed on top of the transparent electrode 12.
It is supported by and integrally attached to the half mirror 10.

The transparent electrode 12 is connected to a drive circuit 14 included in the camera, and depending on the voltage applied between the electrodes 12 by the drive circuit 14, the liquid crystal plate 11 can be changed into a transparent state or an opaque state such as black or gray. can be changed to

This drive circuit 14 operates together with the mechanical shutter 9 in conjunction with the operation of the printer button, and the drive circuit 14 operates in conjunction with the shutter button operation.
When the image 1 becomes transparent, the mechanical shutter 9 is opened in synchronization with the image 1.

In addition, since the liquid crystal plate 11 must always be opaque and block light from the film surface 4 during normal times when no image is recorded on the film surface 4, no voltage is applied between the electrodes 12. It is preferable to use a liquid crystal plate 11 which becomes opaque at the time of the display and becomes transparent only while a voltage is applied between the electrodes 312.

According to the camera configured as described above, when the shutter button is operated, the mechanical shutter 9 becomes transparent in synchronization with the opening of the liquid crystal panel 11, and the light transmitted through the photographic lenses 1 and 2 is made incident on the film surface 4. Images can be recorded. Further, during normal times when photographing is not performed, the liquid crystal plate 11 becomes opaque and blocks light from reaching the film surface 4. In this case, even if interference light may be transmitted due to the performance of the liquid crystal plate 11, this light is reliably blocked by the mechanical shutter 9.

Note that if the transparency (transmittance) of the liquid crystal plate 11 is controlled by varying the strength of the voltage controlled by the drive circuit, the liquid crystal plate 11 can also have an aperture function, so the aperture 8 can be omitted. It is also possible to do so.

<Effects of the Invention> According to the liquid crystal shutter camera of the present invention, transmission and reflection of light can be controlled by changing a fixed liquid crystal plate by voltage control without rotating a large and heavy mirror. Since inertia due to the movement of the mirror does not occur as in the conventional case, it is possible to reduce vibrations during shutter operation and easily obtain a good photographed image.

Also, since the reflecting mirror is a half mirror, the amount of light reflected to the finder system depends on whether the LCD shutter is ON or OFF.
F (It is constant regardless of whether the shutter is ON or 0FFI, and the captured image can always be measured with the finder.

[Brief explanation of the drawing]

1 and 2 are respectively schematic configuration diagrams of a camera according to an embodiment of the present invention, FIG. 3 is a sectional view showing a part of a liquid crystal shutter, and FIGS. 4 and 5 are respectively diagrams of a conventional camera. FIG. In the drawings, 1.2 is a TA shadow lens, 4 is a film surface, 5 is a focusing plate, 6 is a pentaprism), 7 is an eyepiece, 10 is a half mirror 1, 11 is a liquid crystal plate, and 14 is a WLVH circuit. Patent application Agent: Fuji Photo Film Co., Ltd.

Claims (1)

[Claims] In a camera equipped with a mirror that switches the light transmitted through the photographic lens to the viewfinder side and the film side, the mirror is a half mirror, a finder is provided at a position where the reflected light from the half mirror is incident, and the half mirror is A liquid crystal shutter characterized in that a film surface is provided at a position where transmitted light is incident, a liquid crystal plate is integrally provided on the film surface side of the half mirror, and a drive circuit is provided that makes the liquid crystal plate transparent by shutter operation. camera.