JP2017142288A - Imaging device and method for controlling the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology that can obtain an accurate final amount of strobe light emission in an imaging device including a mirror unit without increasing the amount of power necessary for preliminary strobe light emission.SOLUTION: When a release switch (SW2) 7b is turned on, an imaging device rotates, with a mirror driving unit 101, a sub mirror holder 504 toward a main mirror holder 502 at a mirror lowering position to cause the sub mirror holder 504 to stand by at a position closed with respect to the main mirror holder 502, and causes a strobe unit 601 to perform preliminary light emission in this state to calculate the final amount of light emission of the strobe unit 601 on the basis of the photometric value of a subject luminous flux guided by a finder optical system 4 measured by a photometric sensor 23. The imaging device rotates, with the mirror driving unit 101, the sub mirror holder 504 in a mirror raising direction from the closed position to be moved to a mirror raising position together with the main mirror holder 502, and causes the strobe unit 601 to perform final light emission in this state at the calculated final amount of light emission.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an imaging apparatus such as a single-lens reflex camera capable of flash photography, and more particularly to a technique for controlling the operation of a quick return mirror during flash photography.

  An imaging apparatus such as a single-lens reflex camera is equipped with a mirror unit having a main mirror holder that holds a main mirror and a sub mirror holder that holds the sub mirror and is supported rotatably with respect to the main mirror holder. . During the viewfinder observation, the mirror unit enters the imaging optical path and is disposed at the mirror down position, and at the time of imaging, is retracted from the imaging optical path and is disposed at the mirror up position.

  At the mirror down position of the mirror unit, the subject light flux that has passed through the photographing optical system is reflected by the main mirror and guided to the finder optical system, and the subject light flux that has passed through the main mirror is reflected by the sub mirror and guided to the focus detection unit. . The subject light beam guided to the finder optical system is separated into two light beams by the pentaprism, one light beam is guided to the eyepiece lens, and the other light beam is guided to the photometric sensor for photometry. At the mirror-up position of the mirror unit, the subject light flux that has passed through the photographing optical system is guided to the imaging surface of the image sensor and subjected to photoelectric conversion.

  Also, when performing flash photography, when the main mirror is in a predetermined position, preliminary light emission is performed, and the main light emission quantity at the time of shooting is determined by determining the light emission amount of the main light emission based on the photometric result of the photometric sensor during preliminary light emission A technique for performing the above has been proposed (Patent Document 1).

JP 2007-322895 A

  By the way, many of the main mirrors of the mirror unit are composed of half mirrors because it is necessary to guide the light beam to the focus detection unit. For this reason, the light amount of the light beam reflected by the finder optical system is reduced by the amount of the light beam that has reached the main mirror at the mirror down position and transmitted to the sub mirror side, and the light amount guided to the photometric sensor is also reduced. Therefore, in Patent Document 1, in order to obtain an accurate strobe main light emission amount in a shooting scene that is dark and has a long subject distance, it is necessary to increase the strobe preliminary light emission amount, resulting in an increase in power consumption.

  Therefore, an object of the present invention is to provide a technique capable of obtaining an accurate main flash emission amount without increasing the amount of electric power required for the preliminary flash emission in an imaging apparatus including a mirror unit.

  In order to achieve the above object, the image pickup apparatus of the present invention can move between a first position holding the first mirror and being in the photographing optical path and a second position retracting from the photographing optical path. A first mirror holder and a first mirror holder rotatably attached to the first mirror holder, holding the second mirror and retreating from the photographing optical path and a third position located in the photographing optical path A second mirror holder that is movable between a fourth position and the second mirror holder while the first mirror holder is located at the first position during viewfinder observation. Is located at the third position, the subject light flux that has passed through the photographing optical system of the lens unit is reflected by the first mirror and guided to the finder optical system, and the subject light flux that has passed through the first mirror is Reflected by the second mirror The first mirror holder is moved to the second position and the second mirror holder is moved to the fourth position when passing through the photographing optical system. A mirror unit that guides a subject light beam to the image sensor; and the second mirror holder is driven between the third position and the fourth position, and the second mirror holder is moved from the third position to the Mirror driving means for moving the first mirror holder from the first position to the second position by moving to the fourth position, and photometry for measuring the subject light flux guided to the finder optical system And means for instructing focus detection by the focus detection means by a first operation of the operation member, and instructing imaging by the image sensor by a second operation of the operation member, and irradiating light toward the subject Do A light emission driving means for driving the light section; and the first mirror located at the first position by the mirror driving means when an instruction for imaging by the imaging device based on the second operation of the instruction means is given. The second mirror holder in the third position is rotated toward the holder, and the second mirror holder is made to stand by at a position where the second mirror holder is closed with respect to the first mirror holder. Based on the photometric value of the subject light beam guided to the finder optical system by preliminarily emitting the light emitting unit by the driving unit, the main light emission amount of the light emitting unit is calculated, and the mirror driving unit calculates the first light emission amount. The second mirror holder is rotated from the closed position toward the fourth position to move the first mirror holder from the first position to the second position, and the calculated main light emission Control means for causing the light emitting unit to emit main light by the light emission driving means.

  According to the present invention, an accurate strobe main light emission amount can be obtained without increasing the amount of power required for strobe preliminary light emission in an imaging apparatus including a mirror unit.

1 is a block diagram showing a system configuration of a digital single-lens reflex camera which is a first embodiment of an imaging apparatus of the present invention. It is a schematic sectional side view of a digital single-lens reflex camera. It is a disassembled perspective view of a mirror unit. It is the schematic explaining operation | movement of a mirror unit. It is a flowchart figure explaining operation | movement of a digital single-lens reflex camera. It is a flowchart figure explaining operation | movement of the digital single-lens reflex camera which is 2nd Embodiment of the imaging device of this invention. It is a flowchart figure explaining operation | movement of the digital single-lens reflex camera which is 3rd Embodiment of the imaging device of this invention. It is a flowchart explaining a camera operation when the preliminary light emission mode 2 is selected.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a block diagram showing a system configuration of a digital single-lens reflex camera which is a first embodiment of an imaging apparatus of the present invention.

  As shown in FIG. 1, the digital single-lens reflex camera (hereinafter referred to as a camera) according to the present embodiment has an interchangeable lens unit 210 detachably attached to the camera body 1 via a mount contact portion 21.

  First, the camera body 1 will be described. In FIG. 1, a microcomputer 100 (hereinafter referred to as MPU 100) controls the entire camera. Connected to the MPU 100 are a mirror drive unit 101, a focus detection circuit 102, a shutter drive circuit 103, a strobe drive circuit 600, a video signal processing circuit 104, a switch sense circuit 105, and a photometry circuit 24 of the finder optical system 4. The MPU 100 is also connected with a display drive circuit 107, a battery check circuit 108, and a power supply circuit 110, and these circuits are driven under the control of the MPU 100.

  The mirror unit 500 includes a main mirror 501 and a sub mirror 503 configured by half mirrors. The mirror unit 500 moves to a position (mirror up position) retracted from the photographing optical path during photographing and enters a photographing optical path during viewfinder observation ( Move to the mirror down position.

  The main mirror 501 reflects the subject luminous flux that has passed through the photographing lens 200 constituting the photographing optical system of the lens unit 210 at the mirror-down position of the mirror unit 500 and guides it to the finder optical system 4 and transmits a part of the subject luminous flux. To the sub mirror 503. The sub mirror 503 reflects the subject luminous flux that has passed through the main mirror 501 and guides it to the focus detection unit 31. In addition, at the mirror-up position of the mirror unit 500, the subject light flux that has passed through the photographing lens 200 is guided to the imaging surface of the image sensor 33 and subjected to photoelectric conversion.

  The subject light flux guided to the finder optical system 4 is guided to the pentaprism 22. The pentaprism 22 is an optical member that converts the photographic light beam reflected by the main mirror 501 into an erect image and reflects it. The user can observe the subject image from the eyepiece 18 through the pentaprism 22. The pentaprism 22 also guides part of the subject light flux to the photometric sensor 23.

  The photometric sensor 23 detects a part of the photographic light beam with a light receiving element divided corresponding to each area on the observation surface. The photometric circuit 24 converts the luminance signal of each area on the observation surface based on the output value of the photometric sensor 23 and outputs it to the MPU 100. The MPU 100 calculates an exposure value based on the luminance signal output from the photometry circuit 24. In addition, during main flash emission, the MPU 100 calculates the amount of light necessary for main flash emission based on the luminance signal output from the photometry circuit 24 during preliminary flash emission.

  The strobe drive circuit 600 includes a capacitor for causing the strobe unit 601 to emit light, and controls the strobe unit 601 so that light is emitted with the main flash emission amount calculated by the MPU 100. The strobe unit 601 includes an Xe tube, a reflector, a Fresnel panel, and the like. The strobe unit 601 obtains power from a capacitor of the strobe driving circuit 600 and emits light to irradiate the subject with strobe light. Here, the strobe unit 601 corresponds to an example of a light emitting unit of the present invention, and the strobe driving circuit 600 corresponds to an example of a light emission driving unit of the present invention. The light source of the strobe unit 601 is not limited to the Xe tube, and may be a light source capable of continuous light emission such as an LED.

  The mirror drive unit 101 includes a motor, a gear train, and the like that rotate the mirror unit 500 between a mirror up position (see FIG. 2C) and a mirror down position (see FIG. 2A).

  The focus detection unit 31 includes a field sensor, a reflection mirror, a secondary imaging lens, a diaphragm, a line sensor including a plurality of CCD sensors, and the like disposed in the vicinity of an imaging surface (not shown). The signal output from the focus detection unit 31 is supplied to the focus detection circuit 102, converted into an image signal of the subject, and then transmitted to the MPU 100. The MPU 100 performs a focus detection calculation by a phase difference detection method based on the supplied image signal of the subject.

  Then, the MPU 100 calculates the defocus amount and the defocus direction, and drives the focus lens of the photographing lens 200 to the in-focus position via the lens control circuit 201 and the AF drive circuit 202 of the lens unit 210 based on the calculation result. .

  The mechanical focal plane shutter 106 blocks the subject light beam guided to the image sensor 33 during viewfinder observation, and also at the time of imaging due to the time difference between the front blade group and the rear blade group (not shown) depending on the release signal. Operate to obtain the desired exposure time. The focal plane shutter 106 is controlled by the shutter drive circuit 103 according to a command from the MPU 100.

  The image sensor unit 114 includes an image sensor 33, a stacked piezoelectric element 112, an optical low-pass filter 113, and the like. As the image sensor 33, a CCD sensor, a CMOS sensor, a CID sensor, or the like is used. A clamp / CDS (correlated double sampling) circuit 34 performs basic analog processing before A / D conversion and can also change the clamp level. The AGC (automatic gain adjustment device) 35 performs basic analog processing before A / D conversion and can change the AGC basic level. The A / D converter 36 converts the analog signal output from the image sensor 33 into a digital signal.

  The infrared cut filter 32 is formed in a substantially rectangular shape, and cuts unnecessary infrared light of the subject luminous flux incident on the image sensor 33. The surface of the infrared cut filter 32 is covered with a conductive material in order to prevent foreign matter from adhering. The optical low-pass filter 113 is configured by laminating and laminating a plurality of birefringent plates and phase plates made of quartz, and further laminating an infrared cut filter. The stacked piezoelectric element 112 is vibrated by the piezoelectric element driving circuit 111 that has received a command from the MPU 100, and the vibration is transmitted to the optical low-pass filter 113.

  The video signal processing circuit 104 performs general image processing by hardware such as gamma / knee processing, filter processing, and monitor display information synthesis processing on digital image data. The color image data for monitor display output from the video signal processing circuit 104 is displayed on the monitor 19 via the monitor drive circuit 115.

  Further, the video signal processing circuit 104 can also store image data in the buffer memory 37 through the memory controller 38 in accordance with an instruction from the MPU 100. Further, the video signal processing circuit 104 has a function of performing image data compression processing such as JPEG. The video signal processing circuit 104 can also store image data once in the buffer memory 37 and sequentially read out unprocessed image data through the memory controller 38 when continuous shooting such as continuous shooting is performed. is there. Accordingly, the video signal processing circuit 104 can sequentially perform image processing and compression processing regardless of the speed of the image data output from the A / D converter 36.

  The memory controller 38 has a function of storing image data output from the external interface 40 such as a USB output connector in the memory 39 and a function of outputting image data stored in the memory 39 to the external interface 40. The memory 39 may be exemplified by a flash memory that can be attached to and detached from the camera body 1.

  The release switch (SW1) 7a is turned on by a first operation (for example, half-pressing operation or the like) of a release button (not shown), and transmits a shooting preparation start instruction signal to the MPU 100 via the switch sense circuit 105. The release switch (SW2) 7b is turned on by a second operation of the release button (for example, full-pressing operation) and transmits a shooting start instruction signal to the MPU 100 via the switch sense circuit 105. The release button corresponds to an example of the operation member of the present invention.

  The switch sense circuit 105 is connected to a main operation dial 8, a sub operation dial 20, a shooting mode setting dial 14, a focus mode switching SW 45, a main SW 43, and an AF mode switching SW 44. The focus mode switching SW 45 is a switch for selecting a focus mode, and can select either AF (auto focus) / MF (manual focus). The AF mode switching SW 44 is a switch for selecting an AF mode, and can select one of the one-shot AF / AI servo AF / AI focus AF.

  The display drive circuit 107 drives the external display device 9 and the in-finder display device 41 in accordance with instructions from the MPU 100. The battery check circuit 108 performs a battery check for a predetermined time in accordance with an instruction from the MPU 100 and sends the check result to the MPU 100. The power supply unit 42 supplies necessary power to each element of the camera in accordance with an instruction from the MPU 100 via the power supply circuit 110.

  Next, the lens unit 210 will be described. The lens unit 210 includes a lens control circuit 201, and the lens control circuit 201 communicates with the MPU 100 of the camera body 1 via the mount contact portion 21. The mount contact portion 21 also has a function of transmitting a signal to the MPU 100 when the lens unit 210 is connected to the camera body 1.

  Thereby, the lens control circuit 201 communicates with the MPU 100 and drives the photographing lens 200 and the diaphragm 204 via the AF driving circuit 202 and the diaphragm driving circuit 203. In FIG. 1, for convenience of explanation, one photographic lens 200 is illustrated, but actually, the photographic lens 200 is configured by a plurality of lens groups.

  The AF drive circuit 202 is configured by, for example, a stepping motor or the like, and performs a focusing operation by changing the position of the focus lens of the photographing lens 200 in the optical axis direction under the control of the lens control circuit 201. The aperture driving circuit 203 is configured by, for example, auto iris, and is configured to obtain an optical aperture value by changing the aperture diameter of the aperture 204 under the control of the lens control circuit 201.

  2A is a schematic side sectional view of the camera when the mirror unit 500 is in the mirror down position, and FIG. 2B is a standby position in which the sub mirror 503 is closed and overlapped with the main mirror 501 in the mirror down position. It is a schematic sectional side view of a camera at a certain time. FIG. 2C is a schematic sectional side view of the camera when the mirror unit 500 is in the mirror up position.

  As shown in FIG. 2, the main mirror 501 of the mirror unit 500 is held by the main mirror holder 502, and the sub mirror 503 is held by the sub mirror holder 504. The main mirror holder 502 is supported so as to be rotatable with respect to the mirror box 400, and the sub mirror holder 504 is supported so as to be rotatable with respect to the main mirror holder 502. The mirror unit 500 is driven by the mirror driving unit 101 and rotates between the mirror down position shown in FIG. 2A and the mirror up position shown in FIG.

  In the mirror-down position shown in FIG. 2A, the mirror unit 500 enters the photographing optical path, and the subject light flux that has passed through the photographing lens 200 is reflected by the main mirror 501 and partially transmitted through the main mirror 501. And reflected by the sub mirror 503. The subject light beam reflected by the main mirror 501 is guided to the finder optical system 4 and separated into two light beams by the pentaprism 22. One light beam is guided to the eyepiece 18, and the other light beam is guided to the photometric sensor 23. Then it is metered. The subject light flux reflected by the sub mirror 503 is guided to the focus detection unit 31.

  Therefore, in the state shown in FIG. 2A, the subject light flux that has passed through the photographing lens 200 is not guided to the image sensor 33. At this time, the light amount of the subject image that can be confirmed by the photographer via the eyepiece lens 18 of the finder optical system 4 and the light amount of the light beam measured by the photometric sensor 23 are reduced by the light amount guided to the focus detection unit 31. It becomes.

  In the state shown in FIG. 2B, the sub mirror 503 is closed and overlapped with the main mirror 501 at the mirror down position. For this reason, the subject luminous flux that has reached the main mirror 501 is all reflected without being guided to the focus detection unit 31, and is guided to the pentaprism 22 of the finder optical system 4. Therefore, the amount of light of the finder image that can be confirmed by the photographer via the eyepiece 18 is increased, and the visibility of the subject is improved. In addition, since the amount of light flux guided to the photometric sensor 23 increases, it is possible to improve the photometric accuracy in a low luminance environment.

  In the mirror-up position shown in FIG. 2C, the mirror unit 500 is retracted from the photographing optical path, and the subject light flux that has passed through the photographing lens 200 is not guided to the finder optical system 4 and the focus detection unit 31, and thus the image sensor. The light is guided to 33 and imaged and subjected to photoelectric conversion.

  FIG. 3 is an exploded perspective view of the mirror unit 500. As shown in FIG. 3, the main mirror holder 502 is provided with rotating shafts 502 a and 502 b, and the rotating shaft 502 a is rotatably supported with respect to the mirror box 400. Further, the main mirror holder 502 is formed with an opening 502c, and the subject luminous flux transmitted through the main mirror 501 reaches the sub mirror 503 through the opening 502c.

  A hole 504 a is formed in the sub mirror holder 504, and the hole 504 a is supported so as to be rotatable with respect to the rotation shaft 502 b of the main mirror holder 502. The sub mirror holder 504 is formed with a drive shaft 504c. When power is transmitted from the mirror drive unit 101 to the drive shaft 504c, the sub mirror holder 504 rotates.

  When the mirror unit 500 is in the mirror-down state, the sub mirror holder 504 rotates toward the main mirror holder 502, whereby the sub mirror holder 504 comes into contact with the main mirror holder 502 and the main mirror holder 502 is pushed up. Thereby, the mirror up operation is performed. On the other hand, when the mirror unit 500 is in the mirror up state, the main mirror holder 502 is pulled down to the sub mirror holder 504, whereby the mirror down operation is performed.

  Here, the main mirror 501 is the first mirror of the present invention, the sub mirror 503 is the second mirror of the present invention, the main mirror holder 502 is the first mirror holder of the present invention, and the sub mirror holder 504 is the present invention. This corresponds to an example of the second mirror holder. The mirror down position of the main mirror holder 502 corresponds to an example of the first position of the present invention, and the mirror up position of the main mirror holder 502 corresponds to an example of the second position of the present invention. Further, the mirror down position of the sub mirror holder 504 corresponds to an example of the third position of the present invention, and the mirror up position of the sub mirror holder 504 corresponds to an example of the fourth position of the present invention.

  Next, the operation of the mirror unit 500 will be described with reference to FIG. 4A and 4F are diagrams when the mirror unit 500 is in the mirror-down position, and FIGS. 4C and 4D are diagrams when the mirror unit 500 is in the mirror-up position. is there. FIGS. 4B and 4E are views when the sub mirror 503 is closed and overlapped with the main mirror 501 in the mirror down position.

  In the mirror down state of the mirror unit 500 shown in FIG. 4A, the sub mirror holder 504 is in contact with a positioning shaft 508 attached to the mirror box 400 while being biased by a spring (not shown). The main mirror holder 502 is in a mirror-down state by abutting against a positioning shaft 507 attached to the mirror box 400 while being biased by a spring (not shown).

  In this state, when power is transmitted to the drive shaft 504c of the sub mirror holder 504 by the mirror drive unit 101 in the direction of arrow F in the figure, the sub mirror holder 504 rotates toward the main mirror holder 502 about the rotation shaft 502b. Move. Then, the sub mirror holder 504 rotates to the position where it closes and overlaps with the main mirror holder 502, that is, the position shown in FIG.

  At the position shown in FIG. 4B, the sub mirror holder 504 abuts on the main mirror holder 502, and the urging force at this time may be a force that does not cause the main mirror holder 502 to move away from the positioning shaft 507. In this state, when power is transmitted to the drive shaft 504c of the sub mirror holder 504 by the mirror drive unit 101 in the direction of arrow F, the sub mirror holder 504 rotates and the main mirror holder 502 is pushed up. Then, the sub mirror holder 504 rotates together with the main mirror holder 502 to the mirror up position shown in FIG.

  In the mirror-up state shown in FIG. 4C, the main mirror holder 502 is pressed against the elastic stopper 505 attached to the mirror box 400 by the sub-mirror holder 504, and the mirror unit 500 keeps the position retracted from the photographing optical path. Yes. In the mirror up state shown in FIG. 4C, as shown in FIG. 4D, the mirror drive unit 101 transmits the power to the drive shaft 504c of the sub mirror holder 504 in the direction F shown in the figure to mirror the sub mirror holder 504. Down operation is started.

  At this time, the main mirror holder 502 is pushed down simultaneously with the sub mirror holder 504 by a spring or cam (not shown) connected to the sub mirror holder 504. Then, the main mirror holder 502 comes into contact with the positioning shaft 507, and the sub mirror holder 504 is closed and overlapped with the main mirror holder 502 as shown in FIG.

  In the state shown in FIG. 4E, the mirror drive unit 101 transmits the power in the direction of arrow F to the drive shaft 504c of the sub mirror holder 504, so that the sub mirror holder 504 rotates in the down direction and contacts the positioning shaft 508. Touch. Thereby, the sub mirror holder 504 returns to the mirror down position of the mirror unit 500 shown in FIG.

  Next, the operation of the camera will be described with reference to FIG. The processing shown in FIG. 5 is executed by the MPU 100 or the like by developing a program stored in a storage unit such as a ROM (not shown) in a RAM (not shown).

  In FIG. 5, when the release switch SW1 (7a) is turned on in step S501, the MPU 100 performs a photometric operation by the photometric sensor 23 and a focus detection operation by the focus detection unit 31 in step S502, and proceeds to step S503. In step S503, the MPU 100 determines whether or not the strobe light emission is necessary based on the photometry result in step S502. If it is determined that the strobe light is necessary, the process proceeds to step S504. Otherwise, the process proceeds to step S516.

  In step S504, when the release switch (SW2) 7b is turned on, the MPU 100 proceeds to step S505. In step S505, the MPU 100 operates the mirror driving unit 101, causes the mirror driving unit 101 to rotate the sub mirror holder 504 toward the main mirror holder 502 in the mirror down position, and proceeds to step S506.

  In step S506, the MPU 100 determines whether the sub mirror holder 504 is closed and overlapped with the main mirror holder 502 in the mirror down position (standby position), and if so, the process proceeds to step S507. In step S507, the MPU 100 causes the strobe drive circuit 600 to perform preliminary light emission of the strobe unit 601 and proceeds to step S508. The light beam reflected by the subject and passed through the photographing lens 200 by the preliminary light emission here is reflected by the main mirror 501 and the sub mirror 503 of the mirror unit 500 at the standby position, and is reflected to the photometric sensor 23 via the finder optical system 4. Led.

  In step S508, the MPU 100 performs photometry with the photometry sensor 23 during preliminary light emission of the strobe unit 601, calculates the amount of light necessary for the main flash emission based on the luminance signal output from the photometry circuit 24, and ends the photometry operation. Then, the process proceeds to step S509.

  In step S509, the MPU 100 causes the mirror drive unit 101 to rotate the sub mirror holder 504 from the standby position in the mirror up direction by the mirror driving unit 101, and proceeds to step S510. In step S510, the MPU 100 determines whether the mirror unit 500 has reached the mirror-up position (FIG. 4C), and if it has reached, proceeds to step S511.

  In step S511, the MPU 100 controls the focal plane shutter 106 to run the front curtain to start exposure to the image sensor 33, and proceeds to step S512. In step S512, the MPU 100 causes the strobe unit 601 to perform main light emission with the light emission amount necessary for the main light emission calculated in step S508 by the strobe driving circuit 600, and proceeds to step S513. In step S513, the MPU 100 controls the focal plane shutter 106 to run the trailing curtain to end the exposure to the image sensor 33, and proceeds to step S514.

  In step S514, the MPU 100 causes the mirror drive unit 101 to rotate the sub mirror holder 504 together with the main mirror holder 502 in the mirror down direction, and proceeds to step S515. In step S515, the MPU 100 determines whether or not the mirror unit 500 has reached the mirror-down position (FIG. 4F). If it has reached, the process is terminated and the mirror unit 500 is lowered until the next shooting operation. Wait in position.

  On the other hand, the processes in steps S516 to S522 after the determination that the strobe emission is unnecessary in step S503 are the same as those in steps S504, S505, S510, S511, and S513 to S515, and thus the description thereof is omitted. .

  As described above, in this embodiment, after focusing, the sub mirror holder 504 in the mirror down position is rotated to a standby position near the position of the main mirror holder 502 to wait, and strobe preliminary light emission is performed in this state. Yes. For this reason, the light metering sensor 23 is reflected by both the main mirror 501 and the sub mirror 503, and the light flux is guided to increase the amount of light.

  As a result, it is possible to efficiently measure the light amount with less strobe preliminary light emission amount than in the past to obtain the correct strobe light emission amount, and it is possible to select a small size capacitor with a small capacity for the strobe drive circuit 600. Become. In addition, since the power used for flash pre-flash can be reduced compared to the conventional flash, the time to charge the power used for flash pre-flash and main flash becomes faster, and the continuous shooting speed for continuous shooting that requires flash fire is increased. improves.

  Further, in the present embodiment, it is possible to shorten the time for the sub mirror holder 504 to move to the mirror up position after preliminary light emission. Therefore, the release time lag can be shortened, and when the subject is a person, an imaging operation can be performed before the eyes are closed in response to the preliminary light emission, thereby reducing the number of failed photos.

(Second Embodiment)
Next, a camera which is a second embodiment of the imaging apparatus of the present invention will be described with reference to FIG. Note that portions that overlap or correspond to the first embodiment will be described with reference to the drawings and symbols.

  FIG. 6 is a flowchart for explaining the operation of the camera. The processing shown in FIG. 6 is executed by the MPU 100 or the like by developing a program stored in a storage unit such as a ROM (not shown) in a RAM (not shown). In the present embodiment, the first embodiment is different from the first embodiment except that step S605 in FIG. 6 is added and the process in step S609 is different. It is the same. That is, steps S601 to S604, steps S606 to S608, and steps S610 to S623 in FIG. 6 are the same as steps S501 to S504, steps S505 to S507, and steps S509 to S522 in FIG. To do.

  In FIG. 6, in step S605, when the mirror unit 500 is in the mirror down position, the MPU 100 performs photometry with the photometry sensor 23 and records the photometric value of the subject in a RAM (not shown) or the like via the photometry circuit 24. The process proceeds to step S606.

  In step S609, the MPU 100 compares the photometric value obtained in step S605 with the photometric value obtained in the preliminary flash emission in step S608, and calculates the amount of light necessary for the main flash emission based on the difference value. Then, the photometry operation is finished, and the process proceeds to step S610.

  In this embodiment, the flash unit is based on the difference between the photometric value of the photometric sensor 23 when the mirror unit 500 is in the mirror down position and the photometric value of the photometric sensor 23 when preliminary light emission is performed at the standby position of the sub mirror 503. The amount of light necessary for light emission is calculated. As a result, it is possible to eliminate the influence of reflection by natural light and obtain a more accurate amount of strobe light emission without greatly changing the time from when the release switch (SW2) 7b is turned on until the start of exposure (release time lag). It becomes possible. Other configurations and operational effects are the same as those in the first embodiment.

(Third embodiment)
Next, a camera that is a third embodiment of the imaging apparatus of the present invention will be described with reference to FIGS. Note that portions that overlap or correspond to the first and second embodiments will be described with reference to the drawings and symbols.

  FIG. 7 is a flowchart for explaining the operation of the camera. The process shown in FIG. 7 is executed by the MPU 100 or the like by developing a program stored in a storage unit such as a ROM (not shown) in a RAM (not shown). In the present embodiment, the second embodiment is different from the second embodiment except that step S705 of FIG. 7 is added and the processing of FIG. 8 is added accordingly. It is the same as the form. That is, steps S701 to S704 and steps S706 to S724 in FIG. 7 are the same as steps S601 to S604 and steps S605 to S623 in FIG.

  In FIG. 7, in step S <b> 705, the MPU 100 determines whether the preliminary light emission mode 1 is selected from the preliminary light emission mode 1 and the preliminary light emission mode 2 by a user operation or automatically. If the preliminary light emission mode 1 is selected, the MPU 100 proceeds to step S706. If the preliminary light emission mode 1 is not selected, the MPU 100 assumes that the preliminary light emission mode 2 has been selected, and proceeds to step S801 in FIG. move on.

  FIG. 8 is a flowchart for explaining the camera operation when the preliminary light emission mode 2 is selected. The processes in steps S802 to S811 after the preliminary light emission mode 2 is started in step S801 are the same as those in steps S706, S707, S709, S710, and S712 to S717, and thus the description thereof is omitted. .

  Here, the preliminary light emission mode 1 is a mode in which strobe preliminary light emission is performed in a state where the sub mirror holder 504 of the mirror unit 500 is in the standby position (FIG. 2B). The preliminary light emission mode 2 is a mode in which strobe preliminary light emission is performed in a state where the mirror unit 500 is in the mirror down position (FIG. 2A).

  When the preliminary light emission mode 1 is selected by a user operation, for example, it is selected by a selection switch (not shown) provided in the camera. When the camera automatically selects the preliminary flash mode 1, for example, when it is determined that the subject is far from the distance measuring operation in step S702, the preliminary flash mode 1 is selected, and when it is determined that the subject is close, Select flash mode 2.

  This is because, assuming that the preliminary light emission amount of the strobe unit 601 is always constant, the reflected light beam obtained in the preliminary light emission mode 1 is larger than the amount of reflected light beam obtained in the preliminary light emission mode 2.

  For this reason, if the preliminary flash emission is performed in the preliminary flash mode 1, if the distance to the subject is too close, the reflected light amount obtained by the preliminary flash emission is too large and the photometric sensor 23 may malfunction. This is to prevent this. In the present embodiment, it is possible to obtain a more suitable main light emission amount by selecting the preliminary light emission mode according to the distance to the subject. Other configurations and operational effects are the same as those of the first and second embodiments.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various change is possible within the range which does not deviate from the summary.

1 Camera Body 4 Finder Optical System 23 Photometric Sensor 24 Photometric Circuit 31 Focus Detection Unit 33 Image Sensor 100 MPU
200 photographic lens 500 mirror unit 501 main mirror 502 main mirror holder 503 sub mirror 504 sub mirror holder 600 strobe drive circuit 601 strobe unit

Claims (5)

A first mirror holder capable of moving between a first position holding the first mirror in the imaging optical path and a second position retracting from the imaging optical path; and the first mirror holder A second, which is pivotably attached, is capable of moving between a third position that holds the second mirror and is located in the photographing optical path and a fourth position that is retracted from the photographing optical path. When the viewfinder is observed, the first mirror holder is located at the first position and the second mirror holder is located at the third position. The subject light flux that has passed through the optical system is reflected by the first mirror and guided to the finder optical system, and the subject light flux that has passed through the first mirror is reflected by the second mirror and guided to the focus detection means, The first mirror during shooting Folder with moves to the second position, and said second mirror holder moves to the fourth position, the mirror unit for guiding the subject light flux passing through the photographing optical system to the imaging device,
Driving the second mirror holder between the third position and the fourth position, and moving the second mirror holder from the third position to the fourth position; Mirror driving means for moving the first mirror holder from the first position to the second position;
A photometric means for measuring a subject luminous flux guided to the finder optical system;
Instruction means for instructing focus detection by the focus detection means by a first operation of the operation member, and instructing imaging by the image sensor by a second operation of the operation member;
Light emission driving means for driving a light emitting unit that emits light toward a subject;
When there is an instruction for imaging by the imaging element based on the second operation of the instruction unit, the mirror driving unit moves the third position toward the first mirror holder at the first position. The second mirror holder is rotated to stand by at a position where the second mirror holder is closed with respect to the first mirror holder, and in this state, the light emission drive unit causes the light emitting unit to perform preliminary light emission. Based on the photometric value of the subject luminous flux guided to the finder optical system by the photometric means, the main light emission amount of the light emitting unit is calculated, and the second mirror holder is moved from the closing position by the mirror driving means. The first mirror holder is rotated from the first position to the second position by rotating toward the fourth position, and the light emission driving means uses the calculated light emission amount to move the first mirror holder to the second position. Imaging apparatus characterized by comprising a control means for the emission of light unit.   The control means rotates the second mirror holder from the fourth position to the third position by the mirror driving means after the image pickup by the image pickup element is completed, and thereby the first mirror holder. The imaging apparatus according to claim 1, wherein the imaging apparatus is moved from the second position to the first position.   When there is an instruction for imaging by the imaging element based on the second operation of the instruction unit, the control unit is directed toward the first mirror holder at the first position by the mirror driving unit. Before the second mirror holder at the third position is rotated, the light emitting unit performs preliminary light emission by the light emission driving unit, and at this time, the photometric unit measures the subject luminous flux guided to the finder optical system. And the photometric value by the photometric means of the subject luminous flux guided to the finder optical system when the light emission drive means preliminarily emits light while the second mirror holder is in the closed position The imaging device according to claim 1, wherein a main light emission amount of the light emitting unit is calculated based on a difference between the imaging device and the light emitting unit.   And a selection unit that selects a mode in which the light emitting unit performs preliminary light emission by the light emission driving unit without waiting for the second mirror holder to be in the closed position depending on the distance from the subject obtained from the focus detection unit. The imaging apparatus according to any one of claims 1 to 3, wherein the imaging apparatus is characterized. A first mirror holder capable of moving between a first position holding the first mirror in the imaging optical path and a second position retracting from the imaging optical path; and the first mirror holder A second, which is pivotably attached, is capable of moving between a third position that holds the second mirror and is located in the photographing optical path and a fourth position that is retracted from the photographing optical path. When the viewfinder is observed, the first mirror holder is located at the first position and the second mirror holder is located at the third position. The subject light flux that has passed through the optical system is reflected by the first mirror and guided to the finder optical system, and the subject light flux that has passed through the first mirror is reflected by the second mirror and guided to the focus detection means, The first mirror during shooting Folder with moves to the second position, and said second mirror holder moves to the fourth position, the mirror unit for guiding the subject light flux passing through the photographing optical system to the imaging device,
Driving the second mirror holder between the third position and the fourth position, and moving the second mirror holder from the third position to the fourth position; Mirror driving means for moving the first mirror holder from the first position to the second position;
A photometric means for measuring a subject luminous flux guided to the finder optical system;
Instruction means for instructing focus detection by the focus detection means by a first operation of the operation member, and instructing imaging by the image sensor by a second operation of the operation member;
A method of controlling an imaging apparatus, comprising: a light emission driving unit that drives a light emitting unit that emits light toward a subject,
When there is an instruction for imaging by the imaging element based on the second operation of the instruction unit, the mirror driving unit moves the third position toward the first mirror holder at the first position. Rotating the second mirror holder to wait in a position where the second mirror holder is closed with respect to the first mirror holder;
A step of calculating a main light emission amount of the light emitting unit based on a photometric value obtained by subjecting the luminous flux of the subject guided to the finder optical system by the light emitting driving unit and the subject luminous flux guided by the photometric unit;
A step of moving the first mirror holder from the first position to the second position by rotating the second mirror holder from the closed position toward the fourth position by the mirror driving means; When,
And a step of causing the light emitting unit to perform main light emission by the light emission driving means with the calculated main light emission amount.

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