JPH0430232B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a light transmission type display device which has a function of transmitting light when not being driven and displaying an image by transmitting light in a pattern consisting of a large number of pixels according to a drive video signal when being driven. The present invention also relates to a structure of a light supply device that supplies light from inside or outside to the light transmission type display device.

FIGS. 1a and 1b are structural diagrams of a viewfinder device in a conventional video camera, where a is a video camera using a single-lens reflex optical viewfinder, and FIG. 1b is a video camera using an electronic viewfinder.

In the method shown in Figure 1a, the photographic lens 1 is
A part of the incident light is guided to the optical viewfinder 3 using a half prism 2, which allows the subject to be viewed directly, does not require electricity like an electronic viewfinder, and is cost-effective. is also advantageous. However, since the amount of light that reaches the image pickup device 4 is reduced by the amount of light that is taken out to the viewfinder, the sensitivity of the camera is lowered, and furthermore, there is a drawback that the reproduced screen cannot be viewed.

In Fig. 1b, an electronic viewfinder 5 made of a cathode ray tube is used, so it is possible to directly check the output signal of the image sensor 4 as well as view a once recorded playback image, but the disadvantage is that the cathode ray tube consumes a large amount of power. There is.

FIG. 2 is an explanatory diagram showing one embodiment of the viewfinder device for a video camera according to the present invention. In order to take advantage of the advantages of the two types of viewfinder devices and eliminate their drawbacks, a light transmission type display device, In order to selectively introduce external light to the back surface of the light transmission type display device, a light supply device using a half prism movable in two states is provided, and its purpose is to:
To provide a finder device with high sensitivity, small size and light weight, and low power consumption. 7 is a total reflection mirror, 8 is a light transmission type display device, 9 is an eyepiece lens, 10 is a light supply device made of frosted glass for taking in external light and supplying light, and 6 is taking in light from the photographing lens 1. This is a movable half prism configured to be movable between the broken line position and the solid line position where light from the frosted glass 10 is taken in.

The present invention will be explained below with reference to the drawings.

In FIG. 2, during normal photographing with a sufficient amount of incident light, the movable half prism 6 is at the position indicated by the broken line, and the light transmission type display device is not driven and does not block light, allowing the light from the movable half prism to pass through. Therefore, the operation is the same as that of a video camera using a single-lens reflex optical viewfinder, and of the light incident from the photographic lens 1, the light reflected upward by the movable half prism 6 is transferred to the total reflection mirror 7, a light transmission type. The image reaches the photographer's eye via the display device 8 and the eyepiece lens 9. On the other hand, the light that has passed straight through the movable half prism located at the position of the broken line forms an image on the image sensor 4.

Next, when playing back the recorded screen, as shown by the solid line in FIG. Light is supplied to the back side of the mold display device 8. At this time, when the light transmission type display device 8 is driven, a contrast is created between the part that transmits light and the part that blocks light. Therefore, if the light transmission type display device is driven by the recorded video signal, it will function as an electronic viewfinder.

Furthermore, if the amount of incident light is insufficient during recording, if the movable half prism is at the same position as during playback and the light transmission type display device is driven by the output signal of the image sensor 4, it can be used as an electronic finder. It can be made to function. On the other hand, since the light reaching the image sensor 4 does not pass through the movable half prism, the amount of light is not reduced, so the sensitivity of the camera can be increased.

FIG. 3 is an explanatory diagram showing another embodiment of the finder device in the video camera according to the present invention, in which a finder lens 11 forming an optical system separate from the photographing system, and a part of the incident light from below are shown. It has a light supply device 14 consisting of a photoelastic material 12 having the property of emitting light from the side, and a lamp 13 serving as a light emitting source.

In the above configuration, when photographing, light emitted from the subject reaches the image sensor 4 via the photographic lens 1, and also reaches the image sensor 4 through the viewfinder lens 11 and the photoelastic material 1.
2. The light passes through the eyepiece lens 9 and reaches the photographer's eye.

On the other hand, during reproduction, the reproduced image can be viewed by driving the light-transmissive display device 8 and blocking the incident light from the viewfinder lens. However, when there is insufficient incident light such as at night, the lamp 13 By turning on the lamp, the photoelastic material 12 radiates a part of the incident light from the lamp to the back surface of the light transmission type display element, so that the reproduced image can be clearly seen.

Note that the light-transmissive display device in the present invention is typified by a light-shielding display device using liquid crystal, but if it is a display device that transmits light when not driven, it may be a display device consisting of a self-luminous element such as a light-emitting diode. There is no problem even if it is, and it falls within the scope of the present invention. In addition, the light supply device supplies light to the back surface to display a clear image when the light transmission type display device is light-shielding. Either a system that takes in light from the outside, as shown in FIG. Furthermore, the present invention provides a finder device that transmits light from the rear when not being driven and has the function of an electronic finder when being driven, and can be used not only for television cameras but also for optical microscopes,
It is also easy to apply it to televisions that also serve as windows.

As described in detail above, according to the present invention, by providing the light transmission type display device and the light supply device in the viewfinder device, the function of the electronic viewfinder and the function of the optical viewfinder can be selected as necessary. In addition to being able to take advantage of the advantages of both, such as being able to see the subject directly, checking the output signal of the image sensor with low power consumption, and viewing the reproduced image, it is also possible to use a light transmission type display device or a light supply using a photoelastic element. Since the device is constructed in the form of a thin plate, the present invention has great significance, such as being effective in reducing the size and weight of the finder device.

[Brief explanation of drawings]

FIG. 1a is a structural diagram of a video camera using a conventional single-lens reflex optical viewfinder. FIG. 1b is a structural diagram of a video camera using a conventional electronic viewfinder. FIG. 2 is an example of the structure of a video camera using the finder device according to the present invention. FIG. 3 is an example of the structure of a video camera using the finder device according to the present invention. DESCRIPTION OF SYMBOLS 1...Photographing lens, 4...Imaging element, 6...Movable half prism, 8...Light transmission type display device, 10... Light supply device, 12... Photoelastic material, 13... Lamp.

Claims (1)

[Scope of Claims] 1. A viewfinder device for a camera for checking the photographing state, wherein a light transmission type device is provided in the incident light path from the subject, and the light transmission type display device transmits light from the subject during photography. What is claimed is: 1. A finder device characterized by having a function of transmitting an image for image pickup, driving with a drive video signal during playback, blocking incident light, and displaying an image. 2 comprises a photographic lens and the light supply device that takes in light from the outside and supplies it to the light transmission type display device, and is movable to a position where it receives light from the light supply device or a position where it receives incident light from the photographic lens; The finder device according to claim 1, further comprising a half prism that selectively takes in external light. 3. A patent claim characterized in that a photoelastic element is used, which is located in the optical path reaching the light transmission type display device and has the function of transmitting light and the function of emitting part of the incident light from the other side to the optical path. The finder device according to item 1.