JP2000105403A - Display device inside finder of camera having multipoint range-finding function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily confirm depth of field in a display device inside the finder of a camera having multipoint range-finding function by which range-finding can be performed at plural range-finding points inside a finder visual field. SOLUTION: The respective plural focusing frames disposed inside the finder visual field are displayed by light emission. When a range-finding result is obtained at one of the plural range-finding points and focusing condition is obtained, a light emitting means is driven and the focusing frame corresponding to one range-finding point is displayed by the light emission with first brightness. Next, when the focusing condition is obtained, whether or not an object on the respective range-finding positions other than the one range-finding point is inside the depth of field is decided. As the result of this decision, the focusing frame corresponding to the range-finding point which is decided to be inside the depth of field is displayed by the light emission with second brightness having lower luminance than that of the first brightness by driving the light emitting means.

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 viewfinder of a camera having a multi-point distance measuring function.

[0002]

2. Description of the Related Art There is known a single-lens reflex camera having a multi-point distance measuring function, which has a plurality of focus frames indicating the positions of a plurality of distance measuring points in a finder visual field. Further, in such a single-lens reflex camera having a plurality of focus frames, a focus frame corresponding to a currently selected distance measuring point is displayed by light emission so that a photographer can visually recognize a currently selected distance measuring point. Things are known.

Conventionally, in a single-lens reflex camera or the like, when confirming the depth of field prior to photographing, the photographer can visually check the depth of field by operating a preview (aperture) button provided on the camera body. I was checking the depth of field. For this reason, conventionally, it was necessary to operate operation buttons other than the release button in order to confirm the depth of field, and it was not easy to confirm the depth of field.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has been made in view of a finder of a camera having a multi-point distance measuring function capable of measuring a distance at each of a plurality of distance measuring points in a finder visual field. It is an object of the present invention to provide a display device in a finder in which a depth of field can be easily confirmed in a display device.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a display device in a finder of a camera having a multi-point distance measuring function capable of measuring a distance at each of a plurality of distance measuring points in a finder visual field. A plurality of focus frames disposed in the finder field of view, each indicating a position of the plurality of focus frames; a light-emitting means for causing each of the plurality of focus frames to emit light; and performing the following first, second and third controls. And control means. In the first control, the control means obtains a distance measurement result at any one of the plurality of distance measurement points to obtain an in-focus state, and drives the light emitting means to drive the one distance measurement point. Is displayed at the first brightness. In the second control, when the control unit obtains the in-focus state, the control unit determines whether the subject at each of the focus detection points other than the one focus detection point is within the depth of field. In the third control, the control unit sets the focus frame corresponding to the ranging point determined to be within the depth of field as a result of the determination of the second control by driving the light emitting unit to the first frame. The light emission display is performed at the second brightness lower than the brightness of.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. FIG. 5 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 ranging function, and has a camera body 1
0, and a photographing lens 40 detachably attached to the front part 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
Is sent to a body microcomputer (control means) 34 provided in the camera body 10 via the.

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 a 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 taking lens 40 passes through a half mirror portion 11a provided substantially at the center 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. 2, the camera according to the present embodiment automatically focuses (AF) at 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 FIG. 9, a center ranging point C, a left ranging point L and a right ranging point R in the finder field of view FV shown in FIG. , Three light deflecting units (light deflecting means), that is, a central light deflecting unit 15a, a left light deflecting unit 15b, and a right light deflecting unit 15c are provided. These central light deflection units 1
5a, the left light deflection unit 15b and the right light deflection unit 15c
Central AF frame (focus frame) C observed in the finder visual field FV via the eyepiece 19
F, functions as a left AF frame (focus frame) LF and a right AF frame (focus frame) RF. The center AF frame CF, the left AF frame LF, and the right AF frame RF form a finder field of view F.
The positions of a center ranging point C, a left ranging point L, and a right ranging point R in V are shown.

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. Each light deflecting unit 15a, 15
The ridges of the plurality of prisms 15p constituting the b and 15c are located in the left-right direction of the finder visual field, that is, the camera body 10p.
5 (in the direction perpendicular to the plane of FIG. 5).

Each light deflecting portion of the focusing plate 15 configured as described above is provided with a light emitting device 23 from below the focusing plate 15.
The light beam emitted from the corresponding light source is incident. 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 units having the same structure, that is, a central light emitting unit 24a, a left light emitting unit 24b, and a right light emitting unit 24c. (See FIG. 7). 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.
Opening 13 formed in front of bottom plate of mirror box 13
Each is arranged so as to face the inside of the mirror box 13 through a.

Each of the light emitting sections 24a, 24b, 24c is an LE
D, and a light beam from this light source 24d is deflected to form a corresponding light deflector (15a, 15b or 15).
and a prism 24e for projecting light toward c). The three prisms 24e are integrally formed as a single prism. A condensing lens is integrally formed on the exit surface of each prism 24e. Further, the light source 24
d and the entrance 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 e is fixed. Similarly, the exit surface of the prism 24e and the corresponding aperture formed in the bottom wall of the mirror box 13 are fixed. Between the portions 13a, a second portion that regulates the range of the light beam emitted from the exit surface of the prism 24e
The mask 24g is fixed (see FIG. 6). FIG. 7
The first mask 24f and the second mask 24g are not shown.

The light beam emitted from the light source 24d of each light emitting unit passes through the corresponding first mask 24f, prism 24e, second mask 24g, and opening 13a, and the corresponding light deflecting unit (1).
5a, 15b or 15c) at a fixed incident angle. 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.

FIG. 10 shows a light beam B from the central light emitting portion 24a.
L1 is incident on the corresponding central light deflector 15a and is deflected. Of the light beam BL1, the light beam BL1a emitted from the central light deflector 15a on the focus plate upper surface 15x
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. 10, only the state of the light beam BL1 with respect to the central light deflecting section 15a has been described.
The same applies to the light beam BL2 from the left light emitting unit 24b entering the right light deflecting unit 15c from the left light emitting unit 24c. That is, the left light deflection unit 1
As for the light beam BL2 incident on the light beam 5b, only the light beam emitted from the left light deflection unit 15b reaches the eyepiece lens 19, and the light beam BL3 incident on the right light deflection unit 15c is reflected on the right light deflection unit 15c.
Only the light beam emitted from the lens reaches the eyepiece lens 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.

In this embodiment, in the finder display device having the above configuration, the distance measurement result is obtained at least one of the center ranging point C, the left ranging point L and the right ranging point R. When the (defocus amount) is obtained,
The AF frame corresponding to the focus detection point (the closest focus detection point) for which the minimum defocus amount has been calculated is illuminated to indicate to the photographer that the camera is in focus at the focus detection point indicated by the AF frame. Make it visible. At this time, the light emitting device 23 is controlled to cause the AF frame corresponding to the distance measuring point for which the minimum defocus amount has been calculated to emit the first AF frame, so that the first AF frame is emitted.
Display with the brightness of. Note that if any of the center ranging point C, the left ranging point L, and the right ranging point R does not obtain a ranging result (defocus amount), and is in an in-focus state, By blinking at least one AF frame (for example, the center AF frame CF), the photographer can visually recognize that the subject is out of focus.

Further, in this embodiment, after the focusing operation is performed at the distance measuring point (focusing operation distance measuring point) for which the minimum defocus amount is calculated, each distance measuring point other than the focusing operation distance measuring point is performed. Determine whether the subject at the point is within the depth of field,
If it is determined that the AF frame is within the depth of field, the AF frame corresponding to the distance measuring point is controlled by the light emitting device 23 to dim light emission (for example, illuminated with half the amount of light emission at full light emission). )
As a result, the display is turned on at the second brightness. According to this control, it is easy to determine whether or not the subject at each focusing point other than the focusing operation focusing point is within the depth of field by visually recognizing the dimmed AF frame. can do.

FIG. 3 shows that when the center AF point CF is in focus at the center AF point CF, the corresponding light emitting section 24a
3 shows a state in which the display is lit by full light emission. In the figure, both the left AF frame LF indicating the left ranging point L and the right AF frame RF indicating the right ranging point R are turned off. That is, in FIG. 3, focusing is performed at the center ranging point C, but each ranging point (left ranging point L and right ranging point R) other than the central ranging point C which is a focusing operation ranging point. ) Indicates that the subject is outside the depth of field.

FIG. 4 shows a state in which the center AF frame CF is in focus at the center distance measuring point C and the corresponding light emitting section 24a
Of the left AF frame LF, and at the same time, the left AF frame LF is １ ／ of the time when the corresponding light emitting unit 24b emits the full light.
The state in which the light emission amount is lit is shown. In the figure, the right AF frame RF indicating the right ranging point R is turned off. That is, FIG. 4 shows that the object is in focus at the center ranging point C, the subject at the left ranging point L is within the depth of field, and the subject at the right ranging point R is outside the depth of field. It is shown that there is. Note that a plurality of lines drawn radially around each AF frame shown in each of FIGS. 3 and 4 indicate that the AF frame is lit and displayed, and the length of each line is the length of the line. The luminescence amount is shown.

FIG. 1 shows one embodiment of the light deflection portion light emission display processing by the body microcomputer 34. In the AF single-lens reflex camera of the present embodiment, when the 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 calculation is performed. When the subject is focused on the defocus amount 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 (the in-focus distance measuring point) at which the minimum defocus amount is calculated is stored in a RAM or the like, and the AF lens of the photographing optical system 41 is stored based on the defocus amount. A drive amount for driving the group is obtained, and the AF lens group is driven by the drive amount (S103, S105, S107). After that, it is determined whether the focusing point is in focus or out of focus.
If out of focus, the processes of steps S105 and S107 are executed again, and if it is determined that focus is achieved, the process proceeds to the next step S111 (S109).

In the process of step S111, based on the subject distance information and the photographing lens information, it is determined whether or not the subject located at a focus detection point other than the focus detection focus point is within the current depth of field. If it is determined that none of the subjects at the ranging points other than the in-focus ranging point is within the depth of field, the AF frames (CF, L) corresponding to the in-focus ranging point are determined.
F or RF) in order to display only with full light emission.
The light emission amount of the corresponding light source 24a, 25a or 26a is set to the full light emission amount (S113, S117).

On the other hand, after the processing in step S111, if it is determined that any of the objects located at the focus detection points other than the focus detection focus point is within the depth of field, first, the focus detection point is set to that focus detection point. In order to display the corresponding AF frame (CF, LF or RF) with a light emission amount of 1/2 of the full light emission, the light emission amount of the corresponding light source 24a, 25a or 26a is set as 1/2 of the full light emission. Then, in order to cause the AF frame (CF, LF, or RF) corresponding to the in-focus state ranging point to be displayed with full light emission, the light emission amount of the corresponding light source 24a, 25a or 26a is set to the full light emission amount (S11).
3, S115, S117).

In the process of step S119, step S119
Only the light source for which the light emission amount has been set in each of the processing of 115 and S117 is caused to emit light (full light emission or 1/2 light emission) according to the light emission amount. Then start the timer,
The photometric calculation is performed to set the photometric value, and then release is permitted and the process returns (S121, S123, S1).
25, S127). The timer process of step S121 is a process of turning off the light source turned on in the process of step S119 after a predetermined time (for example, 5 seconds) elapses after starting the timer.

According to the above-described control, the AF frame corresponding to the in-focus distance measuring point emits the full light, and at the same time, if the other distance measuring point is within the depth of field, the corresponding AF point is detected. Since the AF frame emits dimmed light, it can be easily determined whether or not each AF point is within the depth of field.

In the above embodiment, each AF frame (CF, CF, CF) is illuminated by the corresponding light emitting portion (24a, 24b, 24c) with the light deflecting portion (15a, 15b, 15c) formed on the focus plate 15. LF, RF) is turned on, blinks, or turned off. However, the structure for turning on, blinking, or turning off each AF frame is not limited to the configuration of the present embodiment. It can be lit.

In the present embodiment, three light deflecting units functioning as focus frames are provided, and the number of light emitting units corresponding to the three light deflecting units is provided. However, two or four light deflecting units 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.

A conventional preview button may be provided in the AF single-lens reflex camera of the present embodiment.

In the present 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.

[0035]

As described above, according to the display device in the finder of the camera of the present invention, by observing the light emission state of each focus frame, it is possible to determine the distance measurement points other than the focus measurement point in focus. It is possible to easily confirm whether or not a certain subject is at the depth of field.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating an example of light deflection unit light emission display processing performed by a body microcomputer of an AF single-lens reflex camera to which the present invention has been applied.

FIG. 2 is a view showing a finder field of view of an AF single-lens reflex camera to which the present invention is applied.

FIG. 3 is a diagram illustrating a state in which a central AF frame in a finder visual field is lit and displayed with full light emission;

FIG. 4 is a diagram showing a state in which a central AF frame in a finder field of view is lit and displayed with full light emission, and a left AF frame is lit and displayed with a light emission amount of １ ／.

FIG. 5 is a block diagram illustrating a main configuration of an AF single-lens reflex camera to which the present invention is applied.

FIG. 6 is a cross-sectional view showing a main part of an AF single-lens reflex camera to which the present invention is applied.

FIG. 7 is a sectional view taken along the line VII-VII in FIG. 6;

FIG. 8 is a top view of the focus plate viewed from above in FIG. 7;

FIG. 9 is an enlarged perspective view showing the focus plate shown in FIG. 8;

10 is a cross-sectional view showing a part of the central light deflecting unit shown in FIG. 9 in a cross section.

[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 FV finder field of view

Claims (2)

[Claims] 1. A display device in a finder of a camera having a multi-point distance measuring function capable of measuring a distance at each of a plurality of distance measuring points in a finder visual field, wherein respective positions of the plurality of distance measuring points in a finder visual field are provided. A plurality of focus frames disposed in the viewfinder field of view; a light emitting means for emitting and displaying each of the plurality of focus frames; and a ranging result at any one of the plurality of ranging points. When you get the focus state,
Driving the light emitting means to display a focus frame corresponding to the one ranging point at a first brightness;
A second control for determining, when the in-focus state is obtained, whether or not a subject located at each of the focus detection points other than the one focus detection point is within the depth of field; and As a result of the determination of the control 2, the focus frame corresponding to the distance measuring point determined to be within the depth of field is driven by the light-emitting means to a second brightness lower than the first brightness. And control means for performing a third control for causing the display to emit light in the finder. A display device in a finder of a camera having a multi-point distance measuring function. 2. The multi-point distance measuring function according to claim 1, wherein the control means performs the second control based on subject distance information and photographing lens information. Display device in a camera viewfinder.