JP2000089336A - Display device within finder picture plane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device within a finder picture plane capable of realizing display at the time of executing specified operation with high visibility even when an index is always displayed. SOLUTION: In this display device, information displayed within the finder picture plane of a camera is constituted of area display, ranging point display and photometric area display. The ranging area display and the photometric area display are always displayed within the finder picture plane as marking on a focusing glass 1. The point display is displayed by turning on and emitting light when the specified operation is performed by a light emission unit 10 and a display optical system 13. The display information of the ranging point display is equivalent to one part of the display information of the ranging area display, and displayed so as not to be superposed in a state where the ranging point display is aligned with the ranging area display.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device in a finder screen, and more particularly to a display device in a finder screen for displaying various information necessary for photographing in a finder screen of a single-lens reflex camera.

[0002]

2. Description of the Related Art A general viewfinder of a camera has a function of displaying various information necessary for photographing in a viewfinder view. Information necessary for shooting includes exposure-related data (shutter speed, aperture value, exposure compensation value, etc.), shooting area (view frame display), ranging area (focus frame display), metering area (metering frame display), focus The detection result (in-focus / out-of-focus, front / back focus), focus adjustment direction, flash light-related data, and the like are included. Of these pieces of information, the distance measurement area and the photometry area are displayed in a finder screen on which a subject image is displayed.

In a camera equipped with a multipoint AF (autofocus) function, one of a plurality of ranging points in a ranging area is automatically selected by the camera or manually selected by a user. It is necessary to further display which focus point is currently selected. As one method for displaying the focus detection points, a method is known in which a selected focus detection point is superimposed and displayed in a finder screen by an LCD (liquid crystal display). However, in this method, since the distance measurement point is displayed by dark display of the local focus frame, there is a problem that the visibility decreases when the finder screen becomes dark (for example, when the subject has low brightness).

Therefore, when priority is given to visibility, it is desirable to perform display such as a bright frame having a higher luminance than that of the finder screen. When trying to display on the finder screen with higher brightness than the finder screen with the current single-lens reflex camera, the structure of the LED (light e
A configuration for electrically driving a light-emitting body such as a mitting diode) will be employed. By using a luminous body,
The selected ranging point can be displayed. However, it is inconvenient if the user does not know where the plurality of ranging points to be selected are located before the display. Therefore,
Indices relating to a plurality of ranging points need to be constantly displayed in the finder screen.

[0005] However, it is disadvantageous in terms of power consumption that the indicator relating to the distance measuring point is always lit and displayed by a display method using a light emitting body. In addition, when photometry is performed through a finder, there is a possibility that light from a light emitting body may enter the photometry element, and thus there is a problem in terms of the effect on photometry. Therefore, a configuration in which the selected ranging point is displayed for light emission only for a short period of time when necessary (at a timing when photometry is not performed) and a configuration in which indicators relating to a plurality of ranging points are constantly displayed without using a light emitting body are provided. Required. A display device adopting such a display method is proposed in Japanese Patent Application Laid-Open No. 3-192340. According to the configuration, for example, indices related to a plurality of distance measuring points are always displayed on a marking grating formed on a focusing screen, and one of them is illuminated with a light emitter to form a red light emission image. Displays the selected ranging point.

[0006]

However, Japanese Patent Application Laid-Open No. 3-1923 / 1991
According to the display device proposed in Japanese Patent Application Publication No. 40-240, etc., which of the focus detection points is selected can be determined only by the fact that the constantly displayed index changes from black to red. For this reason, there is a problem that visibility is somewhat lacking.

The present invention has been made in view of such a situation, and a display in a finder screen which can realize a display at the time of executing a specific operation with high visibility even when an index is always displayed. It is intended to provide a device.

[0008]

According to a first aspect of the present invention, there is provided a finder screen display device for displaying information in a finder screen of a camera. Is composed of a first display that is always displayed in the viewfinder screen, and a second display that is displayed by emitting light when a specific operation is performed, and the display information of the second display is the display information of the first display. It corresponds to a part of display information, and is displayed so that the second display does not overlap with the first display in a state of being coincident with the first display.

According to a second aspect of the present invention, in the finder screen display device according to the first aspect, the display information of the first display includes information on all positions and ranges of a plurality of ranging points. The display information of the second display includes information about a position and a range of a ranging point automatically selected by a camera or a ranging point selected by a photographer among the plurality of ranging points. .

According to a third aspect of the present invention, in the finder screen display device according to the first aspect, the finder screen comprises a finder light beam incident on a reversing prism for reversing a finder image on a focusing screen. The first display is constituted by a frame provided on an optical surface on or near a reticle, a half mirror surface is formed on at least one reflection surface of the inverting prism, and the finder passes through the half mirror surface. The second display is introduced as a superimposed display in the finder screen by merging the display light beam with the light beam.

According to a fourth aspect of the present invention, in the finder screen display device according to the first aspect, the finder screen is constituted by a finder light beam reflected by a penta roof prism and guided to an eyepiece optical system. A third mirror surface is formed with a half mirror surface, and the display light flux is merged with the finder light flux through the half mirror surface to introduce the second display into the finder screen and emit the display light flux. A display optical system is provided so that an emission surface composed of a plane faces the half mirror surface, and the emission surface of the display optical system and the third reflection surface are positioned parallel and at a predetermined interval; Further, the following conditional expression is satisfied. D ≦ 0.0004 × FL where D is the exit surface of the display optical system and the third of the penta roof prism.
FL: focal distance of the eyepiece optical system.

According to a fifth aspect of the present invention, in the finder screen display device according to the third or fourth aspect, the reflectance of the half mirror surface with respect to the finder light beam is higher at a peripheral portion than at a central portion, and The transition of the reflectance from the center to the periphery is stepwise.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A display device in a finder screen embodying the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of a finder to which the present embodiment is applied. This viewfinder is a viewfinder for a single-lens reflex camera equipped with a multi-point AF function.
(1), condenser lens (2), penta roof prism
(3), eyepiece optical system (4), protective glass (5), photometric element (6), photometric lens (7), off-screen display LCD (8), off-screen display prism (9), light source unit (10) And a display optical system (13).

A finder image (subject image) is formed on a reticle (1) by a photographing lens (not shown).
The viewfinder screen is composed of the viewfinder light beams emitted from the camera. The finder light beam emitted from the focusing screen (1) is condensed by the condenser lens (2) and enters the penta roof prism (3). The penta roof prism (3) is an inverting prism that inverts the viewfinder image on the focusing screen (1) to make an erect image. The finder light reflected by the penta roof prism (3) is connected to the eyepiece optical system (4) and the protective glass.
It passes through (5) and reaches the pupil (not shown).

The photometric element (6) is a photometric means for receiving a part of the finder light beam emitted from the penta roof prism (3) and performing spot photometry, multi-segment photometry and the like. The out-of-screen display LCD (8) is a display device that performs out-of-screen display (shutter speed, aperture value, exposure correction value, etc.). The display light beam from the off-screen display LCD (8) passes through the out-of-screen display prism (9), enters the penta roof prism (3), and enters the eyepiece optical system (4) together with the finder light beam.

The information displayed in the finder screen is
It is a distance measurement area, a distance measurement point, and a photometry area.
, Each display (F1 to F3, f1 to f3). The ranging area is configured by a ranging area display (F1, F2) that is always displayed in the viewfinder screen. This distance measurement area display
(F1, F2) is always fixedly displayed without being turned on / off.
The photometry area is composed of a photometry area display (F3), and is always fixedly displayed in the finder screen, similarly to the distance measurement area.
The ranging points are constituted by ranging point indications (f1 to f3) displayed by emitting light when performing a specific operation. The distance measurement point displays (f1 to f3) are light emission displays that are turned ON / OFF by electric driving. Note that the specific operation refers to automatic selection of a ranging point by a camera or manual selection of a ranging point by a photographer, which will be described later in detail.

Distance measurement area display (F1, F2) and photometry area display
(F3) is composed of a marking frame (F) processed and formed on the reticle (1) as shown in FIG. 2, and is observed on the finder screen as shown in FIG. AF area display (F
1) indicates a ranging area at the time of wide focus, and a ranging area display (F2) indicates a ranging area at the time of spot focusing. The photometry area display (F3) indicates the photometry area at the time of spot photometry. These area displays (F1-F3) are
(1) It may be configured by providing a frame (F) on a nearby optical surface. For example, a frame (F) may be provided on the condenser lens (2), or a flat plate on which the frame (F) is formed may be provided between the reticle (1) and the condenser lens (2). Also, instead of composing the frame (F) with markings,
It may be constituted by a display element such as an LCD.

The ranging point displays (f1 to f3) are constituted by a light source unit (10) and a display optical system (13) disposed in front of the penta roof prism (3). The light source unit (10)
There are provided three LEDs (11) and a mask member (12) having three openings at corresponding positions. The display optical system (13) includes a lens (14) and a triangular prism (15). Three display light beams are emitted from the light source unit (10), pass through the display optical system (13), and are emitted from an emission surface (15S) formed of a plane of the triangular prism (15). Note that LE
Another light emitter may be used instead of D (11).

The third reflecting surface (3S) of the penta roof prism (3)
Has a half mirror surface (3H). The display optical system (13) described above has an emission surface (1) on this half mirror surface (3H).
5S) so that the display optical system (1
The exit surface (15S) of 3) and the third reflecting surface of the penta roof prism (3)
(3S) is parallel and located at a predetermined interval.
Therefore, the display light beam emitted from the display optical system (13) merges with the finder light beam through the half mirror surface (3H). In this way, the ranging point displays (f1 to f3) are introduced as superimposed displays in the finder screen. FIG. 4 shows distance measurement point displays (f1 to f3) observed in the viewfinder screen.

The reflection surface on which the half mirror surface (3H) is formed is not limited to the third reflection surface (3S), but may be another reflection surface. However, the third reflective surface located in front of the viewfinder
A configuration in which the display light flux is introduced from the (3S) into the penta roof prism (3) does not adversely affect the finder image performance, and is advantageous in reducing the size of the entire finder. If necessary, a half mirror surface may be formed on a plurality of reflection surfaces, and a display light beam may be introduced into the penta roof prism (3) from the plurality of reflection surfaces.

When any one of the three ranging points in the ranging area is automatically selected by the camera or manually selected by the photographer, the currently selected ranging point is displayed. (f1 to f3) are displayed. That is, when the camera automatically selects the focus detection point, the focusing is completed using the information on the focus detection point of the lit display (f1 to f3). When the photographer himself selects the ranging point, focusing is performed using the information on the ranging point of the lit display (f1 to f3). For example, if the photographer manually selects and sets the AF points,
The display is switched from the state of FIG. 3 to any of the states of FIGS. Then, the states of FIGS. 5 to 8 are cyclically switched by a dial operation or a switch operation, and at least one ranging point display (f1 to f3) is shown. FIG. 9 shows another example of the distance measurement point display (f1 'to f3').

As can be seen from FIGS. 5 to 8, the display information of the distance measurement area display (F1, F2) includes information on the positions and ranges of all three distance measurement points. For example, the left ranging area display (F1) includes information on the position and range of the left ranging point (f1). Further, the display information of the ranging point display (f1 to f3) includes information on the position and range of the ranging point selected from among the three ranging points. That is,
Since the ranging point information indicated by the ranging point display (f1 to f3) corresponds to a part of the ranging area information indicated by the ranging area display (F1, F2), the ranging area display (F1, F2) is not included. This is an index for the distance measurement point display (f1 to f3). Thus, the distance measurement area display
Since (F1, F2) is always displayed in the viewfinder screen and serves as an index for the ranging point display (f1 to f3), the target ranging point display (f1 to f3) is displayed before the flash It is convenient to be able to easily know where it is located.

The area display (F1 to F3) and the ranging point display (f
Since the shapes and positions of 1 to f3) are different, the focus point is displayed in a place where no fixed display exists in the viewfinder screen.
The emission images of (f1 to f3) appear. As described above, the display information of the ranging point display (f1 to f3) is displayed in the ranging area display (F1, F2).
Of the display information of the
Since 3) is displayed so as not to overlap with the distance measurement area display (F1, F2), it is possible to achieve high visibility due to its unexpectedness. The brightness of the LED (11) is adjusted according to information related to the brightness of the viewfinder screen (photometric value obtained by the photometric element (6), open F-number of the taking lens, diffusion characteristics of the focusing screen, etc.). It may be controlled to change. For example, based on the photometric value at the ranging point of each display (f1 to f3), if the superimposed ranging point display (f1 to f3) is performed according to the brightness of that part, There is a merit that the distance display (f1 to f3) is easy to see.

As described above, the method in which the display light beam is made to enter the penta roof prism (3) from the half mirrored third reflecting surface (3S) adversely affects the finder image performance in the current single-lens reflex camera. Therefore, it can be said that this is a desirable method for making the entire viewfinder compact. However, the third reflecting surface (3S) of the penta roof prism (3)
Is tilted forward, so that when the display light beam is to be merged with the finder light beam, the display light beam is obliquely incident on the third reflecting surface (3S). Therefore, an eccentric optical system is formed for the display light flux (for example, when a mirror is used instead of the triangular prism (15)), and an image flow in the vertical direction of the screen occurs on the display image as it is. To cancel the inclination of the display light beam with respect to the third reflection surface (3S), a prism-shaped optical member may be provided. In the viewfinder shown in FIG. 1, the inclination of the display light beam is canceled by disposing the triangular prism (15) close to the third reflection surface (3S).

If the exit surface (15S) and the third reflection surface (3S) are brought into contact, the spectral reflectance of the half mirror surface (3H) changes only in the contact area, so that stable half mirror characteristics are obtained. Can not be obtained. As a result, the finder screen is colored only in the portion corresponding to the contact area. Therefore, an air layer is required between the exit surface (15S) and the third reflection surface (3S). However, if an air layer is provided between the emission surface (15) and the third reflection surface (3S), the space between the emission surface (15S) and the third reflection surface (3S) is increased as shown in FIG. Reflection occurs. This inter-plane reflection, as shown in FIG.
Ghost (g1
~ G3).

In order to make the ghosts (g1 to g3) inconspicuous, the angle of incidence of the display light beam to the pupil and the ghost light to the pupil of the ghost light depend on the eyepiece magnification determined by the focal length of the eyepiece optical system (4). The upper limit of the surface distance between the exit surface (15S) and the third reflecting surface (3S) may be regulated so that the difference between the incident angle and the third reflection surface (3S) falls within the range of the eye resolution. Assuming the angle of each surface of the penta roof prism of the current general single-lens reflex camera, if the surface spacing is up to 0.0004 times the eyepiece focal length, ghost (g1
~ G3) is difficult to confirm.

Therefore, from the above viewpoint, the display optical system (13)
Of the penta roof prism (3) and the third reflecting surface (3
Regarding S), it is desirable to satisfy the following conditional expression. Generally, the eyepiece focal length FL is about 60-80mm,
It is desirable that the surface distance D is about 10 to 20 μm. D ≦ 0.0004 × FL where D: distance between the exit surface (15S) of the display optical system (13) and the third reflecting surface (3S) of the penta roof prism (3), FL: eyepiece optical system (4) The focal length of

As described above, if the third reflecting surface (3S) of the penta roof prism (3) is formed as a half mirror, the reflectance of the third reflecting surface (3S) with respect to the finder light beam is naturally lower than in the prior art. Screen brightness is sacrificed. Therefore, in order to improve the brightness of the viewfinder as much as possible, in the area of the half mirror surface (3H) that does not contribute to the passage of the display light flux, increase the reflectance of the half mirror surface (3H) or use a metal film. It is desirable to use a perfect mirror surface. One example is shown in FIG. FIG.
This shows a state where the third reflection surface (3S) is viewed from a direction perpendicular to the surface. Of the half mirror surface (HM1) formed on the third reflection surface (3S), the peripheral portion (A0) that does not contribute to the passage of the display light flux has a higher reflectance than the central portion (A1) necessary for display. Or, it is a complete mirror surface made of a metal film.

However, as shown in FIG. 12, when the reflectivity of the central portion (A1) is digitally changed with respect to the peripheral portion (A0), the central portion of the screen relative to the peripheral portion of the screen when looking through the viewfinder is viewed. The sharp decrease in brightness, that is, the shading in the central area of the screen becomes more conspicuous. In order to solve this, it is effective to adopt a configuration in which the reflectance changes gradually or stepwise from the low reflectance area in the central part (A1) of the half mirror to the high reflectance area in the peripheral part (A0).
For example, as shown in FIG. 13, the reflectance of the half mirror surface (HM2) with respect to the finder light beam is higher at the peripheral portion (A0) than at the central portion (A1), and from the central portion (A1) to the peripheral portion (A0). So that the reflectance of the intermediate portion (A2) is about halfway between the reflectance of the central portion (A1) and the reflectance of the peripheral portion (A0) so that the transition of the reflectance of the surface becomes stepwise. desirable. As a result, the boundary between the dark screen central area and the bright screen peripheral area in the finder screen is blurred, and the shadow in the central area of the screen becomes less noticeable. When the ranging point display (f1 to f3) for superimposed display is configured in a region other than the center region of the finder screen, the reflectance may be changed around the corresponding region.

[0030]

As described above, according to the first to fifth aspects of the present invention, when a specific operation is performed, a display with high visibility can be performed, and the display serving as an index is constantly displayed. It is possible to do. Therefore, even when the index is always displayed, the display at the time of executing the specific operation can be realized with high visibility. Further, according to the fourth aspect, it is possible to prevent a ghost of the display image from occurring in the finder screen, and according to the fifth aspect, it is possible to obtain a bright finder image together with the display image in the finder screen. it can.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a schematic configuration of a finder to which an embodiment of the present invention is applied.

FIG. 2 is a front view showing a reticle used in the viewfinder shown in FIG. 1;

FIG. 3 is a diagram showing a distance measurement area display and a photometry area display in a viewfinder screen display.

FIG. 4 is a view showing a ranging point display in a viewfinder screen display.

FIG. 5 is a view showing an example of display in a finder screen.

FIG. 6 is a diagram showing an example of display in a finder screen.

FIG. 7 is a view showing an example of display in a finder screen.

FIG. 8 is a view showing an example of display in a finder screen.

FIG. 9 is a view showing another example of the display in the finder screen.

FIG. 10 is an enlarged view showing a configuration of a main part of the finder shown in FIG. 1;

FIG. 11 is a view showing an example of a display in a finder screen where a ghost appears.

FIG. 12 is a diagram illustrating an example of a reflectance distribution of a half mirror surface formed on a third reflection surface of a penta roof prism.

FIG. 13 is a diagram showing another example of the reflectance distribution of the half mirror surface formed on the third reflecting surface of the penta roof prism.

[Explanation of symbols]

 F ... Frame F1 ... Distance measurement area display (first display) F2 ... Distance measurement area display (first display) F3 ... Metering area display f1 ... Distance measurement point display (second display) f2 ... Distance measurement point display (second display) Display) f3 ... distance measurement point display (second display) f1 '... distance measurement point display (second display) f2' ... distance measurement point display (second display) f3 '... distance measurement point display (second display) 1 … Focusing plate 2… Condenser lens 3… Penta roof prism (reversed prism) 3S… Third reflecting surface 3H… Half mirror surface HM1… Half mirror surface HM2… Half mirror surface 4… Eyepiece optical system 5… Protective glass 6… Photometric element 7 … Photometric lens 8… Out-of-screen display LCD 9… Out-of-screen display prism 10… Light source unit 11… LED 12… Mask member 13… Display optics 14… Lens 15… Triangle prism 15S… Emission surface

Claims (5)

[Claims] 1. A finder screen display device for displaying information in a finder screen of a camera, wherein the information is always displayed in the finder screen.
A display, and a second display that is displayed by emitting light when a specific operation is performed. The display information of the second display corresponds to a part of the display information of the first display. A display device in a finder screen, wherein a display is displayed so as not to overlap in a state where the display matches the first display. 2. The display information of the first display includes information on all positions and ranges of a plurality of ranging points, and the display information of the second display includes a camera among the plurality of ranging points. 2. The display device in a finder screen according to claim 1, further comprising information on a position and a range of a focus detection point automatically selected or a focus detection point selected by a photographer. 3. The finder screen is composed of a finder light beam incident on a reversing prism for reversing a finder image on a reticle, and a first frame provided on an optical surface on or near the reticle. A display is formed, and a half mirror surface is formed on at least one reflection surface of the inverting prism, and the display light flux is merged with the finder light flux through the half mirror surface to thereby display the second display in the finder screen. 2. The display device in a finder screen according to claim 1, wherein the information is introduced as a superimposed display. 4. The finder screen is composed of a finder light beam reflected by a penta roof prism and guided to an eyepiece optical system, wherein a half mirror surface is formed on a third reflection surface of the penta roof prism. The second display is introduced into the finder screen by merging the display light flux with the finder light flux through the display finder screen, and the display optical system that emits the display light flux directs the emission surface composed of a plane to the half mirror surface. 2. The finder screen according to claim 1, wherein an exit surface of the display optical system and the third reflection surface are located parallel and at a predetermined interval, and further satisfy the following conditional expression. Inner display device; D ≦ 0.0004 × FL where D: the exit surface of the display optical system and the third of the penta roof prism
FL: focal distance of the eyepiece optical system. 5. The reflectivity of the half mirror surface with respect to the finder light beam is higher in a peripheral part than in a central part, and the transition of the reflectance from the central part to the peripheral part is stepwise. The display device in a finder screen according to claim 3 or 4.