JPH05134294A - Finder - Google Patents

Abstract

PURPOSE:To provide a finder capable of keeping power consumption as little as possible and also always forming a clear image. CONSTITUTION:A liquid crystal display 16 is installed on the upper surface of a focus plate 13, and a light emitting mechanism 24 is arranged on the side part of the liquid crystal display 16. When a camera 10 is used under a bright environment, a half mirror 12 lies at a descending position. At this time, light transmitted through a photographic lens 11 is reflected on the half mirror 12, and then, an image is formed on the focus plate 13. When the camera is used under a dark environment, the half mirror 12 lies at an ascending position. At this time, the light transmitted through the photographic lens 11 is detected by an image pickup element 21, and the image is displayed on the liquid crystal display 16. The liquid crystal display 16 is irradiated with the light from the light emitting mechanism 24. The image on the focus plate 13, or on the liquid display 16 is observed through a pentagonal prism 14 and an eyepiece 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a finder provided in, for example, an electronic still camera.

[0002]

2. Description of the Related Art Conventionally, as a viewfinder for an electronic still camera or a movie camera, an optical viewfinder, a transmission type liquid crystal viewfinder and a light emitting type electronic viewfinder are known. Some optical viewfinders are provided in a normal still camera or an electronic still camera and are configured to form an image on a focusing screen via a taking lens and a mirror. That is, the photographer can see the image on the focusing screen through the eyepiece lens. The transmissive liquid crystal viewfinder is configured to display an image detected by, for example, an image sensor on a liquid crystal display. The light emitting electronic viewfinder displays an image on a cathode ray tube, for example.

[0003]

Since the optical viewfinder and the transmission type liquid crystal viewfinder see the image by the light received from the outside, there is a problem that the image is difficult to see in a dark environment. The emissive electronic viewfinder
Since it always emits light even in a bright environment, there is a problem that power consumption increases. It is an object of the present invention to provide a finder that can always see a clear image while minimizing power consumption.

[0004]

A finder according to the present invention comprises a liquid crystal display arranged on an image plane of an optical system including at least a mirror, and an image formed on the image plane.
Means for observing without operating the liquid crystal display, means for displaying an image on the liquid crystal display with the mirror retracted from the optical path of the optical system, and means for emitting light to the liquid crystal display It is characterized by having and.

[0005]

The present invention will be described below with reference to the illustrated embodiments. FIG. 1 shows an electronic still camera 10 equipped with a finder which is an embodiment of the present invention. This figure shows a state in which the finder is used as an optical finder. That is, in this state, the image obtained through the taking lens 11 is formed on the image forming surface of the focusing screen 13 through the half mirror 12, and the photographer views the image through the pentaprism 14 and the eyepiece lens 15. You can

The focusing screen 13 is arranged horizontally in the figure, and a liquid crystal display 16 is provided on the focusing screen 13 so as to be in close contact therewith. Shooting lens 11 and half mirror 1
The image plane of the optical system including 2 is the upper surface of the focusing screen 13, that is, the lower surface of the liquid crystal display 16. In the illustrated state, the liquid crystal display 16 does not work. Therefore, the image observed through the eyepiece lens 15 is only the image formed on the image plane of the focusing screen 13. The pentaprism 14 is provided above the liquid crystal display 16, and the eyepiece 1
5 is disposed behind the penta prism 14.

The half mirror 12 is rotatably supported by a pin 17 located behind the focusing screen 13 and is rotationally displaced downward in the state of FIG. 1, but is upward in the state of FIG. 3 as will be described later. It is rotated and held in a horizontal position. As is well known, the half mirror 12 has a property of reflecting a part of light and transmitting other light.
That is, in the state of FIG. 1, the light reflected by the half mirror 12 reaches the focusing screen 13 and the half mirror 1
The light that has passed through 2 is the image pickup device 21 provided behind it.
Reach

The image pickup device 21 is composed of, for example, a CCD and converts the detected optical signal into an electric signal and outputs it. The processing circuit 22 is provided on the back side of the image sensor 21, performs a predetermined process on a signal input from the image sensor 21,
This is output to the liquid crystal display 16 and the recording medium 23. The recording medium 23 is, for example, a floppy disk, and records the video signal input from the processing circuit 22.

A light emitting mechanism 24 is provided on the side of the liquid crystal display 16. The light emitting mechanism 24 does not operate in the state of FIG. 1, but in the state of FIG.
The liquid crystal display 16 emits light.

FIG. 2 shows a light emitting mechanism 24 and a liquid crystal display 1.
6 is a diagram of the focusing screen 13, the focusing screen 13, and the half mirror 12 as viewed from the front, that is, from the left side of FIG. 1. As shown in this figure, the light emitting mechanism 24 has a pair of cylindrical reflecting mirrors 26 provided on both sides of the liquid crystal display 16 and the focusing screen 13, and inside each of these reflecting mirrors 26, a light emitting element 27 is provided. Is provided. A diffusing plate 28 is provided in a notch formed in a part of the reflecting mirror 26, and the diffusing plate 28 faces the half mirror 12.

A mirror auxiliary plate 18 is connected to the free end of the half mirror 12. The mirror auxiliary plate 18 is bendable with respect to the half mirror 12. In the state of FIG. 1, the end portion of the mirror auxiliary plate 18 is separated from the half mirror 12,
It is in contact with the bottom surface 19 of the camera body, and the mirror auxiliary plate 1
Reference numeral 8 is located below the half mirror 12 and the image pickup device 21. On the other hand, in the state of FIG. 3, the mirror auxiliary plate 18 is in close contact with the lower surface of the half mirror 12 and is in a horizontal state, and is located above the image sensor 21. The configuration in which the mirror auxiliary plate 18 rotates relative to the half mirror 12 in accordance with the rotational position of the half mirror 12 is publicly known, and the description thereof will be omitted.

Next, the operation of the apparatus of this embodiment will be described. When the electronic still camera 10 is used in a bright environment, as shown in FIGS. 1 and 2, the half mirror 12 is rotationally displaced downward and is set at a position inclined by about 45 degrees, and the mirror auxiliary plate 18 is set at the position. The end portion is brought into contact with the bottom surface 19 of the camera body and is set below the half mirror 12. In this state, a part of the light passing through the taking lens 11 is reflected by the half mirror 12 and is imaged on the imaging surface of the focusing screen 13. The photographer can see the image on the focusing screen 13 through the pentaprism 14 and the eyepiece lens 15. That is, in this state, the finder of this embodiment functions as an optical finder. At this time, the liquid crystal display 16 is not working.

Light which is not reflected from the half mirror 12 to the focusing screen 13 is transmitted through the half mirror 12 and the image pickup device 21.
Detected by. The image sensor 21 converts the detected optical signal into an electric signal and outputs it to the processing circuit 22. By the shutter release operation, the electric signal output from the image sensor 21 is subjected to predetermined processing by the processing circuit 22 and recorded on the recording medium 23 as a video signal.

When the electronic still camera 10 is used in a dark environment, the half mirror 12 is rotationally displaced upward and positioned below the focusing screen 13 as shown in FIGS. The plate 18 is in close contact with the lower surface of the half mirror 12. That is, the half mirror 12 is retracted from the optical path in the state shown in FIG. 1, and the image pickup device 21 faces the taking lens 11. Therefore, the taking lens 11
Virtually all the light passing through is detected by the image sensor 21. The image pickup device 21 converts the optical signal into an electric signal and outputs the electric signal to the processing circuit 22. The processing circuit 22 performs predetermined processing on the electric signal and outputs the electric signal to the liquid crystal display 16. At this time, the light emitting circuit 25 causes the light emitting mechanism 24 to operate.
Illuminates the liquid crystal display 16, but the light emitting mechanism 24 does not emit light directly to the liquid crystal display 16, but diffuses the light by the half mirror 12, the mirror auxiliary plate 18, and the focusing screen 13, Irradiate 16.

FIG. 5 shows the diffusion action of the light emitted from the light emitting mechanism 24. Part of the light passing through the diffuser plate 28 (FIG. 3) of the light emitting mechanism 24 is reflected by the half mirror 12, and the other light passes through the half mirror 12 and is reflected by the mirror auxiliary plate 18. Due to the mirror auxiliary plate 18, light does not leak to the lower side, that is, the image pickup device 21 (FIG. 3) side. The light reflected by the mirror auxiliary plate 18 passes through the half mirror 12, and enters the focusing screen 13 together with the light reflected by the half mirror 12. The focusing screen 13 diffuses the incident light. Due to such an action, the light emitted from the light emitting mechanism 24 is efficiently and uniformly diffused, and is applied to the liquid crystal display 16.

In FIG. 3, the image obtained through the taking lens 11 is displayed on the liquid crystal display 16, and the liquid crystal display 16 is uniformly illuminated by the light emitting mechanism 24. Therefore, the image on the liquid crystal display 16 is the same as that of the pentaprism 14 and the eyepiece 1.
Clearly visible through 5. When the surroundings are dark like this, the finder of the present embodiment functions as a light emitting finder. During shooting, the shutter release operation causes the electric signal output from the processing circuit 22 to be recorded in the recording medium 23 as a video signal.

FIG. 6 is a flow chart showing the switching control of the operation of the finder of this embodiment. In step 101, it is determined whether or not a changeover switch (not shown) provided on the main body of the electronic still camera 10 has been turned on. If the viewfinder is difficult to see due to the dark surroundings, the photographer turns this switch on. As a result, step 102 is executed and the half mirror 12
Then, the mirror auxiliary plate 18 is raised and the state shown in FIG. 3 is set. In step 103, the liquid crystal display 16 is activated and the image output from the processing circuit 22 is displayed. In step 104, the light emitting element 27 of the light emitting mechanism 24 is turned on. As a result, the image on the liquid crystal display 16 can be seen in a clear state, and the finder of this embodiment functions as a light emitting finder.

On the other hand, if it is determined in step 101 that the changeover switch has not been turned on, steps 102 to 104 are not executed. Therefore, in this case, the half mirror 12 and the mirror auxiliary plate 18
Is in the lowered position (FIG. 1) and the liquid crystal display 16 is inactive. That is, at this time, the finder acts as an optical finder, and power supply for operating the liquid crystal display 16 is not required, so that power consumption can be saved.

Although the above embodiment is an example in which the present invention is applied to an electronic still camera, the present invention is not limited to this and can be applied to various other cameras.

[0020]

As described above, according to the present invention, it is possible to obtain a viewfinder in which power consumption can be minimized and a clear image can always be seen regardless of the environment in which the camera is used.

[Brief description of drawings]

FIG. 1 is a diagram showing an electronic still camera to which an embodiment of the present invention is applied and a case where the electronic still camera is used as an optical finder.

FIG. 2 is a front view showing a configuration of a light emitting mechanism, a liquid crystal display and its surroundings, corresponding to the state of FIG.

FIG. 3 is a diagram showing a case where the electronic still camera of FIG. 1 is used as a light emitting finder.

FIG. 4 is a front view showing a configuration of a light emitting mechanism, a liquid crystal display and its surroundings, corresponding to the state of FIG.

FIG. 5 is a diagram showing a light diffusion action by a half mirror, a mirror auxiliary plate, and a focusing plate.

FIG. 6 is a flowchart showing switching control between an optical finder and a light emitting finder.

[Explanation of symbols]

 11 Shooting Lens 12 Half Mirror 13 Focus Plate 14 Penta Prism 15 Eyepiece 16 Liquid Crystal Display 18 Mirror Auxiliary Plate 24 Light Emitting Mechanism

Claims (1)

[Claims] 1. A liquid crystal display disposed on an image forming plane of an optical system including at least a mirror, a means for observing an image formed on the image forming plane without operating the liquid crystal display, and the mirror. A finder comprising means for displaying an image on the liquid crystal display and a means capable of emitting light to the liquid crystal display in a state in which is retracted from the optical path of the optical system.