JP2015225192A - Electronic imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic imaging apparatus capable of preventing damage to an SH blade or an imaging element caused by sunlight during power-off.SOLUTION: A light-shielding plate driving unit for driving a light-shielding plate to a position for covering an opening of a translucent mirror holding frame is arranged on the undersurface of a mirror box. The light-shielding plate is driven during power-off to prevent sunlight from passing through a translucent mirror and being incident to an SH blade or an imaging element.

Description

  The present invention relates to an electronic imaging apparatus, and more particularly to an apparatus that divides imaging light by a reflecting member.

  Conventionally, a semi-transparent mirror is placed in the shooting optical path so that the subject can be confirmed with the image sensor while exposing the subject light, and part of the light is transmitted to the image sensor and the remaining light is reflected to the viewfinder. The structure to be made is proposed. In Patent Document 1, a light-shielding member having a semi-transparent mirror holding frame tip as a rotation axis is driven by a toggle spring to a position approaching the semi-transparent mirror holding frame at the mirror up position, and from the semi-transparent mirror holding frame at the mirror down position. A structure that is driven away is disclosed.

Japanese Patent Laid-Open No. 11-295810

  However, in the prior art disclosed in Patent Document 1 described above, sunlight can be incident through the semi-transmissive mirror even when the power is turned off, and if the sunlight is incident, there is a possibility that the SH blade and the image sensor are damaged. there were.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an electronic image pickup apparatus that prevents damage to SH blades and an image sensor due to sunlight when the power is turned off in a configuration in which the subject can be confirmed with a viewfinder while exposing the subject light with the image sensor. That is.

  In order to achieve the above object, according to the present invention, the semi-transparent mirror 203 is held in an electronic imaging apparatus that is rotatably provided with a semi-transparent mirror 203 that separates subject light into the imaging element and the other. A semi-transparent mirror holding frame 204 having an opening 204-f through which subject light passes, a mirror box 200 that rotatably holds the semi-transparent mirror holding frame 204, and the vicinity of the subject-side tip of the semi-transparent mirror holding frame 204 A light shielding member 205 having a rotation center at the center, a biasing spring 206 for biasing the light shielding member 205 and the semi-transparent mirror holding frame 204 in the opening direction by rotation, and an inner wall of the mirror box above the photographing optical axis, And a semi-transparent mirror holding frame 204 and a light shielding plate 205 are arranged in a photographing light beam when waiting for photographing. It is configured to be able to rotate between a position (mirror down position) and a second position (mirror up position) retracted from the photographing light beam at the time of shooting. At the mirror up position, the light shielding plate 205 is provided on the inner wall of the mirror box. In addition, the semi-transparent mirror holding frame 204 and the light shielding plate 205 are energized at the mirror down position when the power is turned on. The light-shielding plate driving member 401 or 501 is held at a position where it is in contact with each other in predetermined areas 204-e and 205-c by the urging force of the spring 206, and the mirror unit 112 is disposed at the mirror-down position when the power is turned off. By being driven to a position in contact with the light shielding plate 205, the light shielding plate 205 is held in a state of covering the opening 204-f of the semi-transmissive mirror holding frame 204. It is characterized in.

  According to a second aspect of the present invention, in the first aspect, the light shielding plate driving member 401 is disposed at a position escaped from the inner surface of the mirror box 200 when the power is turned on, and approaches the photographing optical axis by a substantially linear locus when the power is turned off. It is characterized by being in contact with the light shielding plate 205.

  According to a third aspect of the present invention, in the first aspect, the light shielding plate driving member 401 is disposed at a position escaped from the inner surface of the mirror box 200 when the power is turned on, and the rotating shaft 501-a disposed on the subject side when the power is turned off. As a rotation center, the light-shielding plate 205 is brought into contact with the light-shielding plate 205 by being rotationally driven.

  According to a fourth aspect of the present invention, in the first aspect, the light shielding plate driving motor 402 or 502 for driving the light shielding plate driving member 401 or 501 is disposed on the lower surface of the mirror box 200.

  According to the present invention, it is possible to prevent damage to the SH blade and the image sensor due to sunlight when the power is turned off even when the subject is exposed with the image sensor and the subject can be confirmed with the viewfinder. An electronic imaging device can be provided.

1A is a front perspective view of an electronic imaging apparatus to which the present invention is applied. FIG. (B) is a back side perspective view of the electronic imaging device to which the present invention is applied. It is a figure which has the flash device of the electronic imaging device to which this invention is applied in a use position. It is a block diagram of the electronic imaging device to which the present invention is applied. It is a perspective view of the mirror box unit to which the first embodiment of the present invention is applied. It is a side view of the components in a mirror box and an image sensor to which the present invention is applied. (A) is the perspective view seen from the imaging optical axis side of the mirror unit to which this invention is applied. (B) is the perspective view seen from the imaging | photography optical axis reverse side of the mirror unit to which this invention is applied. It is a down position side view of the mirror unit to which the present invention is applied. It is a side view near the up position of the mirror unit to which the present invention is applied. It is an up position side view of a mirror unit to which the present invention is applied. It is the side view which showed the imaging | photography standby state of the mirror unit and light-shielding plate drive unit to which this invention is applied. It is the side view which showed the light-shielding plate drive start of the mirror unit and light-shielding plate drive unit to which this invention is applied. It is the side view which showed the power supply OFF state of the mirror unit and light-shielding plate drive unit to which this invention is applied. (A) is a flowchart at the time of power-off of the electronic imaging device to which the present invention is applied. FIG. 6B is a flowchart when the electronic imaging apparatus to which the present invention is applied is turned on. It is a perspective view of a mirror box unit to which a second embodiment of the present invention is applied. It is the side view which showed the imaging | photography standby state of the mirror unit and light-shielding plate drive unit to which this invention is applied. It is the side view which showed the light-shielding plate drive start of the mirror unit and light-shielding plate drive unit to which this invention is applied. It is the side view which showed the power supply OFF state of the mirror unit and light-shielding plate drive unit to which this invention is applied.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  The outline of the operation of the digital single-lens reflex camera will be described below with reference to FIGS. FIG. 1 is an external perspective view of a digital single-lens reflex camera to which the present invention is applied. FIG. 2 is an external perspective view of the flash unit of the digital single-lens reflex camera to which the present invention is applied moved to the light emitting position. FIG. 3 is a block diagram of the digital single-lens reflex camera in the present embodiment.

  In this embodiment, a digital single-lens reflex camera with a detachable lens is illustrated, but the present invention is not limited to this, and any imaging apparatus having a transflective mirror that can move between a photographing position and a photographing retreat position will be described. Applicable.

  As will be described later, the digital single-lens reflex camera according to the present embodiment does not include a so-called phase difference AF unit below the mirror box, and does not include a reflecting mirror for guiding subject light to the phase difference AF unit. The mirror unit 112 includes a semi-transmissive mirror, transmits a part of the subject light transmitted through the photographing optical system, guides it to an image sensor (not shown), and reflects the remaining subject light to the finder unit 113. The photographer can observe the subject light.

  When the main power switch 107 provided on the upper exterior cover 101 of the camera body 100 is operated to the ON position, the camera microcomputer 10 starts the camera in a predetermined sequence.

  When the operation microcomputer 12 detects the operation of the operation member by the operation detection circuit 12, the camera microcomputer 10 performs a corresponding setting. For example, when the shooting mode dial 108 is operated to select a shooting mode, a program diagram for determining a combination of shutter speed and aperture corresponding to the selected shooting mode is set. When the electronic dial 105 is operated, settings such as exposure correction are performed. When the ISO sensitivity setting button 106 is operated, an ISO sensitivity condition is set.

  A series of shooting operations when the automatic setting mode is selected with the shooting mode dial 108 will be described. When it is detected by the operation detection circuit 12 that the release button 104 has been pushed to the first position, the camera microcomputer 10 drives the shooting condition control circuit 13 to determine an appropriate shutter speed and aperture value. The subject light is measured by a photometric sensor (not shown) provided near the viewfinder unit 113. Alternatively, subject light that has passed through the semi-transmissive mirror and entered the image sensor may be measured.

  If it is determined from the obtained photometric result that the subject light is lower than the predetermined luminance, the camera microcomputer 10 drives the motor control circuit 14 and drives a motor (not shown) to move the flash unit 103 to the light emitting position. Then, it moves to a predetermined position by the rotational movement (position shown in FIG. 2).

  When it is detected by the operation detection circuit 12 that the release button 104 has been pushed to the second position, the camera microcomputer 10 drives the motor control circuit 14 so that the subject light reaches an image sensor (not shown), The mirror unit 112 is retracted to a predetermined position, and the flash control circuit 11 is driven to emit light at a predetermined timing and irradiate the subject with appropriate light.

  The camera microcomputer 10 drives the image sensor driving circuit 15 in a state where the subject light has reached the image sensor, and acquires the subject light as electronic data by photoelectric conversion. The acquired electronic data is subjected to predetermined data processing such as amplification, conversion, and correction by the data processing circuit 16 to become photographed image data.

  The camera microcomputer 10 drives the recording processing circuit 17 to record the obtained captured image data in a memory (not shown). When the photographer operates an image reproduction button (not shown), the camera microcomputer 10 drives the reproduction processing circuit 18 to display the photographed image stored in the memory on the display device 110 provided on the camera rear exterior cover 111.

  Reference numeral 109 denotes an accessory shoe, which can be connected to the attached external accessory by attaching an external accessory such as an external strobe and being connected to a circuit inside the camera at a contact portion.

  FIG. 4 is a perspective view of a mirror box unit of a digital single lens reflex camera to which the present invention is applied. A known mirror driving unit 201 for driving the mirror unit 112 is fixed to the side surface of the mirror box 200. The mirror drive unit 201 includes a motor, a gear (not shown), a spring, a mirror unit drive lever, and the like. A finder unit (not shown) is fixed to the upper part of the mirror box 200. The mirror unit 112 that reflects part of the subject light to the viewfinder unit includes a semi-transmissive mirror 203, a semi-transmissive mirror holding frame 204, a light shielding plate 205, and a light shielding plate biasing spring 206.

  The semi-transmissive mirror 203 is fixed to the semi-transmissive mirror holding frame 204 with a double-sided tape (not shown). The fixing method of the semi-transparent mirror 203 to the semi-transparent mirror holding frame 204 may be any method as long as it has sufficient strength. An antireflection sheet 207, which is a known technique, is attached to the inner wall of the mirror box 200 to prevent harmful reflection light.

  The antireflection sheet 207 is not an essential component of the present invention, and it is desirable that an antireflection structure such as antireflection coating is adopted, but it may be provided if necessary. A light shielding plate drive rectilinear member 401 (described later) is disposed on the lower surface of the mirror box 200, and is disposed at a position that does not protrude into the mirror box 200 when the power is turned on. The mirror unit 112 collides with the shock absorbing member 208 and is held at the up position during photographing.

  FIG. 5 is a side view of the structure inside the mirror box and the image sensor. The semi-transparent mirror holding frame 204 to which the semi-transparent mirror 203 is fixed has a first position where the photographer observes the subject light (hereinafter referred to as a mirror down position) with the holding frame rotation axis 204-a as the rotation center and at the time of photographing. It is configured to be rotatable to a second position (hereinafter referred to as a mirror up position) retracted from the photographing light beam, and is configured to be held at the mirror down position and the mirror up position, respectively.

  The semi-transmissive mirror holding frame 204 is configured to be able to rotate and hold the mirror down position and the mirror up position by driving the drive shaft 204-b by a mirror unit drive lever (not shown) and a mirror unit drive spring. Yes. An up position drive pin 300 is provided on at least one of the inner side walls of the mirror box 200. The operation of the up position drive pin 300 will be described later.

  The light shielding plate 205 is made of a light and strong metal in order to reduce the influence on the operation of the mirror unit 112. In addition, harmful light antireflection sheets 205-a and 205-b are attached to the front and back of the light shielding plate 205 to reduce reflection of harmful light during focusing and photographing. The width of the front end of the light shielding plate 205 on the image sensor side only needs to be wide enough to cover the opening provided in the transflective mirror holding frame 204, and is narrower than the width near the rotation center. The load is reduced. The material may be anything as long as it does not affect the driving of the mirror unit 112. The antireflection sheet may also be an antireflection coating or an antireflection shape (for example, a continuous shape of a mountain valley).

  A light shielding plate rotation shaft 204-c serving as a rotation center of the light shielding plate 205 is provided in the vicinity of the subject-side tip of the semi-transparent mirror holding frame 204, and the light shielding plate 205 is rotatably attached. The light shielding plate 205 is rotatable about the light shielding plate rotation shaft 204-c with respect to the semitransparent mirror holding frame 204, and the rotational shaft 204- of the semitransparent mirror holding frame 204 together with the semitransparent mirror holding frame 204. It is configured to be rotatable around a.

  The light shielding plate 205 is urged by an urging spring 206 in a direction away from (opening) the semi-transparent mirror holding frame 204. The urging spring 206 has a winding portion disposed on the light shielding plate rotation shaft 204-c, one end abutting against the semi-transmissive mirror holding frame 204, and the other end abutting against the light shielding plate 205. The urging spring 206 may be in the vicinity of the light shielding plate rotating shaft 204-c on one side, but may be on both sides. When the mirror unit 112 is disposed at the mirror down position, the light shielding plate 205 is held in a state of being separated (opened) from the semi-transmissive mirror holding frame 204 by the biasing force of the biasing spring 206 (the state of FIG. 5). .

  When the mirror unit 112 is disposed at the mirror down position, the subject light transmitted through the semi-transmissive mirror 203 can enter the image sensor 302 from the opening 204-f provided in the semi-transmissive mirror holding frame 204. It has become. At this time, if the harmful light is reflected on the light shielding plate 205, the image quality is deteriorated and affects the focusing accuracy. However, the harmful light reflection preventing sheet 205-b can reduce the harmful reflected light. Further, when the mirror unit 112 is disposed at the mirror down position, the image quality obtained by the image sensor 302 is improved when subject light is incident between the subject-side tip of the semi-transmissive mirror holding frame 204 and the lower surface of the mirror box 200. However, since the light shielding plate 205 blocks harmful light, it is possible to prevent the image quality obtained by the image sensor 302 from being deteriorated.

  Using the image data obtained from the image sensor 302, it is possible to perform a focusing operation by so-called contrast AF or imaging surface phase difference AF, which are known techniques. In addition, photometry can be performed using an image sensor or a dedicated photometer if provided.

  In the present invention, the subject light transmitted through the semi-transmissive mirror 203 is converted into an electrical signal by the image sensor 302 and a focusing operation is performed. Therefore, the phase difference AF unit conventionally provided on the lower surface of the mirror box 200 becomes unnecessary. Since image data is obtained by subject light transmitted through the opening 204-f of the semi-transparent mirror holding frame 204 at the mirror down position, a focusable range is determined by the size of the opening. The present invention is not particularly limited by the focusable range, but it is desirable that an opening size of 50% or more of the photographing size is provided because the focusable area is wide and the usability is good. When the size of the semi-transmissive mirror 203 is reduced, the size of the opening 204-f of the semi-transmissive mirror holding frame 204 is also reduced. Therefore, the larger the size of the semi-transmissive mirror 203 is, the more convenient for the photographer.

  FIG. 6 is a perspective view of the mirror unit 112. On the side surface of the semi-transparent mirror holding frame 204, there is provided a mirror positioning abutment surface 204-d that abuts on the mirror positioning portion 303 provided on the inner surface of the mirror box 200, and the angle of the semi-transmission mirror 203 at the mirror down position. Is maintained at a predetermined angle. A holding frame for holding the position of the semi-transparent mirror holding frame 204 in contact with the light shielding plate 205 and holding the light shielding plate 205 apart (opened) by the biasing force of the biasing spring 206. A contact surface 204-e is provided. As a corresponding portion of the light shielding plate 205, a light shielding plate contact surface 205-c is provided. The light shielding plate contact surface 205-c is provided as a different plane from the other areas of the light shielding plate 205. This is to ensure the strength by securing the thickness of the tip of the semi-transmissive mirror holding 04. The positions other than the light shielding plate contact surface 205-c are set at positions that can be arranged as close to the semi-transmissive mirror holding 204 as possible at the mirror up position.

  In this embodiment, the light-shielding plate contact surface 205-c is a flat surface different from other regions. However, the present invention is not limited to this, and even at the same position, it is semi-transmissive at the mirror-up position. The opening 204-f of the mirror holding frame 204 may be covered.

  In the vicinity of the rotation center of the light shielding plate 205, a pin abutting portion 205-d that abuts on the up position driving pin 300 is provided at a position substantially symmetrical with respect to the photographing optical axis. The pin contact portion 205-d is provided on a wall portion 205-e provided to increase the strength provided on both side surfaces of the light shielding plate 205. Further, the pin contact portion 205-d is provided as a surface extending in a direction farther from the photographing optical axis than the light shielding plate rotation shaft 204-c provided in the semi-transmissive mirror holding frame 204. In addition, although pin contact part 205-d is supposed to be provided in wall part 205-e, in this invention, it is not essential and may be provided from light-shielding plate contact surface 205-c. The surface on the finder side of the pin contact portion 205-d contacts the up position drive pin 300. The urging spring 206 is disposed so as to abut on the finder side surface of the pin abutting portion 205-d.

  FIG. 7 is a side view showing the operation of the mirror unit 112. FIG. 7A is a mirror down position, and is a side view of FIG. 5 viewed from the reverse side. FIG. 7B is a side view showing the pin contact portion 205-d of the light shielding plate 205 starting to contact the up position drive pin 300 or starting to separate. FIG. 7C shows the mirror up position which is the retracted state at the time of exposure.

  The operation of the mirror unit 112 will be described with reference to FIG. In the mirror down position, the semi-transmissive mirror holding frame 204 is held while maintaining a predetermined angle with the mirror positioning portion 303 and the positioning receiving surface 204-d being in contact with each other. The mirror positioning part 303 has a shape that avoids interference with the wall part 205-e of the light shielding plate 205, but may be arranged so as not to interfere by making the distance from the photographing optical axis different. In that case, the wall 205-e of the light shielding plate 205 is disposed at a position close to the photographing optical axis. Thus, the photographer can correctly recognize the subject light reflected by the semi-transmissive mirror 203 through the finder optical system.

  The subject light transmitted through the semi-transmissive mirror 203 is incident on the image sensor 302, and the subject light is converted into an electrical signal, and a focusing operation is performed by a known technique. When the photographer operates the release button 104, focusing control and shooting condition setting are performed by the above-described camera operation. After photographing becomes possible, the semi-transmissive mirror holding frame 204 is rotationally driven by a mirror unit drive lever (not shown), and starts moving to the mirror up position. The light shielding plate 205 moves together with the semi-transmissive mirror holding frame 204, and the up position driving pin 300 and the pin contact portion 205-d of the light shielding plate 205 start to contact each other before the mirror up position (state of FIG. 7B). . The place where the up position driving pin 300 and the pin contact portion 205-d of the light shielding plate 205 abut is on the subject side with respect to the rotation center of the light shielding plate 205. The light shielding plate 205 is driven in the direction approaching (closing) the semi-transparent mirror holding frame 204 by receiving a rotational driving force in the direction approaching (closing) the holding frame 204.

  In the picture of the embodiment, the end portion of the biasing spring 206 on the light shielding plate 205 side is in a state of interfering with the light shielding plate 205, but in actuality the position where the end portion contacts the pin contact portion 205-d. It is arrange | positioned in the position contact | abutted to.

  When the semi-transmissive mirror holding frame 204 is driven to the mirror-up position by the mirror unit drive lever, the subject-side tip of the semi-transmissive mirror holding frame 204 collides with the impact interference member 208 and is held at a predetermined compression position (FIG. 7). (C) state). At this time, the light shielding plate 205 is held in a state of being closest (closed) to the semi-transmissive mirror holding frame 204 by the up position driving pin 300.

  After the mirror unit 112 is driven to the mirror up position, photographing data acquisition (exposure) is performed by the image sensor 302. At this time, the light shielding plate 205 is held in a state of covering the opening 204-f of the semi-transmissive mirror holding frame 204, and prevents harmful light from the viewfinder from reaching the image sensor 302. In addition, an antireflection sheet 205-a is attached to the photographing optical axis side to reduce reflection due to harmful light transmitted through the photographing optical system. This makes it possible to reduce harmful light from entering the subject light being exposed.

  After the exposure operation, when the semi-transparent mirror holding frame 204 is moved to the mirror down position, the light shielding plate 205 and the semi-transmissive mirror holding frame 204 are moved to the photographing optical axis as the semi-transmissive mirror holding frame 204 approaches the photographing optical axis. To approach, it begins to move away from the up position drive pin 300 and moves away (opens) from the semi-transparent mirror holding frame 204 by the biasing force of the biasing spring 206 (state shown in FIG. 7B).

  Next, the operation when the main power switch 107 is operated by the photographer and the power is turned off will be described in detail with reference to FIG. When the operation detection circuit 12 detects that the main power switch 107 has been operated to the power OFF position, the camera microcomputer 10 controls the camera in a state where the power can be turned OFF by a predetermined sequence. The operation of the light shielding member drive unit 400 performed at this time will be described in detail. Except for the operation of the light shielding member drive unit 400, the camera power supply may be turned off by a known sequence. FIG. 8 is a side view showing the mirror unit 112 and the light shielding plate driving unit 400 showing the operation when the power of the camera is turned off by the main power switch 107.

  FIG. 8A is a side view showing the mirror unit 112 and the light shielding plate driving unit 400 in a photographing standby state. The light shielding plate driving unit 400 includes a light shielding plate driving motor 402, a connecting gear 403, a light shielding plate driving rectilinear member 401, a holding frame (not shown), and the like. The light shielding plate driving unit 400 is disposed on the lower surface side of the mirror box 200, and is disposed in a space where the conventional phase difference AF unit is disposed. In the present embodiment, the above-described configuration is used. However, the present invention is not limited to this, and any configuration that can drive the light shielding plate is applicable. FIG. 8B is a side view showing that the light-shielding plate driving rectilinear member 401 starts to come into contact with the light-shielding plate 205 after the photographer turns off the power. FIG. 8C is a side view showing a state in which the light shielding plate 205 is driven to a position where the light shielding plate driving rectilinear member 401 covers the semitransparent mirror holding frame opening 204-f of the semitransparent mirror holding frame 204.

  When the photographer operates the main power switch 107 and the operation detection circuit 12 detects that the main power switch 107 is operated to the power OFF position, the camera microcomputer 10 uses the motor control circuit 14 to switch the light shielding plate drive motor 402. The light shielding plate drive rectilinear member 401 is driven by the interlocking of the racks provided on the connecting gear 403 and the light shield plate drive rectilinear member 401. The light shielding plate drive rectilinear member 401 is driven in the photographing optical axis direction and starts to come into contact with the light shielding plate 205 (state of FIG. 8B), and the light shielding plate 205 covers the transflective mirror holding frame opening 204-f. And is held at that position (the state shown in FIG. 8C).

  In the present embodiment, the mode in which the light-shielding plate driving rectilinear member 401 is moved perpendicularly to the photographing optical axis is exemplified. However, the present invention is not limited to this, and light shielding is performed while approaching the photographing optical axis. Any configuration that can drive the plate 205 is applicable.

  When the light shielding plate 205 is held in a state of being close (closed) to the semitransparent mirror holding frame 204, the light shielding plate 205 covers the opening 204-f of the semitransparent mirror holding frame 204. It is possible to prevent light from entering an SH blade (not shown) or the image sensor 302.

  Next, the operation when the photographer operates the main power switch 107 and turns on the power will be described. In the power-off state, the mirror unit 112 is held at the mirror down position, and the light shielding plate 205 is in contact with the light shielding plate driving rectilinear member 401 and approaches (closes) the semi-transmissive mirror holding frame 204. (The state shown in FIG. 8C).

  When the photographer operates the main power switch 107 and the operation detection circuit 12 detects that the main power switch 107 is operated to the power ON position, the camera microcomputer 10 drives the light shielding plate driving motor 402 by the motor control circuit 14. Then, the light-shielding plate driving rectilinear member 401 is driven in a direction away from the photographing optical axis. As the light-shielding plate driving rectilinear member 401 moves away from the photographing optical axis, the light-shielding plate 205 moves away (opens) from the semi-transparent mirror holding frame 204 by the biasing force of the biasing spring 206 (state of FIG. 8B). ).

  Thereafter, the mirror unit 112 and the light-shielding plate driving rectilinear member 401 are arranged in a photographing standby state (the state shown in FIG. 8A).

  FIG. 9 is a flowchart when the power is turned on and off. FIG. 9A is a flowchart when the power is turned off. FIG. 9B is a flowchart when the power is turned on. The operations other than the light shielding plate driving unit 400 may be performed in a known sequence and will not be described.

  The operation when the power is turned off will be described with reference to FIG. START is a shooting standby state. In STEP-A1, it is determined whether the main power switch 107 has been operated by the photographer. If it is determined that the main power switch 107 is not operated, the photographing standby state is maintained. If it is determined that the main power switch 107 has been operated, the light shielding plate drive motor 402 is driven in STEP-A2, and the light shielding plate drive rectilinear member 401 starts moving in the photographing optical axis direction. Due to the movement of the light shielding plate drive rectilinear member 401, the light shielding plate 205 approaches the semi-transparent mirror holding frame 204 while the light shielding plate drive rectilinear member 401 contacts the light shielding plate 205.

  After the light shielding plate drive rectilinear member 401 starts moving, if the detection means (not shown) detects that the light shielding plate drive rectilinear member 401 has been driven to a predetermined position in STEP-A3, the light shielding plate drive motor 402 is driven. The light shielding plate drive rectilinear member 401 and the light shielding plate 205 are held in contact with each other. At this time, the light shielding plate 205 is in a state of being close (closed) to the semi-transmissive mirror holding frame 204. After the light shielding plate 205 is arranged in a state of being close (closed) to the semi-transparent mirror holding frame 204, the camera is turned off in a predetermined sequence (STOP).

  The operation when the power is turned on will be described with reference to FIG. START is a power-off state. In STEP-B1, it is determined whether the photographer has operated the main power switch 107. When it is determined that the main power switch 107 has not been operated, the power OFF state is maintained. If it is determined that the main power switch 107 has been operated, the light shielding plate driving motor 402 is driven in STEP-B2, and the light shielding plate driving rectilinear member 401 starts to move away from the photographing optical axis. Due to the movement of the light-shielding plate driving rectilinear member 401, the light-shielding plate 205 is in contact with the light-shielding plate driving rectilinear member 401 and is moved away from the transflective mirror holding frame 204 by the urging force of the urging spring 206. .

  After the light shielding plate drive linearly moving member 401 starts to move, if the detection means (not shown) detects that the light shielding plate drive linearly moving member 401 has been driven to a predetermined position in STEP-B3, the light shielding plate driving motor 402 is driven. The light shielding plate drive linearly moving member 401 is held in a state where it is disposed at a position where it does not protrude from the mirror box 200 (storage position). After the light-shielding plate driving rectilinear member 401 is disposed at the storage position, the camera is turned on in a predetermined sequence.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

  A second embodiment to which the present invention is applied will be described. The up operation and down operation of the mirror unit may be the same as those in the first embodiment, and will be omitted. FIG. 10 is a perspective view of a mirror box unit of a digital single lens reflex camera to which the present invention is applied.

  A known mirror driving unit 201 for driving the mirror unit 112 is fixed to the side surface of the mirror box 200. The mirror drive unit 201 includes a motor, a gear (not shown), a spring, a mirror unit drive lever, and the like. A finder unit (not shown) is fixed to the upper part of the mirror box 200. The mirror unit 112 that reflects part of the subject light to the viewfinder unit includes a semi-transmissive mirror 203, a semi-transmissive mirror holding frame 204, a light shielding plate 205, and a light shielding plate biasing spring 206.

  The semi-transmissive mirror 203 is fixed to the semi-transmissive mirror holding frame 204 with a double-sided tape (not shown). The fixing method of the semi-transparent mirror 203 to the semi-transparent mirror holding frame 204 may be any method as long as it has sufficient strength. An antireflection sheet 207, which is a known technique, is attached to the inner wall of the mirror box 200 to prevent harmful reflection light.

  The antireflection sheet 207 is not an essential component of the present invention, and it is desirable that an antireflection structure such as antireflection coating is adopted, but it may be provided if necessary. A light shielding plate driving rotation member 501 described later is disposed on the lower surface of the mirror box 200, and is disposed at a position that does not protrude into the mirror box 200 when the power is turned on. The mirror unit 112 collides with the shock absorbing member 208 and is held at the up position during photographing.

  The operation when the main power switch 107 is operated by the photographer and the power is turned off will be described in detail with reference to FIG. When the operation detection circuit 12 detects that the main power switch 107 has been operated to the power OFF position, the camera microcomputer 10 controls the camera in a state where the power can be turned OFF by a predetermined sequence. The operation of the light shielding member driving unit 500 performed at this time will be described in detail. Except for the operation of the light shielding member drive unit 500, the camera power supply may be turned off by a known sequence.

  FIG. 11 is a side view showing the mirror unit 112 and the light shielding plate driving unit 500 showing the operation when the power of the camera is turned off by the main power switch 107.

  FIG. 11A is a side view showing the mirror unit 112 and the light shielding plate driving unit 500 in a photographing standby state. The light shielding plate driving unit 500 includes a light shielding plate driving motor 502, connecting gears 503 and 504, a light shielding plate driving rotating member 501, a holding frame (not shown), and the like. The light shielding plate driving unit 500 is disposed on the lower surface side of the mirror box 200, and is disposed in a space where the conventional phase difference AF unit is disposed.

  In the present embodiment, the above-described configuration is used. However, the present invention is not limited to this, and any configuration that can drive the light shielding plate is applicable.

  FIG. 11B is a side view showing that the light shielding plate driving rotation member 501 starts to come into contact with the light shielding plate 205 after the photographer performs the power OFF operation.

  FIG. 11C is a side view showing a state where the light shielding plate 205 is driven to a position where the light shielding plate driving rotating member 501 covers the semi-transmissive mirror holding frame opening 204-f of the semi-transmissive mirror holding frame 204.

  When the photographer operates the main power switch 107 and the operation detection circuit 12 detects that the main power switch 107 is operated to the power OFF position, the camera microcomputer 10 causes the motor control circuit 14 to switch the light shielding plate drive motor 502. The light shielding plate driving rotation member 501 is driven to rotate about the rotation shaft 501-a by connecting the connection gears 503 and 504. The rotation shaft 501-a is also provided with a gear, and a driving force is transmitted from the connection gear 504.

  The light shielding plate driving rotation member 501 is driven to rotate in a direction in which a contact portion provided on the photographer side approaches the semi-transparent mirror holding frame 204, with a rotation shaft 501-a provided on the subject side as a rotation center. The light shielding plate driving rotation member 501 starts to contact the light shielding plate 205 (the state shown in FIG. 11B), and further, the light shielding plate 205 is driven to a position covering the transflective mirror holding frame opening 204-f. It is held (state shown in FIG. 11C).

  When the light shielding plate 205 is held in a state of being close (closed) to the semitransparent mirror holding frame 204, the light shielding plate 205 covers the opening 204-f of the semitransparent mirror holding frame 204. It is possible to prevent light from entering an SH blade (not shown) or the image sensor 302.

  Next, the operation when the photographer operates the main power switch 107 and turns on the power will be described. In the power-off state, the mirror unit 112 is held at the mirror down position, and the light shielding plate 205 is in contact with the light shielding plate driving rotation member 501 and is close (closed) to the semi-transmissive mirror holding frame 204. (The state shown in FIG. 11C).

  When the photographer operates the main power switch 107 and the operation detection circuit 12 detects that the main power switch 107 is operated to the power ON position, the camera microcomputer 10 drives the light shielding plate driving motor 502 by the motor control circuit 14. Then, the light shielding plate driving rotating member 501 is driven to rotate in a direction away from the semi-transmissive mirror holding frame 204. As the light shielding plate drive rotating member 501 moves away from the semi-transparent mirror holding frame 204, the light shielding plate 205 moves away (opens) from the semi-transmissive mirror holding frame 204 by the biasing force of the biasing spring 206.

  Thereafter, the mirror unit 112 and the light-shielding plate driving rotating member 501 are arranged in a photographing standby state (the state shown in FIG. 11A).

  The flow when the power is turned on and turned off is only the difference between the light-shielding plate driving method being the straight drive or the rotational drive, and is omitted because it may be the same as in the first embodiment.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

100 camera body, 101 top exterior cover, 102 front exterior cover,
103 flash unit, 104 release button, 105 electronic dial,
106 ISO sensitivity setting button, 107 Main power switch,
108 shooting mode dial, 109 accessory shoe, 110 display device,
111 Rear exterior cover, 112 Mirror unit, 113 Viewfinder unit,
200 mirror box, 201 mirror drive unit,
202 photographing optical system communication unit, 203 transflective mirror,
204 semi-transparent mirror holding frame, 204-a semi-transparent mirror holding frame rotation axis,
204-b transflective mirror holding frame drive shaft, 204-c light shielding plate rotation shaft,
204-d mirror positioning member contact surface, 204-e holding frame contact surface,
204-f transflective mirror holding frame opening, 205 light shielding plate,
205-a antireflection sheet, 205-b antireflection sheet,
205-c light shielding plate contact surface, 205-d pin contact surface, 205-e light shielding plate wall,
206 biasing spring, 207 anti-reflection sheet, 300 up position drive pin,
302 imaging device, 303 mirror positioning unit,
400 light-shielding plate driving unit (first embodiment), 401 light-shielding plate driving rectilinear member,
402 light shielding plate drive motor, 403 coupling gear,
500 light-shielding plate driving unit (second embodiment), 501 light-shielding plate driving rotating member,
501-a light-shielding plate driving rotary member rotating shaft, 502 light-shielding plate driving motor,
503 connection gear, 504 connection gear

Claims (4)

In an electronic imaging apparatus that is rotatably provided with a semi-transmissive mirror 203 that separates subject light into an imaging element and the other,
A semi-transmissive mirror holding frame 204 that holds the semi-transmissive mirror 203 and has an opening 204-f through which subject light passes;
A mirror box 200 that rotatably holds the transflective mirror holding frame 204;
A light shielding member 205 having a center of rotation near the subject-side tip of the semi-transparent mirror holding frame 204;
A biasing spring 206 that biases the light shielding member 205 and the semi-transparent mirror holding frame 204 in a direction to open by rotation;
A projection 300 is provided on the inner wall of the mirror box above the photographic optical axis and protrudes to a position where it can come into contact with the light shielding plate 205. The semi-transparent mirror holding frame 204 and the light shielding plate 205 are used for photographing light flux when waiting for photographing. It is configured to be able to rotate between a first position (mirror down position) arranged inside and a second position (mirror up position) retracted from the photographing light flux at the time of photographing,
At the mirror up position, the light shielding plate 205 is held in contact with the first convex portion 300 provided on the inner wall of the mirror box in the region 205-d closer to the subject than the center of rotation.
At the mirror-down position when the power is turned on, the semi-transparent mirror holding frame 204 and the light shielding plate 205 are held at positions where they are in contact with each other in predetermined areas 204-e and 205-c by the urging force of the urging spring 206.
When the power is turned off, the light shielding plate 205 is driven to a position where the light shielding plate driving member 401 or 501 comes into contact with the light shielding plate 205 in a state where the mirror unit 112 is disposed at the mirror down position, so that the light shielding plate 205 is opened in the semi-transparent mirror holding frame 204. The electronic imaging apparatus is held in a state of covering the portion 204-f. The light-shielding plate driving member 401 is disposed at a position escaped from the inner surface of the mirror box 200 when the power is turned on, and contacts the light-shielding plate 205 while approaching the photographing optical axis by a linear locus when the power is turned off. The electronic imaging device described. When the power is turned on, the light shielding plate driving member 401 is disposed at a position escaped from the inner surface of the mirror box 200. When the power is turned off, the light shielding plate 205 is rotated about the rotation shaft 501-a disposed on the subject side. The electronic imaging apparatus according to claim 1, wherein the electronic imaging apparatus is in contact with the electronic imaging apparatus. The electronic imaging apparatus according to claim 1, wherein a light shielding plate driving motor 402 or 502 for driving the light shielding plate driving member 401 or 501 is disposed on a lower surface of the mirror box 200.