JP2008011359A - Imaging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging device which protects a half mirror against an impact from the outside in the imaging device where the half mirror is placed. <P>SOLUTION: An imaging device has a half mirror 201 which can move between a reflecting position within an imaging light path and a retraction position for retracting from the imaging light path, a movable mirror driving mechanism 215 driving the half mirror 201, and a vibration detection circuit 216 which detects a vibration of a camera. When detecting an impact of the camera body by the vibration detection circuit 216 (S23), the imaging device controls the movable mirror driving mechanism 215 and retracts the half mirror 201 to the retraction position (S33). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a photographing apparatus having a half mirror that divides a subject luminous flux from a photographing lens.

Some conventional photographing apparatuses employ a half mirror to divide a subject luminous flux into two systems, such as an image recording system such as a film and an image sensor, and a viewfinder optical system. Some recent digital cameras have a through image display function (also referred to as a live view display function or an electronic viewfinder function). This function is to display the output of an image sensor provided for recording of subject image data on a display device such as a liquid crystal monitor for observing the subject image.

As a digital camera having such a through image display function, for example, in Patent Document 1, a movable mirror is configured by a half mirror, and a subject light flux that has passed through a photographing optical system is guided to both an image sensor and a phase difference AF sensor. Such a digital camera has been proposed. According to this configuration, phase difference AF is also possible while displaying a through image. As described above, Patent Document 1 discloses that a subject luminous flux is divided using a half mirror. Japanese Patent Application Laid-Open No. 2004-228688 discloses that although it is not a camera that uses a half mirror, the photographing lens is retracted when the amount of blur is detected and an impact is received in a situation other than camera shake.
Japanese Patent Laid-Open No. 2002-6208 JP-A-9-61869

As in Patent Document 1, when the subject light flux that has passed through the half mirror is received by the image sensor and the subject image is displayed on the display device, the half mirror is made as thin as possible in order to reduce the change in the optical path length. There is a need. In addition, since it is necessary to retract the half mirror from the photographing optical path at the time of photographing, the half mirror must be made movably. Therefore, although it is a very thin half mirror, it is movable and cannot be held firmly, and therefore may be broken by impact or vibration during operation. Further, even if the half mirror is not damaged, if the position is incorrect, the AF characteristics may be affected.

Patent Document 2 discloses a technique for retracting a photographic lens when blurring exceeds a predetermined amount, but this technique is a technique for preventing the lens barrel from directly colliding with the ground and being destroyed. There is no mention that the mechanism is indirectly destroyed by impact.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a photographing apparatus in which a half mirror is arranged to protect the half mirror against an external impact. .

In order to achieve the above object, a photographing apparatus according to a first aspect of the present invention is a half mirror movable between a first position in a photographing optical path and a second position retracted from the photographing optical path, and drives the half mirror. A driving means for detecting, a detecting means for detecting the vibration of the camera, and when the detecting means detects a vibration exceeding a predetermined level, the driving means is controlled to retract the half mirror to the second position. The evacuation means is provided.

In the photographing apparatus according to the second invention, in the first invention, a buffer member with which the half mirror abuts is disposed at the retracted position.
According to a third aspect of the present invention, in the first aspect of the present invention, the half mirror has a light transmission characteristic that transmits a part of the subject luminous flux incident through the photographing lens.

In order to achieve the above object, a photographing apparatus according to a fourth aspect of the present invention is a movable half mirror capable of moving back and forth in a photographing optical path, a driving means for driving the mirror, the camera falling, or an impact applied to the camera. Detecting means for issuing a warning signal, and half mirror retracting means for controlling the driving means to move the half mirror to the retracted position in response to the warning signal.

In order to achieve the above object, a photographing apparatus according to a fifth aspect of the present invention is a movable half mirror capable of moving back and forth in a photographing optical path, a sensor for detecting camera vibration, and a warning signal when the vibration exceeds a predetermined level. A detection means for outputting and a drive means for retracting the half mirror in response to the warning signal are provided.
According to a sixth aspect of the present invention, in the fifth aspect, the driving unit returns the half mirror when the vibration falls within a predetermined level after the half mirror is retracted.
According to a seventh aspect of the present invention, in the fifth aspect of the present invention, a buffer member that reduces the impact of the half mirror is disposed at the retraction position of the half mirror.
Further, an imaging device according to an eighth invention is based on the subject image signal, the imaging device according to the fifth invention, arranged on the imaging optical path, receiving an object light beam and outputting a subject image signal. Through image display means for displaying a moving image of a subject on a display device is provided.
Furthermore, in the eighth aspect of the present invention, the photographing apparatus according to the ninth aspect of the present invention stops the display of the moving image by the through image display means as the half mirror is retracted.
Further, an imaging apparatus according to a tenth aspect of the present invention includes the distance measuring means arranged on the reflection optical path of the half mirror and the imaging means arranged on the transmission optical path of the half mirror in the fifth invention. To do.
Further, an imaging apparatus according to an eleventh aspect of the present invention includes the camera shake correction mechanism according to the fifth aspect of the invention, and drives the camera shake correction mechanism based on the output of the sensor.

According to the present invention, when vibration exceeding a predetermined level is detected by the detection means, the drive means is controlled to include a retracting means for retracting the half mirror to a position retracted from the photographing optical path. It is possible to provide a photographing apparatus that protects the half mirror against an external impact.

Hereinafter, a preferred embodiment using a digital camera to which the present invention is applied will be described with reference to the drawings. FIG. 1 is a block diagram mainly showing an electric system of a digital camera according to an embodiment of the present invention. The lens barrel 10 is detachable from a mount opening (not shown) on the front surface of the camera body 20. The subject luminous flux from the photographing lens including the lenses 101a and 101b in the lens barrel 10 is guided into the camera body 20 through the mount opening. In the present embodiment, the lens barrel 10 and the camera body 20 are configured separately and are electrically connected via the communication contact 300. The attachment / detachment detection switch 259 provided on the camera body 20 can detect the attachment / detachment state.

Inside the lens barrel 10, there are disposed lenses 101a and 101b for focus adjustment and focal length adjustment, and a diaphragm 103 for adjusting the aperture. The lens 101 a and the lens 101 b are driven by an optical system driving mechanism 107, and the diaphragm 103 is connected to be driven by a diaphragm driving mechanism 109. The optical system driving mechanism 107 and the aperture driving mechanism 109 are each connected to a lens CPU 111, and the lens CPU 111 is connected to the camera body 20 via a communication contact 300. The lens CPU 111 controls the lens barrel 10 and controls the optical system driving mechanism 107 to perform focusing and zoom driving, and also controls the aperture driving mechanism 109 to control the aperture value.

In a mirror box in the camera body 20, a movable reflecting mirror 201 (referred to as a movable half mirror for convenience) having a characteristic of transmitting a part of the light beam that has passed through the lenses 101a and 101b is disposed. The movable half mirror 201 is driven by a movable mirror drive mechanism 215 and can rotate along an axis in a direction perpendicular to the paper surface around a rotation shaft 201a. When the movable half mirror 201 is at a position inclined by 45 degrees with respect to the optical paths of the lenses 101a and 101b (the position indicated by the solid line in FIG. 1), a part (for example, 30%) of the subject luminous flux is reflected, and the camera body 20 Is guided to a distance measuring / photometric sensor 217 provided at the bottom. Further, the remainder (for example, 70%) of the subject luminous flux passes through the movable half mirror 201 and is guided in the direction of a CCD (Charge Coupled Devices) 221. When the movable half mirror 201 is substantially parallel to the optical paths of the lenses 101a and 101b and is in a retracted position (a position indicated by a two-dot chain line in FIG. 1) that does not block the subject light beam, the entire subject light beam is guided to the CCD 221.

The structure of the movable mirror 201 will be described later with reference to FIG. In the present embodiment, the center of rotation of the movable half mirror 201 is the lower side in the mirror box, but is not limited to this, and may be the upper side or parallel to the paper surface on either the left or right side. Of course, the center of rotation may be used. The center of rotation is the direction away from the mount opening, that is, the CCD 221 side. In the present embodiment, the reflectance and transmittance of the half mirror are 30% and 70%, respectively, but are not limited to this ratio and can be changed as appropriate.

A distance measuring / photometric sensor 217 is arranged at the bottom of the mirror box in the camera body 20 at a position where the light beam reflected by the movable half mirror 201 is guided. The distance measuring / photometric sensor 217 includes a distance measuring sensor and a photometric sensor. The photometric sensor includes a multi-division photometric element that divides a subject image and performs photometry. The distance measuring sensor is a sensor for measuring a distance by the TTL phase difference method. The arrangement structure of the distance measuring sensor unit 451 including the distance measuring sensor will be described later together with the structure of the movable half mirror 201 with reference to FIG . The output of the distance measurement / photometry sensor 217 is sent to the distance measurement / photometry processing circuit 219. The distance measuring / photometric processing circuit 219 outputs an evaluation photometric value based on the output of the photometric sensor, and measures the focus shift amount of the subject image formed by the lenses 101 and 101b based on the output of the distance measuring sensor. To do. Note that the distance measuring sensor and the photometric sensor may be configured separately or integrally.

Blur sensors 216a, 216b, and 216c for detecting blurring of the camera body 20 are arranged in the body. As shown in FIG. 2, the first blur sensor 216a is a sensor that detects a blur amount in the x-axis direction, the second blur sensor 216b is a sensor that detects a blur amount in the y-axis direction, and a third blur sensor. Reference numeral 216c denotes a sensor that detects a blur amount in the z-axis direction. These shake sensors 216a, 216b, and 216c are composed of gyros, angular velocity sensors, acceleration sensors, shock sensors, and the like, and are connected to the shake detection circuit 216, respectively. The configuration of the shake detection circuit 216 will be described later with reference to FIG.

A focal plane type shutter 203 for controlling the exposure time and shielding the CCD 221 is disposed behind the movable half mirror 201 and on the optical axis of the lenses 101a and 101b and on the photographing optical path. The shutter 203 is driven and controlled by a shutter drive mechanism 213. A dustproof filter 205 is disposed behind the shutter 203. This is because dust generated in the mount opening of the camera body 20 and inside the body adheres to the CCD 221 and the optical element, and the shadow of the dust is reflected in the subject image. It is a filter to prevent it from becoming unsightly. A piezoelectric element 207 is fixed to the entire periphery or a part of the periphery of the dustproof filter 205, and this piezoelectric element 207 is connected to the dustproof filter drive circuit 211 and driven by this circuit. The piezoelectric element 207 is driven by the dust filter driving circuit 211 so that the dust filter 205 vibrates with a predetermined ultrasonic wave, and the dust attached to the front surface of the dust filter 205 is removed using the vibration. In addition, as long as dust attached to the image pickup device itself such as a CCD or an optical element disposed on the front side of the image pickup device can be removed, it is not limited to one using ultrasonic vibration as in the present embodiment. Of course, it may be appropriately replaced with various methods such as a method of blowing off by an air flow using an air pump or a method of collecting and removing dust using static electricity.

An infrared cut filter 209 for cutting an infrared light component from the subject light beam is disposed behind the dust-proof filter 205, and an optical low-pass filter 210 for removing a high frequency component from the subject light beam is disposed behind the dust filter 205. Has been. A CCD 221 serving as an image sensor is disposed behind the optical low-pass filter 210, and the subject image formed by the lenses 101a and 101b is photoelectrically converted into an electrical signal. The dustproof filter 205, the infrared cut filter 209, the optical low-pass filter 210, and the CCD 211 are integrally stored in a sealed package (not shown), and are configured so that dust does not enter the package. In the present embodiment, a CCD is used as an image sensor. However, the present invention is not limited to this, and a CMOS (Complementary Metal Oxide) is used.
Needless to say, a two-dimensional imaging device such as Semiconductor) can be used.

The unit including the CCD 221 is held in a known camera shake correction mechanism that is driven in a direction that cancels the movement of camera shake, and this camera shake correction mechanism is driven and controlled by a camera shake correction mechanism drive circuit 212. Detection of the shake amount for correcting the camera shake is performed by the above-described shake sensor 216a provided in the camera body 20. In addition to the method of mechanically driving the unit including the image sensor as in this embodiment, the image stabilization method acquires image data from which camera shake has been removed by image processing based on the output of the image sensor. Of course, it does not matter if the method is used.

The CCD 221 is connected to the image sensor driving circuit 223 and is driven and controlled by a control signal from the input / output circuit 239. A photoelectric analog signal output from the CCD 221 is amplified and analog-digital converted (AD converted) by the image sensor driving circuit 223. The image sensor driving circuit 223 is connected to an image processing circuit 227 in an ASIC (Application Specific Integrated Circuit) 262, and the image processing circuit 227 performs digital amplification (digital gain adjustment processing) and color of digital image data. Various types of image processing such as correction, gamma (γ) correction, contrast correction, black and white / color mode processing, and through image processing are performed. The image processing circuit 227 is connected to the data bus 261. In addition to the image processing circuit 227, the data bus 261 includes a sequence controller (hereinafter referred to as "body CPU") 229, a compression / decompression circuit 231, a video signal output circuit 233, an SDRAM control circuit 237, and an input / output circuit 239. A communication circuit 241, a recording medium control circuit 243, a flash memory control circuit 247, and a switch detection circuit 253 are connected.

The body CPU 229 connected to the data bus 261 controls the operation of this digital camera. A compression / decompression circuit 231 connected to the data bus 261 is a circuit for compressing image data stored in the SDRAM 238 by JPEG or TIFF. Note that image compression is not limited to JPEG or TIFF, and other compression methods can be applied. The video signal output circuit 233 connected to the data bus 261 is connected to the rear liquid crystal monitor 26 and the finder liquid crystal monitor 29 (abbreviated as “F liquid crystal monitor” in the figure) via the liquid crystal monitor drive circuit 235. The video signal output circuit 233 is a circuit for converting the image data stored in the SDRAM 238 or the recording medium 245 into a video signal for display on the rear liquid crystal monitor 26 and / or the in-viewfinder liquid crystal monitor 29. The rear liquid crystal monitor 26 is disposed on the rear surface of the camera body 20. However, the rear liquid crystal monitor 26 is not limited to the rear surface and may be other display devices as long as the photographer can observe. The in-viewfinder liquid crystal monitor 29 is disposed at a position that can be observed by the photographer through the viewfinder eyepiece, and, like the rear liquid crystal monitor 26, is not limited to the liquid crystal and may be another display device. Note that only the rear liquid crystal monitor 26 may be used for observation of the subject image, and the finder eyepiece and the finder liquid crystal monitor 29 may be omitted.

The SDRAM 238 is connected to the data bus 261 via the SDRAM control circuit 237, and the SDRAM 238 temporarily stores the image data processed by the image processing circuit 227 or the image data compressed by the compression / expansion circuit 231. This is a buffer memory. Input / output connected to the above-described dustproof filter drive circuit 211, camera shake correction mechanism drive circuit 212, shutter drive mechanism 213, movable mirror drive mechanism 215, blur detection circuit 216, distance measurement / photometry processing circuit 219, and image sensor drive circuit 223 The circuit 239 controls data input / output with each circuit such as the body CPU 229 via the data bus 261. The communication circuit 241 connected to the lens CPU 111 via the communication contact 300 is connected to the data bus 261, and exchanges data with the body CPU 229 and the like and communicates control commands.

A recording medium control circuit 243 connected to the data bus 261 is connected to the recording medium 245 and controls recording of image data and the like on the recording medium 245. The recording medium 245 can be loaded with any rewritable recording medium such as an xD picture card (registered trademark), a compact flash (registered trademark), an SD memory card (registered trademark), or a memory stick (registered trademark). And is detachable from the camera body 20. In addition, a hard disk unit such as a microdrive (registered trademark) or a wireless communication unit may be connectable.

A flash memory control circuit 247 connected to the data bus 261 is connected to a flash memory 249. The flash memory 249 stores a program for controlling the flow of the camera. The digital camera is controlled according to the program stored in the flash memory 249. Note that the flash memory 249 is an electrically rewritable nonvolatile memory.

Power switch 257 that is turned on / off in conjunction with a power switch lever for controlling power supply of the camera body 20 and the lens barrel 10, a switch that is linked to a shutter release button, and a playback button that designates a playback mode. , A switch linked to the cross button for instructing the movement of the cursor on the screen of the rear LCD monitor 26, a switch linked to the mode dial for instructing the shooting mode, and an OK linked to the OK button for determining each selected mode. Various switches 255 such as a switch and an attachment / detachment detection switch 259 are connected to the data bus 261 via a switch detection circuit 253. The release button has a first release switch that is turned on when the photographer is half-pressed and a second release switch that is turned on when the photographer is fully pressed. When the first release switch (hereinafter referred to as 1R) is turned on, the camera performs photographing preparation operations such as focus detection, focusing of the photographing lens, and photometry of the subject brightness, and the second release switch (hereinafter referred to as 2R). When the switch is turned on, a shooting operation for capturing image data of a subject image is executed based on the output of the CCD 221 serving as an image sensor.

Next, referring to FIG. A configuration of the shake detection circuit 216 will be described. The first blur sensor 216a is connected between the power supply Vcc and the ground GND, and the output of the first blur sensor 216a is connected to the input terminal of the amplifier circuit 270. The amplifier circuit 270 is a known non-inverting amplifier circuit. The resistor 273 is connected to the non-inverting input terminal of the operational amplifier 271; the resistor 275 is connected between the non-inverting input terminal and the output terminal of the operational amplifier 271; The resistor 277 is connected between the input terminal and the reference voltage Vref.

The output of the amplifier circuit 270 is connected to the input of the window comparator 280. The window comparator 280 is a circuit that outputs a warning signal when it is higher than the reference voltage Vref + voltage α and when it is lower than the reference voltage Vref−voltage α. The window comparator 280 includes a resistor 286 connected between the connection point between the non-inverting input terminal of the operational amplifier 281 and the inverting input terminal of the operational amplifier 282 and the output terminal of the amplifier circuit 270, the non-inverting input terminal of the operational amplifier 281 and the reference voltage Vref + α. Are connected between the resistor 285, the inverting input terminal of the operational amplifier 282 and the reference voltage Vref-α, the diode 283 connected to the output terminal of the operational amplifier 281 and the output terminal of the operational amplifier 282. It is composed of a connected diode 284.

An A / D converter 290 is connected to a connection point between the amplifier circuit 270 and the window comparator 280. The output of the amplifier circuit 270 is converted from analog to digital and output as a camera shake detection signal. This camera shake signal is used for camera shake correction in the camera shake correction mechanism drive circuit 212. The above configuration is the configuration of the shake detection circuit for the first shake sensor 216a, but the same shake detection circuit is also provided for the second shake sensor 216b and the third shake sensor 216c.

Since the shake detection circuit 216 is configured in this way, when vibration or impact is applied to the first shake sensor 216a, a signal is output in response thereto, and is amplified by the amplification circuit 270, as shown in FIG. Like the output OUT of the graph shown, the output changes around the reference voltage Vref. When the window comparator 280 has an output greater than the voltage Vref + α or an output smaller than the voltage Vref−α, it outputs a warning signal from its output terminal. That is, since the output is larger than Vref + α from time t1 to time t2 in FIG. 3B and is smaller than Vref−α after time t3, a warning signal is output during this time. The warning signal output from the window comparator 280 is a signal for warning of an impact applied to the camera body 20, and the camera shake detection signal output from the A / D converter 290 is a signal indicating the amount of camera shake. Both have different vibration frequencies.

Next, the driving means / retracting means of the movable half mirror 201 and the distance measuring sensor unit 451 will be described with reference to FIG. 4A is an external perspective view of the movable half mirror 201 in the reflecting state, and FIG. 4B is an XX cross-sectional view of the movable half mirror 201 in the retracted state. A half mirror 401 that transmits part of the subject luminous flux and reflects part of it is held by a mirror frame 403. The coating film is attached to a very thin plate glass having a thickness of 0.4 mm or less, and the half mirror 401 transmits a part of the light flux and reflects the other light flux as described above. The mirror frame 403 is rotatable around a shaft 411 inserted in the hole 403a, and the rotation shaft 201a in FIG. Both ends of an opening spring 407 are engaged between a pin 409 fixed to the camera body 20 and a driving pin 405 implanted in the mirror frame 403, and a coil portion of the opening spring 407 is wound around a shaft 411. It is disguised. Due to the spring force of the opening spring 407, the mirror frame 403 receives a biasing force in the counterclockwise direction (arrow A direction) in the figure. One end of the drive pin 405 and the locking lever 413 are engaged, and the cam pin 415 implanted at the other end of the locking lever 413 is engaged with the mirror cam 417.

The locking lever 413 is pivotally supported by a mirror box (not shown), and receives a biasing force counterclockwise (arrow B direction) in the figure by the spring force of the opening spring 407 via the drive pin 405. Yes. Therefore, the cam pin 415 of the locking lever 413 is in pressure contact with the cam surface of the mirror cam 417. The cam surface of the mirror cam 417 is formed so that the length in the radial direction from the center of rotation changes. That is, the locking position 417a on the cam surface is formed so that the distance from the rotation center is longer, and the locking release position 417b is formed so that the distance from the rotation center is shorter than the locking position 417a. ing. A cam surface is formed with a step 417c from the locking position 417a to the locking release position 417b in the counterclockwise direction in the drawing, and the cam surface is smoothly displaced from the locking release position 417b to the locking position 417a. It is formed.

When the locking position 417a of the mirror cam 417 is in a position where it abuts on the cam pin 415, the locking lever 413 is restricted from rotating in the direction of arrow B by the mirror cam 417. Hold on. From this state, when the mirror cam 417 is rotated clockwise in the drawing to a position where the unlocking position 417b contacts the cam pin 415 through the step 417c, the locking lever 413 is rotated in the arrow B direction. It becomes possible. Therefore, the mirror frame 403 is rotated in the direction of arrow A by the urging force of the opening spring 407 and displaced to the retracted position. The mirror cam 417 is rotationally driven by a motor (not shown).

The driving means for driving the movable half mirror 201 to the reflection position (the position indicated by the solid line in FIG. 1) in the imaging optical path includes a mirror cam 417, a locking lever 413, and the like. The retracting means for driving the movable half mirror 201 to the retracted position outside the photographing optical path (the position indicated by the two-dot chain line in FIG. 1) includes an opening spring 407. The driving unit and the retracting unit are not limited to such a configuration, and other configurations may be used as long as the movable half mirror 201 can be driven.

An elastic member 421 is disposed on the body bottom surface 423 in the mirror box of the camera body 20 at a position where the mirror frame 403 comes into contact with the retracted position. The elastic member 421 acts as a buffer member when the mirror frame 403 moves to the retracted position, and substantially matches the shape of the peripheral edge of the mirror frame 403. The body bottom surface 423 surrounded by the elastic member 421 is provided with a distance sensor opening 423a as an opening for guiding the subject light flux to the distance sensor unit 451. When the movable half mirror 201 is in the retracted state, the distance sensor opening 423a is sealed by the half mirror 401, the mirror frame 403, the elastic member 421, and the body bottom surface 423.

A frame body 459 of the distance measurement sensor unit 451 is arranged below the body bottom surface 423 so that the distance measurement sensor opening 423a and the frame body opening 459a coincide with each other. In the frame 459, a mirror 453 provided at a position for reflecting the subject light beam incident through the frame opening 459a, a pair of imaging lenses 455 for imaging the subject light beam, and a distance measuring device A distance measuring sensor 457 is provided. The distance measuring sensor unit 451 is an optical system for performing known TTL phase difference distance measuring.

Since the movable half mirror 201 and the distance measuring unit 451 are configured in this manner, when the cam pin 415 is driven to a position in contact with the locking release position 417b by a motor (not shown), the mirror frame 403 and the locking lever 413 are moved. By the urging force of the opening spring 407, the mirror frame 403 is turned to the retracted position as shown in FIG. At this time, the opening 459a of the distance measuring sensor unit 451 is sealed by the movable mirror 201 and the elastic member 421. When the movable mirror 201 moves to the retracted position, the possibility that the user touches with a finger and a fingerprint or the like attaches or is damaged is reduced. In addition, since the elastic member 421 absorbs shock and vibration during operation when moving from the reflecting position to the retracted position, the half mirror 401 is hardly damaged. Further, since the distance measuring sensor unit 451 is covered by the movable half mirror 201, there is no fear that dust such as dust adheres.

In the retracted state of the movable half mirror 201, when the mirror cam 417 is rotated by the motor and the locking position 417a comes into contact with the cam pin 415, the locking lever 413 rotates clockwise (the direction opposite to the arrow B direction). The mirror frame 403 is rotated clockwise (opposite to the arrow A direction) via the drive pin 405 against the urging force of the opening spring 407 and returned to the reflection position. As a result, the movable half mirror 201 reflects part of the subject light that has passed through the lenses 101a and 101b downward, passes through the distance measuring sensor opening 423a and the frame opening 459a, is reflected by the mirror 453, and is an imaging lens. The pupil is divided by 455 and formed on the distance measuring sensor 457. Based on the output of the distance measuring sensor 457, the focus states of the lenses 101a and 101b are detected. In addition, although the photometry element is not provided in the ranging unit 451 of FIG. 4, you may make it equip with a photometry element.

Next, the operation of the digital camera in one embodiment of the present invention will be described using the flowchart shown in FIG. In the power-on reset flow shown in FIG. 5, it is determined whether the power switch 257 of the camera body 20 is turned on (S1). As a result of the determination, if the power switch 257 is off, the process proceeds to step S3 to enter a sleep state that is a low power consumption state. In this sleep state, interrupt processing is performed only when the power switch 257 is turned on, and processing for turning on the power switch is performed in step S5 and subsequent steps. Until the power switch is turned on, operations other than power switch interrupt processing are stopped to prevent the power battery from being consumed. In step S1, if the power switch 257 is on, the process proceeds to step S2, and it is determined whether the attach / detach switch 259 is off. As described above, the attachment / detachment detection switch 259 is a switch that is turned off when the lens barrel 10 is removed from the camera body 20. If it is off, that is, if the lens barrel 10 is detached, the process proceeds to step S51 described later. This is because when the power switch lever of the camera body 20 is operated and the power is turned on with the lens barrel 10 detached, the same processing as when the lens is detached is performed. If it is determined in step S2 that the detachable switch 259 is on, the process proceeds to step S5 and subsequent steps, and processing for turning on the power switch is performed.

In step S5, the movable half mirror 201 is returned. This is because the movable half mirror 201 is in a position retracted from the photographing optical path when the power switch 257 is off (in the state of the two-dot chain line in FIG. 1), but the lens barrel 10 is turned on when the power switch 257 is turned on. This is because the subject luminous flux from is guided to the distance / photometry sensor 217 to perform photometry and distance measurement. Next, a dust removing operation is performed in the dust filter 205 (S7). In this operation, a driving voltage is applied from the dust filter driving circuit 211 to the piezoelectric element 207 fixed to the dust filter 205, and dust and the like are removed by ultrasonic waves as described above.

Subsequently, the shutter driving circuit 213 performs an opening operation of the shutter 203 (S9). As a result, the subject light flux that has passed through the movable half mirror 201 is not blocked by the shutter 203, so that a subject image is formed on the CCD 221. Using the image data picked up by the CCD 221, the rear liquid crystal monitor 26 is instructed to start a through image display for displaying a subject image as a moving image (S 11). The through image display operation is controlled by the image processing circuit 227 in response to the start instruction.

Next, if there is information such as the shooting mode set by a mode dial (not shown), ISO sensitivity, manually set shutter speed, aperture value, etc., those shooting conditions are read (S13). Then, the subject brightness is measured by the distance measuring / photometric sensor 217, the exposure amount is calculated, and exposure control values such as a shutter speed and an aperture value are calculated according to the shooting mode and shooting conditions using the exposure amount (S15). . Further, through image display setting is performed using a photometric value, an exposure amount, and the like (S17). In this step, in order to set the electronic shutter speed and sensitivity conditions for driving the CCD 221, using the photometry / exposure calculation result obtained in step S15 or the previous display image, the rear liquid crystal monitor 26 and / or Alternatively, calculation and setting for displaying an image of appropriate brightness (brightness) on the liquid crystal 29 in the finder is performed.

In step S21, it is determined whether the release button has been pressed halfway, that is, whether the 1R switch is on. If the result of determination is that 1R is on, processing advances to step S31, and a shooting operation subroutine for shooting preparation and shooting is executed. In this shooting operation subroutine, when the release button is pressed halfway during live view display and 1R is turned on, a part of the subject luminous flux reflected from the movable half mirror 201 is guided to the distance measuring / photometric sensor 217. Metering and ranging can be performed in parallel with live view display. When 2R is turned on, the movable half mirror 201 is retracted, and image data is recorded on the recording medium 245 based on the output of the CCD 221 on which the subject image is formed. When the photographing operation subroutine ends, the process returns to step S7 and the above-described steps are repeated.

Returning to step S21, if the result of determination is that the 1R switch is off, processing proceeds to step S23, where it is determined whether or not an impact has been applied to the camera body 20 based on the output of the blur detection circuit 216. Do. This determination is made based on whether or not a warning signal is output from the shake detection circuit 216 based on the output signals of the shake sensors 216a, 216b, and 216c. A warning signal is output when at least one of the three blur sensors exceeds a predetermined level. As a result of the determination, if an impact is applied, the process proceeds to step S33, and the retracting operation of the movable half mirror 201 is performed.

As described above, the retracting operation is performed by driving the motor to rotate the mirror cam 417 and rotating the mirror frame 403 to the position retracted from the photographing optical path by the biasing force of the opening spring 407 (FIG. 1). Of the two-dot chain line). Subsequently, since an impact is applied to the camera body 20 and the image is blurred, the through image display is stopped for the image processing circuit 227 (S35), and the shutter 203 is closed. Perform (S37). In this state, waiting for the impact to stop (S39). When the impact disappears, the return operation of the movable half mirror 201 is performed in the same manner as in step S5. After the return operation is completed, the process returns to step S7 to repeat the above-described operation. .

Returning to step S23, if the result of determination is that there is no impact, processing proceeds to step S25, where it is determined whether the attachment / detachment detection switch 259 is off, as in step S2. When the lens barrel 10 is detached, a through image stop instruction is output (S45) and the shutter 203 is closed (S47) as in step S35. Thereafter, the retracting operation of the movable half mirror 201 is performed (S49). The retracting operation is performed by driving the motor to rotate the mirror cam 417 and rotating the mirror frame 403 to the retracted position from the photographing optical path by the biasing force of the opening spring 407, as in step S33. As described above, since the elastic member 421 is provided at the retracted position of the movable half mirror 201, the elastic member 421 functions as a buffer member, so that the impact can be reduced and damage can be prevented.

When the retracting of the movable half mirror 201 is completed, or when it is determined in step S2 that the attachment / detachment detection switch 259 is off (that is, when the lens barrel 10 is detached), the process proceeds to step S51. It is determined whether or not the detection switch 259 is on. In step S25, after detecting that the lens barrel 10 is detached, it is determined whether or not the lens barrel 10 is attached again. As a result of the determination, if it is mounted, the process proceeds to step S55, and the movable half mirror 201 is returned. As described above, the mirror cam 417 is rotated by driving the motor, the locking lever 413 is rotated clockwise by the cam surface against the urging force of the opening spring 407, and the mirror frame. 403 is inserted in the optical path of the lenses 101a and 101b. When the return of the movable half mirror 201 is completed, the process returns to step S7, and the above steps are repeated.

Returning to step S51, if the attachment / detachment detection switch 259 is off, the process proceeds to step S53 to determine whether the power switch 257 is on. When the lens barrel 10 is detached and the power switch 257 is on, the mount opening remains open even when various operation buttons are operated. Therefore, from the viewpoint of preventing malfunction, the camera operation should not be performed. Yes. For this reason, in step S51, the lens barrel 10 is mounted, and in step S53, the standby state in which the determination of the operation state of the power switch lever is repeated. If it is determined in step S53 that the power switch 257 is off, the process returns to step S3 to enter a sleep state. In step S51, when it is detected that the lens barrel 10 remains detached, the determination in step S53 may be omitted, and the process may proceed to step S3 to enter the sleep state, or the process may proceed to step S9. Modifications such as performing an operation based on an operation by the operation button are possible.

Returning to step S25, if the result of determination is that the attachment / detachment detection switch 259 is on, that is, if the lens barrel 10 is attached to the camera body, the routine proceeds to step S27, where it is determined whether or not the power switch 257 is on. If the result of determination is that it is on, processing returns to step S13 and the above steps are repeated. In step S11, after the through image display is started, the subject light flux that has passed through the movable half mirror 201 is not blocked by the shutter 203 unless various operation buttons are operated in step S19 and subsequent steps. The image data picked up by the CCD 221 is displayed as a moving image on the rear liquid crystal monitor 26 and / or the finder liquid crystal 29 as a moving image.

If it is determined in step S27 that the power switch 257 is off, as in steps S31 and S33, the image processing circuit 227 is instructed to stop displaying the through image (S28), and the shutter 203 is closed. (S29). Thereafter, similarly to step S33 described above, after the retracting operation of the movable half mirror 201 is performed (S30), the process returns to step S3 and enters the sleep state. As described above, since the elastic member 421 is provided at the retracted position of the movable half mirror 201, the elastic member 421 functions as a buffer member, so that the impact can be reduced and damage can be prevented.

As described above, in the present embodiment, in a digital camera capable of displaying a through image, when the output of the blur sensors 216a, 216b, and 216c is detected during operation of the camera and a blur exceeding a predetermined level is detected (S23), The retracting operation of the half mirror 201 is performed (S33). For this reason, it is possible to prevent the thin half mirror from being damaged by the impact applied to the camera body 20. Note that the warning signal output from the shake detection circuit 216 can change the shake level at which the warning signal is output by changing α, and if this value is set to a low value, the impact is detected in advance. You can foresee.

In the present embodiment, when an impact is detected (S23), the live view display is stopped (S35), and the shutter 203 is closed (S47). Disturbed images will not be displayed. Further, when it is detected that the impact has disappeared (S39), the movable half mirror 201 is returned (S41), and the through image display is resumed (S11). For this reason, the live view is stopped only while there is an impact, and the live view is resumed as soon as the impact disappears, so that the subject image can be displayed to the maximum and a photo opportunity is not missed.

Furthermore, in the present embodiment, since it is determined whether or not there is an impact using the outputs of the shake correction sensors 216a, 216b, and 216c, the camera shake correction and the impact detection sensor are combined. This can reduce the size of the camera. Further, the impact in the triaxial direction can be detected by the three sensors.

Further, in the present embodiment, when the movable half mirror 201 is retracted (S33, S49), the movable half mirror 201 is in contact with the elastic member 421, so that the impact applied to the very thin half mirror 401 is increased. Since it can soften, the risk of breakage can be reduced.

Further, in the present embodiment, the movable half mirror 201 is inserted in the photographing optical path, and a part of the subject luminous flux is reflected to the distance measuring / photometric sensor 217, so that the release button is pressed halfway during the through image display. When 1R is turned on, photometry and distance measurement can be performed immediately in parallel with live view display, which is convenient.

Furthermore, in the present embodiment, in the power-on reset routine, when the attachment / detachment detection switch 259 detects that the lens barrel 10 has been detached (S25), the movable half mirror 201 is retracted from the photographing optical path, and the lens mirror When the attachment / detachment detection switch 259 detects that the cylinder 10 has been remounted (S51), the movable half mirror 201 is inserted into the imaging optical path. Therefore, when the lens barrel 10 is removed and the mount portion is in the open state, the movable half mirror 201 is in the retracted state even if a user or the like tries to insert a cleaning tool or the like from the mount opening portion. There is no possibility that the movable half mirror 201 is damaged or a fingerprint is attached.

Further, in the present embodiment, even when the lens barrel 10 is removed at the time of power-off, the movable half mirror 201 is in the retracted state. There is no danger of fingerprints being attached. When the camera is powered on, the movable half mirror 201 is inserted in the photographing optical path, so that the distance measurement operation and the photometry operation can be performed in parallel with the through image display operation.

Furthermore, in the present embodiment, when the movable half mirror 201 is retracted, the distance measuring sensor unit 451 is covered with the movable half mirror 201, so that the distance measuring sensor 457 is not exposed and the risk of dust or the like being attached is reduced. can do. Furthermore, since it is sealed by the elastic member 421 or the like, there is no possibility that dust will enter through the gap.

In the present embodiment, the elastic member 421 is disposed on the body bottom surface 423. However, the elastic member 421 is not limited to this. For example, the elastic member 421 may be disposed at a position where the movable half mirror 201 is in contact with the reflective position. Absent. Furthermore, although the elastic member 421 is disposed on the body bottom surface 423, it is of course possible to embed the entire elastic member 421 in the body bottom surface 423 or to embed a part thereof.

In this embodiment, the CCD 221 serving as an image sensor receives the transmitted light from the movable half mirror 201, and the distance measuring / photometric sensor 217 receives the reflected light from the movable half mirror 201. In addition, the CCD 221 may receive reflected light, and the distance measuring / photometric sensor 217 may receive transmitted light.

Furthermore, in the present embodiment, the image sensor is only the CCD 221, but is not limited thereto, and is separately arranged in the finder optical system, and both the recording image sensor and the output of the image sensor in the finder optical system or It can also be applied to those that display either of them by switching between them.

In the present embodiment, the present invention is applied to a general digital camera. However, the present invention is not limited to this, and may be a photographing device in various devices such as a portable device, and is equipped with a bellows, an extension tube, or the like. Of course, the present invention can also be applied to a dedicated camera attached to various devices such as a microscope and binoculars. Of course, the present invention is not limited to a digital camera and can be applied to any device that receives an impact on a mirror.

It is a block diagram which shows the whole structure of the electric system of the digital camera in one Embodiment to which this invention is applied. It is a figure which shows the arrangement | positioning location of the blur sensor in one Embodiment of this invention. It is a figure explaining the blur detection circuit in one Embodiment of this invention, (A) is a block diagram of a blur detection circuit, (B) is a wave form diagram which shows the output of a blur detection circuit. It is a figure which shows the components structure of the movable half mirror and ranging unit in one Embodiment of this invention, (A) is an external appearance perspective view of a movable half mirror, (B) is a movable half mirror containing a ranging unit. It is XX sectional drawing. It is a flowchart which shows the operation | movement of the power-on reset in one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Lens barrel 20 Camera main body 26 Back surface liquid crystal monitor 29 Liquid crystal monitor 101a, 101b in finder Lens 103 Diaphragm 111 Lens CPU
201 Movable Half Mirror 203 Shutter 205 Dustproof Filter 207 Piezoelectric Element 215 Movable Mirror Drive Mechanism 216 Shake Detection Circuits 216a, 216b, 216c Blur Sensor 217 Distance / Photometric Sensor 219 Distance / Photometric Processing Circuit 221
227 Image processing circuit 229 Body CPU
253 Switch detection circuit 255 Various switches 257 Power switch 259 Attachment / detachment detection switch 270 Amplifier circuit 280 Window comparator 401 Half mirror 403 Mirror frame 421 Elastic member 423 Body bottom surface 451 Distance sensor unit 457 Distance sensor 459 Frame body 459a Frame body opening

Claims (11)

A half mirror movable between a first position in the imaging optical path and a second position retracted from the imaging optical path;
Driving means for driving the half mirror;
Detecting means for detecting camera vibration;
Retreating means for controlling the driving means to retreat the half mirror to the second position when vibration exceeding a predetermined level is detected by the detecting means;
An imaging apparatus comprising:   The imaging apparatus according to claim 1, wherein a buffer member with which the half mirror abuts is disposed at the retracted position.   2. The photographing apparatus according to claim 1, wherein the half mirror has a light transmission characteristic of transmitting a part of a subject light beam incident through the photographing lens. A movable half mirror that can move back and forth in the shooting optical path,
Driving means for driving the mirror;
Detection means for detecting that the camera has been dropped or that an impact has been applied to the camera and issuing a warning signal;
In response to the warning signal, half mirror retracting means for controlling the driving means to move the half mirror to the retracted position;
An imaging apparatus comprising: A movable half mirror that can move back and forth in the shooting optical path,
A sensor that detects camera vibration;
Detecting means for outputting a warning signal when the vibration exceeds a predetermined level;
Drive means for retracting the half mirror in response to the warning signal;
An imaging apparatus comprising:   6. The photographing apparatus according to claim 5, wherein the driving means returns the half mirror when the vibration falls within a predetermined level after the half mirror is retracted.   The imaging apparatus according to claim 5, wherein a buffer member that reduces the impact of the half mirror is disposed at a retracted position of the half mirror.   An image pickup unit that is disposed on the photographing optical path and receives a subject light beam and outputs a subject image signal; and a through image display unit that displays a moving image of the subject on a display device based on the subject image signal. The imaging apparatus according to claim 5, wherein the imaging apparatus is characterized.   9. The photographing apparatus according to claim 8, wherein the moving image display by the through image display means is stopped simultaneously with the retraction of the half mirror.   6. The photographing apparatus according to claim 5, further comprising a distance measuring unit disposed on a reflection optical path of the half mirror and an imaging unit disposed on a transmission optical path of the half mirror.   6. The photographing apparatus according to claim 5, further comprising a camera shake correction mechanism that drives the camera shake correction mechanism based on an output of the sensor.