JP2008028997A - Digital camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve user-freindliness by displaying generated image data whenever the image data are generated in a consecutive photographing mode on a liquid crystal monitor 150. <P>SOLUTION: The digital camera is provided with a CMOS sensor 130 which picks up an object image generated through an interchangeable lens 200 to generate image data; a liquid crystal monitor 150 which displays the generated image data; and a microcomputer 110 having a live view mode controlled to display the generated image data on the liquid crystal display monitor 150 as a motion picture on real time, and a consecutive photographing mode which generates a plurality of image data with a single pick-up operation. The microcomputer 110 controls to display the generated image data on a liquid crystal monitor 150 whenever the image data are generated in the consecutive photographing mode at a time of the live view mode. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a digital camera, and more particularly to a digital camera that includes a movable mirror and can observe a subject image with an electronic viewfinder.

  Many digital single lens reflex cameras include an electronic viewfinder and an optical viewfinder. The subject image formed by the imaging optical system can be switched to an optical viewfinder or an image sensor by a movable mirror disposed in the optical path.

  In the optical viewfinder, there is no deviation between the subject image in the recorded image and the subject image displayed on the optical viewfinder, and the imaging operation can be performed satisfactorily.

  On the other hand, the electronic viewfinder can realize a so-called live view mode in which a real-time image generated by the image sensor is displayed on the display unit. In the live view mode, it is not necessary to have an eyepiece on the viewfinder unlike an optical viewfinder, so that imaging at a high angle or a low angle becomes easy.

A digital single-lens reflex camera provided with a live view mode is disclosed in, for example, Japanese Patent Application Laid-Open No. 2004-151867.
JP 2001-272593 A

  However, with a conventional digital single-lens reflex camera, when imaging is performed in the live view mode, it is difficult to display a real-time image on the display unit during processing of the imaging period and image data.

  Furthermore, there is a digital single-lens reflex camera having a so-called continuous shooting mode that generates a plurality of image data by a single imaging operation. The continuous shooting mode can be used both when using the optical viewfinder and when using the live view mode using the electronic viewfinder. In the live view mode, the real-time image is displayed on the display unit as described above. The period that cannot be continued.

  In the continuous shooting mode, a moving subject is often imaged, and the inability to visually recognize the image of the subject during the imaging period in the continuous shooting mode greatly impairs the usability of the digital single-lens reflex camera.

  The present invention provides a digital camera with improved usability by displaying, on a display unit, generated image data or image data obtained by performing predetermined processing on the generated image data every time image data is generated in the continuous shooting mode. The purpose is to provide.

  A digital camera according to the present invention is a digital camera having a movable mirror that is disposed so as to be movable back and forth with respect to an optical path of an imaging optical system in order to guide a subject image to an optical viewfinder. An image sensor that captures a subject image formed by the imaging optical system when it is retracted from the optical path of the imaging optical system and generates image data, and the generated image data or the image data is subjected to predetermined processing. A display unit for displaying image data, a live view mode for controlling the generated image data or image data obtained by performing predetermined processing on the image data to be displayed on the display unit as a moving image in real time, and a single imaging A control unit having a continuous shooting mode for generating a plurality of image data by operation, and in the live view mode, the control unit displays images in the continuous shooting mode. Each time data is generated, is controlled to display the image data subjected to the predetermined processing on the generated image data or image data to the display unit.

  Thus, even in the continuous shooting mode in the live view mode, image data generated every time image data is generated or image data obtained by performing predetermined processing on the image data is displayed on the display unit. Can be visually recognized.

  According to the present invention, it is possible to provide a digital camera that includes a movable mirror and has improved usability in a continuous shooting mode of a digital camera that can display a subject image in a live view using an electronic viewfinder.

(Embodiment)
[1. (Configuration of digital camera)
The configuration of the camera 10 according to the first embodiment of the present invention will be described below with reference to FIGS.

[1-1. (Overview of overall configuration)
FIG. 1 is a schematic diagram for explaining the outline of the camera 10. The camera 10 includes a camera body 100 and an interchangeable lens 200 that can be attached to and detached from the camera body 100.

  The camera body 100 captures the subject image condensed by the optical system included in the interchangeable lens 200 and records it as image data. The camera body 100 includes a mirror box 120. The mirror box 120 (see FIG. 2) switches the optical path of the optical signal from the optical system included in the interchangeable lens 200 in order to selectively cause the subject image to enter either the CMOS sensor 130 or the eyepiece lens 136. The mirror box 120 includes movable mirrors 121a and 121b, a mirror driving unit 122, a shutter 123, a shutter driving unit 124, a focusing screen 125, and a prism 126.

  The movable mirror 121a is disposed so as to be movable back and forth with respect to the optical path of the imaging optical system in order to guide the subject image to the optical viewfinder. The movable mirror 121b is disposed so as to be movable forward and backward with respect to the optical path of the imaging optical system together with the movable mirror 121a. Then, the movable mirror 121 b reflects a part of the optical signal input from the optical system included in the interchangeable lens 200 and makes it incident on the AF sensor 132.

  When the movable mirror 121a enters the optical path of the imaging optical system, a part of the optical signal input from the optical system included in the interchangeable lens 200 is sent to the eyepiece 136 through the focusing screen 125 and the prism 126. Incident. Further, the optical signal reflected by the movable mirror 121 a is diffused by the focusing screen 125. A part of the diffused optical signal is incident on the AE sensor 133. On the other hand, when the movable mirrors 121 a and 121 b are retracted from the optical path of the imaging optical system, the optical signal input from the optical system included in the interchangeable lens 200 is incident on the CMOS sensor 130.

  The mirror driving unit 122 is composed of mechanical parts such as a motor and a spring, and drives the movable mirrors 121 a and 121 b based on the control of the microcomputer 110.

  The shutter 123 switches between blocking and passing of an optical signal from the interchangeable lens 200. The shutter drive unit 124 is composed of mechanical parts such as a motor and a spring, and drives the shutter 123 under the control of the microcomputer 110. Note that the motor included in the mirror driving unit 122 and the motor included in the shutter driving unit 124 may be different motors, or a single motor may be used.

  A liquid crystal monitor 150 is disposed on the back of the camera body 100. The liquid crystal monitor 150 can display image data generated by the CMOS sensor 130 or image data obtained by performing predetermined processing on the image data.

  The optical system included in the interchangeable lens 200 includes an objective lens 220, a zoom lens 230, a diaphragm 240, a camera shake correction unit 250, and a focus lens 260. The CPU 210 controls these optical systems. The CPU 210 can transmit and receive control signals and information on the optical system to and from the microcomputer 110 on the camera body 100 side.

[1-2. Configuration of camera body)
FIG. 2 is a block diagram illustrating a configuration of the camera body 100. As shown in FIG. 2, the camera body 100 has various parts, and the microcomputer 110 controls them. However, in the present embodiment, one microcomputer 110 is described as controlling the entire camera body 100, but the camera body 100 may be controlled by a plurality of control units.

  The lens mount unit 135 is a member that attaches and detaches the interchangeable lens 200. The lens mount part 135 can be electrically connected to the interchangeable lens 200 using a connection terminal or the like, and can also be mechanically connected by a mechanical member such as a locking member. The lens mount unit 135 can output a signal from the interchangeable lens 200 to the microcomputer 110 and can output a signal from the microcomputer 110 to the interchangeable lens 200. The lens mount part 135 has a hollow structure. Therefore, an optical signal incident from the optical system included in the interchangeable lens 200 passes through the lens mount unit 135 and reaches the mirror box 120.

  The mirror box 120 guides the optical signal that has passed through the lens mount unit 135 to the CMOS sensor 130, the eyepiece lens 136, the AF sensor 132, and the AE sensor 133 according to the internal state. The switching of the optical signal by the mirror box will be described in the section “1-4. Mirror box state”.

  The CMOS sensor 130 converts an optical signal incident through the mirror box 120 into an electrical signal, and generates image data. The generated image data is converted from an analog signal to a digital signal by the A / D converter 131 and output to the microcomputer 110. Note that predetermined image processing may be performed in the course of outputting the generated image data from the CMOS sensor 130 to the A / D converter 131 or in the course of outputting the image data from the A / D converter 131 to the microcomputer 110.

  The eyepiece 136 passes an optical signal incident through the mirror box 120. At this time, in the mirror box 120, as shown in FIG. 1, the optical signal incident from the interchangeable lens 200 is reflected by the movable mirror 121a, and a subject image is formed on the focusing screen 125. Then, the prism 126 reflects this subject image and emits it to the eyepiece lens 136. Thereby, the user can visually recognize the subject image from the mirror box 120. Here, the eyepiece lens 136 may be composed of a single lens or a lens group composed of a plurality of lenses. Further, the eyepiece 136 may be fixedly held in the camera body 100, or may be held movably for diopter adjustment or the like. The optical viewfinder including the focusing screen 125, the prism 126, and the eyepiece 136 is optimally set to display an image with a composition having an aspect ratio of 4: 3. However, the optical viewfinder may be optimally set to display an image having a composition having another aspect ratio. For example, the optical viewfinder may have an optimal configuration for displaying an image with a composition having an aspect ratio of 16: 9 or an optimal configuration for displaying an image with a composition having an aspect ratio of 3: 2. Good.

  The protective material 138 protects the surface of the CMOS sensor 130. By disposing the protective material 138 on the front surface of the CMOS sensor 130, it is possible to prevent foreign matters such as dust from adhering to the surface of the CMOS sensor 130. The protective material 138 can be made of a transparent material such as glass or plastic.

  The ultrasonic vibration generator 134 is activated in response to a signal from the microcomputer 110 and generates ultrasonic vibration. The ultrasonic vibration generated by the ultrasonic vibration generator 134 is transmitted to the protective material 138. Thereby, the protective material 138 vibrates, and foreign matters such as dust attached to the protective material 138 can be shaken off. The ultrasonic vibration generator 134 can be realized by attaching a piezoelectric element to the protective material 138, for example. In this case, the piezoelectric element can be vibrated by passing an alternating current through the piezoelectric element attached to the protective material 138.

  The strobe 137 emits light according to instructions from the microcomputer 110. The strobe 137 may be built in the camera body 100 or may be detachable from the camera body 100. In the case of a detachable strobe, the camera body 100 needs to be provided with a strobe attachment portion such as a hot shoe.

  The release button 141 accepts an instruction from the user for activation of the autofocus operation and photometry operation, and accepts an instruction from the user for starting the recording image recording by the CMOS sensor 130. The release button 141 can accept a half-press operation and a full-press operation. When the release button 141 is pressed halfway by the user in the autofocus mode, the microcomputer 110 instructs the interchangeable lens 200 to perform an autofocus operation based on a signal from the AF sensor 132. In the automatic exposure mode, when the release button 141 is pressed halfway by the user, the microcomputer 110 instructs the interchangeable lens 200 to perform a photometric operation based on a signal from the AE sensor 133. On the other hand, when the release button 141 is fully pressed by the user, the microcomputer 110 controls the mirror box 120, the CMOS sensor 130, and the like to capture a recording image. Then, the microcomputer 110 performs YC conversion processing, resolution conversion processing, compression processing, and the like on the captured recording image as necessary to generate recording image data. The microcomputer 110 records the generated image data for recording on the memory card 300 via the card slot 153. In order for the release button 141 to have a function corresponding to a half-press operation and a function corresponding to a full-press operation, for example, the release button 141 may include two switches. In this case, one switch is turned on by a half-press operation, and the other switch is turned on by a full-press operation.

  The operation unit 140 is a member for transmitting various instructions from the user to the microcomputer 110. In order to explain various operation members, a rear view of the camera body 100 is shown in FIG. On the rear side of the camera body 100, a menu button 140a, a cross key 140b, a set button 140c, a rotary dial 140d, a viewfinder changeover switch 140e, a focus mode changeover switch 140f, a strobe activation button 140h, an LV preview button 140j, an aperture button 140k, An AV button 140m and a power switch 142 are provided. On the upper surface of the camera body 100, a camera shake correction mode switching button 140g and a release button 141 are arranged.

  The menu button 140a is a button for displaying the setting information of the camera 10 on the liquid crystal monitor 150 and allowing the user to change the setting. The cross key 140b is a key for selecting various settings, items, images, and the like displayed on the liquid crystal monitor 150. For example, a cursor or the like can be moved. The set button 140c is a button for determining after selecting various settings, items, images, and the like displayed on the liquid crystal monitor 150. Similar to the cross key 140b, the rotary dial 140d is an operation member for selecting various settings, items, images, and the like displayed on the liquid crystal monitor 150. For example, the rotation dial 140d can move the cursor and the like. it can. The viewfinder changeover switch 140 e is a switch for selecting whether to display a captured image on the eyepiece lens 136 or on the liquid crystal monitor 150. The focus mode changeover switch 140f is a switch for selecting whether the focus mode is set to the manual focus mode or the autofocus mode. The camera shake correction mode switching button 140g is a switch for selecting whether to perform camera shake correction and which mode is to be used as a control mode for camera shake correction. The aperture button 140k is a button for adjusting the aperture in the live view mode. The LV preview button 140j (LV: Live View) is a button for adjusting the aperture and enlarging and displaying a part of the image displayed on the liquid crystal monitor 150 in the live view mode. The AV button 140m is a button for adjusting the diaphragm in the OVF mode (OVF: Optical View Finder).

  Returning to FIG. 2, the liquid crystal monitor 150 receives the signal from the microcomputer 110 and displays an image and information of various settings. The liquid crystal monitor 150 can display image data generated by the CMOS sensor 130 or image data obtained by performing predetermined processing on the image data. The liquid crystal monitor 150 can display the image data held in the memory card 300 after performing predetermined processing such as expansion processing by the microcomputer 110 as necessary. The liquid crystal monitor 150 is provided on the back surface of the camera body 100 as shown in FIG. The liquid crystal monitor 150 is provided so as to be rotatable with respect to the camera body 100. The contact 151 detects the rotation of the liquid crystal monitor 150. The liquid crystal monitor 150 is optimal for displaying an image having a composition with an aspect ratio of 4: 3. However, the liquid crystal monitor 150 can display an image having a composition with another aspect ratio (for example, 3: 2 or 16: 9) under the control of the microcomputer 110.

  The external terminal 152 is a terminal for outputting image data and various setting information to an external device. The external terminal 152 is, for example, a USB terminal (Universal Serial Bus), a terminal for an interface based on the IEEE 1394 standard, or the like. Further, when a connection terminal from an external device is connected, the external terminal 152 notifies the microcomputer 110 of that fact.

  The power supply controller 146 controls supply power supplied from the battery 400 stored in the battery box 143 to members in the camera 10 such as the microcomputer 110. When the power switch 142 is turned on, the power controller 146 starts supplying power supplied from the battery 400 to the members in the camera 10. Further, the power controller 146 has a sleep function, and stops supplying power except for some members in the camera 10 when the camera 10 is not operated for a predetermined time while the power is on. Further, the power controller 146 notifies the microcomputer 110 that the battery cover 144 has been opened based on a signal from the contact 145 that monitors the opening / closing of the battery cover 144. The battery lid 144 is a member that opens and closes the opening of the battery box 143. The power supply controller 146 is configured to supply power to each member in the camera 10 through the microcomputer 110 in FIG. 2, but can be configured to supply power directly from the power supply controller 146 as necessary.

  The tripod fixing part 147 is a member for fixing a tripod (not shown) to the camera body 100, and includes a screw or the like. The contact 148 monitors whether the tripod is fixed to the tripod fixing unit 147 and transmits the result to the microcomputer 110. The contact 148 can be configured by a switch or the like.

  The card slot 153 is a connector for mounting the memory card 300. The card slot 153 may include a control unit and / or software for controlling the memory card 300 as well as a mechanical structure in which the memory card 300 is mounted.

  The buffer 111 is a memory that temporarily stores information when the microcomputer 110 performs signal processing. The information temporarily stored in the buffer 111 is mainly image data, but a control signal or the like may be stored. The buffer 111 can be configured by a storage means such as a DRAM (Dynamic Random Access Memory), an SRAM (Static Random Access Memory), a flash memory, or a ferroelectric memory. It can also be configured with a memory specialized for image storage.

  The AF auxiliary light emitting unit 154 (AF: Auto Focus) is a member that emits auxiliary light when performing an autofocus operation in the dark. The AF auxiliary light emitting unit 154 emits light based on the control of the microcomputer 110. The AF auxiliary light emitting unit 154 includes a red LED (LED: Light-Emitting Diode) and the like.

  The remote control receiving unit 155 is a receiving unit that receives a signal from a remote controller (not shown) and transmits the received signal to the microcomputer 110. Remote control receiver 155 typically includes a light receiving element that receives infrared light from a remote controller.

[1-3. Interchangeable lens configuration)
FIG. 4 is a block diagram illustrating a configuration of the interchangeable lens 200. The interchangeable lens 200 has an imaging optical system, and is configured to control the imaging optical system and the like by the CPU 210.

  The CPU 210 controls the imaging optical system by controlling the operations of actuators such as the zoom motor 231, the aperture motor 241, the camera shake correction unit 250, and the focus motor 261. The CPU 210 transmits information indicating the state of the imaging optical system, the accessory mounting unit 272, and the like to the camera body 100 via the communication terminal 270. Further, the CPU 210 receives a control signal or the like from the camera body 100, and controls the imaging optical system or the like based on the received control signal or the like.

  The objective lens 220 is a lens arranged closest to the subject. The objective lens 220 may be configured to be movable in the optical axis direction or may be configured to be fixed.

  The zoom lens 230 is disposed closer to the image plane than the objective lens 220. The zoom lens 230 is movable in the optical axis direction. By moving the zoom lens 230, the magnification of the subject image can be changed. The zoom lens 230 is driven by a zoom motor 231. The zoom motor 231 can be composed of a stepping motor or a servo motor, and may be any one that can drive at least the zoom lens 230. The CPU 210 monitors the position of the zoom lens 230 by monitoring the state of the zoom motor 231 or the state of another member.

  The diaphragm 240 is disposed on the image plane side with respect to the zoom lens 231. The diaphragm 240 has an opening centered on the optical axis. The opening can be changed by a diaphragm motor 241 and a diaphragm ring 242. The aperture motor 241 is interlocked with a mechanism for changing the aperture size of the aperture, and the aperture size of the aperture can be changed by driving this mechanism. Similarly, the aperture ring 242 is interlocked with a mechanism for changing the aperture size of the aperture, and the aperture size of the aperture can be changed by driving this mechanism. The diaphragm motor 241 is driven based on an electrical control signal given to the microcomputer 110 or the CPU 210 by the user. In contrast, the diaphragm ring 242 receives a mechanical operation from the user and transmits this operation to the diaphragm 240. Further, the CPU 210 can detect whether the aperture ring 242 has been operated.

  The camera shake correction unit 250 is disposed on the image plane side with respect to the diaphragm 240. The camera shake correction unit 250 includes a correction lens 251 for camera shake correction and an actuator that drives the correction lens 251. The actuator included in the camera shake correction unit 250 can move the correction lens 251 in a plane orthogonal to the optical axis. The gyro sensor 252 measures the angular velocity of the interchangeable lens 200. In FIG. 4, for convenience, the gyro sensor 252 is described as one block, but the interchangeable lens 200 includes two gyro sensors 252. One of the two gyro sensors 252 measures an angular velocity around the vertical axis of the camera 10. The other gyro sensor of the two gyro sensors 252 measures an angular velocity centered on the horizontal axis of the camera 10 perpendicular to the optical axis. The CPU 210 measures the camera shake direction and the camera shake amount of the interchangeable lens 200 based on the angular velocity information from the gyro sensor 252. Then, the CPU 210 controls the actuator so as to move the correction lens 251 in a direction that cancels out the camera shake amount. As a result, the subject image formed by the imaging optical system of the interchangeable lens 200 has a camera shake corrected.

  The focus lens 260 is disposed closest to the image plane. The focus motor 261 drives the focus lens 260 in the optical axis direction. As a result, the focus of the subject image can be adjusted.

  The accessory mounting portion 272 is a member that mounts an accessory such as a light shielding hood on the tip of the interchangeable lens 200. The accessory mounting portion 272 is configured by a mechanical mechanism such as a screw or bayonet. Moreover, the accessory mounting part 272 includes a detector for detecting whether or not the accessory is mounted. Then, when the accessory is mounted, the accessory mounting unit 272 notifies the CPU 210 to that effect.

[1-4. (Mirror box status)
The state inside the mirror box 120 in each operation state will be described with reference to FIG. 1, FIG. 5 and FIG.

  FIG. 1 is a schematic diagram showing an internal state of the mirror box 120 in a mode for observing a subject image using an optical viewfinder. In this specification, this state is referred to as state A for convenience. In this state A, the movable mirrors 121a and 121b enter the optical path of the optical signal incident from the interchangeable lens 200. Therefore, a part of the optical signal from the interchangeable lens 200 is reflected by the movable mirror 121a, and the remaining optical signal is transmitted. The reflected optical signal passes through the focusing screen 125, the prism 126, and the eyepiece 136 and reaches the user's eyes. Further, the optical signal reflected by the movable mirror 121 a is reflected by the focusing screen 125, and a part thereof enters the AE sensor 133. On the other hand, part of the optical signal transmitted through the movable mirror 121 a is reflected by the movable mirror 121 b and reaches the AF sensor 132. In this state A, the first shutter 123a is closed. Therefore, the optical signal from the interchangeable lens 200 does not reach the CMOS sensor 130. Therefore, in the state A, it is possible to observe the subject image using the optical viewfinder, perform the autofocus operation using the AF sensor 132, and perform the photometry operation using the AE sensor 133. The subject image cannot be observed using the liquid crystal monitor 150, the image data generated by the CMOS sensor 130 can be recorded, and the autofocus operation cannot be performed using the contrast of the image data generated by the CMOS sensor 130.

  FIG. 5 is a schematic diagram showing an internal state of the mirror box 120 in a mode in which a subject image is input to the CMOS sensor 130. In this specification, this state is referred to as state B for convenience. In this state B, the movable mirrors 121a and 121b are retracted from the optical path of the optical signal incident from the interchangeable lens 200. Therefore, the optical signal from the interchangeable lens 200 does not reach the user's eyes through the focusing screen 125, the prism 126, and the eyepiece 136, and does not reach the AF sensor 132 and the AE sensor 133. In this state B, the first shutter 123a and the second shutter 123b are open. Therefore, the optical signal from the interchangeable lens 200 reaches the CMOS sensor 130. Therefore, in the state B, contrary to the state A, the subject image is observed using the liquid crystal monitor 150, the image data generated by the CMOS sensor 130 is recorded, and the image data generated by the CMOS sensor 130 is recorded. Although it is possible to perform autofocus operation using the contrast, the subject image is observed using an optical viewfinder, the autofocus operation is performed using the AF sensor 132, and the photometry is performed using the AE sensor 133. It can't work. The movable mirrors 121a and 121b and the first shutter 123a are urged in the direction of transition from the state A to the state B by urging means such as a spring. Therefore, since the state A can be instantaneously shifted to the state B, it is suitable for starting exposure.

  FIG. 6 is a schematic diagram showing the state inside the mirror box 120 immediately after the exposure of the subject image to the CMOS sensor 130 is completed. In this specification, this state is referred to as state C for convenience. In this state C, the movable mirrors 121a and 121b retract from the optical path of the optical signal incident from the interchangeable lens 200. Therefore, the optical signal from the interchangeable lens 200 does not reach the user's eyes through the focusing screen 125, the prism 126, and the eyepiece 136, and does not reach the AF sensor 132 and the AE sensor 133. In this state C, the first shutter 123a is open while the second shutter 123b is closed. Therefore, the optical signal from the interchangeable lens 200 does not reach the CMOS sensor 130. Therefore, in the state C, the subject image is observed using the liquid crystal monitor 150, the image data generated by the CMOS sensor 130 is recorded, and the autofocus operation is performed using the contrast of the image data generated by the CMOS sensor 130. It is impossible to observe the subject image using the optical viewfinder, perform the autofocus operation using the AF sensor 132, and perform the photometric operation using the AE sensor 133. Since the second shutter 123b is biased in the closing direction, the state B can be instantaneously shifted to the state C. Therefore, the state C is a state suitable for ending the exposure of the CMOS sensor 130.

  As described above, the state A can be directly shifted to the state B. On the other hand, the transition from the state B to the state A cannot be made unless the state C is passed due to the limitation of the mechanism of the mirror box 120. However, since this is a technical problem arising from the mechanism of the mirror box 120, it is possible to employ a mechanism capable of directly shifting from the state B to the state A without going through the state C.

[1-5. Correspondence between Configuration of Embodiment and Configuration of Present Invention]
The configuration including the focusing screen 125, the prism 126, and the eyepiece 136 is an example of the optical viewfinder of the present invention. The optical system including the objective lens 220, the zoom lens 230, the correction lens 251 and the focus lens 260 is an example of the imaging optical system of the present invention. The movable mirrors 121a and 121b are examples of the movable mirror of the present invention. The CMOS sensor 130 is an example of an image sensor of the present invention. The liquid crystal monitor 150 is an example of the display unit of the present invention. The microcomputer 110 is an example of a control unit of the present invention. In this case, the CPU 210 may be included in addition to the microcomputer 110 as the control unit. The menu button 140a, the cross key 140b, the set button 140c, the rotary dial 140d, and the CPU 210 are examples of the review switching unit of the present invention. Review is a function that allows the user to immediately check the image taken immediately before. The viewfinder changeover switch 140e is an example of a viewfinder changeover unit of the present invention. A sensor that detects the eyepiece may be provided in the vicinity of the eyepiece lens 136. In this case, when an eyepiece is detected, a mode in which a subject image is observed using an optical viewfinder is set, and when an eyepiece is not detected, a live view mode may be set.

[2. (Operation of digital camera)
The operation of the camera 10 according to the first embodiment of the present invention configured as described above will be described below with reference to FIG.

[2-1. (Real-time image display operation)
A display operation for observing a subject image formed by the interchangeable lens 200 in real time will be described. As this display operation, two operations are set. The first is an operation using an optical viewfinder, and the second is an operation using a liquid crystal monitor 150. Each of these operations will be described in detail below.

  In this specification, the function and display for displaying the subject image on the liquid crystal monitor 150 in real time is referred to as “live view”. Further, the control mode of the microcomputer 110 when performing the live view operation in this way is referred to as “live view mode”.

  The live view only needs to display the subject image on the liquid crystal monitor 150 in real time. The image data displayed on the liquid crystal monitor 150 is not stored even if it is stored in the storage means such as the memory card 300 at the same time. Also good.

  Further, when the live view is being displayed, since the optical signal from the interchangeable lens 200 needs to reach the CMOS sensor 130, the inside of the mirror box 120 needs to be in the state B shown in FIG. However, even if the microcomputer 110 is set to the live view mode, the inside of the mirror box 120 is not only the state B but also the state A and the state C according to the respective states such as the imaging operation, autofocus operation, and automatic exposure control operation There is also a period during which the liquid crystal monitor 150 cannot display the live view.

  Further, as described above, the live view is to display the subject image on the liquid crystal monitor 150 in real time. However, real time does not have a strict meaning, and if the user feels common sense in real time, There may be some time delay from the actual movement of the subject. The liquid crystal monitor 150 is normally considered to perform live view display with a time delay of about 0.1 second (this time may be somewhat longer or shorter depending on the hardware of the camera 10), but from 1 second. A case where the delay is about 5 seconds may be included in the concept of live view display as a subject image display in real time.

  The user can switch between the live view mode and the optical viewfinder mode (hereinafter referred to as OVF mode for convenience) by sliding the viewfinder changeover switch 140e shown in FIG.

  When the user slides the viewfinder changeover switch 140e to the OVF mode side, the microcomputer 110 is set to the OVF mode. Then, the microcomputer 110 controls the mirror driving unit 122 and the shutter driving unit 124 to bring the inside of the mirror box 120 into the state A shown in FIG. Accordingly, the user can observe the subject image in real time through the eyepiece lens 136. In this state A, as described above, an autofocus operation using the AF sensor 132 and a photometric operation using the AE sensor 133 are possible.

  When the user slides the viewfinder changeover switch 140e to the live view mode side from the OVF mode, the microcomputer 110 is set to the live view mode. Then, the microcomputer 110 controls the mirror driving unit 122 and the shutter driving unit 124 to bring the inside of the mirror box 120 into the state B shown in FIG. Thereby, the user can observe the subject image in real time using the liquid crystal monitor 150.

[2-2. (Image recording operation)
The operation when capturing an image for recording will be described below. In order to capture an image for recording, it is necessary to focus in advance as intended by the user. As a method of focusing, a manual focus method, a single focus method, a continuous focus method, or the like can be considered.

  Note that the manual focus mode and the auto focus mode can be switched to each other by operating the focus mode switch 140f. In addition, by pressing the menu button 140a to call a menu screen, it is possible to select either the single focus mode or the continuous focus mode in the autofocus mode.

  Here, a case where the single focus mode is used in imaging in the live view mode will be described as an example.

  FIG. 7 is a flowchart for explaining an operation at the time of imaging using the liquid crystal monitor 150 in the single focus mode.

  In the case of imaging in the live view mode, the inside of the mirror box 120 is initially in a state B shown in FIG. The user adjusts the focus and composition while confirming the subject image through the liquid crystal monitor 150 before imaging. The microcomputer 110 monitors whether or not the user presses the release button 141 halfway for focusing (S701). When the user presses release button 141 halfway, microcomputer 110 starts a timer inside microcomputer 110 (S702). In parallel with this, the microcomputer 110 shifts the inside of the mirror box 120 from the state B to the state A through the state C (S703), starts an autofocus operation based on the measurement result of the AF sensor 132, and obtains the result. The locked state is locked (S704). The reason why the inside of the mirror box 120 is shifted to the state A in S703 is that the AF sensor 132 measures the distance.

  Even after the focus is locked, manual focus adjustment using the focus ring 262 is possible (S705). Meanwhile, the microcomputer 110 monitors whether or not the release button 141 is fully pressed (S706).

  In parallel with this, the microcomputer 110 also monitors whether or not the release button 141 is fully pressed before a predetermined time elapses after the release button 141 is pressed halfway (S707). If the full-press operation is performed before a predetermined time elapses after the release button 141 is pressed halfway, the microcomputer 110 proceeds to step S712 and immediately starts an imaging operation. On the other hand, when a predetermined time has elapsed since the release button 141 was not fully pressed and half-pressed, the microcomputer 110 proceeds to step S708.

  In step S708, the microcomputer 110 causes the inside of the mirror box 120 to transition from state A to state B. As a result, the camera 10 can display the subject image on the liquid crystal monitor 150 while the focus is locked. Therefore, the user can determine a favorite composition while looking at the display on the liquid crystal monitor 150 while keeping the focus in a favorite state.

  In this state, the microcomputer 110 monitors whether or not the release button 141 is fully pressed (S710). During this time, as in step S704, the focus state can be changed manually using the focus ring 262 (S709).

  Between step S701 and step S710, when the half-press operation of the release button 141 is released, the microcomputer 110 releases the focus lock and returns to the state where autofocus is possible. Therefore, when the release button 141 is pressed halfway again, it is locked in a new focus state.

  When the microcomputer 110 detects that the release button 141 is fully pressed, the microcomputer 110 controls the mirror driving unit 122 and the shutter driving unit 124 to shift the state of the mirror box 120 from the state B to the state A through the state C. (S711). The reason why the inside of the mirror box 120 is once set to the state A is that the optical signal incident on the CMOS sensor 130 is temporarily interrupted by the shutter 123 to prepare the CMOS sensor 130 to start exposure. Preparation for the start of exposure includes removal of unnecessary charges in each pixel.

  The microcomputer 110 controls the mirror driving unit 122 and the shutter driving unit 124 to shift the inside of the mirror box 120 from the state A to the state B (S712). In this state, the microcomputer 110 exposes the optical signal from the interchangeable lens 200 to the CMOS sensor 130 to capture a recording image for recording (S713). Then, when the time corresponding to the shutter speed has elapsed, the microcomputer 110 controls the shutter driving unit 124 to close the second shutter 123b, and ends the exposure (state C). Thereafter, the microcomputer 110 returns the inside of the mirror box 120 to the state A (S714).

  When the exposure is completed and the inside of the mirror box 120 is in the state A (S714), the microcomputer 110 returns the inside of the mirror box 120 to the state B again and restarts the live view display (S715). In parallel with this, the microcomputer 110 performs image processing and recording of a recording image (S716, S717).

  That is, the microcomputer 110 receives the image data generated by the CMOS sensor 130 and temporarily stores it in the buffer 111. The image data stored at this time is, for example, image data composed of RGB components. The microcomputer 110 performs predetermined image processing such as YC conversion processing, resizing processing, and compression processing on the image data stored in the buffer 111 to generate image data for recording (S716). The microcomputer 110 finally generates an image file compliant with, for example, the Exif standard (Exif: Exchangeable image file format). The microcomputer 110 stores the generated image file in the memory card 300 via the card slot 153 (S717).

  As described above, only by half-pressing the release button 141, the movable mirror 121 moves down and measures the distance, and then returns to the live view mode. As a result, from the autofocus operation using the AF sensor 132 to the live view display can be easily performed by a simple operation of pressing the release button 141 halfway. Therefore, the user can perform composition adjustment by live view display in a state in which the subject is focused with a simple operation.

  Further, when the user wants to change the composition while viewing the liquid crystal monitor 150 after determining the focus state, the user may wait until a predetermined time elapses after the release button 141 is pressed halfway. On the other hand, if the full-press operation is performed immediately after the half-press operation, the imaging starts without displaying the live view (S708 to S711 are skipped in S706), so the half-press operation to the start of the imaging. Can be shortened. This is because the movable mirror is not raised or lowered unnecessarily. Therefore, the user can capture a favorite image without missing the shutter timing.

  Note that the live view cannot be displayed during the autofocus operation (S704) and during the imaging operation (S713). This is because the movable mirror 121 is down during the autofocus operation (S704). This is because during the imaging operation (S713), it is difficult for the CMOS sensor 130 to output image data during exposure.

  In step S716 and step S717, since the mirror box 120 is in the state B, live view display is possible. However, in step S716 and step S717, much of the control capability of the microcomputer 110 is assigned to image processing and recording processing. For this reason, in step S716 and step S717, it is preferable that the microcomputer 110 is not burdened as much as possible other than image processing and recording processing. Therefore, live view display is not performed in step S716 and step S717. Thereby, since the microcomputer 110 does not need to allocate processing capacity for live view display, image processing and recording processing can be performed quickly. As a form in which live view display is not performed, for example, the liquid crystal monitor 150 may be in a blackout state. Further, the live view image stored in the buffer 111 before the full pressing operation may be displayed. Further, setting information of the camera 10, information indicating an operation state, and the like may be displayed.

[2-3. (Sequential shooting mode imaging operation)
The continuous shooting mode is set by operating the menu button 140a, the cross key 140b, the set button 140c, and the rotary dial 140d as the review switching unit of the present invention. In the continuous shooting mode, when the release button 141 is fully pressed, the operations in steps S711 to S717 are performed a preset number of times at preset intervals. The continuous shooting mode can be set in either the live view mode or the OVF mode. In this specification, the continuous shooting mode in the live view mode will be described.

  If it is a single imaging, live view display may not be performed in steps S713 to S717 as described above. However, in the continuous shooting mode in which a plurality of image data is generated by a single imaging operation, a period during which a real-time image cannot be displayed on the display unit continues. In the continuous shooting mode, a moving subject is often imaged, and the inability to visually recognize the image of the subject during the imaging period in the continuous shooting mode greatly impairs the usability of the digital single-lens reflex camera.

  In step S716, each time imaging is completed, display image data is generated from the image data temporarily stored in the buffer 111 and displayed on the liquid crystal monitor 150. Thus, although not a real-time image, the image displayed on the liquid crystal monitor 150 is updated at a preset interval, so that the image of the subject can be visually recognized.

[3. Other Embodiments]
[3-1. (Relationship with review switching unit)
The menu button 140a, the cross key 140b, the set button 140c, and the rotary dial 140d, which are review switching units of the present invention, are set not to display generated image data or image data obtained by performing predetermined processing on the image data. However, in the live view mode, every time image data is generated in the continuous shooting mode, the generated image data or image data obtained by performing predetermined processing on the image data is displayed on the liquid crystal monitor 150 regardless of the setting. You may make it display.

  Even if the review switching unit is set not to display the generated image data or the image data obtained by performing a predetermined process on the generated image data, it is normal that the subject is moving in the continuous shooting mode. It is preferable to display the processed image data or image data obtained by performing predetermined processing on the image data on the liquid crystal monitor 150 so that the movement of the subject can be visually recognized because the usability of the camera is improved.

[3-2. (Relationship with movable mirror)
In the camera 10 according to the first embodiment, the operations from step S711 to step S717 are performed a preset number of times at preset intervals, so that the movable mirrors 121a and 121b capture the preset number of times. Repeatedly moving back and forth in the optical path of the optical system. In this case, since the autofocus operation can be performed when the movable mirrors 121a and 121b enter the optical path of the imaging optical system, the autofocus operation may be controlled every time image data is generated in the continuous shooting mode. .

  Even when the distance between the camera 10 and the subject changes due to the movement of the subject, if the autofocus operation is controlled every time image data is generated in the continuous shooting mode, a focused image is always obtained. be able to. Further, since the mirror driving unit 122 and the shutter driving unit 124 are always interlocked, by sharing a part of these driving units, it is possible to reduce the size and price of the camera.

  On the other hand, when the distance between the camera 10 and the subject does not change due to the movement of the subject, the movable mirrors 121a and 121b are retracted from the optical path of the imaging optical system during the period in which the image data is generated in the continuous shooting mode. You may control. Since it is not necessary to drive the movable mirrors 121a and 121b, continuous shooting can be performed quickly.

[3-3. (Relationship with viewfinder switching unit)
When the viewfinder changeover switch 140e is set to use the optical viewfinder, even if image data is generated in the continuous shooting mode, the generated image data or the image data is subjected to predetermined processing. It may be controlled not to display the image data on the liquid crystal monitor 150.

  When the optical viewfinder is used with an eyepiece on the eyepiece lens 136, the subject can be visually recognized when the movable mirrors 121a and 121b enter the optical path of the imaging optical system. At this time, if the liquid crystal monitor 150 emits light for display in the vicinity of the eyepiece lens 136, it obstructs the visual recognition of the subject in the optical viewfinder, so that the image data generated on the liquid crystal monitor 150 or the image data has a predetermined value. It is preferable to control not to display the image data subjected to the above process.

  When the viewfinder selector switch 140e is set to use the optical viewfinder, the last image data generated in the continuous shooting mode or image data obtained by performing predetermined processing on the image data is displayed on the liquid crystal display. When the image is displayed on the monitor 150 and the viewfinder switch 140e is set to use the live view mode, the generated image data or the image data is generated every time the image data is generated in the continuous shooting mode. The image data that has been subjected to the predetermined processing may be controlled to be displayed on the liquid crystal monitor 150.

  Even if the optical viewfinder is used, after the continuous shooting mode ends, the last image data generated in the continuous shooting mode or image data obtained by performing predetermined processing on the image data is visually recognized on the liquid crystal monitor 150. Therefore, the usability of the camera can be improved.

  The present invention includes a movable mirror, because each time image data is generated in the continuous shooting mode, the generated image data or image data obtained by performing predetermined processing on the image data can be displayed on the display unit. In addition, the present invention is useful when applied to a digital camera that can observe a subject image with an electronic viewfinder.

Schematic diagram for explaining an overview of a camera according to an embodiment of the present invention The block diagram which shows the structure of the camera body concerning embodiment of this invention The rear view of the camera body concerning an embodiment of the invention The block diagram which shows the structure of the interchangeable lens concerning embodiment of this invention The schematic diagram when the inside of the mirror box of the camera concerning embodiment of this invention is in the state B The schematic diagram when the inside of the mirror box of the camera concerning embodiment of this invention is in the state C Flowchart for explaining the operation at the time of imaging using the liquid crystal monitor 150 in the single focus mode

Explanation of symbols

110 Microcomputer 130 CMOS sensor 150 LCD monitor 200 Interchangeable lens

Claims (6)

A digital camera having a movable mirror that is disposed so as to be movable back and forth with respect to the optical path of the imaging optical system for guiding a subject image to an optical viewfinder,
An imaging device that captures an image of a subject formed by the imaging optical system when the movable mirror is retracted from the optical path of the imaging optical system, and generates image data;
A display unit for displaying the generated image data or image data obtained by performing a predetermined process on the image data;
A live view mode for controlling the generated image data or image data obtained by performing predetermined processing on the image data to be displayed on the display unit as a moving image in real time, and generating a plurality of image data by a single imaging operation A continuous shooting mode, and a control unit having
The controller is
In live view mode, each time image data is generated in continuous shooting mode, control is performed to display the generated image data or image data obtained by performing predetermined processing on the image data on the display unit.
Digital camera. After imaging, it further includes a review switching unit that switches whether to display the generated image data or image data obtained by performing a predetermined process on the image data,
The controller is
Regardless of the setting of the review switching unit, in the live view mode, each time image data is generated in the continuous shooting mode, the generated image data or image data obtained by performing a predetermined process on the image data is displayed. The digital camera according to claim 1, wherein the digital camera is controlled to display on the screen. The controller is
The digital camera according to claim 1, wherein in the live view mode, the movable mirror is controlled to be retracted from the optical path of the imaging optical system during a period in which image data is generated in the continuous shooting mode. The controller is
In the live view mode, before the image data is generated in the continuous shooting mode, the movable mirror is caused to enter the optical path of the imaging optical system so as to perform an autofocus operation on the imaging optical system. The digital camera according to claim 1. It further has a viewfinder switching unit that switches between using the optical viewfinder and using the live view mode,
The controller is
When the viewfinder switching unit is set to use an optical viewfinder, even if image data is generated in the continuous shooting mode, the generated image data or an image obtained by performing a predetermined process on the image data The digital camera according to claim 1, wherein the digital camera is controlled not to display data on the display unit. It further has a viewfinder switching unit that switches between using the optical viewfinder and using the live view mode,
The controller is
When the viewfinder switching unit is set to use an optical viewfinder, when the last image data is generated in the continuous shooting mode, a predetermined process is performed on the last generated image data or the image data. Is displayed on the display unit,
When the viewfinder switching unit is set to use the live view mode, each time image data is generated in the continuous shooting mode, the generated image data or an image obtained by performing a predetermined process on the image data Control to display data on the display unit,
The digital camera according to claim 1.

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