JPH04324844A - Display for image plane of camera finder - Google Patents

Abstract

PURPOSE:To protect a guest host liquid crystal which is used for inlaid display in the image plane a camera finder from detrimental beam of light. CONSTITUTION:An inlaid display device for camera finder having a liquid crystal display means, which is installed in the optical path of the finder and conducts displaying by forming an opaque portion in conformity to given electric signals, is equipped with an eye setting sensing means 9 to sense eye setting to the finder or a photographing lens removal/mounting means, a main switch for camera, a light shutting means 8 to shut light incident from an eyepiece 6 intso the optical path of finder as a photo-shield for the liquid crystal display means, and a control means which operates light shutting means when the finder is out of service in response to sensing signals by the use of a single lens reflex mirror 2 or a photographing lens stop device 10.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for protecting an on-screen display element using a liquid crystal in a finder of a camera.

0002

[Prior Art] Camera photometry areas include wide AF area, spot AF area, AE spot area, etc. These photometry areas must be displayed within the shooting screen of the finder. Conventionally, these photometry areas were displayed on the focus plate. The above photometry area was displayed by marking the screen. However, with this method, the unused photometry area is always displayed, which obstructs the viewing of the image.To solve this problem, the focus plate was A method has been developed in which a guest-host liquid crystal is placed parallel to the rear and various areas are displayed on the same liquid crystal, but the focus plate is constantly illuminated by incident light from the photographing lens and incident light from the eyepiece. Therefore, the liquid crystal placed parallel to the focus plate is also constantly exposed to the incident light from the photographic lens and the incident light from the eyepiece lens. However, liquid crystals are sensitive to ultraviolet rays, and exposure to ultraviolet rays shortens their lifespan. One way to solve this problem is to install an ultraviolet absorption filter in front of the liquid crystal element, but since ultraviolet absorption filters also absorb visible light,
There was a problem in that the amount of transmitted light decreased and the finder became dark.

0003

SUMMARY OF THE INVENTION An object of the present invention is to protect a guest-host liquid crystal used for display on a camera's finder screen from harmful light.

0004

[Means for Solving the Problems] In an in-screen display device having a liquid crystal display means provided in a finder optical path and displaying by forming an opaque area using electrical signals, an eye detecting means or a photographing lens close to the finder is provided. A detachment detection means and a main switch of the camera are provided, and as a light shielding means for the liquid crystal display means, a light shielding means for shielding light entering the finder optical path from the eyepiece lens, and a single-lens reflex mirror or a photographing lens diaphragm device are used. and control means for activating each of the light shielding means when the finder is not used in response to each of the detection signals.

[0005]

[Operation] The present invention is designed to prevent harmful light from being irradiated to the liquid crystal display element placed near the focal plane in the viewfinder optical path as much as possible, but the harmful light irradiating the liquid crystal display element is directed from the direction of the photographing lens. There are two possible directions of light: light from the eyepiece and light from the eyepiece. In order to block light from these two directions except when necessary, that is, while the photographer is not looking through the viewfinder, the photographic lens is removed, or the camera's main switch is turned off. It is something to do. The light from the eyepiece is blocked by providing a light shielding means in the optical path from the eyepiece to the finder and closing the light, and the light shielding means is opened only when the photographer approaches the eyepiece.
To prevent unnecessary light from entering from the eyepiece side. On the photographic lens side, use a mechanism that blocks light by raising the single-lens reflex mirror, or a mechanism that blocks light by narrowing down the photographic lens aperture, and raise the mirror upward until the photographic lens is attached. This blocks out unnecessary light, and after the photographic lens is attached, the aperture is closed down except when the eye is brought close to the viewfinder. Alternatively, the guest-host liquid crystal used for on-screen display can be protected from harmful light by blocking light with each of the light blocking means described above until the main switch of the camera is turned on.

[0006]

Embodiment FIG. 1 shows an embodiment of the present invention. In this embodiment, when the photographic lens is removed, the single-lens reflex mirror is raised and the eye shutter provided on the viewfinder eyepiece is closed; when the photographic lens is attached, the viewfinder is closed. By the eyepiece detection means,
The eye shutter is closed and the photographic lens aperture is closed while the eye is not brought close to the viewfinder. In FIG. 1, reference numeral 1 denotes a photographing lens, which forms an image of a subject onto a film and a focus plate 3. 2 is a single-lens reflex mirror that reflects the imaging light beam toward the viewfinder. During photographing, the mirror 2 is retracted upward by the mirror drive section 11, and the imaging light flux is directly sent to the film side. On the focal plate 3, the imaging light beam reflected by the mirror 2 forms an image. The guest-host liquid crystal device (GHLCD) 4 is a display device that displays various frame patterns within the finder screen, and a detailed diagram thereof is shown in FIG. When a voltage is applied to the transparent electrode 4B, the liquid crystal 4C and the dye 4D are arranged in a spiral staircase shape, as shown on the left, and the area where the voltage is applied appears colored. When the voltage is off, the liquid crystal 4C and the dye 4D are in a vertical state, as shown on the right, and the light beam passes through them, making them appear colorless. That is, the guest-host liquid crystal element 4 is a display element that transmits light when the voltage is off, and blocks light and displays a pattern when the voltage is on. 5 is a pentaprism which inverts the imaging light beam to form an erect image of the subject on the screen in the finder. 6 is an eyepiece lens. Reference numeral 7 denotes an aperture, which is incorporated into the photographic lens 1. 8 is an eye shutter, and 9 is an eyepiece detection unit, which emits and receives light to detect whether the photographer is looking into the eyepiece. Reference numeral 10 denotes an aperture drive unit that adjusts the aperture based on photometric data and shuts down the aperture based on a detection signal from the eye detection unit to block unnecessary light. Reference numeral 11 indicates a mirror drive unit, and reference numeral 12 indicates an eye-shutter drive unit, which pulls up the eye-shutter 8 only when the photographer is looking into the finder using the eye-approach detection unit 9.

FIG. 3 is a block diagram of in-screen display control. A
B is a microcomputer that controls the entire automatic control part of the camera, and B is a shooting information screen that displays metering area, AF area, zoom information, override information, exposure information, etc. on the guest host liquid crystal display (GHLCD) 4 provided in the viewfinder. This is the inner display section (4 in FIG. 1). C is an external display section that displays mode display and exposure information. D is the mirror drive unit (
11) in FIG. E is the eye shutter drive unit, F is the aperture drive unit, G is the exposure control unit, H is the eyepiece detection unit (9 in Figure 1), and I is the photometry unit.
The light that has passed through the HLCD 4 is measured by a photometric element. J is A
The F section detects the defocus amount and adjusts the focusing lens position. K is a lens information unit provided in the interchangeable lens, which obtains and stores information related to photometry such as the maximum aperture value, information related to AF such as the conversion coefficient for converting the amount of defocus into the amount of driving of the focusing lens, and zoom position information. . L is a lens control section that drives the lens to an appropriate position based on information obtained from the lens information section K.

Next, the switches arranged on the left side of the figure will be explained. SM is the main switch on the camera body.
When this is turned on, the camera becomes ready for photographing operation, and starts photometry and AF in response to a detection signal from the eye-approach detection section H. S2 is an exposure start switch, and SSEL is a self-timer close switch. .

When the switch SM is turned on, the microcomputer 1 executes the flowchart shown in FIG. First, it is determined whether the photographic lens 1 is attached to the camera body (#1). This determination may be made by providing a switch that is turned on when the lens is attached to the mount of the camera, or may be determined based on whether information from the lens can be read. If the photographing lens is not attached, raise the mirror 2 upward (#3) to block external light from entering the GHLCD 4, and proceed to step #9. When a photographic lens is attached, lower the mirror 2 (#2) to let the subject light enter the focus plate 3 side, and the eyepiece detection section H determines whether the photographer is looking into the finder. (#4
). If the photographer is looking through the finder, the eyepiece ON routine operation is performed (#6). If the photographer is not looking through the viewfinder, perform the eyepiece OFF routine so that no light enters the GHLCD4 from either the single-lens reflex mirror or the finder eyepiece (#
5). Determine whether switch S2 is turned on (#7), and if switch S2 is turned on, perform S2 ON routine operation (photographing operation) (#8)
. If the switch S2 is not turned on, the process returns to step #1. It is determined whether switch SM is still turned on (#9). Switch SM is ON
If so, return to step #1 and switch S
When M is turned off, the diaphragm and eye shutter are closed when the lens is present, and the eye shutter is closed when the lens is absent, and the photographing operation ends. In the above operation, steps #5 and #6. Details of the operation #8 will be described later using another flowchart.

The details of the operation in step #5 in FIG. 4 will be explained using the flowchart in FIG. When the OFF signal is transmitted from the eye proximity detection section 9 (H), first, the eye shutter drive section 11 (E) closes the eye shutter 8. It is determined whether the switch SSEL is turned on (#52). If the switch SSEL is not turned on, the aperture drive unit 10 (F) apertures the aperture 7 (#
53) Prevent light from the photographic lens from entering the GHLCD 4, and return to step #1. switch SSEL
is ON, for subject photometry and distance measurement,
The aperture drive unit 10(F) opens the aperture 7 and proceeds to step #7 in FIG. 3.

The operation of step #6 in FIG. 4 will be explained using the flowchart shown in FIG. Eyepiece detection section 9 (H)
When an ON signal is transmitted from
, the aperture drive unit 10 (F) opens the aperture 7 (#62),
The photometry section I performs photometry (#63), the AF section performs distance measurement (#64), and sends photographing information to the lens information section K. The lens control unit L performs AF based on information from the lens information unit K.
The lens is driven (#65). Exposure information is displayed on display section B or C (#66). It is determined whether the lens is in focus or not using the lens information section K (#67). If it is not in focus, the focus display is not performed and the process proceeds to step #7 in FIG. 4. As a result, the process normally returns to step #1. When in focus, display the focus (
#67), the process proceeds to step #7 in FIG. 4, and if the composition is OK, the process normally proceeds to step #8.

The operation of step #8 (S2 ON routine) in FIG. 4 will be explained using the flowchart shown in FIG. When the switch S2 is turned on, first, the aperture drive unit 10(F) stops the aperture 7 to an appropriate position based on the photographing information (#81). It is determined whether the switch SSEL is turned on (#82). When the switch SSEL is turned on, the eye shutter drive unit 11 (E
) closes the eye shutter 8 (#83), waits for a certain period of time (#84), and performs exposure (#85). switch SS
If EL is not turned on, perform exposure immediately (#
85). Proceed to the next step #9 in FIG.

[0013]

According to the present invention, in response to an eyepiece detection signal, the light from the eyepiece lens and the light from the photographing lens are blocked, thereby blocking the in-screen display element from unnecessary light. It has now become possible to block light from the screen, thereby further extending the lifespan of the in-screen display elements.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of one embodiment of the present invention.

[Fig. 2] Diagram explaining the operation of the guest-host liquid crystal display element of the above embodiment.

[Figure 3] Configuration diagram of the above embodiment

[Fig. 4] Flowchart of the entire photographing operation in the above embodiment.

[
FIG. 5: Flowchart of eyepiece OFF routine in the above embodiment

FIG. 6 is a flowchart of the eyepiece ON routine of the above embodiment.

[Fig. 7] Flowchart of the S2 ON routine of the above embodiment.

[Explanation of symbols]

1 Photographic lens 2 Single-lens reflex mirror 3
Focusing plate 4 Guest-host liquid crystal display element 5
Pentaprism 6 Eyepiece lens 7 Aperture 8 Eye shutter 9 Eyepiece detection section 10 Aperture drive section 11 Mirror drive section 12 Eye shutter drive section

Claims (4)

[Claims] 1. A liquid crystal display means that is provided in the finder optical path and performs display by forming an opaque area using electrical signals, an eyepiece detection means, and a light shielding means that blocks light entering the finder optical path from the eyepiece lens. and a control means for activating the light shielding means in response to an eye proximity detection signal. 2. A liquid crystal display means, which is provided in the viewfinder optical path and performs display by forming an opaque area using electrical signals; a photographic lens attachment/detachment detection means; 1. A camera finder screen display device, comprising a drive means for rotating a reflex mirror upward. 3. A liquid crystal display means that is provided in the finder optical path and performs display by forming an opaque area using an electrical signal, a light shielding means that blocks light entering the finder optical path from the eyepiece lens, and a main body of the camera. 1. A finder screen display device for a camera, comprising control means for rotating a single-lens reflex mirror upward and closing the light shielding means when the switch is turned off in response to a switch. 4. A liquid crystal display means, which is provided in the finder optical path and performs display by forming an opaque area using an electrical signal, an eye proximity detection means, and a photographing lens aperture in response to an off signal of the eye proximity detection signal. A camera finder screen display device comprising: a control means for closing the device.