JP2002214520A - Range-finding device for camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a range-finding device for a camera on which one AF sensor is mounted and which can detect the angle of visibility wide in an up-and- down direction and cope with even a high-speed shutter. SOLUTION: In this range-finding device for the camera, a mirror top board 25 provided with a mirror 26 being a turnable sub mirror is supported by a rotating center beam and four coil beams, and turned by a repulsive force and an attractive force by magnetic field generated by electromagnetic coils 27a and 27b and magnets 29a and 29b arranged at both ends of the board 25 and simultaneously alternately switched in an opposite direction, whereby the mirror 26 is turned up and down to reflect and radiate luminous flux for range- finding toward an AF optical system so as to perform range-finding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distance measuring apparatus for widening a distance measuring range by changing an angle of a sub mirror provided on a quick return mirror of a camera.

[0002]

2. Description of the Related Art In general, when taking a picture with a camera, a photographer operates a shutter button and performs exposure while checking a photographic scene while looking through a finder. When the shutter button is operated, focus adjustment of the photographing lens by distance measurement and exposure adjustment by photometry are performed. FIG. 15 shows a conceptual configuration of a conventional shutter mechanism and a mirror mechanism for widening the distance measurement range. Usually, when observing the subject image with the viewfinder 12, the subject image that has passed through the photographing lens 1 passes through the aperture 2 for adjusting the amount of light, is turned back by the quick return mirror 3, and
Image on the surface. This formed image is bent by the pentaprism 5, passes through the finder 12, and is observed by the photographer. A semi-transmissive portion is provided at the center of the quick return mirror 3, and the light beam passing therethrough is
The light is reflected by the sub mirror 101 and guided to the AF optical system 102. Behind the AF optical system 102, a plurality of distance measuring sensors 103 are provided at positions substantially equivalent to the distance to the surface of the film 11 and detect the amount of defocus on the surface of the film 11.
Is arranged. In order to widen the field of view of the distance measurement range, these distance measurement sensors 9 are arranged vertically and horizontally.

[0003] Behind the quick return mirror 3, there is a focal plane shutter 10 for performing exposure.
And, the film 11 is sequentially arranged. At the time of photographing, the quick return mirror 3 is rotated in the direction of the focus screen mat 4 to be retracted from the optical path, and is exposed so that the subject image reaches the film 11.

Further, as a technique for widening the field of view of the distance measurement range, for example, Japanese Patent Publication No. 2757391 discloses a technique.
A technique has been disclosed in which the angle of a sub-mirror is displaced by a cam and a cam driving member to guide a light beam to a plurality of focus detection means. Also, Japanese Patent Application Laid-Open No. 62-47221 discloses a technique in which the angle of a sub-mirror is changed by a link mechanism linked to an operation lever to switch a light beam to a photometric sensor position or a distance measuring sensor position. Further, Japanese Patent Application Laid-Open No. Hei 7-333682 proposes a camera which is equipped with a digital mirror device (DMD) and switches so that the luminous flux of a subject image is guided to a pentaprism side when observing, and is guided to a film side when photographing. I have. In general, as a small scanning mirror, a technique is known in which a mirror unit is formed on a silicon substrate, and the mirror is rotated and vibrated by a minute displacement drive of a link beam close to the torsion beam.

[0005]

In a configuration in which a plurality of AF sensors are arranged using a sub-mirror fixed to a quick return mirror in the above-described prior art to widen the viewing angle in distance measurement, the distance measurement is performed. The size of the optical system is increased, and a large space is required below the mirror box. As a result, the size of the camera is increased.

In the configuration disclosed in the publication, in which the angle of the sub-mirror is displaced by using a cam mechanism to guide a light beam to a plurality of sensors, a driving time for mechanically driving the cam is required. However, it is not suitable for increasing the shutter speed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a camera distance measuring apparatus equipped with one AF sensor, capable of detecting a wide viewing angle in the vertical direction, and capable of supporting a high-speed shutter.

[0008]

According to the present invention, in order to achieve the above object, a part of a light beam passing through a photographing lens is guided to a distance measuring optical system by using a mirror unit, and a defocus amount of a subject image is obtained. In a camera ranging device that detects
The mirror unit incorporates an actuator for changing an angle of the mirror of the mirror unit with respect to an optical axis of the photographing lens to a first angle or a second angle, and the mirror unit has a first angle when the mirror is at the first angle. Provided is a camera distance measuring device that detects a defocus amount of a subject image based on the first distance measurement result or the second distance measurement result when the angle is the second angle. Further, the first angle is an angle when the actuator is not driven, and the second angle is an angle when the actuator is driven.

In the mirror unit of the distance measuring device for a camera having the above structure, the actuator for rotating the sub-mirror has a mirror top plate on which a mirror serving as a sub-mirror is mounted supported by a plurality of beams and arranged on both sides. The repulsion and the adsorbing force generated by the generated magnetic field generating portion are simultaneously and alternately switched in the opposite direction to rotate the mirror top plate, whereby the mirror is rotated up and down, and the luminous flux for distance measurement is changed to the first. The light is reflected at an angle of the second angle or the second angle and is irradiated toward the AF optical system to measure the distance.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 illustrates a conceptual configuration example of a shutter mechanism and a mirror mechanism as a first embodiment of a camera distance measuring apparatus according to the present invention.

In this embodiment, a photographing lens 1 for converging a subject image, a diaphragm 2 for adjusting the amount of light of the subject image passing through the photographing lens 1, and a rotatable optical path behind the diaphragm 2 are provided. A quick return mirror 3, a focus screen mat surface 4 disposed above the quick return mirror 3 and imaging a reflected subject image, a pentaprism 5 for bending the formed subject image, and a pentaprism 5 A finder 6 for allowing the photographer to observe the object image bent by the above, and a sub-mirror 7 rotatable as described later attached to the back side of the semi-transmissive portion 3a at the center of the quick return mirror 3; A distance measuring (AF) optical system 8 arranged at a position for taking in the light beam reflected by the sub-mirror 7 and receiving the light beam condensed by the AF optical system 8 A distance measuring sensor 9 for generating distance data Te, the focal plane shutter 1 for performing exposure that is disposed behind the quick return mirror 3
0, a film 11, and a photometric sensor 12 provided between the pentaprism 5 and the finder 6.

The distance measuring sensor 9 is disposed at a position where the distance from the quick return mirror 3 to the surface of the film 11 is substantially equivalent, and detects the amount of defocus on the surface of the film 11.

FIG. 2 shows a configuration of the sub-mirror 7 of the present embodiment as viewed from above, and FIG. 3 shows a configuration of a cross section of a line segment M shown in FIG. The sub-mirror 7 of the present embodiment is a mirror which is not driven by a cam mechanism unlike a conventional fixed-type sub-mirror, has a drive mechanism inside the mirror, and can rotate up and down around a center as a rotation center.

In the sub-mirror 7, a box-shaped mirror frame 21 made of a thin plate made of a metal or a film-like polymer compound is provided on the sub-mirror base 20. At the center of the upper surface of the mirror frame 21, the rotation center beams 22a and 22b and the four coil beams 23a and 23
A mirror top plate 25 rotatably supported by b, 24a, 24b is provided. On the mirror top plate 25, a mirror 26 having a high reflectance for reflecting the light beam and irradiating the light beam to the AF optical system 8 is mounted. This mirror 26
Although a separate mirror is mounted on the mirror top 25, a mirror surface may be formed by applying a mirror coating to the surface of the mirror top 25 itself.

Further, at both ends of the upper surface of the mirror top plate 25,
Electromagnetic coils 27a and 27b are arranged respectively,
Each is provided with a connection terminal pair 28a, 28b. Magnets 29a and 29b are arranged on the sub-mirror base 20 below them by a predetermined gap so as to face each other. Further, at both ends of the lower surface of the mirror top plate 25, rotation stoppers 3 for preventing over rotation are provided at positions separated by a predetermined distance.
0a and 30b are provided.

In such a configuration, the electromagnetic coil 27
a and the current flowing to the electromagnetic coil 27b are simultaneously and alternately switched in opposite directions, so that opposing forces of repulsion and adsorption are generated. Here, the current direction is a combination of A: C and B: D. The repulsive force and the attracting force are transmitted to the coil beams 23a, 23b, 24a, and 24b, respectively, as shown by arrows in FIG. 3, and a twist occurs such that one end of the mirror top plate 25 is pushed up and the other end is pushed down. And the rotation center beam 22
It is a force for rotating the mirror top plate 25 around a and 22b. By this rotating power, the sub-mirror 7 can be moved up and down ± 0.6
Rotated at an angle of degrees. When the sub-mirror 7 rotates upward, the light flux above the field is guided to the distance measuring sensor 9, while when the sub-mirror 7 rotates downward, the light flux below the field is reflected. The mechanism leads to the distance measurement sensor 9.

FIG. 4 shows the above-described electromagnetic coils 27a and 27a.
4 shows an example of a coil drive circuit for passing a current through b. This coil drive circuit includes PNP transistors 31 and 3
2, 33 and NPN transistors 34, 35, 36
The electromagnetic coils 27a and 27b are respectively connected to the output terminals. Power is supplied from a battery installed in a camera (not shown).

As shown in FIG. 5, these transistors control the direction of current flowing through the electromagnetic coils 27a and 27b by a combination of turning on and off each transistor, and generate a force generated between the magnets 29a and 29b. To control the orientation. When current does not flow through both the electromagnetic coils 27a and 27b, the mirror 26 is stable at a neutral position (initial position).

By applying a current to only one of the electromagnetic coils, the generated force can be halved and the tilt of the mirror 26 can be halved (± 0.3 degrees). These transistors 31 to 36 are turned on and off by a control device mounted on the camera and described later. Mirror top plate 2
The rotation of 5 is restricted by the rotation stoppers 30a and 30b protruding from the sub-mirror base 20. In this manner, the rotation stoppers 30a, 30
By projecting b, the accuracy of the rotation of the mirror 26 with respect to the sub-mirror base 20 can be increased.

The electromagnetic coils 27a and 27b and the magnet 2
If the force generated between 9a and 29b exceeds the control range and is too large, the mirror top plate 25 is deformed due to the collision with the rotation stoppers 30a and 30b, and the accurate angle cannot be maintained. Rotation stoppers 37a and 37 as shown in FIG.
The shape may be b.

FIG. 7 shows a block diagram of a camera on which the distance measuring apparatus of the present embodiment is mounted. Note that, in the camera of the present embodiment, the TT
The L phase difference detection method is adopted.

This camera includes a control device 41 for controlling the entire camera, an AFIC 42 serving as a processing circuit for autofocus, a photo sensor array 43 disposed on the upper surface of the AFIC 42, and a focusing lens 44. A driving mechanism 45 for moving the focusing lens 44, an LD motor 47 serving as a driving source of the driving mechanism 45, and an LD motor 47
A focusing lens driving circuit 46 for driving the
A mirror up-down / shutter charge drive circuit 4 for driving the quick return mirror 3 and rotating the quick return mirror 3 and running and charging the focal plane shutter 10
A diaphragm driving circuit 50 for driving the AV motor 51 to drive the diaphragm 2 by a diaphragm mechanism (not shown);
A mirror displacement drive circuit 52 for controlling the direction of the current flowing through the AFICs 7a and 27b to switch the light flux incident on the AFIC 42 to switch the distance measurement range;
And a switch (PWSW) 56 for turning on and off the power supply of the camera body, and a shutter magnet energizing circuit 53 for energizing and exposing the front curtain holding magnet 54 and the rear curtain holding magnet 55 provided in the camera. A two-stage switch (1RSW57, 2RSW58) that is sequentially turned on by pressing the illustrated shutter release button, a photometric circuit 59 for detecting the subject brightness from the sensor output of the photometric sensor 12 (SPD60), and winding and winding of the film 11 A film feed drive circuit 61 for performing a return,
For example, it is composed of a non-volatile memory 63 made of an EEPROM and preliminarily storing various data relating to the camera, and a liquid crystal display panel 64 for displaying information necessary for photographing by the camera.

These components will be specifically described. The control device 41 of the present embodiment uses a microcomputer generally called a one-tip microcomputer. The control device 41 includes a ROM for storing program codes for executing processing, various registers for performing calculations, a RAM for storing calculation results, an input / output port for performing communication for controlling peripheral ICs, a timer circuit, , A reset circuit and the like.

The AFIC 42 receives a reset signal from the control device 41 and is reset (initialized). Next, the subject image passing through the focusing lens 44 is formed on the photo sensor array 43, and is obtained here. Based on the detected signal, processing such as light intensity integration and quantization is performed to calculate the amount of defocus as the distance measurement information. This distance measurement information is transferred from the AFIC 42 to the control device 41 by serial communication, and when the light quantity integration is completed, a signal indicating the end of the light quantity integration is sent to the control device 41. Such a distance measuring sequence is performed by setting the angles of the mirror 26 shown in FIG.
By repeatedly performing the switching while switching in the order of 0.6 degrees, it is possible to detect the distance measurement information at the upper and lower three positions including the center, and calculate the optimum focus position based on the distance measurement information at these three positions. Multi-ranging is implemented.

The control device 41 determines the focusing lens 4 based on the distance measurement information (the amount of defocus) obtained by the AFIC 42.
4 is calculated. Further, the focusing lens driving circuit 56 is controlled based on the obtained moving amount, and the LD motor 4 is controlled.
7 and the drive mechanism 45 are driven to move the focusing lens 44 to the focusing position. On the other hand, the mirror up / down shutter charge drive circuit 48 drives the MS motor 49 to retreat the quick return mirror 3 from the optical path or return it into the optical path via a mirror up / down mechanism (not shown). In addition, a shutter charging mechanism (not shown) is driven to charge the shutter after the front curtain and the rear curtain of the focal plane shutter 10 travel.

In the exposure operation by the shutter magnet energizing circuit 53, the first curtain holding magnet 54 and the second curtain holding magnet 55 are energized in advance, and after the mirror-up is completed, the energization of the first curtain holding magnet 54 is released. Then, after the exposure time is over, the energization of the rear curtain holding magnet 55 is released to run the rear curtain. The various data stored in the non-volatile memory 63 include mechanical adjustment data at the factory shipment of the camera, correction data of a processing circuit, and the like.
There are a camera mode, the number of frames set during shooting, and state information required inside the camera.

Next, a main sequence in photographing will be described with reference to flowcharts shown in FIGS. First, when a battery is loaded in the camera and the power is turned on to the electrical system inside the camera, a reset circuit inside the circuit operates, the control device 41 is reset, and the sequence is executed from the beginning.

First, the state of the control device 41 is initialized (step S1). The initialization includes initialization of input / output ports, initialization of operation registers, initialization of RAM,
Information stored in the non-volatile memory 63 such as necessary adjustment values is developed in a memory inside the control device 41. Also, at the time of this initialization, it is determined whether or not the battery is completed in a normal state when the remaining capacity of the loaded battery is exhausted, and when it is not normal, a process of returning to a normal state is performed (step S2). For example, the quick return mirror 3 is not completely lowered, the aperture 2 is not open, the focal plane shutter 10 is not charged, the film 11 is not wound up, or the film 11 is being rewound. Some examples are given.

Next, it is determined whether or not the PWSW 56 is on (step S3). If it is on (YES), the process proceeds to step S9 described later. on the other hand,
If it is not on, it is determined whether it has been turned on from off (step S4). If it is not turned on and remains in the off state (NO), the display on the liquid crystal display panel 64 is turned off and the apparatus enters a standby state (step S5), and returns to step S3.
However, if it is detected that the state has changed from the off state to the on state (YES), the control device 41 reads data necessary for processing from the non-volatile memory 63 and expands the data in a memory inside the device (step S6). Then, the display of the liquid crystal display panel 64 is turned on, and the state of the camera relating to photographing is displayed (step S7). Thereafter, a shooting preparation operation is performed (step S8). For example, in the case of a collapsible camera, there are charging of a main condenser for a strobe (not shown) by extending a photographic lens so as to enable photographing, and the like.

Next, it is determined whether the back cover of the camera (not shown) has been opened or closed (step S9). If the back cover changes from “open” to “closed” in this determination (YE
S) Since there is a possibility that a film has been loaded, the film feed drive circuit 61 is controlled to perform a feed generally called an idle feed operation, and the first frame of the film is set (step S10). ).

Thereafter, it is determined whether or not the 1RSW 57 has been turned on (step S11). By this judgment, 1RSW
If 57 is in the off state (NO), the process returns to step S3 and repeats the process. On the other hand, if the 1RSW 57 is turned on (YES), the communication with the AFIC 42 is performed, and a distance measurement process is performed (step S12).

Here, the subroutine of the distance measuring process performed by the AFIC 42 will be described with reference to the flowchart shown in FIG. First, the mirror displacement drive circuit 52 is controlled to displace the mirror 26 (mirror top plate 25) to +0.6 degrees (upward) (step S31). Next, AF
It communicates with the IC 42, sends a reset signal to the AFIC 42, causes the AFIC 42 to perform light quantity integration, and when the end of the light quantity integration is detected, receives the integration result by communication and calculates upper distance measurement information (step S32). Next, the mirror displacement drive circuit 52 is controlled to displace the mirror 26 to +0 degrees (center) (step S33). That is, the drive of the actuator is turned off. Then, communication with the AFIC 42 is performed, the light amount integration is performed, and the center distance measurement information is calculated in the same manner (step S33). Next, the mirror displacement drive circuit 52 is controlled to displace the mirror 26 to -0.6 degrees (downward) (step S34). Then, it communicates with the AFIC 52 to perform light quantity integration, and similarly calculates lower distance measurement information (step S35).

Next, the process proceeds to a step 13 shown in FIG.
One of the optimum distance measurement information is selected from the three upper, middle, and lower distance measurement information from the AFIC 42, the amount of focus shift is calculated from the selected distance measurement information, and the movement of the focusing lens 44 based on this is calculated. The amount is determined (step S13).

It is determined whether or not this movement amount is within a certain range (step S14).
O), the focusing lens 44 is driven according to the movement amount obtained in step S13 (step S15), and the process returns to step S11 again to repeat the processing. On the other hand, if it is within a certain range (YES), it is determined that the object is in focus, and the photometric circuit 59 is determined.
Thus, the luminance of the object scene is obtained (step S16).

Thereafter, the control device 41 calculates and obtains a shutter speed and an aperture value according to the obtained field luminance (step S17). Then, it is determined whether or not the 2RSW 58 has been turned on (step S18). If the 2RSW 58 is not turned on (NO), the 1RS
It is determined whether or not W57 is turned on (step S
19). Here, if the 1RSW 57 remains in the ON state (YES), it is determined that shooting is continued, and
Returning to step S18, the process is repeated. However, if it is turned off (NO), the process returns to step S3.

Also, in the judgment of step S18, 2RSW
If 58 is turned on (YES), the first curtain holding magnet 54 and the second curtain holding magnet 55 are turned on,
Put the first curtain and the second curtain in the suction holding state (Step S2
0). Next, the mirror up / down shutter charge drive circuit 58 is controlled to perform mirror up, and the aperture drive circuit 50 is controlled to perform aperture reduction by the aperture 2 (step S).
21). Then, the energization of the front curtain holding magnet 54 is turned off, the front curtain is driven to start exposure, and the energization of the rear curtain holding magnet 55 is turned off after the shutter time (exposure time) has elapsed. To complete the exposure (step S22).

Next, the control device 41 controls the mirror up / down / shutter charge drive circuit 48 to lower the mirror of the quick return mirror 3, controls the aperture drive circuit 50, and opens the aperture (step S23). ).
Then, the mirror up / down / shutter charge drive circuit 48 is controlled to perform shutter charge (step S).
24). Further, it is determined whether or not the film 11 is loaded in the camera (step S25). If it is loaded (YES), the film feed drive circuit 61 is controlled to wind up the film 11 by one frame ( Step S2
6) After winding up or when it is determined that the film 11 is not loaded (NO), the process returns to step S3 to repeat the process.

FIG. 12 shows a cross-sectional configuration of a sub mirror according to the distance measuring apparatus of the second embodiment, and will be described. The same components as those of the first embodiment described above are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 3, in the above-described first embodiment, the electromagnetic coils 27a and 27b are arranged on the same plane as the mirror 26.
7a and 27b are arranged on the sub-mirror base 20, and the magnet 7
This is a configuration example in which 1a and 71b are arranged on the lower surface side of the top plate. With such a configuration, the same operation and effect as those of the first embodiment can be obtained. Alternatively, a material made of iron, nickel, or the like, which is attracted to the magnet, may be formed into a plate shape and affixed to the top plate, or the top plate may be formed of these materials.

According to the embodiment described above, since the sub-mirror is rotated by the small actuator,
It is adaptable to high-speed shutters and has a simple structure.
In addition, a plurality of AF sensors have the same effect as a single AF sensor with respect to a submirror fixed to a quick return mirror in the related art, thereby preventing the camera from becoming larger and contributing to downsizing. In addition, in the present embodiment, since the rotation is performed by bending as compared with the related art in which the sub-mirror is displaced using a mechanical cam mechanism, the rotation can be performed in a very short time with a simple configuration, and the movable component is used. Since there is no failure, there is no failure due to mechanical wear and the like, and failure due to external impact is extremely small.

Further, in this embodiment, an example in which the mirror is swung at the three points of upper, middle, and lower has been described. However, the present invention is not limited to this, and by adjusting the magnetic field generated by the electromagnetic coil, It is possible to set more distance measuring points by changing the degree of bending (displacement amount).

FIG. 13 shows an external configuration of a sub-mirror according to the distance measuring apparatus of the third embodiment, which will be described. The same components as those of the first embodiment described above are denoted by the same reference numerals, and description thereof will be omitted.
FIG. 13 is a perspective view of the sub-mirror viewed obliquely from above, and FIG.
Is a top view seen from above. This embodiment is an example of a configuration in which the size of the submirror described in the first and second embodiments is reduced.

This sub-mirror is composed of electromagnetic coils 81a, 8a
1b, a sub-mirror base 82, and a sub-mirror base 82
A mirror frame 83 made of a metal or a film-like polymer compound and having a predetermined gap above the mirror frame 83, a mirror top plate 25 on which the mirror 26 is formed, and an upper surface of the mirror frame 83 Center beams 22a and 22b supporting the mirror top plate 25 from both sides at the center position of
And four coil beams 23a, which rotatably support the mirror top plate 25 on both sides of the rotation center beams 22a, 22b.
23 b, 24 a, 24 b and magnets 84 a, 84 b disposed on the end side of the back surface of mirror top plate 25 (the surface opposite to the mounting surface of mirror 26).

The rotation of the sub-mirror of this embodiment is equivalent to that of the first embodiment, and the same effect can be obtained.

Although the above embodiments have been described, the present invention includes the following inventions.

(1) In a camera distance measuring device for detecting a defocus amount of a subject image by guiding a part of a light beam to a distance measuring optical system by a mirror, an actuator capable of changing an angular displacement amount of the mirror is incorporated. Then, a first distance measurement is performed with the first displacement of the mirror, and a second distance measurement is performed with the second displacement of the mirror.
A distance measuring device for a camera that measures the distance of the subject and detects the defocus amount of the subject image based on the first and second distance measurement results.

(2) The angle of the neutral position of the mirror that does not drive the actuator is defined as the first displacement.

(3) The angle of the mirror when the actuator is driven is defined as a second displacement.

(4) In a distance measuring device of a camera for detecting a defocus amount of a subject image by reflecting a part of a light beam taken in from a photographing optical system by a mirror and guiding the reflected light to a distance measuring light detecting means, Mirror holding means for forming the mirror for reflecting light toward the optical system for distance measurement, rotating center supporting means for supporting the rotation center position of the mirror holding means with two beams, A support means arranged on both sides of each beam of the rotation center support means for rotatably supporting the mirror holding means, and a box-shaped shape formed of a thin plate of an elastic member; Holding frame means for holding the mirror holding means connected to a supporting means, and arranged on both sides of the mirror holding means in a direction perpendicular to the rotation center supporting means and the supporting means, and each of which is opposed by a magnetic field. Rotation driving means for generating a repulsive force and an attractive force that are simultaneously and alternately switched in the direction, and the repellent force and the attractive force are transmitted to the support means, respectively, and push up one end of the mirror holding means, By generating a twist that pushes down the other end and rotating the mirror holding means about the rotation center support means, the light flux reflected by the mirror is swung and irradiates the distance measuring light detection means. A distance measuring device for a camera.

(5) The swinging of the light beam reflected by the mirror is performed with the center of the light receiving surface of the distance measuring light detecting means as an initial position, depending on the direction of the repulsive force and the attraction force of the rotating drive means. The distance measuring device for a camera according to the above mode (4), wherein the light beam is guided to three positions, that is, positions where the light beam is swung to the right and left sides.

(6) The camera distance measuring apparatus according to the above item (4), further comprising a stopper means for limiting a rotation range of the mirror holding means.

(7) The rotating drive means comprises: a pair of electromagnetic coils arranged on the same plane as the mirror forming surface of the mirror holding means; and a pair of magnets opposed to these electromagnetic coil pairs with a predetermined gap therebetween. Wherein the direction of current flowing through the electromagnetic coil is simultaneously and alternately switched in the opposite direction to generate the repulsive force and the attracting force. .

(8) The rotating drive means includes a magnet pair disposed on the same plane below the mirror forming surface of the mirror holding means, and an electromagnetic coil opposed to the magnet pair with a predetermined gap therebetween. The distance measurement of the camera according to the above item (4), comprising a pair, wherein the repulsive force and the attracting force are generated by simultaneously and alternately switching the directions of currents flowing through the electromagnetic coils in opposite directions. apparatus.

[0054]

As described above in detail, according to the present invention, 1
It is possible to provide a ranging device for a camera that includes a plurality of AF sensors, can detect a wide vertical viewing angle, and can support a high-speed shutter.

[Brief description of the drawings]

FIG. 1 is a diagram showing a conceptual configuration example of a shutter mechanism and a mirror mechanism as a first embodiment of a camera distance measuring apparatus according to the present invention.

FIG. 2 is a diagram illustrating a configuration of a sub mirror according to the first embodiment as viewed from above.

FIG. 3 is a diagram showing a configuration of a cross section of a submirror taken along a line A shown in FIG. 2;

FIG. 4 is a diagram illustrating an example of a coil drive circuit of an electromagnetic coil.

FIG. 5 is a diagram showing transistor ON and OFF in a coil drive circuit.
It is a figure for explaining rotation of a mirror to combination of OFF.

FIG. 6 is a view showing a modification of the rotation stopper.

FIG. 7 is a diagram illustrating a block configuration of a camera on which the distance measuring device according to the first embodiment is mounted.

FIG. 8 is a first half of a flowchart for describing a main sequence of photographing according to the first embodiment.

FIG. 9 is an intermediate portion of a flowchart for describing a main sequence of photographing according to the first embodiment.

FIG. 10 is a latter half of a flowchart for describing a main sequence of photographing according to the first embodiment.

FIG. 11 is a flowchart illustrating a subroutine of a distance measurement process performed by the AFIC.

FIG. 12 is a diagram illustrating a cross-sectional configuration of a submirror according to the distance measuring apparatus of the second embodiment.

FIG. 13 is a perspective view of a sub mirror according to a distance measuring apparatus of a third embodiment as viewed obliquely from above.

14 is a top view of the sub mirror shown in FIG. 13 as viewed from above.

FIG. 15 is a diagram showing a conceptual configuration of a conventional shutter mechanism and a mirror mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Photography lens 2 ... Aperture 3 ... Quick return mirror 4 ... Focus screen matte surface 5 ... Penta prism 6 ... Finder 7 ... Submirror 8 ... Distance measuring (AF) optical system 9 ... Distance measuring sensor 10 ... Focal plane shutter 11 ... Film 20: Submirror base 21: Mirror frame 22a, 22b: Rotating center beam 23a, 23b, 24a, 24b: Coil beam 25: Mirror top plate 26: Mirror 27a, 27b: Electromagnetic coil 28a, 28b: Connection terminal pair 29a, 29b ... Magnets 30a, 30b ... Rotation stopper

Claims (3)

[Claims] 1. A distance measuring device for a camera which guides a part of a light beam having passed through a photographing lens to a distance measuring optical system by using a mirror unit and detects a defocus amount of a subject image. An actuator for changing an angle of a mirror of the mirror unit with respect to an optical axis of the photographing lens to a first angle or a second angle, and a first distance measurement when the mirror is at the first angle A distance measuring device for a camera, which detects a defocus amount of a subject image based on a result or a second distance measurement result at the second angle. 2. The apparatus according to claim 1, wherein the first angle is an angle when the actuator is not driven.
A distance measuring device for the camera according to the above. 3. The camera distance measuring device according to claim 2, wherein the second angle is an angle when the actuator is driven.