JP2000029119A - In-finder display device for camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device capable of allowing a photographer to visualize only an index correctly by displaying only the index selected at present correctly by the way of light emission. SOLUTION: This in-finder display device for camera is provided with a finder optical system for observing an image on a focusing plate 15, AF frames 15a, 15b and 15c which are provided in the focusing plate 15 or its vicinity and consists of light deflection means and a lighting source for individually illuminating these AF frames from the outside of the focusing plate and constituted so that the light deflection means constituting each AF frame deflect a luminous flux from the corresponding lighting source into the observing optical path of the finder optical system. At this time, the light reflection means is composed of an assembly of plural prisms 15p extended in parallel and each ridge of the prism constituting one of two adjacent AF frames of the plural AF frames and each ridge of the prism constituting the other are extended in directions crossing each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a display device in a viewfinder of a camera.

[0002]

2. Description of the Related Art It is known that a single-lens reflex camera having a multi-point distance measuring function has a plurality of focus frames (AF frames) indicating a plurality of focus ranges in a finder visual field. Further, among single-lens reflex cameras having such a plurality of focus frames, there is known a single-lens reflex camera in which a currently selected focus frame is displayed by light emission so as to be visually recognized by a photographer.

As described above, in the type in which the currently selected focus frame is displayed by light emission, each focus frame is constituted by an aggregate (light deflecting means) of fine prisms formed on a focus plate, and the corresponding focus frame is provided outside the finder optical path. There is a type in which a light beam from a light emitting unit (illumination light source) is applied to a currently selected focus frame so that a photographer can visually recognize the focus frame.

In a conventional single-lens reflex camera having such a focus frame light emitting display function, when a currently selected focus frame is illuminated by a corresponding light emitting unit, a focus frame adjacent to the focus frame (currently selected focus frame) is displayed. Peripheral light of the light emitted from the light-emitting unit irradiates the focus frame that is not set), and as a result, not only the currently selected focus frame,
A part of the focus frame adjacent to the focus frame is also displayed by light emission, which causes a problem that it is difficult for the photographer to correctly recognize the currently selected focus frame.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has a plurality of indices such as a focus frame formed of an aggregate of fine prisms in a finder optical path.
By illuminating each of the indices with a corresponding illumination light source and displaying the indices in a viewfinder display device, only the currently selected indices are displayed in a correct manner and the photographer correctly recognizes only the indices. It is an object of the present invention to provide a display device in a viewfinder of a camera which enables the display.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a finder optical system for observing an image on a focus plate disposed at a position optically equivalent to an image forming plane of a photographing optical system; and a specific area within a field of view of the finder optical system. A plurality of indices comprising light deflecting means provided on or near the focus plate; and a plurality of illumination light sources for individually illuminating the plurality of indices from outside the focus plate. The light deflecting means constituting the index is:
In a display device in a viewfinder of a camera that deflects a light beam from a corresponding illumination light source into an observation optical path of an observer of a viewfinder optical system, a light deflecting unit forming each index is formed by an aggregate of a plurality of prisms extending in parallel with each other. That is, among the plurality of indices, each ridge line of the plurality of prisms constituting one of two adjacent indices and each ridge line of the plurality of prisms constituting the other index extend in a direction intersecting with each other. Features.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. FIG. 10 shows an AF single-lens reflex camera to which the present invention is applied. This single-lens reflex camera is an AF single-lens reflex camera having a multi-point distance measuring function, and has a camera body 10 and a photographing lens 40 detachably mounted on a front portion of the camera body 10.

The photographing lens 40 has a photographing optical system 41 including an AF lens group which moves forward and backward along a photographing optical axis O in a lens barrel (not shown). The AF lens group includes a gear train 30 provided in the camera body 10, the camera body 10 and the photographing lens 40.
Are driven by the rotation of an AF motor 32 provided on the camera body 10 via an AF coupler 50 provided over the camera body 10 and a gear train 43 provided in the lens barrel.
The photographing lens 40 has a built-in lens ROM 45 in which lens information is stored in advance. The lens information stored in the lens ROM 45 includes a plurality of lens information contacts provided in the camera body 10 and the photographing lens 40, respectively. 52
Through the body microcomputer 34 provided in the camera body 10.

Further, in the camera body 10, a mirror box 13 for supporting the quick return mirror 11 therein, a pentaprism 17 fixed above the mirror box 13, and an eyepiece fixed behind the pentaprism 17 A lens (Fine loupe) 19 is provided. Mirror box 13 and pentaprism 17
A focusing plate (focusing screen) 15 is fixed therebetween. In the camera body 10, a focus detection device 21 and a light emitting device 23 are provided below the mirror box 13.
Is provided.

In the photographing standby state before the release, most of the subject light flux that has entered the camera body 10 through the photographing optical system 41 is first reflected upward by the quick return mirror 11 to form an image on the focus plate 15. You. The formed subject image (laterally inverted image) is inverted right and left by the pentaprism 17, and is observed through the eyepiece 19 as an erect image whose right, left, up, and down directions are correct.

On the other hand, a part of the subject light beam entering the camera body 10 through the photographing lens 40 passes through a half mirror portion 11a provided at a substantially central portion of the quick return mirror 11, and is behind the quick return mirror 11. Incident on the sub-mirror 12 provided on the side. The light beam that has entered the sub-mirror 12 is reflected downward and enters the focus detection device 21.

As shown in FIG. 9, the camera of this embodiment automatically focuses (AF) at any one of the center ranging point C, the left ranging point L, and the right ranging point R in the finder visual field FV.
It employs a three-point ranging method. Focus detection device 21
Is a phase difference detection type distance measuring sensor, and incorporates three AF sensor units (not shown) corresponding to the center distance measuring point C, the left distance measuring point L, and the right distance measuring point R, respectively.

The body microcomputer 34 performs a predetermined exposure calculation based on a photometric signal obtained from a TTL photometric device (not shown) and film sensitivity information, and calculates an appropriate shutter speed and aperture value. Further, the body microcomputer 34
Photographing processing based on these proper shutter speed and aperture value, that is, the quick return mirror 11 is flipped from the standby position to the photographing position, and a shutter mechanism (not shown)
Then, an aperture mechanism (not shown) is driven to expose the film. Further, the body microcomputer 34 performs
The AF motor 32 is driven to move the AF lens group to a focusing position to focus on the subject.

As shown in FIGS. 1 and 2, the focus plate 15
The upper surface (mat surface) 15x has three light deflecting units (light deflecting units) corresponding to the center ranging point C, the left ranging point L, and the right ranging point R in the finder field of view FV shown in FIG. (Means) That is, a central light deflecting unit 15a, a left light deflecting unit 15b, and a right light deflecting unit 15c are provided. Each of these light deflecting units 15a, 15b, and 15c functions as a focus frame (AF frame) that is observed in the finder visual field via the eyepiece lens 19.

Each of the light deflecting portions 15a, 15b, 15c has a hollow rectangular frame shape, and the frame portion is formed of a plurality of fine prisms 15p formed integrally with the focus plate 15 and extending parallel to each other. . That is, each light deflecting unit 15a, 1
5b and 15c are a plurality of prisms 1 extending parallel to each other.
It consists of a 5p aggregate.

As shown in FIG. 2, each ridge line of the plurality of prisms 15p constituting the central light deflecting portion 15a is positioned in the left-right direction of the finder field (left-right direction in FIG. 2), that is, the left-right direction of the camera body 10. Direction (perpendicular to the plane of FIG. 10). On the other hand, the left light deflection unit 15
b, each ridge line of the plurality of prisms 15p intersects each ridge line of the plurality of prisms 15p forming the central light deflecting unit 15a at an angle of approximately 45 degrees, and the right light deflecting unit 15
Each of the plurality of prisms 15p constituting c extends in a direction substantially orthogonal to each ridge line. Also, each ridge line of the plurality of prisms 15p constituting the right light deflection unit 15c is
a, intersect each ridge line of the plurality of prisms 15p at an angle of approximately 45 degrees, and extend in a direction substantially orthogonal to each ridge line of the plurality of prisms 15p forming the left-side light deflection unit 15b.

That is, three adjacent light deflecting units 15a, 15a
Each of the ridge lines of the plurality of prisms 15p constituting one of the two adjacent light deflecting units and each of the ridge lines of the plurality of prisms 15p constituting the other light deflecting unit extends in directions intersecting each other. ing. 2, the arrow A indicates the ridge direction of each prism 15p of the central light deflection unit 15a, and the arrow B indicates each prism 15p of the left light deflection unit 15b.
The arrow C indicates the right light deflection unit 1
5c shows the ridge direction of each prism 15p. A light beam emitted from a corresponding light source of the light emitting device 23 from below the focus plate 15 is incident on each light deflector of the focus plate 15 configured as described above. Hereinafter, the light emitting device 23 will be described in detail.

The light emitting device 23 is disposed below the front portion of the mirror box 13 and includes three light emitting portions having the same structure, that is, a central light emitting portion 24a, a left light emitting portion 24b, and a right light emitting portion 24c. (See FIG. 4). The center light emitting portion 24a, the left light emitting portion 24b, and the right light emitting portion 2
4c is provided corresponding to the central light deflector 15a, the left light deflector 15b, and the right light deflector 15c, respectively.
The mirror box 13 is disposed so as to face the inside of the mirror box 13 through a central opening 13a, a left opening 13b, and a right opening 13c formed at a front portion of the bottom plate.

Each light-emitting section is provided with a light source 24d composed of an LED.
And a prism 24e for deflecting the light beam from the light source 24d and projecting it toward the corresponding light deflecting unit (15a, 15b or 15c). A condensing lens is integrally formed on the exit surface of each prism 24e. Also,
Between the light source 24d and the incident surface of the prism 24e, a first mask 24f that regulates the range of the incident light beam from the light source 24d incident on the incident surface of the prism 24e is fixed. Surface and corresponding openings (13a, 13b) formed in the bottom wall of the mirror box 13.
Alternatively, between 13c), a second mask 24g that regulates the range of the light beam emitted from the exit surface of the prism 24e is fixed (see FIG. 11). Note that the first mask 24f and the second mask 24g are not shown in FIG.

The luminous flux emitted from the light source 24d of each light emitting section passes through the corresponding first mask 24f, prism 24e, second mask 24g, and opening (13a, 13b or 13c), and the corresponding light deflecting section (15a). , 15b or 15c)
At a constant angle of incidence. The incident light enters the corresponding light deflecting unit from a direction substantially orthogonal to the ridge direction of each prism 15p of the light deflecting unit. In other words, as shown in FIG. 2, the light beam BL1 projected from the central light emitting unit 24a toward the central light deflecting unit 15a is moved relative to the central light deflecting unit 15a by the ridge line of each prism 15p of the central light deflecting unit 15a. Light is incident from a direction substantially perpendicular to the direction A. Similarly, the light beam BL2 projected from the left light emitting unit 24b toward the left light deflecting unit 15b is substantially perpendicular to the ridge direction B of each prism 15p of the left light deflecting unit 15b. The light beam BL3 that is incident from the right direction and is projected from the right light emitting unit 24c toward the right light deflecting unit 15c is directed to the right light deflecting unit 15c by the ridge direction C of each prism 15p of the right light deflecting unit 15c. And incident from a direction substantially orthogonal to.

FIG. 3 shows a light beam BL from the central light emitting portion 24a.
1 shows a state in which the light is incident on the corresponding central light deflecting unit 15a and is deflected. Of the light beam BL1, the focus plate upper surface 1
Light beam BL1a emitted from 5x central light deflection unit 15a
Is a focus plate upper surface 15 in a direction substantially orthogonal to the focus plate 15.
The light exits from x and goes to the pentaprism 17. On the other hand, of the light beam BL1, the light beam BL1b emitted from a portion other than the central light deflecting portion 15a on the focus plate upper surface 15x emits from the focus plate upper surface 15x at an emission angle substantially similar to the incident angle on the focus plate lower surface 15w. Therefore, it does not go to the pentaprism 17. That is, the light flux B incident on the central light deflection unit 15a
In L1, only the light beam emitted from the central light deflection unit 15a reaches the eyepiece lens 19.

In FIG. 3, only the state of the light beam BL1 with respect to the central light deflecting unit 15a has been described. However, the light beam BL2 from the left light emitting unit 24b entering the left light deflecting unit 15b and the right light beam entering the right light deflecting unit 15c. The same applies to the light beam BL3 from the portion 24c. That is, the left light deflection unit 15
As for the light beam BL2 incident on the light beam b, only the light beam emitted from the left light deflector 15b reaches the eyepiece 19, and the light beam BL3 incident on the right light deflector 15c is only the light beam emitted from the right light deflector 15c. Reach 19. Therefore, the irradiation light from any one of the light emitting units (24a, 24b or 24c) is converted into the corresponding light deflection unit (15a, 15b or 15c).
When the light is incident on c), the light deflector is illuminated and displayed in the viewfinder field. The display device in the viewfinder of the single-lens reflex camera of the present embodiment includes the respective light deflection units 15a, 15b, 1
5c and the light emitting units 24a, 24b, 24c.

One of the light deflecting units selected by the structure of each of the light deflecting units 15a, 15b, and 15c formed on the focus plate 15 and the arrangement of the light emitting units 24a, 24b, and 24c as described above. When light is displayed by receiving irradiation light from a corresponding light-emitting unit, even if ambient light of the irradiation light hits an adjacent light deflection unit, a part of the light deflection unit is displayed by light emission. Instead, only the selected light deflecting unit can emit light. That is, for example, as shown in FIG. 6, the right light emitting unit 2 illuminating the right light deflection unit 15c
In the case where the irradiation range of the irradiation light from 4c is within the range of the circle shown by the two-dot chain line in the drawing, that is, assuming that a part of the central light deflection unit 15a is illuminated by the peripheral light of the irradiation light from the right light emitting unit 24c Also, as shown in FIG.
Only c is displayed by light emission. In FIG. 7, the right light deflection unit 15c
A plurality of lines drawn radially around indicate that the right light deflector 15c is emitting light.

FIG. 12 shows a focus plate 15 to which the present invention is applied.
As a comparative example, a focus plate 150 to which the present invention is not applied
Is shown. The focus plate 150 includes a central light deflecting unit 1.
50a, left light deflector 150b and right light deflector 150
c is provided, and each ridge line of the plurality of prisms 15p constituting each light deflecting unit uniformly extends in the left-right direction of the finder field. Focusing plate 15 having such a configuration
According to 0, when any one of the selected light deflecting units receives and emits light from the corresponding light emitting unit and is illuminated and displayed, if peripheral light of the irradiated light hits the adjacent light deflecting unit, A part of the light deflecting unit is displayed with light emission together with the selected light deflecting unit. However, such a problem does not occur in the AF single-lens reflex camera of the present embodiment as described above.

FIG. 8 shows an example of the light deflection portion light emission display processing by the body microcomputer 34. AF of this embodiment
In a single-lens reflex camera, when a release button (not shown) is half-pressed, a defocus amount is calculated at each of the center ranging point C, the left ranging point L, and the right ranging point R, and the calculated defocus amount is calculated. When the subject is focused on and the release button is fully pressed, a release operation is performed. When the release button is half-pressed, the process enters the flow chart shown in FIG.

When the release button is half-pressed, first, a defocus amount is calculated at each of the center ranging point C, the left ranging point L, and the right ranging point R (S101). Next, the defocus amount at the distance measuring point at which the minimum defocus amount is calculated is stored in a RAM or the like, and a drive amount for driving the AF lens group of the photographing optical system 41 is obtained based on the defocus amount. Then, the AF lens group is driven by this driving amount (S10).
3, S105, S107). Thereafter, it is determined whether the object is in focus or out of focus. If not, steps S105 and S1 are performed again.
07, and if it is determined that the subject is in focus, the next step S
The process proceeds to S111 (SS109).

In the process of step S111, step S111
The focus area (the central light deflector 15) corresponding to the distance measuring point for which the minimum defocus amount has been calculated in the process of 103
a, the corresponding light emitting unit (the central light emitting unit 24a,
The light source 24 of the left light emitting portion 24b or the right light emitting portion 24c)
d is emitted. Subsequently, the timer is started, and then the release is permitted and the process returns (S113, S1).
15). The timer process of step S113 is a process of turning off the light source 24d that was turned on in the process of step S111 after a predetermined time (for example, 5 seconds) has elapsed from the start of the timer.

As described above, according to the AF single-lens reflex camera of the present embodiment to which the present invention is applied, one of a plurality of focus frames (light deflecting units) provided in the finder field is displayed by light emission. In this case, only the selected focus frame can be illuminated without displaying part of the adjacent focus frame,
Therefore, it is possible to make the photographer visually recognize which focus frame is currently selected.

In the above embodiment, the three light deflecting units 15a, 15b and 1 functioning as focus frames are provided.
5c is formed on the focus plate 15, but instead of this structure, each light deflector may be formed on a transparent plate or the like provided near the focus plate 15.

In this embodiment, three light deflecting portions functioning as focus frames are provided, and the number of light emitting portions corresponding to the three light deflecting portions is provided. However, two or four light deflecting portions are provided. One or more light-emitting units may be provided, and the number of light-emitting units corresponding to the number of the light deflection units may be provided.

In the present embodiment, the plurality of light deflecting units are configured as focus frames, but may be configured as indices used for purposes other than the focus frame.

In this embodiment, one of the plurality of light deflecting units selected by the light deflecting unit light emission display processing shown in FIG.
One of the light deflecting units is controlled to emit light. However, the present invention is not limited to this control mode.
A configuration may be employed in which one or more light deflecting units simultaneously emit and display light.

In this embodiment, the present invention is applied to an AF single-lens reflex camera. However, the present invention can be applied to a lens shutter camera.

[0034]

As described above, according to the display device in the finder of the camera of the present invention, the light deflecting means constituting each index is constituted by an aggregate of a plurality of prisms extending in parallel to each other, and Among them, each ridge line of a plurality of prisms constituting one of two adjacent indices and each ridge line of a plurality of prisms constituting the other index are configured to extend in a direction intersecting each other, and thus are currently selected. Only the indicator is correctly displayed with light emission, and the photographer can correctly recognize only the indicator.

[Brief description of the drawings]

FIG. 1 is a perspective external view showing a focus plate of an AF single-lens reflex camera to which the present invention is applied.

FIG. 2 is an enlarged plan view showing a central light deflector, a left light deflector, and a right light deflector formed on a focus plate shown in FIG.

FIG. 3 is a cross-sectional view showing a part of the central light deflecting unit shown in FIG. 2 in cross section.

FIG. 4 is a sectional view taken along the line VI-VI in FIG. 11;

FIG. 5 is a top view of the focus plate as viewed from above in FIG. 4;

FIG. 6 is an explanatory diagram showing a state in which a right light deflection unit formed on a focus plate is illuminated by a corresponding illumination light source.

FIG. 7 is an explanatory diagram showing a state in which only the right light deflection section is illuminated and displayed by the illumination shown in FIG. 6;

FIG. 8 is a flowchart illustrating an example of light deflection unit light emission display processing by the body microcomputer.

FIG. 9 is a diagram showing an arrangement of a center ranging point, a left ranging point, and a right ranging point in a finder visual field FV.

FIG. 10 is a block diagram showing a main configuration of an AF single-lens reflex camera to which the present invention is applied.

FIG. 11 is a cross-sectional view showing a main part of an AF single-lens reflex camera to which the present invention is applied.

FIG. 12 is a perspective external view showing a focus plate to which the present invention is not applied.

[Explanation of symbols]

 Reference Signs List 10 Camera body 11 Quick return mirror 13 Mirror box 15 Focus plate 15a Central light deflecting unit 15b Left light deflecting unit 15c Right light deflecting unit 15p Prism 15x Focus plate top surface 23 Light emitting device 24a Central light emitting unit 24b Left light emitting unit 24c Right light emitting unit 24d Light source 24e prism 40 shooting lens 41 shooting optical system

Claims (3)

[Claims] A viewfinder optical system for observing an image on a focusing plate disposed at a position optically equivalent to an image forming plane of a photographing optical system; and indicating a specific area in a field of view of the viewfinder optical system. A plurality of indices provided on the focus plate or in the vicinity thereof, each of the indices including light deflecting means; and a plurality of illumination light sources for individually illuminating the plurality of indices from outside the focus plate. The light deflecting means is a display device in a finder of a camera that deflects a light beam from a corresponding illumination light source into an observation optical path of an observer of a finder optical system. Each of the ridges of the plurality of prisms that constitute one of two adjacent indices and the ridges of the plurality of prisms that constitute the other index are formed of a prism assembly. Characterized in that it extends in a direction difference, the camera viewfinder display device. 2. The display device according to claim 1, wherein the plurality of indices are formed integrally with the focus plate. 3. The display device in a viewfinder of a camera according to claim 1, wherein the camera is an AF single-lens reflex camera having a multi-point distance measuring function, and each of the plurality of indices is configured as a focus frame. A display device in a camera finder.