JP2007312196A - Live view capable camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a live view capable camera for decreasing a shutter time lag when photographing from a live view display state. <P>SOLUTION: The camera includes a cam member with a cam face comprising: a charge region (cam region a) for applying charge operation to a normally open type shutter 213 and a moving reflection mirror 201; a standby region (cam region b) for maintaining the shutter 213 to a charge completion state and holding the moving reflection mirror 201 to a reflection position; a live view region (cam region c) for maintaining the shutter 213 to the charge completion state and holding the moving reflection mirror 201 to a saving position; and a photographing region (cam region d) wherein the shutter screen of the shutter 213 can be run and for holding the moving reflection mirror 201 to a photographing region. A motor is driven to select each region of the cam member depending on a mode of the camera. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

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

In conventional cameras, the subject image is observed with an optical viewfinder. However, recent compact digital cameras abolish the viewfinder optical system together with the optical viewfinder, and continuously acquire images acquired by the image sensor. More and more, so-called live view display functions for displaying on a display device such as a liquid crystal monitor are increasing.

Such a live view display function is effective, for example, at the time of macro photography because no parallax occurs. For this reason, various examples mounted on a digital single lens reflex camera have been proposed. For example, the optical viewfinder display mode and the electronic viewfinder display mode can be selected, and when the electronic viewfinder display mode is selected, the movable mirror is retracted from the photographing optical path and the focal plane shutter is fully opened to guide the subject image to the image sensor. A digital single-lens reflex camera capable of live view has been proposed in which a subject image obtained thereby is continuously displayed on a liquid crystal monitor disposed outside (Patent Document 1).
JP 2002-369042 A

By the way, in order to perform live view display, the shutter is fully opened, but at this time, the shutter remains in an uncharged state. For this reason, it is necessary to charge the shutter when photographing, and there is a problem that the release time lag becomes very long as much as the shutter charge is applied.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a camera capable of live view in which a shutter time lag is reduced when shooting is performed from a live view display state.

In order to achieve the above object, a live viewable camera according to a first aspect of the present invention includes an imaging device, a reflection position that reflects a subject light beam, a reflection mirror that moves to a retraction position that is retreated from the subject light beam, and the reflection mirror. Disposed between the mirror and the image sensor, a pair of shutter curtains can be run by being charged, and the shutter image that has been fully charged is displayed and the image formed on the image sensor is displayed. A display unit that performs charging of the shutter and driving of the reflecting mirror, and a first region that charges the shutter and continuously maintains the charged state; and Shutter cam means for the shutter composed of the second area where the shutter is not charged, and the reflection mirror from the retracted position to the opposite side. A third region that is driven to a position and positioned at the reflection position; and a fourth region that is continuously driven from the reflection position to the retracted position to position the reflective mirror at the retracted position In the normal shooting preparation state, the reflecting mirror is positioned at the reflecting position by the third area of the mirror cam means, and the shutter is moved by the first area of the shutter cam means in synchronization with this. In the shooting preparation state in which the image is formed on the image sensor and displayed on the display means to enable live view, the reflecting mirror is retracted by the fourth area of the mirror cam means. In synchronism with this, the first region of the shutter cam means positions the shutter in a charge-completed state so that the shutter Control means for controlling the curtain to an open state is provided.

In order to achieve the above object, a live viewable camera according to a second aspect of the present invention comprises an imaging device, a reflection position that reflects a subject light beam, a reflection mirror that moves to a retraction position that is retreated from the subject light beam, and the reflection mirror. Disposed between the mirror and the image sensor, a pair of shutter curtains can be run by being charged, and the shutter image that has been fully charged is displayed and the image formed on the image sensor is displayed. A display unit that performs charging of the shutter and driving of the reflecting mirror, and a first region that charges the shutter and continuously maintains the charged state; and A shutter cam portion for a shutter including a second area where the shutter is not charged, and the reflection mirror is reflected from the retracted position. A third region (non-driving region) that is driven to a position and positioned at the reflection position; and subsequently, the reflection mirror is driven from the reflection position to the retracted position, and the reflection mirror is positioned at the retracted position. A mirror cam portion formed of a fourth region (retracted position holding region) to be formed, and while the first region charges the shutter and the charge position, the third region brings the mirror to the reflection position. Driving, and subsequently, the fourth area drives the mirror to the retracted position, and then the second area moves the shutter to the retracted position while the fourth area moves the mirror to the retracted position. In the normal shooting preparation state, the reflecting mirror is positioned at the reflection position by the third region of the cam member, and the shutter is charged by the first region of the cam member. In the shooting preparation state in which the image is formed on the image sensor and displayed on the display means and the live view is enabled, the reflection mirror is moved by the fourth region of the cam member. Control means for controlling the shutter curtain to be in an open state by positioning the shutter in a fully charged state by the first region of the cam member that is positioned in the retracted position.
According to a third aspect of the present invention, in the second aspect of the invention, the shutter cam portion and the mirror cam portion of the cam member are configured as separate cams.
Further, in the camera capable of live view according to the fourth invention, in the third invention, the shutter cam portion and the mirror cam portion further rotate integrally.

In order to achieve the above object, a live viewable camera according to a fifth aspect of the present invention includes a movable reflecting mirror that is movable to a reflection position on a photographing optical path of a photographing lens and a retreat position that is retracted from the photographing optical path, An image sensor that is disposed on the photographing optical path of the photographing lens, receives a subject image formed by the photographing lens, and outputs a photoelectric conversion signal, and is disposed between the image sensor and the movable reflecting mirror, A normal open type shutter for controlling the exposure time of the subject image on the image sensor during photographing, a display device for live view display of the subject image based on the photoelectric conversion signal, and the live view display In performing the above, the shutter is kept in the open state when the charging is completed, and the movable reflecting mirror is driven to the retracted position to In performing Bubyu display comprises a driving control means for driving the reflection position the movable reflecting mirror with keeping an open state the shutter in the charge completion state.

The camera capable of live view according to the sixth invention is the camera according to the fifth invention, wherein the drive control means positions the movable reflecting mirror at the retracted position and closes the shutter front curtain during photographing. Once driven, the opening operation is performed.
According to a seventh aspect of the present invention, in the fifth aspect of the present invention, the drive control means includes a charge cam mechanism for driving the movable reflecting mirror. The cam surface has a non-live view display area, a live view area, and a shooting area formed continuously, and the non-live view display area is a cam surface for positioning the movable reflection mirror at the reflection position. The live view area and the shooting area are cam surfaces for positioning the movable reflecting mirror at the retracted position.
Further, the camera capable of live view according to the eighth invention is the camera according to the fifth invention, wherein the drive control means has a charge cam mechanism for driving the shutter, and the cam surface of the charge cam mechanism. The non-live view display area, the live view area, and the shooting area are continuously formed. The non-live view display area and the live view area hold the shutter in a charged state, and the shooting area is the shutter. The position of the shutter curtain is allowed to travel.
Furthermore, the camera capable of live view according to the ninth invention is the cam for driving the shutter front curtain closed once between the live view area and the shooting area in the fifth invention. Has a surface.

In order to achieve the above object, a live viewable camera according to the tenth aspect of the present invention is a motor, a reflection position that enters the light beam from the photographing lens and reflects the light beam, and retreats from the light beam passage area from the photographing lens. A movable reflecting mirror driven to the retracted position, a normally open type shutter disposed behind the movable reflecting mirror, a charge region for charging the shutter and the movable reflecting mirror by rotation of the motor, A standby area for holding the shutter in a fully charged state and holding the movable reflecting mirror in the reflecting position; a live view area for holding the shutter in a fully charged state and holding the movable reflecting mirror in the retracted position; The shutter curtain of the shutter can be moved and the movable reflecting mirror is raised. A cam member having a cam surface composed of an imaging region held at a retracted position, and a control unit that controls driving so as to select each region of the cam member by rotating the motor according to a camera mode; .

According to an eleventh aspect of the present invention, in the camera according to the tenth aspect, in the photographing mode in the normal mode, the control means drives and controls the cam member from the standby area to the photographing area. In the shooting state in the view, the cam member is driven and controlled from the live view area to the shooting area.
The camera capable of live view according to a twelfth aspect of the present invention is the camera according to the tenth aspect, wherein the shutter temporarily closes the shutter front curtain by a cam surface between the live view area and the shooting area. .
Further, the camera capable of live view according to the twelfth aspect of the present invention is the camera of the tenth aspect, wherein the shutter is held in the charge area until the shutter travels after the shutter is charged in the charge area. .

In the camera capable of live view according to the present invention, when performing live view display, the shutter is kept open in a charged state and the movable reflecting mirror is driven to the retracted position, so it is necessary to charge the shutter during shooting. Therefore, it is possible to provide a camera capable of live view in which the shutter time lag is reduced when shooting is performed from the live view display state.

Hereinafter, a preferred embodiment using a digital single lens reflex camera to which the present invention is applied will be described with reference to the drawings. FIG. 1 is a block diagram illustrating a schematic configuration of an internal mechanism of a digital single-lens reflex camera according to an embodiment. FIG. 1A is a block diagram illustrating an internal configuration along the optical axis direction of a photographing lens, and FIG. FIG. 3 is a block diagram of an internal configuration viewed from the front side of a main body 200.

A release button 21 is disposed on the upper surface of the camera body 200. 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. 6) as an image sensor.

A movable reflecting mirror 201 is disposed in the mirror box of the camera body 200 on the optical axis of the photographing lens 101 (see FIG. 6) disposed inside the lens barrel 100. The movable reflecting mirror 201 captures a subject image and a reflection position inclined by 45 degrees with respect to the optical axis of the photographing lens 101 in order to reflect a subject light beam to a finder optical system (for example, a pentaprism 207). In order to guide to a CCD (Charge Coupled Device) 221), it can be rotated to a retracted position retracted from the photographing optical path. The rotation axis of the movable reflecting mirror 201 is along the direction perpendicular to the paper surface of FIG. The movable reflecting mirror 201 reflects the subject luminous flux upward. In the present embodiment, the light is totally reflected upward. However, the present invention is not limited to this, and the reflection direction of the subject light flux is most appropriate in terms of the arrangement of the mechanism member and the optical member regardless of whether the camera body 200 is on the right side or the left side. You may choose to be.

A focusing screen 205 is disposed on the reflection optical axis of the movable reflection mirror 201, which is a matte surface for forming an image of a subject light beam by the photographing lens 101. The distance from the movable reflection mirror 201 is equivalent to that of the CCD 221. Arranged in position. Above the focusing screen 205, a pentaprism 207 for horizontally inverting the subject image is disposed. The finder eyepiece 33 is an eyepiece of the finder optical system, and the photographer can look into the eyepiece 33 to check the subject image.

Near the center of the movable reflecting mirror 201 described above is a half mirror, and on the back surface of the movable reflecting mirror 201, a sub mirror 203 is provided for distance measurement for reflecting the subject light beam that has passed through the half mirror section. ing. The sub mirror 203 is rotatable with respect to the movable reflection mirror 201. When the movable reflection mirror 201 is retracted from the photographing optical path and the subject light beam is incident on the CCD 221, the sub mirror 203 is rotated to a position covering the half mirror portion. When the movable reflection mirror 201 is at the subject image observation position (reflection position) as shown in the figure, it rises with respect to the movable reflection mirror 201 and is open so that a part of the subject luminous flux can be reflected by the distance measuring unit. The movable reflecting mirror 201 is driven by a shutter / mirror driving unit 303. Further, a distance measuring unit 218 including a TTL phase difference type distance measuring circuit 217 (see FIG. 6) including a distance measuring sensor is disposed on the reflected light path of the sub-mirror 203. The amount of focus shift of the subject image formed by is detected.

A normally open type focal plane shutter 213 is disposed behind the movable reflecting mirror 201 for exposure time control. The shutter 213 includes a shutter controller 213a including a shutter drive mechanism 215 (FIG. 6) and a shutter mirror. Drive control is performed by the drive unit 303. A CCD 221 serving as an image sensor is disposed behind the shutter 213 and photoelectrically converts a subject image formed by the photographing lens into an electric signal. 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.

A battery 305 for supplying power to the entire camera body 200 is disposed on the left side when viewed from the front of the camera body 200. Further, as will be described later, a mirror shutter (hereinafter abbreviated as “MS”) motor 301 serving as a driving source for the shutter 213 and the movable reflecting mirror 201 is disposed on the right side of the main body, and transmits the driving force of the MS motor 301. The shutter / mirror driving unit 303 for the motor is disposed below the MS motor 301 so as to engage with the driving shaft of the MS motor 301. A shutter control unit 213 a for controlling the driving of the shutter 213 is disposed beside the movable reflecting mirror 201.

Next, the driving mechanism of the movable reflecting mirror 201 and the shutter 213 will be described with reference to FIGS.
2A and 2B are diagrams showing the shutter 213 and the movable reflecting mirror 201, where FIG. 2A is a perspective view of the shutter 213, FIG. 2B is a front view of the shutter 213, and FIG. 2C is a perspective view of the mirror. ) Shows the mirror-down state of the movable reflecting mirror 201, and (E) shows the mirror-up state. As shown in FIG. 2A, a shutter control unit 213a is disposed on the side of the shutter 213, and a shutter set lever 213b protrudes below the shutter control unit 213a. In the initial state, the shutter set lever 213b is in the position (a) indicated by the oblique line in FIG. 2B, and in the shutter charge completed state, the shutter set lever 213b is in the position indicated by the solid line (A) in FIG. Moving.

As described above, the shutter 213 is a normally open type focal plane shutter. In the normal state, the shutter front curtain and the rear curtain are stored in the storage chamber, and the front of the CCD 221 is open. Prior to shooting with the CCD 221, the first and second curtain magnets are held. By returning the shutter set lever 213b to the initial state (a) in this state, the shutter front curtain moves to a closed state that blocks the photographing optical path. When the front curtain magnet is released in this state, exposure starts when the shutter front curtain starts running, and after the exposure time elapses, the shutter rear curtain starts running when the rear curtain magnet is released. End the exposure. After these exposure operations are completed, when the shutter set lever 213b is charged to the position (a) in the charging completed state, the shutter 213 is charged, and the shutter rear curtain is retracted from the photographing optical path and stored in the storage chamber. The front is open. As described above, the normal open type focal plane shutter is a shutter that is open in a normal state and temporarily closed before and after photographing.

When the movable reflecting mirror 201 is in the down state, the sub mirror 203 is rotated to a position opened with respect to the movable reflecting mirror 201 as shown in FIG. As shown in FIG. 2 (D), a mirror down spring 345 is provided on the rotating shaft side of the movable reflecting mirror 201, and this mirror down spring 345 is attached in the counterclockwise direction in FIG. It is energized. The movable reflecting mirror 201 biased by the mirror down spring 345 is regulated at a position of 45 degrees with respect to the photographing optical path by a position regulating pin 349. The mirror drive lever 341 has an L-shape, and is biased by a mirror drive spring 343 in the counterclockwise direction, that is, the up direction for raising the mirror. One end of the mirror driving lever 341 is disposed at a position where it can engage with an engaging pin 347 fixed to the movable reflecting mirror 201. Note that the spring force of the mirror drive spring 343 is always stronger than the spring force of the mirror down spring 345.

In the mirror down state, the mirror drive lever 341 is rotated clockwise by the mirror charge lever 351 against the urging force of the mirror drive spring 343, and is in the position shown in FIG. In this state, when the mirror charge lever 351 that locks the mirror drive lever 341 moves to the right, the mirror drive lever 341 rotates counterclockwise by the biasing force of the mirror drive spring 343. With this rotation, the movable reflecting mirror 201 is rotated from the down position to the up position via the engagement pin 347, and the state shown in FIG. From this state, the mirror charge lever 351 moves to the left against the urging force of the mirror drive spring 343 and reaches the position shown in FIG.

FIG. 3 is an exploded perspective view of the shutter / mirror driving unit 303 to which the driving force of the MS motor 301 is transmitted. The driving force of the MS motor 301 is transmitted to the cam gear 357 via the gear 363. A mirror charge cam 353 having a circumferential surface that changes in the radial direction of the rotation axis of the cam gear 357 is fixed on the upper surface of the cam gear 357, and one end of the mirror charge lever 351 is provided on the cam surface 353a of the mirror charge cam 353. Is engaged. The other end of the mirror charge lever 351 is in contact with the mirror drive lever 341. Since the mirror drive lever 341 is spring-biased in a direction to rotate the mirror charge lever 351 clockwise (see FIG. 2), one end of the mirror charge lever 351 is in pressure contact with the mirror charge cam 353. Become. Accordingly, as the cam gear 357 rotates, the mirror charge cam 353 integrated with the cam gear 357 rotates, and the mirror charge lever 351 pressed against the cam surface of the mirror charge cam 353 rotates.

A cam surface 355a of a shutter charge cam 355 having a circumferential surface that changes in the radial direction of the rotation axis of the cam gear 357 is fixed to the lower surface of the cam gear 357. The shutter charge cam 355 includes a shutter charge lever 361. One end is engaged. The other end of the shutter charge lever 361 is in contact with the shutter set lever 213b. Accordingly, as the cam gear 357 rotates, the shutter charge cam 355 integrated therewith also rotates, and the shutter charge lever 361 engaged with the cam surface of the shutter charge cam 355 rotates, and the shutter set lever 213b. Also rotate.

4A shows the cam surface 353a of the mirror charge cam 353 seen from the AA direction, and FIG. 4B shows the cam surface 355a of the shutter charge cam 355 seen from the BB direction. As shown in the figure, the cam surface 353a of the mirror charge cam 353 is composed of four areas: a lift cam a, a top dead center area b, a bottom dead center area c, and a bottom dead center area d. As shown in the figure, the cam surface 355a of the shutter charge cam 355 is composed of four areas: a lift cam a, a top dead center area b, a bottom dead center area c, and a bottom dead center area d. Note that the relative rotational positional relationship between the mirror charge cam 353 and the shutter charge cam 355 in FIG. 4 has been described with the same reference position, but the arrangement of the mirror charge lever 351 and the shutter char lever 361 indicates the mutual relationship. The reference position changes. Although not shown, a plurality of photo interrupters are provided for detecting the rotation or movement of the mirror charge cam 353, the shutter charge cam 355, or a member driven integrally with these. By these photo interrupters, b detection for outputting L level while in the region b and d detection for outputting L level while in the region d are performed (see FIG. 5).

The cam area a is a charge area. In this area, both the mirror charge lever 351 and the shutter charge lever 361 rotate. As the mirror charge lever 351 is rotated, the mirror drive lever 341 is also rotated to charge the mirror drive spring 343, and the movable reflecting mirror 201 is lowered by the urging force of the mirror down spring to become a reflection position. Further, as the shutter charge lever 361 rotates, the shutter set lever 213b moves from the position shown in FIGS. 2B and 2A to the position shown in FIG.

The cam area b is a standby area, the mirror charge cam 353 is at the top dead center, and the movable reflecting mirror 201 is in the down state (see FIG. 2D), that is, an observation position (reflection) that reflects the subject light beam to the finder optical system. Position). In this state, the subject luminous flux is guided to the finder optical system, so that the subject image can be observed by the finder, and the subject luminous flux is also guided to the photometric element 211 described later, so that photometry is possible, and further, the sub mirror 203 As a result, the subject luminous flux is guided to the distance measuring unit 218, so that distance measurement and driving of the photographing lens to the in-focus position (automatic focus adjustment) are possible. The shutter charge cam 355 is also at the top dead center, and is in a charged state as shown in FIGS. Although the shutter 213 is in a charged state, the shutter set lever 213b is not retracted, so that the shutter curtain cannot run and exposure is not performed.

The cam area c is a live view area, the mirror charge cam 353 is at the bottom dead center, and the movable reflecting mirror 201 is in the up state (see FIG. 2E), that is, at the retracted position retracted from the photographing optical path. Further, the shutter charge cam 355 is at the top dead center, and the shutter set lever 213b remains in the charged state shown in FIGS. In this state, it is impossible to observe the subject image with the optical viewfinder, but since the subject image is formed on the CCD 211 as the image sensor, the image information from the CCD 221 can be output. Based on this, it is possible to display a subject image on the liquid crystal monitor 26.

The cam area d is an imaging area, the mirror charge cam 353 is at the bottom dead center, and the movable reflecting mirror 201 is in the up state (see FIG. 2E), that is, at the retracted position retracted from the imaging optical path. The shutter charge cam 355 is at the bottom dead center, and the shutter set lever 213b is moved to the position shown in FIGS. 2B and 2A so that the shutter front curtain and the rear curtain can run (retracted position). ing. This state is when 2R is turned on by operating the release button 21, and the shutter front curtain and the rear curtain respectively run according to the release of the suction of the shutter magnet that holds the shutter 213. Can be imaged and recorded.

The mirror charge cam 353 and the shutter charge cam 355 rotate counterclockwise in the drawing (counterclockwise), and rotate the mirror charge lever 351 and the shutter charge lever 361 having the cam follower configuration as described above. In the normal mode, charging is completed in the cam area b and the camera is in a standby state (observable with the optical viewfinder), and is driven to the cam area d according to the operation of the release button 21 to perform photographing. On the other hand, in the live view mode, the shutter charge is completed in the cam area c and the movable reflection mirror 201 is mirrored up to perform live view display, and the cam area d is driven in accordance with the operation of the release button 21 to perform photographing.

Next, with reference to FIG. 6, an overall configuration mainly including an electric system of the digital single-lens reflex camera will be described. In the digital single-lens reflex camera according to the present embodiment, as described above, the interchangeable lens 100 and the camera body 200 are configured separately, and both are electrically connected by the communication contact 300. Note that the interchangeable lens 100 and the camera body 200 can be configured integrally.

Inside the interchangeable lens 100, lenses 101 and 102 for focus adjustment and focal length adjustment, and a diaphragm 103 for adjusting the aperture amount are arranged. The lens 101 and the lens 102 are driven by a lens driving mechanism 107, and the diaphragm 103 is connected to be driven by a diaphragm driving mechanism 109. The lens 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 200 via a communication contact 300. The lens CPU 111 controls the inside of the interchangeable lens 100. The lens CPU 111 controls the lens driving mechanism 107 to perform focusing and zoom driving, and also controls the aperture driving mechanism 109 to perform aperture value control.

In the camera main body 200, the movable reflecting mirror 201, the sub mirror 203, the focusing screen 205, and the pentaprism 207 are arranged as described above. The movable reflecting mirror 201 is driven by a mirror driving mechanism 219. An eyepiece lens 209 for observing a subject image is disposed on the emission side of the pentaprism 207, and a photometric sensor 211 is disposed at a position on the side of the pentaprism 207 that does not interfere with the observation of the subject image. The focusing screen 205, the pentaprism 207, and the eyepiece lens 209 constitute a part of the finder optical system.

As described above, the sub mirror 203 is provided on the back surface of the movable mirror 201, and the distance measuring circuit 217 including the focus sensor is disposed in the reflection direction of the sub mirror 203. Further, a shutter 213 is disposed behind the movable mirror 201, and this shutter 213 is driven and controlled by a shutter drive mechanism 215. Further, a CCD 221 as an image sensor is disposed behind the shutter 213, and the subject image formed by the lenses 101 and 102 is photoelectrically converted into an electric signal. The CCD 221 is connected to a CCD drive circuit 223, and analog / digital conversion (AD conversion) is performed by the CCD drive circuit 223. The CCD drive circuit 223 is connected to the image processing circuit 227 via the CCD interface 225. The image processing circuit 227 performs various types of image processing such as color correction, gamma (γ) correction, and contrast correction. Also, image data for live view display on the liquid crystal monitor 26 is generated.

The image processing circuit 227 is an ASIC (Application Specific Integrated).
Circuit-specific integrated circuit) 271 is connected to the data bus 261. In addition to the image processing circuit 227, the data bus 261 includes a body CPU 229, a compression circuit 231, a flash memory control circuit 233, an SDRAM control circuit 236, an input / output circuit 239, a communication circuit 241, a recording medium control circuit 243, and a video signal output. A circuit 247 and a switch detection circuit 253 are connected.

The body CPU 229 connected to the data bus 261 controls the flow of this digital single lens reflex camera. A compression circuit 231 connected to the data bus 261 is a circuit for compressing the image data stored in the SDRAM 237 with JPEG or TIFF. Note that image compression is not limited to JPEG or TIFF, and other compression methods can be applied. A flash memory control circuit 233 connected to the data bus 261 is connected to a flash memory 235. The flash memory 235 stores a program for controlling the flow of the single-lens reflex camera. The CPU 229 controls the digital single-lens reflex camera according to the program stored in the flash memory 235. Note that the flash memory 235 is an electrically rewritable nonvolatile memory. The SDRAM 237 is connected to the data bus 261 via the SDRAM control circuit 236, and the SDRAM 237 temporarily stores the image data processed by the image processing circuit 227 or the image data compressed by the compression circuit 231. This is a buffer memory.

The input / output circuit 239 connected to the above-described photometric sensor 211, shutter drive mechanism 215, distance measuring circuit 217, and mirror drive mechanism 219 controls input / output of data with each circuit such as the body CPU 229 via the data bus 261. . The communication circuit 241 connected to the lens CPU 111 via the communication contact 300 is connected to the data bus 261, and exchanges data with the body CPU 229 and the like and communicates control commands. A recording medium control circuit 243 connected to the data bus 261 is connected to the recording medium 245 and controls recording of image data and the like on the recording medium 245. The recording medium 245 can be loaded with any rewritable recording medium such as an xD picture card (registered trademark), a compact flash (registered trademark), an SD memory card (registered trademark), or a memory stick (registered trademark). And is detachable from the camera body 200. In addition, the hard disk may be configured to be connectable via a communication contact.

The video signal output circuit 247 connected to the data bus 261 is connected to the liquid crystal monitor 26 via the liquid crystal monitor drive circuit 249. The video signal output circuit 247 is a circuit for converting the image data stored in the SDRAM 237 and the recording medium 245 into a video signal to be displayed on the liquid crystal monitor 26. The liquid crystal monitor 26 is disposed on the back surface of the camera body 200. However, the liquid crystal monitor 26 is not limited to the back surface as long as the photographer can observe the image. A switch for detecting the first and second strokes of the shutter release button, a switch for instructing a reproduction mode, a switch for instructing the movement of the cursor on the screen of the liquid crystal monitor 26, a switch for instructing a photographing mode, and each selected mode The various switches 255 such as an OK switch for determining etc. are connected to the data bus 261 via the switch detection circuit 253.

Next, the flow of live view display will be described with reference to FIG. When live view display is started by operating an operation button (not shown) of the camera body 200, first, photometry / exposure amount calculation is performed (S1). Here, since it is still in the cam region b (see FIG. 5) and the movable reflection mirror 201 is in the reflection position, the photometric element 211 measures a part of the subject light beam guided from the movable reflection mirror 201, and this photometry Based on the value, the body CPU 229 calculates an exposure value such as a shutter speed and an aperture value. Subsequently, initial setting for performing live view is performed (S2). In this initial setting, power is supplied to the CCD 221, live view display conditions are set in order to keep the brightness of the live view display on the liquid crystal monitor 26 appropriate, and the mirror up operation of the movable reflecting mirror 201 is also performed. The latter will be described later with reference to FIG. Note that live view display is started in the live view initial setting.

Next, it is determined whether or not the release button 21 is half-pressed, that is, whether or not 1R is on (S3). If the result of determination is that it is on, processing advances to step S5, and an automatic focus adjustment (AF) subroutine is executed. In this subroutine, automatic focus adjustment and photometry are performed while the subject image is live-viewed on the liquid crystal monitor 26. This automatic focus adjustment and photometry operation are carried out through the cam areas d and a to the cam area b, and in this area, the movable reflecting mirror 201 is lowered to the reflection position and photometry is performed by the distance measuring element 211 and the sub mirror. The distance measuring circuit 217 performs the distance measuring operation and the photographing lens focusing operation on the basis of the subject light flux guided by 203. When the distance measuring operation is completed, the camera moves to the cam area c again and the live view display is resumed.

When the automatic focus adjustment (AF) in step S5 ends, it is subsequently determined whether or not the release button 21 has been fully pressed, that is, whether or not 2R is on (S7). As a result of the determination, if 2R is on, the process proceeds to step S9, and the photographing operation is executed. This shooting operation subroutine will be described later with reference to FIG. When the shooting operation is completed, the process returns to the initial setting of the live view in step S2, and the above steps are repeated. Returning to step S7, if 2R is off, the process proceeds to step S11 to determine whether 1R is on. If the release button 21 is half-pressed but not fully pressed, a standby state is made in which the determinations in steps S7 and S11 are made. When the photographer's hand is released from the release button 21, the process returns to step S3, and the above steps are repeated.

Returning to step S3, if 1R is off, the process proceeds to step S13, where the display mode is switched, that is, the subject image is displayed in the live view to the optical display in the viewfinder optical system by an operation button (not shown). It is determined whether or not switching has been performed. If the display mode has not been switched, the process returns to step S3. On the other hand, when the display mode is switched, in step S15, in order to stop the live view display of the subject image on the liquid crystal monitor 26, processing such as power supply stop of the CCD 221 is performed. The live view display is started in the initial setting of the live view in step S2, and until the live view display is stopped in step S15, the liquid crystal monitor 26 continuously displays the image data repeatedly acquired by the CCD 221. Live view display is made. Subsequently, in step S17, the shutter 213 and the movable reflecting mirror 201 are initialized. In the live view, the movable reflection mirror 201 is moved to the up position (reflection position), but the subject image is observed with the optical finder, and the liquid crystal monitor 26 displays the shooting information. This is a process for returning. In this initialization, the MS motor 301 is driven until the mirror charge cam 353 and the shutter charge cam 355 described above pass through the cam area d and the cam area a and reach the cam area b.

The live view initial setting in step S2 will be described in detail with reference to the flowchart shown in FIG. 8 and the time chart shown in FIG. Before performing live view, the mirror charge cam 353 and the shutter charge cam 355 are in the cam area b, and when initializing the live view, the MS motor 301 drives the cam gear 357 to the cam area c in which live view is performed. First, the MS motor 301 is rotated (t1 in FIG. 10), and the mirror charge cam 353 and the shutter charge cam 355 are driven from the cam area b to the cam area c (S21). During this time, the mirror drive lever 341 moves from the position shown in FIG. 2D toward the position shown in FIG. 2E, and the movable reflecting mirror 201 is moved to the up (retracted) position by the spring force of the mirror drive spring 343. Rotate. Further, since the cam surface 355a of the shutter cam 355 does not change and remains at the top dead center, it remains at the position shown in FIGS. 2B and 2A and maintains the shutter charge state. When reaching the c region, b detection becomes H level (S23, t2 in FIG. 10), and the rotation of the MS motor 301 is stopped (S25). As a result, the movable reflecting mirror 201 is in the up (retracted) position, and the shutter 213 remains in the shutter charge state. As described above, since the shutter 213 is a normally open shutter, the shutter 213 remains open in a normal state, and no shutter opening operation for performing live view is particularly necessary.

In this state, since the movable reflecting mirror 201 is in the retracted position and the shutter 213 remains open, a subject image is formed on the CCD 221 and readout of image information from the CCD 221 as an imager is started ( S27, t3 in FIG. Based on the read image information, live view display is performed on the liquid crystal monitor 26 (S29). In order to perform live view display, image information is repeatedly read from the CCD 221 (for example, 30 frames / second) and displayed as a moving image.

Next, the photographing operation in step S9 will be described in detail using the flowchart shown in FIG. 9 and the time chart shown in FIG. As described above, this subroutine acquires a still image based on the output from the CCD 221 and records it on the recording medium 245 when the release button 21 is fully pressed during live view. The live view is performed in the cam area c, and when moving to the shooting operation, the front and rear curtain magnets of the shutter 213 are attracted and held, and then the mirror charge cam 353 and the shutter charge cam 355 are directly placed in the cam area d. What is necessary is just to drive. As described above, since the shutter 213 is a normally open type, it is in a shutter open state, and therefore is temporarily closed for exposure time control. Further, since the movable reflecting mirror 201 is at the retracted position, it is sufficient that the position is maintained.

First, power is supplied to the shutter front curtain and rear curtain holding magnet Mg to hold the front curtain and rear curtain (S71). Thereafter, driving of the MS motor 301 is started (S73, t11 in FIG. 11). By this drive, the drive starts from the cam area c toward the cam area d. Since the cam surface 353a of the mirror charge cam 353 is not changed between the cam region c and the cam region d, the movable reflecting mirror 201 maintains the retracted position as it is, but the cam surface 355a of the shutter charge cam 355 is dead from the top dead center. The shutter front curtain changes from the open position to the closed position (t12 in FIG. 11). At substantially the same time, when the d detection switch for detecting the transition from the cam area c to the cam area d detects the L level (S75), the MS motor 301 stops driving (S77).

In this state, the movable reflecting mirror 201 is retracted from the photographing optical path, and the shutter 213 is ready for exposure, so that the photographing operation is started (S79). First, energization of the magnet Mg holding the shutter front curtain is stopped, and the travel of the shutter front curtain is started (t13 in FIG. 11). When the time corresponding to the shutter speed calculated or set in advance elapses, the running of the shutter rear curtain is started (t14 in FIG. 11). After the shutter trailing curtain starts running, when the time to finish the trailing curtain has elapsed, the MS motor 301 is driven (S81), and the cam area d is shifted to the cam area b through the cam area a.

When the MS motor 301 is driven and the cam region d is shifted to the cam region a (t15 in FIG. 11), the cam surface 353a of the mirror charge cam 353 and the cam surface 355a of the shutter charge cam 355 become the lift region, and the mirror charge lever. 351 and the shutter charge lever 361 rotate to perform the charging operation of the movable reflecting mirror 201 and the charging operation of the shutter 213, respectively. When entering the cam area b from the cam area a, the b detection switch detects the L level (S83, t16 in FIG. 11), and the MS motor 301 stops driving (S85). When the photographing operation in step S79 is completed, the image information of the still image is read from the CCD 221 in parallel with the above-described operation and displayed on the liquid crystal monitor 26 for a predetermined time. When the shooting operation subroutine ends, the process returns to the live view initial setting in step S2, moves from the cam area b to the c area, and resumes the live view.

Next, the shooting operation in the normal mode in which live view is not performed, that is, the subject is observed with the optical viewfinder will be described with reference to the time chart of FIG. As described above, the observation of the subject in the normal mode is performed in the cam area b, that is, the standby area. When the release button 21 is operated and 2R is turned on, a shooting operation is executed in the cam area d from the cam area b through the cam area c.

First, when the release button 21 is operated and 2R is turned on, the MS motor 301 starts driving (t21 in FIG. 12). When entering the cam area c, the b detection switch becomes H level (t22 in FIG. 12), and the movable reflecting mirror 201 moves from the reflecting position to the retracted position. Further, the MS motor 301 continues to drive and turns on the shutter magnet just before the transition to the cam area d. (T23 in FIG. 12). From this operation, the shooting operation in the live view is the same as the flowchart shown in FIG.

As described above, in the embodiment of the present invention, the normal open type shutter 213 is used, and the live surface region (cam region c) and the cam surface 353a of the shutter charge cam 353 and the cam surface 355a of the mirror charge cam 355, respectively. Since the shooting area (cam area d) is provided adjacently and the charge of the shutter 213 is held in the live view area (cam area c), only the shutter front curtain closing operation is performed in preparation for the shooting operation. For this reason, the shutter time lag can be shortened. That is, the shutter time lag can be shortened by the amount that does not require an imaging preparation operation such as the up / down operation of the movable reflecting mirror 201 or the shutter charging operation of the shutter 213. Also, energy loss for performing these up / down operations and shutter charge operations can be reduced.

In one embodiment of the present invention, a normally open type shutter 213 is used, and when the shutter is fully charged, the movable reflective mirror 201 is in a standby position (cam area b) where it is in a reflective position and live in which it is in a retracted position. Since the two states of the view area (cam area c) can be taken, it is not necessary to newly perform a shutter charge when shifting to the photographing operation, and the shutter time lag can be shortened.

In the embodiment of the present invention, the two cams of the mirror charge cam 351 and the shutter charge cam 355 are used. However, the present invention is not limited to this. For example, a single cam can be used for mirror charging and shutter charging. You may make it divide into. Of course, a cam hole may be used instead of the cam surface. Furthermore, although the cam rotates only in one direction, it may be rotated forward and backward by loosening the cam shape. In this case, the live view mode and the normal mode (observation with an optical viewfinder) may be used. Switching can be done quickly. Furthermore, although the cam surface for performing the closing operation of the shutter front curtain is the live view area (cam area c), it can also be the shooting area (cam area d). Similarly, the cam surface for driving the movable reflecting mirror 201 to the retracted position can be changed from the standby area to the live view area.

In this embodiment, the image sensor is one of the CCDs 221, but it is needless to say that the present invention can be applied to a camera that performs live view display by switching the outputs of a plurality of image sensors. Further, the movable reflecting mirror 201 switches the optical path between the finder optical system and the image sensor, but is not limited to this, and is configured to switch between, for example, an image sensor for image recording and an image sensor for object image observation. Of course, the present invention can be applied. Furthermore, in the present embodiment, the movable reflecting mirror 201 performs mirror charging when the mirror is raised, but conversely, mirror charging may be performed when the mirror is down.

1 is a block diagram showing a schematic configuration of an internal mechanism of a digital single-lens reflex camera according to an embodiment of the present invention, in which (A) shows an internal configuration along an optical axis direction of a photographing lens, and (B) shows a front surface of the camera body. It is a block diagram which shows the internal structure seen from the direction. 1A and 1B are diagrams showing a shutter and a movable reflecting mirror of a digital single lens reflex camera according to an embodiment of the present invention, wherein FIG. 1A is a perspective view of the shutter, FIG. 1B is a front view of the shutter, and FIG. FIG. 4D is a perspective view of the reflection mirror, FIG. 4D is a view showing a mirror-down state of the movable reflection mirror, and FIG. It is a partial detail drawing of the shutter mirror drive unit of the digital single-lens reflex camera concerning one Embodiment of this invention. 2A and 2B are diagrams illustrating a cam area of a digital single-lens reflex camera according to an embodiment of the present invention, where FIG. 3A illustrates a mirror charge cam, and FIG. 2B illustrates a cam area of a shutter charge cam. It is an expanded view of the cam area | region of the digital single-lens reflex camera concerning one Embodiment of this invention. 1 is a block diagram mainly showing an overall configuration of an electric system of a digital single-lens reflex camera according to an embodiment of the present invention. It is a flowchart of the live view display of the digital single-lens reflex camera in one Embodiment of this invention. It is a flowchart of the live view initial setting of the digital single-lens reflex camera in one Embodiment of this invention. 5 is a flowchart of a photographing operation of a digital single lens reflex camera according to an embodiment of the present invention. It is a time chart in the live view display of the digital single-lens reflex camera in one Embodiment of this invention. It is a time chart which shows imaging | photography operation | movement of the live view display of the digital single-lens reflex camera in one Embodiment of this invention. 6 is a time chart illustrating a shooting operation during normal shooting of the digital single-lens reflex camera according to the embodiment of the present invention.

Explanation of symbols

21 Release button 26 LCD monitor 33 Viewfinder 100 Lens barrel 200 Camera body 201 Movable reflection mirror 203 Sub mirror 213 Focal plane shutter 213b Shutter set lever 221 CCD
229 Body CPU
279 CCD in the viewfinder
227 Image processing circuit 285 CCD switching circuit 301 MS motor 303 shutter / mirror drive unit 341 mirror drive lever 353 mirror charge cam 355 shutter charge cam 357 cam gear 361 shutter charge lever

Claims (13)

In cameras that can be viewed live,
An image sensor;
A reflection mirror that moves to a reflection position that reflects the subject luminous flux and a retraction position that is retracted from the subject luminous flux;
A shutter disposed between the reflecting mirror and the image pickup device, capable of running a pair of shutter curtains by being charged, and being in a shutter curtain open state in a charged state;
Display means for displaying an image formed on the image sensor;
A cam member that charges the shutter; a first region that charges the shutter and continuously maintains the charge state; and a second region that does not continuously charge the shutter. Shutter cam means for a shutter comprising:
A third region that drives the reflecting mirror from the retracted position to the reflecting position and is positioned at the reflecting position, and continuously drives the reflecting mirror from the reflecting position to the retracted position to move the reflecting mirror to the reflecting position. Mirror cam means comprising a fourth region located at the retracted position;
In a normal shooting preparation state, the reflecting mirror is positioned at the reflecting position by the third area of the mirror cam means, and in synchronization with this, the shutter is positioned at the completion of charging by the first area of the shutter cam means and waiting for shooting. In the shooting preparation state in which the image formed on the image sensor is displayed on the display means and a live view is possible, the reflecting mirror is positioned at the retracted position by the fourth region of the mirror cam means. Control means for controlling the shutter curtain to be in an open state by synchronizing the shutter with the first region of the shutter cam means synchronously;
Live viewable camera with. In cameras that can be viewed live,
An image sensor;
A reflection mirror that moves to a reflection position that reflects the subject luminous flux and a retraction position that is retracted from the subject luminous flux;
A shutter disposed between the reflecting mirror and the image pickup device, capable of running a pair of shutter curtains by being charged, and being in a shutter curtain open state in a charged state;
Display means for displaying an image formed on the image sensor;
A cam member for charging the shutter and driving the reflection mirror, wherein the shutter is charged and the first region that continuously holds the charged state and the shutter is continuously charged. A shutter cam portion for a shutter composed of a second region that is not present, a third region <non-driving region> in which the reflecting mirror is driven from the retracted position to the reflecting position and positioned at the reflecting position, and continuous thereto Then, a mirror cam portion comprising a fourth area <retracted position holding area> for driving the reflecting mirror from the reflecting position to the retracted position and positioning the reflecting mirror at the retracted position is formed. While the region is charging and charging the shutter, the third region drives the mirror to the reflective position, followed by the fourth region. A cam member which the second region does not perform charging of the shutter while driving the serial mirror to the retracted position, followed by the fourth region is then positioned in the retracted position the mirror,
In a normal shooting preparation state, the reflecting mirror is positioned at the reflecting position by the third region of the cam member, the shutter is positioned at the charging completion state by the first region of the cam member, and the imaging device is on standby. In the imaging preparation state in which the image formed above is displayed on the display means and the live view is possible, the reflecting mirror is positioned at the retracted position by the fourth region of the cam member, and the first of the cam member is Control means for controlling the shutter curtain to be in an open state by positioning the shutter in a charge completion state according to a region;
Live viewable camera with.   3. The live viewable camera according to claim 2, wherein the shutter cam portion and the mirror cam portion of the cam member are configured as separate cams. 4. The live viewable camera according to claim 3, wherein the shutter cam portion and the mirror cam portion further rotate integrally. A movable reflecting mirror movable to a reflection position on the photographing optical path of the photographing lens and a retreat position retracted from the photographing optical path;
An image sensor that is disposed on the photographing optical path of the photographing lens, receives a subject image formed by the photographing lens, and outputs a photoelectric conversion signal;
A normally open type shutter that is disposed between the imaging element and the movable reflecting mirror, and controls the exposure time of the subject image on the imaging element at the time of shooting;
A display device for live view display of the subject image based on the photoelectric conversion signal;
When performing the live view display, the shutter is kept open in the charge completed state, and the movable reflecting mirror is driven to the retracted position, and when performing the non-live view display, the shutter is opened in the charge completed state. And a drive control means for driving the movable reflecting mirror to the reflecting position,
A camera capable of live view.   6. The drive control unit according to claim 5, wherein, during photographing, the movable reflecting mirror is positioned at the retracted position, and the shutter front curtain is once driven to a closed state and then the opening operation is performed. Live viewable camera.   The drive control means has a charge cam mechanism for driving the movable reflecting mirror, and a non-live view display area, a live view area, and a photographing area are continuously formed on the cam surface of the charge cam mechanism. The non-live view display area is a cam surface for positioning the movable reflection mirror at the reflection position, and the live view area and the shooting area are for positioning the movable reflection mirror at the retracted position. 6. The live viewable camera according to claim 5, wherein the camera has a cam surface.   The drive control means has a charge cam mechanism for driving the shutter, and a non-live view display area, a live view area, and a photographing area are continuously formed on the cam surface of the charge cam mechanism. 6. The non-live view display area and the live view area hold the shutter in a charged state, and the photographing area is a position that allows the shutter curtain of the shutter to travel. Live viewable camera.   9. The live viewable camera according to claim 8, further comprising a cam surface between the live view area and the shooting area for driving the shutter front curtain to a closed state. In cameras that can be viewed live,
A motor,
A movable reflecting mirror that is driven to a reflection position that enters the light flux from the photographing lens and reflects the light flux and a retreat position that retreats from a light flux passage area from the photographing lens;
A normally open type shutter disposed behind the movable reflecting mirror;
A charging area for charging the shutter and the movable reflecting mirror by rotation of the motor, a standby area for holding the shutter in a fully charged state and holding the movable reflecting mirror at the reflecting position, and charging the shutter A live view area that holds the movable reflecting mirror in the retracted position, and a photographing area that allows the shutter curtain of the shutter to run and holds the movable reflecting mirror in the retracted position. A cam member having a cam surface;
Control means for driving and controlling so as to select each region of the cam member by rotating the motor according to the mode of the camera;
A camera capable of live view.   The control means controls driving of the cam member from the standby area to the shooting area in the shooting state in the normal mode, and moves the cam member from the live view area to the shooting area in the shooting state in live view. 11. The live viewable camera according to claim 10, wherein driving control is performed. 11. The live viewable camera according to claim 10, wherein the shutter temporarily closes the shutter front curtain by a cam surface between the live view area and the shooting area. 11. The live viewable camera according to claim 10, wherein after the shutter is charged in the charge area, the shutter charge is held until the shutter travels in the photographing area.