JP2008011358A - Digital camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digital camera which reduces the power consumption when a subject image is displayed by a moving image based on an output of an imaging element. <P>SOLUTION: A digital camera has an imaging element CCD221 which receives a subject light flux, a back side liquid crystal monitor 26 which displays the through image of a moving image of a subject based on a subject image signal output from the CCD221, and a shutter 203 which interrupts a subject light flux entering the CCD221. The shutter 203 includes a focal plane shutter having a front curtain and a rear curtain which can independently operate, releases only the shutter front curtain in the through image display, mechanically retains the shutter rear curtain without energization to an electric magnet for a shutter rear curtain retention, and drives the shutter rear curtain after driving the front curtain upon imaging operation. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a digital camera having a through image display function, and more specifically, a so-called through image display function (also referred to as a live view display function or an electronic viewfinder function) for displaying an image acquired by an image sensor as a moving image on a display device. The present invention relates to a digital camera.

In conventional digital cameras, the subject image was observed using an optical viewfinder, but recently, the optical viewfinder has been eliminated, and instead the output of an image sensor provided for recording subject image data is displayed. Also use it. That is, there are an increasing number of images having a through image display function for displaying an image acquired by an image sensor on a display device such as a liquid crystal monitor for observing a subject image.

As a digital camera having such a through image display function, for example, in Patent Document 1, a movable mirror is retracted from a photographing optical path, a focal plane shutter is fully opened, and a subject image is guided to an image sensor, and thus obtained. A digital camera is disclosed that continuously displays a subject image as a moving image on a liquid crystal monitor.
JP 2002-369042 A

In the digital camera disclosed in Patent Document 1, when displaying a through image, after the shutter front curtain and the rear curtain are run, only the rear curtain is moved from the light shielding position to the exposure position (the position retracted from the shutter opening). ), And the shutter rear curtain is attracted and held by a magnet. Although the shutter open state is created in this way, when a through image display is performed for a long time, there is a problem that the current consumption for attracting and holding by the shutter rear curtain holding magnet increases and the power source battery is consumed. .

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a digital camera in which current consumption is reduced in displaying a through image.

In order to achieve the above object, a digital camera according to a first aspect of the present invention is an imaging device including an imaging device for receiving a subject luminous flux, and a display device for displaying a moving image of a subject based on a subject image signal output from the imaging means. A live view display means for displaying on the image pickup device, and a shutter means for blocking the subject luminous flux incident on the imaging device, the shutter means including a focal plane shutter having a front curtain and a rear curtain that can be operated independently of each other, The front curtain is shifted from the closed state to the open state at the start of the moving image display of the through image display means, and is shifted from the open state to the closed state at the end of the subsequent moving image display.

According to a second aspect of the present invention, there is provided the digital camera according to the first aspect, wherein the shutter means includes a charge mechanism for independently charging the front curtain and the rear curtain, and holds the front curtain and the rear curtain in a charged state. Holding mechanism.
In the digital camera according to a third aspect of the present invention, in the second aspect of the invention, the shutter means travels the front curtain at the start of moving image display of the through image display means, and the front end at the end of the moving image display. Charge the curtain.
Further, in the digital camera according to the fourth invention, in the second invention, the holding mechanism can sequentially release the holding by rotation of one gear.
Further, in a digital camera according to a fifth aspect based on the second aspect, the shutter means changes the timing of releasing the holding of the front curtain and the rear curtain according to the exposure time during the photographing operation.
Further, in the digital camera according to the sixth invention, in the second invention, the shutter means changes the timing of holding the front curtain and the rear curtain in bulb shooting.

In order to achieve the above object, a digital camera according to a seventh aspect of the present invention is an image pickup device including an image pickup device for receiving a subject luminous flux, and a display device for displaying a moving image of a subject based on a subject image signal output from the image pickup device. A live view display means for displaying on the image pickup device, and a shutter means for blocking the subject luminous flux incident on the imaging device, the shutter means including a focal plane shutter having a front curtain and a rear curtain that can be operated independently of each other, In the moving image display of the through image display means, only the front curtain is opened and closed, and during the photographing operation, the rear curtain is caused to travel after the front curtain travels.

In order to achieve the above object, a digital camera according to an eighth aspect of the present invention is a display device for displaying a moving image of a subject based on an imaging means including an imaging device for receiving a subject luminous flux and a subject image signal output from the imaging device. Through image display means for displaying on the image sensor, and shutter means for blocking the subject light beam incident on the image sensor, and the shutter means opens only the shutter front curtain in the moving image display of the through image display means, The shutter rear curtain is mechanically held without energizing the electromagnet for holding the shutter rear curtain, and the shutter rear curtain is caused to travel after the front curtain during the photographing operation.

In a digital camera according to a ninth aspect based on the eighth aspect, the shutter means has a cam mechanism, and the shutter rear curtain is held by the cam mechanism during the through image display.
The digital camera according to a tenth aspect of the present invention is the digital camera according to the eighth aspect, wherein the shutter means opens the shutter rear curtain for a predetermined time by mechanical holding during long exposure or bulb photography. Hold.

According to the present invention, the shutter means includes a focal plane shutter having a front curtain and a rear curtain that can be operated independently, and the front curtain is shifted from the closed state to the open state at the start of moving image display of the through image display means, Since the transition from the open state to the closed state is performed at the end of the subsequent moving image display, it is possible to provide a digital camera in which current consumption is reduced in the through image display.

Hereinafter, a preferred first embodiment using a digital camera to which the present invention is applied will be described with reference to the drawings. FIG. 1 is an external perspective view of a digital camera according to an embodiment of the present invention as viewed from the back. This camera is composed of a camera body 20 and a lens barrel 10 as an interchangeable lens. 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, 101b, etc. (see FIG. 2) 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 a communication contact 300 (see FIG. 2). Also, the attachment / detachment state can be detected by an attachment / detachment detection switch 259 (see FIG. 2) provided in the camera body 20.

On the upper surface of the camera body 20, a release button 21, a mode dial 22, a power switch lever 23, a control dial 24, and the like are arranged. The release button 21 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 it is turned on, a photographing operation for capturing image data of a subject image is executed based on the output of a CCD (Charge Coupled Devices) 221 (see FIG. 2) as an image sensor.

The mode dial 22 is an operation member that is configured to be rotatable. By matching a picture display or symbol representing a shooting mode provided on the mode dial 22 with an index, a full-auto shooting mode (AUTO) or a program shooting mode is set. (P), aperture priority shooting mode (A), shutter speed priority shooting mode (S), manual shooting mode (M), portrait shooting mode, landscape shooting mode, macro shooting mode, sports shooting mode, night scene shooting mode, etc. Each shooting mode can be selected. The power switch lever 23 is an operation member for turning on / off the power supply of the digital camera, and is configured to be rotatable at two positions, on / off. The control dial 24 is an operation member configured to be rotatable, and a desired set value, mode, or the like can be selected by rotating the control dial 24 on an information display screen or the like.

On the back of the camera body 20, a rear liquid crystal monitor 26, a playback button 27, a menu button 28, a cross button 30, an OK button 31, and a viewfinder eyepiece 33 are arranged. The rear liquid crystal monitor 26 is a display device for displaying a subject image as a through image for observation, reproducing and displaying a photographed subject image, and displaying camera information and menus. Any liquid crystal display can be used as long as it can perform these displays. Note that the camera body 20 may be configured to freely change the angle. The viewfinder eyepiece 33 is an eyepiece window for observing a subject image, and an in-finder liquid crystal monitor 29 described later is disposed therein, and the subject image can be observed through the finder eyepiece 33. Yes. The playback button 27 is an operation button for instructing to display a subject image recorded after shooting on the rear liquid crystal monitor 26. In accordance with the operation of the playback button 27, the image data of the subject stored in the later-described SDRAM 238 or the recording medium 245 in the compression mode such as JPEG is expanded and then displayed on the rear liquid crystal monitor 26.

The cross button 30 is an operation member for instructing the movement of the cursor in the two-dimensional direction of the X direction and the Y direction on the rear liquid crystal monitor 26, and for displaying the subject image recorded on the recording medium 245. Also used to select playback images. In addition to providing four buttons for up, down, left, and right, it is also possible to replace with a switch that can be operated in a two-dimensional direction, such as a switch that can detect the operation direction in two dimensions, such as a touch switch. is there. The OK button 31 is an operation member for confirming various items selected by the cross button 30, the control dial 24, or the like. The menu button 28 is a button for switching to a menu mode for setting various modes of the digital camera. When the menu mode is selected by operating the menu button 28, a menu screen is displayed on the rear liquid crystal monitor 26. . The menu screen has a plurality of hierarchical structures. Various items are selected with the cross-shaped button 30, and selection is determined by operating the OK button 31.

The release button 21, the power switch lever 23, the playback button 27, the menu button 28, the cross button 30, and the OK button 31 are all linked to the on / off switch. Signals generated in response to the operation of the operation buttons linked to these on / off switches and the operation members such as the mode dial 22 and the control dial 24 are detected by the switch in an ASIC (Application Specific Integrated Circuit) 262. It is transmitted to the circuit 253 (see FIG. 2).

Next, referring to FIG. 2, an overall configuration mainly including an electric system of the digital camera will be described.
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 amount. 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 perform aperture value control.

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 path of the lenses 101a and 101b (the position indicated by the solid line in FIG. 2), 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 (70%) of the subject luminous flux passes through the movable half mirror 201 and is guided in the direction of the CCD 221. When the movable half mirror 201 is substantially parallel to the optical paths of the lenses 101a and 101b and is at a retracted position (a position indicated by a two-dot chain line in FIG. 2) that does not block the subject light beam, the entire subject light beam is guided to the CCD 221. 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. 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 output of the distance measurement / photometry sensor 217 is sent to the distance measurement / photometry processing circuit 219. The distance measurement / photometry processing circuit 219 outputs an evaluation photometric value based on the output of the photometry 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 measurement sensor. To do. Note that the distance measuring sensor and the photometric sensor may be configured separately or integrally.

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 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, and the image processing circuit 227 performs digital amplification (digital gain adjustment processing) of digital image data, color correction, gamma (γ) correction, contrast correction, monochrome / color mode. Various image processing such as 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 where it can be observed by the photographer through the viewfinder eyepiece 33, and like the rear liquid crystal monitor 26, other liquid crystal display devices may be used. Note that only the rear liquid crystal monitor 26 may be used for observation of the subject image, and the finder eyepiece 33 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. The input / output circuit 239 connected to the above-described dustproof filter drive circuit 211, shutter drive mechanism 213, movable mirror drive mechanism 215, distance measurement / photometry processing circuit 219, and image sensor drive circuit 223 is connected to the body CPU 229 via the data bus 261. Control input / output of data with each circuit. 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.

A power switch 257 that is turned on / off in conjunction with a power switch lever 23 for controlling the power supply of the camera body 20 and the lens barrel 10, and a switch that detects the first stroke and the second stroke of the shutter release button 21. A switch linked to the playback button 27 for instructing the playback mode, a switch linked to the cross button 30 for instructing the movement of the cursor on the screen of the rear liquid crystal monitor 26, and a switch linked to the mode dial 22 for instructing the shooting mode. In addition, various switches 255 such as an OK switch linked to an OK button 31 for determining each mode and the like, and the attachment / detachment detection switch 259 are connected to the data bus 261 via the switch detection circuit 253. The detection of the attachment / detachment state of the lens barrel 10 is not limited to a mechanical detection switch, and may be, for example, a photoelectric detection switch using a photosensor, a method by communication with the lens CPU 111, or a contact with the lens barrel 10. There are various methods such as detection of the energized state of the two contacts.

Next, the shutter drive mechanism 213 of the shutter 203 will be described with reference to FIGS. The drive shaft of the front curtain motor 401 meshes with the gear 403, and this gear 403 meshes with the cam gear 405. A front curtain cam 407 is fixed to the cam gear 405, and a cam surface is formed on the front curtain cam 407 so that the distance in the radial direction from the rotation shaft changes (see FIG. 5A). Will be described later). One end of the front curtain charge lever 409 whose pivot shaft is pivotally supported by the camera body 20 is pressed against the front curtain cam 407 by the pulling force of the spring 413, and the other end is engaged with one end of the front curtain lever 411. A biasing force is applied to the other end of the front curtain lever 411 by a spring 415 in the clockwise direction in FIG. When the elliptical cam surface of the front curtain cam 407 is in pressure contact with the front curtain charge lever 409, the front curtain lever 411 is positioned to be attracted to the front curtain magnet 417. When the short curtain cam surface of the front curtain cam 407 is in pressure contact with the front curtain charge lever 409 and the front curtain magnet 417 is not energized, the front curtain lever 411 is separated from the front curtain magnet 417. Become. The front curtain lever 411 is engaged with a driving pin of a known shutter front curtain provided in the shutter unit 400, and is retracted from the position where the opening is covered in accordance with the movement of the front curtain lever 411. Move between positions.

Similar to the front curtain shutter drive mechanism, the rear curtain shutter drive mechanism is also configured. The drive shaft of the rear curtain motor 421 meshes with the gear 423, and this gear 423 meshes with the cam gear 425. A rear curtain cam 427 is fixed to the cam gear 425, and a cam surface is formed on the rear curtain cam 427 so that the distance in the radial direction from the rotation shaft changes (see FIG. 5B). Will be described later). One end of the rear curtain charge lever 429 whose pivot shaft is supported by the camera body 20 is pressed against the rear curtain cam 427 by the pulling force of the spring 433, and the other end is engaged with one end of the rear curtain lever 431. The other end of the rear curtain lever 431 is biased clockwise by a spring 435 in FIG. When the oval cam surface of the rear curtain cam 427 is in pressure contact with the rear curtain charge lever 429, the rear curtain lever 431 is positioned to be attracted to the rear curtain magnet 437. When the short curtain cam surface of the rear curtain cam 427 is in pressure contact with the rear curtain charge lever 429 and the rear curtain magnet 437 is not energized, the rear curtain lever 431 is separated from the rear curtain magnet 437. Become. The rear curtain lever 431 is engaged with a known shutter rear curtain drive pin provided in the shutter unit 400, and is retracted from the position where the rear curtain lever 431 covers the opening in accordance with the movement of the rear curtain lever 431. Move between positions.

In this way, the drive mechanisms for the front curtain shutter and the rear curtain shutter are configured independently. FIG. 5A shows the relationship between the rotation angle of the leading curtain cam 407 and the lift amount of the cam surface. The rotation angle of 60 ° to 180 ° is the front curtain charge section. In this section, the front curtain charge lever 409 rotates clockwise in FIG. 4 and the front curtain lever 411 rotates counterclockwise. To do. When the angle reaches 180 °, the top dead center of the front curtain cam (the ellipse portion of the front curtain cam 407) is reached, and the front curtain lever 411 is in contact with the front curtain magnet 417. When the front curtain cam 407 is further rotated and between 180 ° and 240 ° (mechanical holding section), the length of the cam surface in the radial direction does not change, and the front curtain lever 411 is in a position in contact with the front curtain magnet 417. Hold. The front curtain cam 407 further rotates, and the front curtain lever 411 rotates in the clockwise direction and moves away from the front curtain magnet 417 in the range of 240 ° to 270 ° (lever retracting section). A front curtain PI (photo interrupter) is disposed at a position where the movement of the cam gear 405 or the front curtain charge lever 409 can be detected. As shown in FIG. 5A, when the leading curtain cam 407 reaches top dead center 180 °, the leading curtain PI outputs a falling signal, and when reaching the bottom dead center 270 °, the leading curtain PI outputs a rising signal. Output. Therefore, the front curtain PI outputs a signal when entering and leaving the mechanical holding section. It is not always necessary to change the PI signal past the top dead center and the bottom dead center, and it is generally known that the top dead center, the bottom dead center, and the PI signal are shifted in order to adjust the timing in terms of mechanism.

Since the operation of the drive mechanism of the rear curtain shutter is the same as that of the drive mechanism of the front curtain shutter, detailed description is omitted, but as shown in FIG. 5B, the rotation angle of the rear curtain cam 427 is from 60 ° to 180 °. The rear curtain charging section is between 0 °, the mechanical holding section is between 180 ° and 240 °, and the lever retracting section is between 240 ° and 270 °. The trailing curtain PI outputs a falling signal and a rising signal at the beginning and end of the mechanical holding section, respectively. The driving means for the front curtain and the rear curtain is not limited to such a configuration, and can be driven independently, and the mechanism that can mechanically hold the front curtain / rear curtain lever on the front curtain / rear curtain magnet. Any other configuration may be used.

Next, the operation of the digital camera in the first embodiment of the present invention will be described with reference to the flowcharts shown in FIGS. In the power-on reset flow shown in FIG. 6, 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 23 of the camera body 20 is operated and the power is turned on while the lens barrel 10 is 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 in an off state (in the state of a two-dot chain line in FIG. 2). 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). This shutter opening operation runs only the shutter front curtain, and will be described later in detail with reference to FIG. The subject light flux that has passed through the movable half mirror 201 by the shutter opening operation 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 the mode dial 22 or the like, ISO sensitivity, manually set shutter speed or aperture value, 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.

Next, it progresses to step S19 and it is determined whether it is a reproduction | regeneration mode. This playback mode is a mode in which when the playback button 27 is operated, still image data recorded on the recording medium 245 is read and displayed on the rear liquid crystal monitor 26 and / or the finder liquid crystal 29. If the reproduction mode is set as a result of the determination, the process proceeds to step S31 to instruct the image processing circuit 227 to stop the through image display. Thereafter, after closing the shutter 203 (S33), the still image data recorded on the recording medium 245 is read out, the image data is expanded by the compression / expansion circuit 231, and the video signal output circuit 233 and the liquid crystal monitor are read out. The still image is reproduced and displayed on the rear liquid crystal monitor 26 and / or the finder liquid crystal 29 via the drive circuit 235 (S35). Note that the closing operation of the shutter 203 in step S33 charges only the front curtain, and will be described in detail with reference to FIG. If another manual operation such as half-pressing the release button 21 is performed during the reproduction operation, the reproduction operation is terminated and the process returns to step S7 to repeat the above-described operation.

Returning to step S19, if the playback mode has not been set, the process proceeds to step S21 to determine whether the menu mode has been set. This determines whether the menu button 28 is operated and the menu mode is set. As a result of the determination, if the menu mode is set, a through image stop instruction is output (S37), as in the case where the playback mode is set, and the shutter 203 is closed (step S33) (step S33). S39). Thereafter, a menu setting operation is performed (S41). Various setting operations such as white balance, ISO sensitivity setting, and drive mode setting can be performed by the menu setting operation. When the menu setting operation is completed, the process returns to step S7, and the above operation is repeated.

Returning to step S21, if the result of determination is that the menu mode has not been set, processing proceeds to step S23, where it is determined whether the release button 21 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 S43, and a shooting operation subroutine for shooting preparation and shooting is executed. Details of this subroutine will be described later with reference to FIG. When the photographing operation subroutine ends, the process returns to step S7 and the above-described steps are repeated.

Returning to step S23, if the result of determination is that the 1R switch is off, 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) as in steps S31 and S33 in the reproduction mode, and the shutter 203 is closed as in step S33 (S47). Thereafter, the retracting operation of the movable half mirror 201 is performed (S49).

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. 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, the lens barrel 10 is attached in step S51 and the standby state in which the determination of the operation state of the power switch lever 23 is repeated in step S53. 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 similarly to step S33. The shutter 203 is closed (S29). Thereafter, similarly to step S49 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, in this embodiment, in a digital camera capable of displaying a through image, the movable half mirror 201 is inserted into the photographing optical path when the power is turned on, and a part of the subject light flux is reflected on the distance measuring / photometric sensor 217. Therefore, photometry and distance measurement can be performed immediately at power-on, which is convenient.

In the power-on reset routine, when the attachment / detachment detection switch 259 detects that the lens barrel 10 is detached (S25), the movable half mirror 201 is retracted from the photographing optical path, and the lens barrel 10 is remounted. When this is detected by the attachment / detachment detection switch 259 (S51), the movable half mirror 201 is inserted into the photographing 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, even when the lens barrel 10 is removed at the time of power-off, the movable half mirror 201 is in the retracted state. Similarly, the movable half mirror 201 is damaged or a fingerprint is attached by the user or the like. There is no fear of. 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.

Next, the subroutine of the photographing operation in step S43 will be described with reference to FIG. As described above, this subroutine is executed when the release button 21 is half-pressed. First, distance measurement and automatic focus adjustment are performed (S71). This is because 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 subject measuring luminous flux is used to measure the distance measuring / photometric processing circuit 219 and the body. The CPU 229 and the like detect the focus shift amounts of the lenses 101a and 101b by the TTL phase difference method, and the lenses 101a and 101b are brought into focus by the optical system drive mechanism 107 via the lens CPU 111 based on the detected focus shift amounts. Drive.

Next, photometry / exposure amount calculation is performed (S73). The subject light flux reflected by the movable half mirror 201 is also received by the distance measurement / photometry sensor 217 and processed by the distance measurement / photometry processing circuit 219, thereby detecting the subject brightness BV. The body CPU 229 obtains the exposure amount EV using the subject luminance BV, and further obtains the exposure conditions such as the shutter speed and the aperture according to the photographing mode.

Next, it is determined whether or not the release button 21 is fully pressed, that is, whether or not 2R is on (S75). If the result of determination is that it is off, processing advances to step S77 to determine whether 1R is on. If the release button 21 is half-pressed to jump to this shooting operation subroutine and the release button 21 remains half-pressed, a standby state is made in which the determination is repeated in steps S75 and S77. When the hand is released from the release button 21 and 1R is turned off, the process returns to the power-on reset step S7.

Returning to step S75, if the result of determination is that the 2R switch is on, that is, if the release button 21 is fully pressed, the operation moves to an imaging operation for acquiring a still image. First, the process proceeds to step S78, and a shutter closing operation is performed as in step S33. This is to perform initialization of the shutter by performing the charge operation of the front curtain when performing the photographing operation. In step S79, a through image stop instruction is output to the image processing circuit 227. This is due to the movement of the movable half mirror 201 to the retracted position and the opening / closing operation of the shutter 203 in order to obtain a still image, and the subject image incident on the CCD 221 is disturbed. This is to prevent the through image from becoming unsightly. Subsequently, the retracting operation of the movable half mirror 201 is performed in the same manner as in step S49 (S81).

Subsequently, the aperture driving mechanism 109 performs the aperture operation of the aperture 103 to the set aperture value or the aperture value calculated in S73 (S83). When the narrowing-down operation is completed, an exposure operation by the CCD 221 is then performed (S85). The details of this exposure operation will be described later with reference to FIGS. 10 to 12. However, since the shutter front curtain is moved to the initial position in step S78 (that is, in the charged state), the exposure operation is the front curtain. The trailing curtain is caused to travel after the exposure time has elapsed after traveling.

When the exposure operation ends, an instruction to open the aperture 103 is output to the lens CPU 111 (S89). Further, the image signal stored in the CCD 221 is read (S91), and image processing is performed by the image processing circuit 227 or the like (S93). After processing such as signal compression in the compression / decompression circuit 231, image data is recorded on the recording medium 245 (S95). When the recording of the image data is finished, it is determined in step S97 whether the 1R switch is on, that is, whether the release button 21 is half pressed. When the 1R switch is turned off, the process proceeds to step S97, and the return operation of the movable half mirror 201 is performed in the same manner as in step S55. When the return operation is completed, the routine returns to the power-on reset routine.

In the shooting operation subroutine of the present embodiment, the movable half mirror 201 is retracted during an imaging operation for acquiring a still image. For this reason, a decrease in the amount of transmitted light in the movable half mirror 201 is eliminated, the amount of subject light can be increased in acquiring a still image, and photographing at a high shutter speed is possible. Further, when the imaging operation is finished, the movable half mirror 201 is returned in step S99. Therefore, when the release button 21 is half-pressed again after shooting, photometry and distance measurement are immediately performed in parallel with the live view display. It can be carried out.

Next, the shutter opening subroutine of step S9 (FIG. 6) will be described with reference to FIG. When this subroutine is performed, the lift amount of the front curtain cam in FIG. 5A is in the mechanical holding section, that is, the front curtain is in a charged state. In this state, when the front curtain motor 401 is turned on (S101), the front curtain magnet 417 is not energized. Therefore, the front curtain lever 411 is moved by the lever retracting section of the front curtain cam 407 and the biasing force of the spring 415. It rotates in a direction to retract from the magnet 417.

Following the turning on of the front curtain motor 401, the output of the front curtain PI is input (S103), and when the rising signal is detected (S105), the front curtain motor 401 is turned off and stopped. That is, as shown in FIG. 5A, the leading signal of the leading curtain PI indicates that the lever retracting section has ended. At the time of execution of step S9, since the rear curtain lever 431 is in the mechanical holding section of the shutter rear curtain, the rear curtain charge state is maintained even when the rear curtain magnet 437 is not energized and is retracted from the shutter opening. It is in the state. In step S105, since the front curtain lever 411 is retracted and the shutter front curtain has finished running, the shutter opening is completely opened, and the subject light beam is incident on the CCD 221. When the front curtain motor 401 is turned off in step S107, the process returns to the original routine.

Next, the shutter closing subroutine of steps S33, S39, S42, S47, and S29 (FIG. 6) will be described with reference to FIG. At the start of this shutter closing subroutine, the shutter front curtain is in a state where it has finished running. In FIG. 5A, the front curtain cam lift amount is at the bottom dead center (270 ° to 60 °). When this subroutine is entered, the front curtain motor 401 is turned on (S111), and the front curtain lever 411 is rotated in a direction to be attracted to the front curtain magnet 417 by the front curtain charge section of the front curtain cam 407. In this section, as the front curtain lever 411 rotates, the shutter front curtain gradually moves to a position where the shutter opening is shielded.

Next, the output of the front curtain PI is input (S113), and when the falling signal is detected (S115), the front curtain motor 401 is turned off and stopped. That is, as shown in FIG. 5A, the falling signal of the leading curtain PI indicates that the mechanical holding section has been reached. In this state, the leading curtain magnet 417 is not energized even if the leading curtain magnet 417 is not energized. The curtain lever 411 has a suction position of the front curtain magnet 417 (it is not attracted unless it is energized), and the front curtain completely shields the shutter opening. For this reason, the subject luminous flux does not enter the CCD 221. When the front curtain motor 401 is turned off in step S117, the process returns to the original routine.

In this embodiment, independent of the shutter rear curtain, only the shutter front curtain can be run and a charging operation can be performed. Similarly, the shutter rear curtain can be run and charged independently of the shutter front curtain. Furthermore, it is not necessary to energize the shutter magnet in order to maintain the state of each shutter curtain. That is, the charge state is mechanically held in the mechanical holding section. For this reason, when the through image display is performed, the shutter front curtain is held in the state after the shutter front curtain travels (in the range of top dead center (180 ° to 240 °) with the front curtain lift amount in FIG. 5A). ) The shutter rear curtain can hold the rear curtain charge state in the mechanical holding section (the range of 180 ° to 240 ° in the rear curtain lift amount in FIG. 5B). As a result, it is not necessary to continue energizing the rear curtain magnet in order to maintain the shutter open state during live view display, and it is possible to prevent the power battery from being consumed.

Next, the exposure operation subroutine of step S85 (FIG. 7) will be described with reference to FIGS. When this subroutine is entered, it is first determined whether or not bulb photography is to be performed while the release button 21 is fully depressed (S121). This determination is made based on whether or not bulb shooting has been selected in the menu setting operation (S41) of the menu mode. If bulb shooting has been set, the process jumps to step S231 in FIG. If bulb exposure has not been set, the process proceeds to step S123 to determine whether the exposure time is 8 seconds or longer. It is determined whether a long exposure of 8 seconds or more is set manually or the like, or whether a long exposure time of 8 seconds or more is set as a result of the exposure amount calculation in step S73. If an exposure time of 8 seconds or longer is set, the process jumps to step S181 in FIG. In this embodiment, the determination is made based on whether or not it is 8 seconds or longer. However, the present invention is not limited to this, and it may be seconds such as 2 seconds, 4 seconds, etc.

If it is determined in step S123 that the long exposure of 8 seconds or longer has not been set, the process proceeds to step S125, the front curtain magnet 417 is energized, and the front curtain magnet 417 attracts the front curtain lever 411. Subsequently, the front curtain motor 401 is turned on (S127), the front curtain cam 407 is rotated, the front curtain PI signal is input (S129), and when the leading signal of the front curtain PI is detected (S131), the front curtain motor is detected. 401 is turned off and the rotation is stopped (S133). By this series of operations, the front curtain lever 411 is attracted and held by the front curtain magnet 417, and the front curtain charge lever 409 is separated from the front curtain lever 411. As a result, when the energization of the front curtain magnet 417 is released, the front curtain lever 411 rotates clockwise in FIG. 4, and the shutter front curtain becomes ready to run.

Subsequently, the suction holding operation of the trailing curtain lever 431 is performed for the trailing curtain as in the leading curtain. First, the rear curtain magnet 437 is energized (S135), whereby the rear curtain magnet 437 attracts the rear curtain lever 431. Subsequently, the rear curtain motor 421 is turned on (S137), the rear curtain cam 427 is rotated, the rear curtain PI signal is input (S139), and when the rear curtain PI rising signal is detected (S141), the rear curtain motor is detected. 421 is turned off and the rotation is stopped (S143). By this series of operations, the rear curtain lever 431 is attracted and held by the rear curtain magnet 437, but the rear curtain charge lever 429 is in a state of being separated from the rear curtain lever 431. As a result, when the energization of the rear curtain magnet 437 is released, the rear curtain lever 431 rotates in the clockwise direction in FIG. 4 and the shutter rear curtain becomes ready to run. In the present embodiment, the suction holding operation of the rear curtain lever 431 is started after the suction holding operation of the front curtain lever 411 is completed, but it is needless to say that both may be executed in parallel.

Subsequently, an exposure time timer is started (S145), the energization of the front curtain magnet 417 is released, and the shutter front curtain starts to travel (S147). Then, it is determined whether or not the exposure time timer has completed (S149), that is, it is determined whether the exposure time set manually or the exposure time set by the exposure amount calculation has elapsed. When the set time measuring operation is completed, the exposure time measuring timer is stopped (S151), the energization of the rear curtain magnet 437 is released (S153), and the shutter rear curtain starts running. Waiting for a time (for example, about 10 mS) required for completion of the trailing curtain travel (S155), when this time elapses, the shutter front curtain charging operation (closing operation) is started.

The shutter front curtain charging operation is the same as the flow shown in FIG. 9, but first the front curtain motor 401 is turned on to start rotation (S157). Subsequently, the output of the front curtain PI is input (S159), and when the falling signal of the front curtain PI is detected (S161), the front curtain motor 401 is turned off because the front curtain charge is completed (S163). Subsequently, the shutter rear curtain is charged in the same manner as the shutter front curtain. First, the shutter rear curtain motor 421 is turned on to start rotation (S165). Subsequently, the output of the rear curtain PI is input (S167), and when the trailing signal of the rear curtain PI is detected (S169), the rear curtain motor 421 is turned off. Through steps S157 to S171, the shutter front curtain and rear curtain charging operation is completed. In the present embodiment, the rear curtain shutter charge is performed after the completion of the front curtain shutter charge, but it is needless to say that both may be performed in parallel.

Next, the long exposure time will be described with reference to FIG. If it is determined in step S123 that the exposure time is 8 seconds or longer, the process jumps to step S181, and in this step, the front curtain magnet 417 is energized. As described above, since the shutter front curtain charging operation is completed in step S42 before the exposure operation starts, the front curtain lever 411 is attracted and held by energizing the front curtain magnet 417. Thereafter, the retracting operation of the front curtain charge lever 409 engaged with the front curtain lever 411 is performed in steps S183 to S189. That is, the front curtain motor 401 is turned on (S183), rotation driving is started, the output of the front curtain PI is inputted (S185), and the leading signal of the front curtain PI is inputted (S187), then the front curtain motor 401 is turned off. (S189). Thus, when the energization of the front curtain magnet 417 is released, the shutter front curtain can start running.

Next, a time obtained by subtracting 1 second from the exposure time is calculated, and this time is set in the clock timer, the timer is started (S191), and then the energization of the front curtain magnet 417 is immediately canceled to release the shutter front curtain. Is started (S193). In the shooting operation with a short exposure time shown in FIG. 10, after the front curtain motor 401 is turned on and the front curtain charge lever 409 is retracted (S127 to S133), the rear curtain motor 421 is turned on and the rear curtain motor 421 is turned on. The retraction operation of the charge lever 429 was performed. In the long exposure shown in FIG. 11, the shutter front curtain is caused to travel first in consideration of the time required for retracting the rear curtain charge lever 429 and allowing the rear curtain to travel (1 second in this embodiment). After that, the retracting operation of the trailing curtain charge lever 429 is performed before the shutter trailing curtain starts.

In step S195, when the timekeeping operation of the timekeeping timer is completed, the timekeeping timer starts the timekeeping operation for 1 second. Immediately thereafter, the rear curtain magnet 417 is energized to attract and hold the rear curtain lever 431. Thereafter, the retracting operation of the trailing curtain charge lever 429 engaged with the trailing curtain lever 431 is executed in steps S201 to S207. That is, the rear curtain motor 421 is turned on (S201), rotation driving is started, the output of the rear curtain PI is input (S203), and the rear curtain PI rising signal is input (S205), the rear curtain motor 421 is turned off. (S207). Thus, when the energization of the rear curtain magnet 437 is released, the shutter rear curtain can be started to travel. Thereafter, when it is detected that the timekeeping operation has been completed for one second (S209), the timekeeping timer is stopped (S211), the process jumps to step S153 in FIG. I do.

As described above, the shooting operation in the long exposure seconds in this embodiment starts the travel of the shutter front curtain first, and performs the retreat operation of the rear curtain charge lever 429 engaged with the rear curtain cam 427 after the travel. ing. For this reason, the time lag until the start of the front curtain travel can be shortened. Further, by using the mechanical holding section of the rear curtain (see FIG. 5B), it is possible to shorten the current application time for attracting and holding the rear curtain magnet 417 for holding the rear curtain. For this reason, even when it becomes long-time exposure, consumption of a power supply battery can be suppressed. In this embodiment, the preparation for the trailing curtain traveling such as the retracting time of the trailing curtain charge lever 429 is set to 1 second, and 1 second is subtracted in step S191. This time is the minimum time required by the shutter drive mechanism. That's all there is to it.

Next, the valve time will be described with reference to FIG. If it is determined in step S121 that bulb shooting is being performed, the process jumps to step S231, and in this step, the front curtain magnet 417 is energized. As described above, since the shutter front curtain charging operation is completed in step S42 before the exposure operation starts, the front curtain lever 411 is attracted and held by energizing the front curtain magnet 417. Thereafter, the retracting operation of the front curtain charge lever 409 engaged with the front curtain lever 411 is performed in steps S233 to S239. Since this operation is the same as that in steps S183 to S189 described above, the description thereof is omitted. Thus, when the energization of the front curtain magnet 417 is released, the shutter front curtain can start running.

Subsequently, the energization of the front curtain magnet 417 is released (S245), and the travel of the shutter front curtain is started. In the shooting operation of the short exposure time of FIG. 10 and the long exposure time of FIG. 11, the exposure time is determined, but in bulb shooting, only during the time when the release button 21 is fully pressed, The shutter is open. In step S243, when 2R of the release button 21 is off, that is, when the end of shooting is detected, the shutter closing operation is started. In closing the shutter, first, the rear curtain magnet 437 is energized to attract and hold the rear curtain lever 431. The retracting operation of the trailing curtain charge lever 429 engaged with the trailing curtain lever 431 is performed in steps S247 to S253. Since this evacuation operation is the same as steps S201 to S207, description thereof is omitted. If the rear curtain motor 421 is turned off in step S253, the process jumps to step 153 in FIG.

As described above, in bulb shooting according to the present embodiment, the shutter leading curtain starts to travel first, and after the 2R switch that is the shooting end is turned on, the trailing shutter charge lever 429 engaged with the trailing shutter cam 427 is engaged. A retracting operation is performed to run the shutter rear curtain. Further, by using the rear curtain mechanical holding section (see FIG. 5B), it is possible to shorten the current application time for attracting and holding the rear curtain magnet 417 for holding the rear curtain. For this reason, it is possible to suppress the consumption of the power supply battery even during long-time bulb photography. In this embodiment, since the retracting operation of the trailing curtain charge lever 429 is performed after the 2R switch is turned off, it takes some time to start the trailing curtain travel, but the bulb photography itself takes a long time. Therefore, it is not a big problem in terms of exposure accuracy.

Next, a second embodiment of the present invention will be described with reference to FIGS. In the first embodiment of the present invention, the front-curtain motor 401 and the rear-curtain motor 421 are separately provided and the drive mechanisms for the shutter front curtain and the shutter rear curtain are configured separately, but the second embodiment is a single unit. A shutter motor 451 is provided to constitute a shutter front curtain and rear curtain drive mechanism using this driving force. This second embodiment is an external perspective view seen from the rear side shown in FIG. 1, the overall configuration mainly including the electric system shown in FIG. 2, the flow of power-on reset shown in FIG. 6, and the flow of photographing operation shown in FIG. Are the same, only the differences will be described.

First, the shutter drive mechanism 213 of the shutter 203 will be described with reference to FIGS. The drive shaft of the shutter motor 451 meshes with the cam gear 453 via a gear 452 (not shown in FIG. 14). A front curtain cam 455 is fixed to the cam gear 453, and a cam surface is formed on the front curtain cam 455 so as to change the radial distance from the rotation shaft (described later with reference to FIG. 15). . One end of the front curtain charge lever 471 whose pivot shaft is pivotally supported by the camera body 20 is pressed against the front curtain cam 455 by the pulling force of the spring 477, and the other end is engaged with one end of the front curtain lever 473. A biasing force is applied to the other end of the front curtain lever 473 by a spring 479 in the clockwise direction in FIG. When the oval cam surface of the front curtain cam 455 is in pressure contact with the front curtain charge lever 471, the front curtain lever 473 is positioned to be attracted to the front curtain magnet 475. In the position where the short-curve cam surface of the front curtain cam 455 is in pressure contact with the front curtain charge lever 471, if the front curtain magnet 475 is not energized, the front curtain lever 473 is separated from the front curtain magnet 475. Become. The front curtain lever 473 is engaged with a driving pin of a known shutter front curtain provided in the shutter unit 400, and the position of covering the opening according to the movement of the front curtain lever 473 is retracted from the opening. Move between positions.

The aforementioned cam gear 453 meshes with the cam gear 459 via the gear 457. A rear curtain cam 461 is fixed to the cam gear 459, and a cam surface is formed on the rear curtain cam 461 so as to change the radial distance from the rotation shaft (described later with reference to FIG. 15). . One end of the rear curtain charge lever 481 whose pivot axis is pivotally supported by the camera body 20 is pressed against the rear curtain cam 461 by the pulling force of the spring 487, and the other end is engaged with one end of the rear curtain lever 483. A biasing force is applied to the other end of the trailing curtain lever 483 by a spring 489 in the clockwise direction in FIG. When the oval cam surface of the rear curtain cam 461 comes into pressure contact with the rear curtain charge lever 481, the rear curtain lever 483 is positioned to be attracted to the rear curtain magnet 485. In the position where the short-curve cam surface of the rear curtain cam 461 is in pressure contact with the rear curtain charge lever 481, if the rear curtain magnet 485 is not energized, the rear curtain lever 473 is separated from the rear curtain magnet 485. Become. The rear curtain lever 483 is engaged with a driving pin of a known shutter rear curtain provided in the shutter unit 400, and is retracted from the position where the opening is covered in accordance with the movement of the rear curtain lever 483. Move between positions.

Thus, the drive mechanism for the front curtain shutter and the rear curtain shutter is configured. FIG. 15 is a diagram showing the relationship between the rotation angle of the front curtain cam 455 and the rear curtain cam 461 and the lift amount of the cam surface. When the rotation angle of the front curtain cam 455 is between 60 ° and 180 °, the front curtain charge section is established. In this section, the front curtain charge lever 471 rotates clockwise in FIG. Rotate clockwise. When the top dead center is 180 ° (ellipse portion), the front curtain lever 473 comes into contact with the front curtain magnet 475. The front curtain cam 455 further rotates, and the length of the cam surface in the radial direction does not change between 180 ° and 240 ° (mechanical holding section), and the front curtain lever 473 is in a position in contact with the front curtain magnet 475. Hold. The front curtain cam 455 further rotates, and the front curtain lever 473 rotates clockwise between 240 ° and 270 ° (lever retracting section) and moves away from the front curtain magnet 475. A front curtain PI (photo interrupter) is disposed at a position where the movement of the cam gear 453 or the front curtain charge lever 471 can be detected. As shown in FIG. 15, when the leading curtain cam 455 reaches a point (190 °) slightly past the top dead center, the leading curtain PI outputs a falling signal, and when the leading curtain PI reaches the bottom dead center 270 °, the leading curtain PI outputs a rising signal. Therefore, the front curtain PI outputs a signal when entering and leaving the mechanical holding section.

The rear curtain charge section is when the rotation angle of the rear curtain cam 455 is between 60 ° and 180 °, and operates in the same manner as in the case of the front curtain. When the top dead center is 180 ° (ellipse portion), the trailing curtain lever 483 is in a position in contact with the trailing curtain magnet 485. The rear curtain cam 461 further rotates, and the length of the cam surface in the radial direction does not change between 180 ° and 300 ° (mechanical holding section), so that the rear curtain lever 483 is in a position in contact with the rear curtain magnet 485. Hold. In the case of the first curtain, the angle is 180 ° to 240 °. However, in the case of the second curtain, the drive source is obtained from the same shutter motor 451. The rotation angle is different. The rear curtain cam 461 further rotates, and the rear curtain lever 483 rotates clockwise between 300 ° and 330 ° (lever retracting section), and moves away from the rear curtain magnet 485. A rear curtain PI (photo interrupter) is disposed at a position where the movement of the cam gear 459, the rear curtain charge lever 481, the rear curtain lever 483, or the like can be detected. As shown in FIG. 15, when the leading curtain cam 455 reaches around the top dead center (190 °), the trailing curtain PI outputs a falling signal, and when reaching the bottom dead center 330 °, the trailing curtain PI Outputs a rising signal. Therefore, the trailing curtain PI outputs a signal when entering and leaving the mechanical holding section.

Thus, in the second embodiment, one shutter motor 451 is arranged, the mechanical holding section is set to a section from 180 ° to 240 ° with respect to the front curtain, and 180 ° with respect to the rear curtain. A section of 300 ° is assigned to the shutter, and shutter driving at the time of photographing is performed using the difference between the sections.

Next, the operation of the second embodiment will be described. As described above, the power-on reset shown in FIG. 10 and the shooting operation routine shown in FIG. 11 are the same in the second embodiment, and only the differences will be described. First, when the shutter opening subroutine shown in FIG. 16 is entered, the shutter motor 451 is turned on (S301), and driving is started. When this subroutine is performed, the lift amount of the front curtain cam in FIG. 15 is in the mechanical holding section, and the front curtain at the top dead center is in a charged state. When the shutter motor 451 is turned on in this state, the front curtain magnet 475 is not energized, so the front curtain lever 473 is retracted from the front curtain magnet 475 by the lever retracting section of the front curtain cam 455 and the biasing force of the spring 479. It rotates in the direction to do. The cam gear 459 and the rear curtain cam 461 also rotate via the gear 457. Since the rear curtain cam 461 is in the rear curtain mechanism holding section from 240 ° to 300 °, the shutter motor 451 rotates in this section. Even so, the rear curtain charge lever 481 and the rear curtain lever 483 do not rotate.

Subsequent to turning on the shutter motor 451, the output of the front curtain PI is input (S303), and when the rising signal is detected (S305), the shutter motor 451 is turned off and stopped between 270 ° and 300 °. That is, as shown in FIG. 15, the leading signal of the leading curtain PI indicates that the lever retracting section has ended. At the time of execution of step S9, the rear curtain lever 483 is in the mechanical holding section for the shutter rear curtain, and during execution of this subroutine, the rear curtain charge state is maintained even if the rear curtain magnet 475 is not energized. And is in a state of being retracted from the shutter opening. In step S305, since the front curtain lever 473 is retracted and the shutter front curtain has finished traveling, the shutter opening is completely opened. For this reason, there is nothing covering the shutter opening, and the subject luminous flux is incident on the CCD 221. When the front curtain motor 401 is turned off in step S307, the process returns to the original routine.

Next, the shutter closing subroutine (steps S33, S39, S42, S47, S29 (FIG. 6)) in the second embodiment will be described with reference to FIG. At the start of this shutter closing subroutine, the shutter front curtain has finished running, and in FIG. 15, the front curtain cam lift amount is at the bottom dead center. When this subroutine is entered, the shutter motor 451 is turned on (S311), and the front curtain lever 473 is rotated in a direction to be attracted to the front curtain magnet 475 by the front curtain charge section of the front curtain cam 455. In this section, as the front curtain lever 473 rotates, the shutter front curtain gradually moves to a position where the shutter opening is shielded. In addition, the cam gear 459 and the rear curtain cam 461 are also rotated via the gear 457, and the rear curtain charge lever 481 is pressed against the cam gear 459 so that the rear curtain lever 483 is also in contact with the rear curtain magnet 485. The curtain is also charged.

Next, the output of the trailing curtain PI is input (S313), and when the falling signal is detected (S315), the shutter motor 451 is turned off and stopped. That is, as shown in FIG. 15, the trailing signal of the trailing curtain PI indicates that the mechanical holding section has been reached. In this state, the leading curtain lever 473 is not required even if the leading curtain magnet 475 is not energized. Is the attracting position of the front curtain magnet 475 (actually not attracted), and the front curtain completely shields the shutter opening. For this reason, the subject luminous flux does not enter the CCD 221. When the shutter motor 451 is turned off in step S317, the process returns to the original routine. In the present embodiment, the trailing curtain PI is detected in step S313, but it is of course possible to detect the leading curtain PI.

In the present embodiment, the shutter front curtain and the shutter rear curtain can be driven by one shutter motor 451, and the camera body 20 can be downsized. Similarly to the first embodiment, it is not necessary to energize the shutter magnet in order to maintain the state of each shutter curtain. That is, the charge state is mechanically held in the mechanical holding section. For this reason, when the through image display is performed, the shutter front curtain is held in a state after the shutter front curtain travels (the top dead center is 180 ° to 240 ° at the front curtain lift amount in FIG. 15), and the shutter rear curtain is mechanical. The trailing curtain charge state can be maintained in the target holding section (in the trailing curtain lift amount in FIG. 15, the top dead center is in the range of 180 ° to 300 °). As a result, when the through image is displayed, it is not necessary to continue energizing the rear curtain magnet in order to open the shutter, and it is possible to prevent the power battery from being consumed.

Next, the subroutine of the exposure operation in the second embodiment in step S85 (FIG. 7) will be described with reference to FIGS. When this subroutine is entered, first, as in the first embodiment, while the release button 21 is fully pressed, it is determined whether or not bulb photography for performing exposure is performed (S321). If bulb shooting has been set, the process jumps to step S431 in FIG. If bulb exposure has not been set, the process advances to step S323 to determine whether the exposure time is 4 seconds or longer. It is determined whether a long exposure of 4 seconds or more has been set manually or the like, or whether a long exposure time of 4 seconds or more has been set as a result of the exposure amount calculation in step S73. If an exposure time of 4 seconds or longer is set, the process jumps to step S381 in FIG. In this embodiment, the determination is made based on whether or not it is 4 seconds or longer. However, as described in the first embodiment, the time may be 2 seconds, 8 seconds, or the like, and the exposure time generally exceeds 1 second. I need it.

In step S323, if long exposure of 4 seconds or more has not been set, the process proceeds to step S325, and both the front curtain magnet 475 and the rear curtain magnet 485 are energized, whereby the front curtain magnet 475 is turned on. The lever 411 is attracted, and the rear curtain magnet 485 attracts the rear curtain lever 483. Subsequently, the shutter motor 451 is turned on (S327), the front curtain cam 455 and the rear curtain cam 461 are rotated, the signal of the rear curtain PI is input (S329), and the rising signal of the rear curtain PI is detected (S331). Then, the shutter motor 451 is turned off and the rotation is stopped (S333). By this series of operations, the front curtain lever 473 is attracted and held by the front curtain magnet 475, and the front curtain charge lever 471 is separated from the front curtain lever 473. As a result, when the energization of the front curtain magnet 475 is released, the front curtain lever 473 rotates clockwise in FIG. 14, and the shutter front curtain is ready to run. Similarly, the trailing curtain lever 483 is attracted and held by the trailing curtain magnet 485, and the trailing curtain charge lever 481 is separated from the trailing curtain lever 483. As a result, when the energization of the rear curtain magnet 485 is released, the rear curtain lever 473 rotates clockwise in FIG. 14, and the shutter rear curtain is ready to run.

Subsequently, the exposure time timer is started (S345), the energization of the front curtain magnet 475 is released, and the shutter front curtain starts to travel (S347). Then, it is determined whether or not the exposure time counting timer has completed timing (S349), that is, it is determined whether the exposure time set by the manually set exposure time or exposure amount has elapsed. When the set time counting operation is completed, the exposure time counting timer is stopped (S351), the energization of the rear curtain magnet 485 is released (S353), and the shutter rear curtain starts running. Waiting for a time (for example, about 10 mS) required for completion of the trailing curtain travel (S355), when this time has elapsed, the charging operation of the shutter leading curtain and the shutter trailing curtain is started.

In charge operation of the shutter front curtain and rear curtain, first, the shutter motor 451 is turned on to start rotation (S357). Subsequently, the output of the rear curtain PI is input (S359). When the trailing edge signal of the rear curtain PI is detected (S361), the shutter motor 451 is turned off because the shutter charge is completed (S363). When the exposure operation is completed, the routine returns to the power-on reset routine.

Next, the long exposure time will be described with reference to FIG. If it is determined in step S323 that the exposure time is 4 seconds or longer, the process jumps to step S381, and in this step, the front curtain magnet 475 is energized. As described above, since the shutter front curtain charging operation is completed in step S42 before the exposure operation starts, the front curtain lever 473 is attracted and held by energizing the front curtain magnet 475. Thereafter, the retracting operation of the front curtain charge lever 471 engaged with the front curtain lever 473 is performed in steps S383 to S389. That is, the shutter motor 451 is turned on (S383), rotation driving is started, the output of the front curtain PI is input (S385), and the rising signal of the front curtain PI is input (S387), the shutter motor 451 is turned off (S387). S389). Since the front curtain PI is detected and the shutter motor 451 is stopped by the rising signal, the front curtain cam lift amount in FIG. 15 is stopped at 270 °. Thus, when the energization of the front curtain magnet 475 is released, the shutter front curtain can start running.

Next, as in the first embodiment, an exposure time obtained by subtracting 1 second from the exposure time is calculated, this time is set in a timer, the timer is started (S391), and then the front curtain magnet 475 is immediately started. Is deenergized and the shutter front curtain starts to travel (S393). Similarly to the first embodiment, even in the long exposure of the second embodiment, taking into account the time required for retracting the trailing curtain charge lever 481 and allowing the trailing curtain to travel (1 second in this embodiment), After the shutter front curtain travels first, the retracting operation of the rear curtain charge lever 481 is performed before the shutter rear curtain starts. Therefore, as a matter of course, instead of 1 second in the present embodiment, the time x that is the exposure time> x> the trailing curtain drive time (preparation time) may be set. When the shutter front curtain travels, a subject image is formed on the CCD 221 and imaged. That is, at the time of imaging, the front curtain is lifted using the section of 270 ° to 300 ° as the front curtain cam lift amount of FIG. 15, and the rear curtain charge state is maintained.

In step S395, when the timekeeping operation of the timekeeping timer is completed, a timekeeping operation for 1 second is subsequently started by the timekeeping timer. Immediately thereafter, the rear curtain magnet 485 is energized to attract and hold the rear curtain lever 483. Thereafter, the retracting operation of the rear curtain charge lever 471 engaged with the rear curtain lever 473 is executed in steps S401 to S407. That is, the shutter motor 451 is turned on (S401), rotation driving is started, the output of the rear curtain PI is inputted (S403), and the rising signal of the rear curtain PI is inputted (S405), the shutter motor 451 is turned off (S405). S407). Thus, when the energization of the rear curtain magnet 475 is released, the shutter rear curtain can be started to travel. Thereafter, when the completion of the timing operation of the timing timer that has been counting one second is detected (S409), the timing timer is stopped (S411), and the process jumps to step S353 in FIG. I do.

As described above, also in the shooting operation in the long exposure seconds in the second embodiment, the shutter front curtain starts to travel first, and the retracting operation of the rear curtain charge lever 471 engaged with the rear curtain cam 461 is performed after traveling. I am doing so. For this reason, the time lag until the start of the front curtain travel can be shortened. In this embodiment, the preparation for the trailing curtain travel such as the retracting time of the trailing curtain charge lever 429 is set to 1 second, and 1 second is subtracted in step S391. This time is the minimum time required by the shutter drive mechanism. That's all there is to it.

Further, in the second embodiment, a short-time exposure is performed by using the timing difference between the front curtain mechanical holding release section and the rear curtain mechanical holding release section of both the front curtain cam 455 and the rear curtain cam 461. And long exposure time. For this reason, even during long exposure, the energization time of the current for attracting and holding the rear curtain magnet 485 for holding the rear curtain can be shortened, and consumption of the power supply battery can be suppressed.

Next, the valve time in the second embodiment will be described with reference to FIG. If it is determined in step S321 that bulb shooting is being performed, the process jumps to step S431, and in this step, the front curtain magnet 475 is energized. As a result, the front curtain lever 473 is sucked and held. Thereafter, the retracting operation of the front curtain charge lever 471 engaged with the front curtain lever 473 is performed in steps S433 to S439. Since this operation is the same as that in steps S383 to S389 described above, description thereof will be omitted. Thus, when the energization of the front curtain magnet 417 is released, the shutter front curtain can start running.

Subsequently, the energization of the front curtain magnet 475 is released (S441), and the travel of the shutter front curtain is started. In the bulb shooting, the shutter is opened only during the time when the release button 21 is fully pressed. Therefore, in step S443, when 2R of the release button 21 is turned off, that is, the end of shooting is detected, the shutter is closed. To start. In closing the shutter, first, the rear curtain magnet 485 is energized, and the rear curtain lever 483 is attracted and held. The retracting operation of the trailing curtain charge lever 481 engaged with the trailing curtain lever 483 is performed in steps S447 to S453. Since this evacuation operation is the same as steps S401 to S407, description thereof is omitted. In step S453, when the shutter motor 451 is turned off, the operation jumps to step 353 in FIG. When these series of bulb photographing operations are completed, the routine returns to the power-on reset routine.

As described above, in the first and second embodiments of the present invention, the shutter front curtain and the shutter rear curtain can be operated independently, and the through image display is performed in the mechanical holding section (in FIG. This is performed in the target holding section (through image section in FIG. 15). In this mechanical holding section, the rear curtain of the shutter is not held by the rear curtain magnets 437 and 485, but is held by the rear curtain cams 427 and 461, the rear curtain charge levers 429 and 481, etc. A current consumption for attracting and holding the curtain magnets 437 and 485 is not required, and consumption of the power supply battery can be reduced.

In the first and second embodiments, the CCD 221 serving as an image sensor receives light transmitted through the movable half mirror 201, and the distance measuring / photometric sensor 217 receives light reflected from the movable half mirror 201. On the contrary, the CCD 221 may be configured to receive reflected light, and the distance measuring / photometric sensor 217 may be configured to receive transmitted light. Further, although the subject luminous flux is divided into the CCD 221 and the distance measurement / photometry sensor 217 using the movable half mirror 201, it is of course possible to guide the subject luminous flux using a total reflection mirror when necessary.

Further, in the first and second embodiments, the image pickup device is only the CCD 221, but the image pickup device is not limited to this, and another image pickup device is arranged in the viewfinder optical system, and the recording image pickup device and the viewfinder optical system are used. The present invention can also be applied to a case where a through image is displayed by switching both or any of the outputs of the image sensor.

In the first and second embodiments, the present invention is applied to a general digital camera. However, the present invention is not limited thereto, and may be a photographing device in various devices such as a portable device, a bellows, an extension tube, and the like. Of course, it may be applied to a dedicated camera attached to various devices such as a microscope and binoculars. The present invention is not limited to a general digital camera, and can be applied to any digital camera that displays a through image using the output of an image sensor.

It is the external appearance perspective view which looked at the digital camera in 1st Embodiment of this invention from the back surface. It is a block diagram which shows the whole structure of the electric system of the digital camera in 1st Embodiment to which this invention is applied. It is a perspective view which shows the components structure of the shutter drive mechanism in 1st Embodiment of this invention. It is a top view which shows the structure of the shutter drive mechanism in 1st Embodiment of this invention. In the first embodiment of the present invention, (A) the lift amount of the front curtain cam and the signal output relationship of the front curtain PI, (B) the relationship between the lift amount of the rear curtain cam and the signal output of the rear curtain PI. is there. It is a flowchart which shows the operation | movement of the power-on reset in 1st Embodiment of this invention. It is a flowchart of the imaging | photography operation | movement in 1st Embodiment of this invention. It is a flowchart of shutter opening in 1st Embodiment of this invention. It is a flowchart of shutter closing in a 1st embodiment of the present invention. It is a flowchart of the exposure operation | movement in 1st Embodiment of this invention. It is a flowchart of the exposure operation | movement in 1st Embodiment of this invention. It is a flowchart of the exposure operation | movement in 1st Embodiment of this invention. It is a perspective view which shows the components structure of the shutter drive mechanism in 2nd Embodiment of this invention. It is a top view which shows the structure of the shutter drive mechanism in 2nd Embodiment of this invention. It is a figure which shows the relationship between the lift amount of the front curtain cam and the rear curtain cam, and the signal output of front curtain PI and rear curtain PI in 2nd Embodiment of this invention. It is a flowchart of shutter opening in 2nd Embodiment of this invention. It is a flowchart of shutter closing in 2nd Embodiment of this invention. It is a flowchart of the exposure operation | movement in 2nd Embodiment of this invention. It is a flowchart of the exposure operation | movement in 2nd Embodiment of this invention. It is a flowchart of the exposure operation | movement in 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Lens barrel 20 Camera main body 21 Release button 23 Power switch lever 26 Back surface liquid crystal monitor 29 In-finder liquid crystal monitor 33 Viewfinder eyepiece 101a, 101b Lens 103 Diaphragm 111 Lens CPU
201 Movable half mirror 203 Shutter 205 Dustproof filter 207 Piezo element 209 Infrared cut filter 210 Optical low-pass filter 215 Movable mirror drive mechanism 217 Distance / photometry sensor 219 Distance / photometry processing circuit 221 CCD
227 Image processing circuit 229 Body CPU
253 Switch detection circuit 255 Various switches 257 Power switch 259 Attachment / detachment detection switch 261 Data bus 401 Front curtain motor 405 Cam gear 407 Front curtain cam 409 Front curtain charge lever 411 Front curtain lever 417 Front curtain magnet 421 Rear curtain motor 423 Gear 425 Cam gear 427 Rear Curtain cam 429 Rear curtain charge lever 431 Rear curtain lever 437 Rear curtain magnet 451 Shutter motor 453 Cam gear 455 Front curtain cam 459 Cam gear 461 Rear curtain cam 471 Front curtain charge lever 473 Front curtain lever 475 Front curtain magnet 481 Rear curtain charge lever 483 Rear Curtain lever 485 Rear curtain magnet

Claims (10)

An imaging means including an imaging device for receiving a subject luminous flux;
Based on the subject image signal output from the imaging means, a through image display means for displaying a moving image of the subject on a display device;
Shutter means for blocking a subject luminous flux incident on the image sensor;
Comprising
The shutter means includes a focal plane shutter having a front curtain and a rear curtain that can be operated independently, and the front curtain is shifted from a closed state to an open state at the start of moving image display of the through image display means, and then the A digital camera that shifts from an open state to a closed state at the end of video display.   2. The shutter unit according to claim 1, further comprising: a charging mechanism that charges each of the front curtain and the rear curtain independently; and a holding mechanism that holds the front curtain and the rear curtain in a charged state. The digital camera described. 3. The digital camera according to claim 2, wherein the shutter means travels the front curtain at the start of moving image display of the through image display means, and charges the front curtain at the end of the moving image display.   The digital camera according to claim 2, wherein the holding mechanism can sequentially release the holding by rotation of one gear.   3. The digital camera according to claim 2, wherein the shutter means changes the release timing of the holding of the front curtain and the rear curtain according to the exposure time during the photographing operation.   3. The digital camera according to claim 2, wherein the shutter means changes the holding timing of the front curtain and the rear curtain in bulb shooting. An imaging means including an imaging device for receiving a subject luminous flux;
Through image display means for displaying a moving image of a subject on a display device based on a subject image signal output from the image sensor;
Shutter means for blocking a subject luminous flux incident on the image sensor;
Comprising
The shutter means includes a focal plane shutter having a front curtain and a rear curtain that can be operated independently, and only the front curtain is opened and closed during the moving image display of the through image display means, and the front curtain is used during a photographing operation. A digital camera characterized in that the rear curtain is made to travel after traveling. An imaging means including an imaging device for receiving a subject luminous flux;
Through image display means for displaying a moving image of a subject on a display device based on a subject image signal output from the image sensor;
Shutter means for blocking a subject luminous flux incident on the image sensor;
Comprising
The shutter means opens only the shutter front curtain during the moving image display of the through image display means, and the shutter rear curtain mechanically holds the current magnet without energizing the shutter rear curtain holding electromagnet to perform the shooting operation. In this case, the digital camera is characterized in that the shutter rear curtain is caused to travel after the front curtain travels. 9. The digital camera according to claim 8, wherein the shutter means has a cam mechanism, and the shutter rear curtain is held by the cam mechanism during the through image display. 9. The digital camera according to claim 8, wherein the shutter means holds the shutter rear curtain for a predetermined time by the mechanical holding during long exposure or bulb photography.