JP2007006097A - Camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a camera without causing void in a display screen of an image display executing live view display when emitting auto-focusing auxiary light rays. <P>SOLUTION: The camera comprises: a flash device 300 for irradiating a subject with supplemental lighting during range-finding operation by an AF sensor unit 205 when the luminance of the subject is low; a live view display imaging device 212b for performing imaging operation in a given cycle; a liquid crystal monitor 222 for displaying image data acquired by the live view display imaging device 212b; and a body control microcomputer 201 for controlling a camera body 200. The body control microcomputer 201 has control so that image data acquired by the live view display imaging device 212b are not display updated by the liquid crystal monitor 222 while the flash device 300 emitts the auxiary light rays. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a camera, and more particularly to a camera having a live view display function.

  In most current digital compact cameras, for example, an image display device such as a liquid crystal display is continuously updated by sequentially updating image data generated by an image sensor in the digital camera at a predetermined cycle. The function to display is provided. Such a display is generally referred to as a live view display or a live view display (hereinafter referred to as a live view display).

  As an example of adding a live view display function to a digital single lens reflex camera, for example, a technique disclosed in Patent Document 1 has been proposed.

In the technique disclosed in Patent Document 1, in addition to a first image pickup unit having a first image pickup element which is a normal image pickup element for an electronic camera, a first image pickup element for live view display is used. Second imaging means having two imaging elements is provided. Then, in order to guide the subject light beam that has passed through the photographing lens unit of the electronic camera to the second imaging unit, an optical path changing unit or a light beam dividing unit is provided in the electronic camera. Specifically, a half mirror is used as a part of the finder optical system of the electronic camera, and the light beam that has passed through the half mirror is guided to the second imaging unit, which is an image sensor for live view display. Light is received by the second image sensor. In this way, live view display is possible.
JP 2000-165730 A

  Usually, in a single-lens reflex camera having an autofocus (AF) function, when a subject has low luminance, irradiation of auxiliary illumination light is performed during distance measurement. This causes the following problems. In other words, if the auxiliary illumination light is irradiated during the live view display, the display screen of the image display device that is performing the live view display at that time becomes white for a moment (out-of-white), and then a certain amount of The problem is that the screen does not return to the display screen before the whiteout until time elapses. This phenomenon is caused by saturation of the amount of light received by the image sensor for live view display.

The technique disclosed in Patent Document 1 is not an invention proposed in consideration of this problem.
The present invention has been made in view of the above circumstances, and provides a camera in which a display screen of an image display device that is performing live view display does not cause overexposure when irradiated with distance measuring auxiliary illumination light. With the goal.

  In order to achieve the above object, a camera according to a first aspect of the present invention includes a distance measuring unit that detects a defocus amount of a photographing lens, and a live view display imaging unit that images a subject at a predetermined period. A display means for sequentially updating and displaying the image data acquired by the live view display imaging means, and an auxiliary illumination for the subject when the distance is measured by the distance measuring means when the subject has low brightness. Auxiliary illumination light irradiating means for projecting light, and image data acquired by the live view display imaging means while the auxiliary illumination light irradiating means irradiates auxiliary illumination light on the subject. And a control means for prohibiting display updating.

  In order to achieve the above object, a camera according to a second aspect of the present invention includes a distance measuring unit that detects a defocus amount of a photographing lens, and a live view display imaging unit that images a subject at a predetermined period. A display means for sequentially updating and displaying the image data acquired by the live view display imaging means, and an auxiliary illumination for the subject when the distance is measured by the distance measuring means when the subject has low brightness. Auxiliary illumination light irradiating means for projecting light, and control means for prohibiting the imaging operation of the live view display imaging means while the auxiliary illumination light irradiating means irradiates the subject with auxiliary illumination light, It is characterized by comprising.

  According to the present invention, it is possible to provide a camera in which a display screen of an image display device that is executing live view display does not cause overexposure when irradiation with auxiliary ranging illumination light is performed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First embodiment]
The configuration of the camera according to the present embodiment will be described below with reference to FIG.

  First, as shown in FIG. 1, the camera 1 includes a lens barrel 100, a camera body 200, and a flash device 300. In the lens barrel 100, a photographing optical system 102 composed of a plurality of optical lenses is disposed. The photographing optical system 102 is configured to be movable in the optical axis direction by a lens driving mechanism 103 to be described later, and transmits a light beam from a subject (not shown) in the internal direction of the camera body 200.

  An exposure opening having a predetermined aperture for guiding the light beam that has passed through the photographing optical system 102 to the inside of the camera body 200 is formed at a substantially central portion on the front side of the camera body 200. A photographing optical system mounting portion (not shown) is formed at the peripheral edge of the exposure opening. The lens barrel 100 is detachably attached to the camera body 200 via the photographing optical system mounting portion (not shown). Therefore, various lens barrels 100 can be attached to the camera body 200 according to the purpose at the time of shooting.

  Each part of the lens barrel 100 is controlled by a lens control microcomputer (hereinafter referred to as “Lucom”) 101 provided in the lens barrel 100. On the other hand, each part of the camera body 200 is controlled by a body control microcomputer (hereinafter referred to as Bucom) 201 as a control means provided in the camera body 200. Here, when the lens barrel 100 is attached to the camera body 200, the Lucom 101 and the Bucom 201 are communicably connected via the communication connector 101a. In this case, as a camera system, the Lucom 101 is operated so as to be subordinate to the Bucom 201.

  First, the configuration and operation control of the lens barrel 100 will be described. The lens barrel 100 includes a photographing optical system 102, a lens driving mechanism 103, a diaphragm 104, and a diaphragm driving mechanism 105. In FIG. 1, the photographing optical system 102 represents a plurality of optical lenses constituting the photographing optical system 102 as a single optical lens. The photographing optical system 102 is driven in the optical axis direction by a DC motor (not shown) existing in the lens driving mechanism 103.

  Further, a stop 104 is provided behind the photographic optical system 102. The diaphragm 104 is driven to open and close by a stepping motor (not shown) existing in the diaphragm drive mechanism 105. By controlling the opening / closing of the diaphragm 104 in this way, the amount of light flux from the subject incident on the camera body 200 via the photographing optical system 102 is controlled.

  Here, the control of the DC motor in the lens driving mechanism 103 and the control of the stepping motor in the aperture driving mechanism 105 are performed by the Lucom 101 that has received a command from the Bucom 201.

  Hereinafter, the configuration and operation control of the camera body 200 will be described.

  First, a finder device including a first reflecting mirror 202a, a focusing screen 202b, a finder optical system 202c, and an eyepiece lens 202d is provided inside the camera body 200. Note that the first reflecting mirror 202a is configured to use a half mirror, whereby the first reflecting mirror 202a can partially transmit the light flux.

  Further, in the vicinity of the finder optical system 202c (details will be described later with reference to FIG. 2), as shown in FIG. 1, a focus display superimpose LED 240 is arranged connected to the Bucom 201. . The focus display superimpose LED 240 projects the LED light so as to be superimposed on the subject screen in the viewfinder field, and displays a focus display (display indicating that the focusing operation has been completed) in the viewfinder field. That is, the user can confirm the end of the focusing operation by the focusing display displayed by the superimposing LED 240 for focusing display. The focus display superimpose LED 240 operates under the control of the Bucom 201.

  When the camera is in a normal state (a state in which a subject image is observed through the eyepiece lens 202d in the viewfinder device), that is, in a state where the first reflection mirror 202a is positioned at the DOWN position as shown in FIG. A part of the light beam from the subject incident through the system 102 is reflected by the first reflecting mirror 202a. As a result, an image for observation is formed through the focusing screen 202b, the finder optical system 202c, and the eyepiece lens 202d. Note that the live view display imaging device 212b, which is an imaging device for live view display and is a part of the live view display imaging means, is in the vicinity of the viewfinder optical system 202c (details of the position will be described later with reference to FIG. 2). Is provided).

  A photometric circuit 204 connected to the Bucom 201 is provided in the vicinity of the finder optical system 202c. A part of the light beam that has passed through the finder optical system 202c enters a photosensor (not shown) in the photometry circuit 204. In the photometry circuit 204, a well-known photometry process is performed based on the light amount of the light beam detected by the photosensor. The result processed by the photometry circuit 204 is transmitted to the Bucom 201. In the Bucom 201, the exposure amount at the time of photographing is calculated based on the result input from the photometry circuit 204. This result is transmitted from Bucom 201 to Lucom 101. In the Lucom 101, drive control of the diaphragm 104 is performed based on the exposure amount notified from the Bucom 201.

  The light beam transmitted through the first reflecting mirror 202a and reflected by the sub-mirror 203 is guided to an AF sensor unit 205 for performing an automatic focus adjustment process (AF process). The sub mirror 203 is provided on the back side of the reflecting mirror surface of the first reflecting mirror 202a. When the first reflecting mirror 202a is moved to an UP position (not shown), the sub mirror is accordingly accompanied. 203 is configured to be folded.

  An area sensor (not shown) is provided inside the AF sensor unit 205, and a light beam incident on the area sensor is converted into an electric signal. The output from the area sensor is transmitted to the Bucom 201 via the AF sensor driving circuit 206. Then, ranging processing is performed in the Bucom 201, and the focus state (defocus amount) of the photographing optical system 102 necessary for focus adjustment is calculated. This result is transmitted from Bucom 201 to Lucom 101. In the Lucom 101, drive control of the photographing optical system 102 is performed based on the drive amount notified from the Bucom 201.

  At the time of image capturing, as in the conventional single-lens reflex camera, the first reflecting mirror 202a and the sub mirror 203 are retracted to the UP position (not shown), and the imaging light beam enters the imaging element 212a for imaging. Such driving of the first reflecting mirror 202 a is performed by the mirror driving mechanism 207. The mirror drive mechanism 207 is controlled by the Bucom 201. As the first reflecting mirror 202a is moved to the UP position in this way, the light flux from the subject that has passed through the photographing optical system 102 enters the direction of the shutter unit 208. The spring force for driving the front curtain and rear curtain constituting the focal plane type shutter unit 208 is charged by the shutter charge mechanism 209. The front curtain and the rear curtain are driven by the shutter control circuit 210. The shutter charge mechanism 209 and the shutter control circuit 210 are controlled by the Bucom 201.

  At this time, the light beam that has passed through the photographing optical system 102 and entered the camera body 200 does not enter the finder optical system 202c at all. Therefore, the viewfinder is blacked out, and live view display is performed by the live view display image sensor 212b displayed on the liquid crystal monitor 222 (display means connected to the Bucom 201 via the image processing controller 218). Absent. However, since the imaging light flux at this time is incident on the imaging sensor 212a for shooting, the imaging sensor 212a is used instead of the imaging device 212b for live view display and the liquid crystal monitor 222 performs live. It is possible to perform view display.

  In the live view display, predetermined calculation or the like is performed on the image data of the subject image incident on the live view display imaging element 212b (or the photographing imaging element 212a), and the image data is almost in real time. Is displayed on the liquid crystal monitor 222. At this time, since the image data is sequentially displayed successively, the subject image captured by the digital camera appears to the human vision as being displayed as a moving image on the liquid crystal monitor 222.

  In addition, operation control related to live view display is performed by the image processing controller 218. Then, the Bucom 201 instructs the image processing controller 218 to start and stop the live view display operation.

  The light beam that has passed through the shutter unit 208 is incident on a photographing image sensor 212 a disposed behind the shutter unit 208. The electrical signal (image signal) obtained by the imaging element 212a for photographing is read out and digitized via the imaging interface circuit 217 at every predetermined timing. Image data obtained by digitization by the imaging interface circuit 217 is stored in a buffer memory 219 configured by SDRAM or the like via an image processing controller 218. Here, the buffer memory 219 is a memory for temporarily storing data such as image data, and is used as a work area when various processes are performed on the image data.

  Further, after the image shooting is completed, the image processing controller 218 reads the image data read out via the imaging interface circuit 217 and stored in the buffer memory 219. The image data read by the image processing controller 218 is stored in the buffer memory 219 after being subjected to known image processing such as white balance correction, gradation correction, and color correction. Thereafter, the image data after image processing stored in the buffer memory 219 is read by the image processing controller 218, converted into a video signal, resized to a predetermined size for display, and then output and displayed on the liquid crystal monitor 222. The The user can confirm the photographed image with the image displayed on the liquid crystal monitor 222.

  Here, in addition to the buffer memory 219, a flash ROM 220 and a recording medium 221 are provided as recording means for recording a captured image, connected to the image processing controller 218.

  At the time of recording a captured image, the image data after the image processing processed by the image processing controller 218 and recorded in the buffer memory 219 is compressed by a known compression method such as the JPEG method. The JPEG data obtained by this JPEG compression is stored in the buffer memory 219 and then recorded on the FlashRom 220 or the recording medium 221 as a JPEG file to which predetermined header information is added. Here, the FlashRom 220 is assumed to be a memory built in the camera, and the recording medium 221 is assumed to be mounted outside the camera. For example, as the recording medium 221, a memory card or a hard disk drive configured to be detachable from the camera is used.

  Note that when an image is reproduced from a JPEG file recorded on the FlashRom 220 or the recording medium 221, the JPEG data recorded on the FlashRom 220 or the recording medium 221 is read and decompressed by the image processing controller 218. Thereafter, the decompressed data is converted into a video signal, resized to a predetermined size for display, and output and displayed on the liquid crystal monitor 222.

  The Bucom 201 is connected to a nonvolatile memory 223 that stores predetermined control parameters necessary for camera control. The non-volatile memory 223 is composed of, for example, a rewritable EEPROM.

  Further, a battery 225 as a power source is connected to the Bucom 201 via a power circuit 224. In the power supply circuit 224, the voltage of the battery 225 is converted into a voltage required by each part of the camera system and supplied to each part of the camera system.

  The Bucom 201 includes an operation display LCD 226 for notifying the user of the operation state of the camera by display output, and a camera operation SW (camera operation switch) 227 for detecting operation states of various operation members of the camera. And are connected.

  Further, the camera body 200 is provided with a flash device 300. The flash device 300 includes a flash control circuit 301, a charging and light emitting circuit 303, and a light emitting unit 307. The charging and light emission control of the light emitting unit 307 is performed by the charging and light emitting circuit 303 controlled by the flash control circuit 301. The flash control circuit 301 is controlled by the Bucom 201. In the camera according to the present embodiment, when the subject has a low luminance, the flash device 300 emits light toward the subject, and shooting is performed to compensate for the lack of luminance of the subject.

  Hereinafter, an example of the configuration of the finder optical system 202c will be described with reference to FIG.

  The second reflecting mirror (half mirror) 202c2, the third reflecting mirror 202c3, the fourth reflecting mirror (half mirror) 202c4, and the imaging lens 202c5 shown in FIG. 1 are members included in the viewfinder optical system 202c in FIG. is there. In other words, in the present embodiment, the finder optical system 202c includes a second reflecting mirror (half mirror) 202c2, a third reflecting mirror 202c3, a fourth reflecting mirror (half mirror) 202c4, and an imaging lens 202c5. Hereinafter, specific arrangement positions of the respective constituent members in the configuration example shown in FIG. 2 will be described.

  The first reflecting mirror 202 a is disposed on the optical axis of the photographing optical system 102. Then, the second reflecting mirror 202c2 is disposed on the optical path of the light beam reflected by the first reflecting mirror 202a at a substantially right angle, in the right direction in FIG. A focusing screen 202b is disposed on the optical path of the light beam between the first reflection mirror 202a and the second reflection mirror 202c2.

  A photometric sensor 204a and a focus display superimpose LED 240 are disposed behind the second reflecting mirror 202c2 (rightward in the figure).

  A third reflection mirror 202c3 is disposed on the optical path of the light beam reflected upward at a substantially right angle by the second reflection mirror 202c2. Then, on the optical path of the light beam reflected by the third reflecting mirror 202c3 at a substantially right angle, in the same figure in the left direction, that is, in the direction opposite to the direction from the first reflecting mirror 202a toward the second reflecting mirror 202c2. Is provided with a fourth reflecting mirror 202c4.

  Further, an imaging lens 202c5 and a live view display imaging element 212b are disposed behind the fourth reflection mirror 202c4 (leftward in the figure).

  Further, on the optical path of the light beam reflected substantially at right angles by the fourth reflecting mirror 202c4, the light beam is parallel to the optical axis of the photographing optical system 102 and in the same direction as the light beam incident on the photographing optical system 102. An eyepiece 202d is disposed. In the finder optical system 202c having such a configuration, an optical path followed by a light beam emitted from a subject (not shown) will be described below.

  First, the light beam emitted from the photographing optical system 102 enters the first reflecting mirror 202a and is reflected in the direction of the focusing screen 202b. The light beam once forms an image on the focusing screen 202b. Thereafter, the light beam emitted from the focusing screen 202b is incident on the second reflecting mirror 202c2. As described above, the second reflecting mirror 202c2 is formed of a half mirror, and the light beam that has passed through the second reflecting mirror 202c2 enters the photometric sensor 204a provided in the photometric circuit 204 shown in FIG.

  Further, as shown in the drawing, a focus display superimpose LED 240 is installed behind the second reflecting mirror 202c2 (the same side as the side where the photometric sensor 204a is disposed). Then, the focus display superimpose LED 240 projects the LED light so as to be superimposed on the subject screen shown in the viewfinder field of view, and the focus display is displayed in the viewfinder field of view. The user can know that the focusing operation has been completed by this focusing display. Note that the position of the focus display superimpose LED 240 is not limited to the rear of the second reflecting mirror 202c2, but may be any position as long as it is behind the reflecting member whose reflecting surface is a half mirror. is there.

  On the other hand, the light beam reflected by the second reflection mirror 202c2 is further reflected by the third reflection mirror 202c3 in the direction of the fourth reflection mirror 202c4 formed of a half mirror. The light beam that has passed through the fourth reflecting mirror 202c4 is imaged by the live view display imaging element 212b via the imaging lens 202c5.

  The light beam reflected by the fourth reflecting mirror 202c4 enters the eyepiece lens 202d, and the user of the camera 1 can visually confirm the subject image via the eyepiece lens 202d.

  With the configuration of the finder optical system 202c as described above, the user can display a subject image formed on the focusing screen 202b, that is, an image displayed on an optical viewfinder (OVF) of the TTL (Through The Lens). A similar image can be observed on the liquid crystal monitor 222 as a live view display.

  Here, the imaging lens 202c5 and the live view display imaging device 212b are arranged behind the fourth reflection mirror 202c4. However, the arrangement positions of the imaging lens 202c5 and the live view display imaging device 212b are as described above. Needless to say, it is not limited to the rear of the four reflecting mirrors 202c4, and may be arranged behind any one of the second reflecting mirrors 202c2 to 202c4. In addition, the reflection mirror which arrange | positions the image formation lens 202c5 and the image pick-up element 212b for live view display behind itself must be comprised with the half mirror.

  Of course, a pentaprism may be used instead of the finder optical system 202c. In this case, any one reflecting surface of the pentaprism may be a half mirror, and an imaging lens and a live view display imaging device may be provided behind the half mirror.

  Next, with reference to FIG. 3, the external appearance (upper surface and rear surface) and various operation members of the camera according to the present embodiment will be described.

  First, the upper surface side of the camera 1 will be described. As shown in the figure, a power lever 401, a release button 402, and a mode dial 403 are provided on the upper surface of the camera 1 as operation members.

  The power lever 401 is an operation member for turning on / off the power of the camera 1. When the power lever 401 is turned, the main power source of the camera 1 is switched on / off.

  The release button 402 is a button for executing a shooting preparation operation and an exposure operation. This release button is composed of a two-stage switch of a first release switch and a second release switch. When the release button 402 is pressed halfway, the first release switch is turned on to perform photometry processing or distance measurement. A shooting preparation operation such as processing is executed. Further, when the release button 402 is fully pressed, the second release switch is turned on to perform the exposure operation.

  A mode dial 403 is an operation member for setting a shooting mode at the time of shooting. When the mode dial 403 is rotated, a shooting mode at the time of shooting is set. For example, five modes of a program AE mode (P), an aperture priority AE mode (A), a shutter priority AE mode (S), a manual mode (M), and a scene mode (SCN) can be set.

  The program AE mode is a mode in which an exposure operation is performed according to the exposure conditions (aperture value and shutter speed) calculated by the camera 1. The aperture priority AE mode is a mode in which exposure is performed with the shutter speed set according to the aperture value set by the user.

  The shutter priority AE mode is a mode in which exposure is performed with an aperture value set according to the shutter speed set by the user.

  The manual mode is a mode in which exposure is performed with an aperture value and a shutter speed set by the user.

  The scene mode is a mode in which shooting is performed under conditions suitable for various shooting scenes. In the scene mode, it is necessary to set a desired scene on the menu screen with the mode dial 403 set to SCN.

  The control dial 404 is an operation member that is operated while another operation member is pressed. By rotating the control dial 404, it is possible to change the setting of the function related to the operation member currently pressed by the user. Here, when the setting using the control dial 404 is performed, the operation state of the camera 1 at that time is displayed on the operation display LCD 226. The user can change the setting while viewing this display.

  Hereinafter, the back side of the camera 1 will be described. On the back side of the camera 1, as shown in the figure, a playback button 419, a cross button 424, and an OK button 425 are provided as operation members. A liquid crystal monitor 222 is provided as a display member.

  The playback button 419 is a button for switching the operation mode of the camera 1 to a playback mode in which an image can be played back from a JPEG file recorded on the Flash ROM 220 or the recording medium 221.

  The liquid crystal monitor 222 is a display member that performs menu screen display, live view display, and the like. The menu screen is composed of menu items having a plurality of hierarchical structures, and the user can select a desired menu item with the cross button 424 and determine the item selected with the OK button 425. Here, the menu items include, for example, a setup menu for the Flash ROM 220 and the recording medium 221, a shooting menu for setting image data image quality, image processing, scene mode, and the like, playback conditions for image playback, and settings for image printing. There are a playback menu that allows the user to perform various operations, a custom menu that allows various fine settings according to the photographer's preference, and a setup menu that sets the operating state of the camera such as the type of warning sound.

  Note that the setting of the live view display mode, which is a function of the camera according to the present embodiment, may be included in any menu item of the shooting menu, custom menu, and setup menu among the various menus described above.

  Also, for example, when setting the scene mode, a desired scene can be selected on the menu screen while the mode dial 403 is set to the scene mode (SCN). Examples of this scene include portrait, sports, commemorative photo, landscape, night view, and the like. In accordance with the selected scene, shooting conditions such as exposure conditions, flash emission conditions, photometry mode, AF method, and continuous shooting interval are set.

  Hereinafter, with reference to the flowchart shown in FIG. 4, operation control during shooting when the camera according to the present embodiment is set to the live view display mode will be described. This operation control is operation control performed by Bucom 201. The operation of each component in the camera when performing the operation control has been described in detail with reference to FIG.

  First, the imaging interface circuit 217 is caused to select the live view display imaging device 212b as the imaging device to be used (step S1). Of course, it is possible to simultaneously select both the imaging element 212a for photographing and the imaging element 212b for live view display. Next, an instruction to start a live view display operation is issued to the image processing controller 218 (step S2). Thereafter, as described above with reference to FIG. 1, live view display is performed by the image processing controller 218.

  Subsequently, it is determined whether or not the release button 402 is half-pressed by the user (the first release switch is turned on) (step S3). If it is determined that the user has not pressed the release button 402 halfway (the first release switch is ON), it is determined whether or not the user has performed an operation for changing the shooting mode (step S15). If it is determined that an operation for changing the shooting mode has been performed, the process returns to the main process (not shown). On the other hand, if it is determined that the operation for changing the shooting mode has not been performed, the process returns to step S3.

  If it is determined in step S3 that the user has pressed the release button 402 halfway (the first release switch is turned on), the photometric circuit 204 performs photometric processing to generate luminance data. This result is transmitted to Bucom 201, and the exposure amount is calculated in Bucom 201 (step S4).

  Simultaneously with step S4, a step of performing distance measurement and focus adjustment specific to the present embodiment is executed (step S5). Details of step S5 will be described later with reference to FIG. Then, a display indicating that the in-focus operation has been completed by the distance measurement and focus adjustment performed in step S5 (in-focus display) is displayed on the in-focus display superimpose LED 240 in a superimposed manner in the viewfinder field ( Step S6).

  Thereafter, it is determined whether or not the second release switch has been turned on by the user, that is, whether or not the release button 402 has been fully pressed (step S7). If it is determined in step S7 that the second release switch is not turned on, the process branches from step S7 to step S16 to determine whether or not the first release switch remains turned on (step S16). ). If it is determined in step S16 that the first release switch remains on, the process returns to step S7 again to determine whether the second release switch has been turned on.

  If it is determined in step S7 that the second release switch has been turned ON, an instruction to temporarily stop the live view display operation is issued to the image processing controller 218 (step S8).

  Thereafter, the imaging interface circuit 217 is caused to select the imaging element 212a for imaging as the imaging element to be used (step S9). Subsequently, the mirror driving mechanism 207 moves the first reflecting mirror 202a to the UP position described above (step S10). Next, a photographing operation is performed (step S11).

  Specifically, the photographing operation is to cause the diaphragm driving mechanism 105 to narrow down the diaphragm 104 based on the exposure amount calculated in step S4, and to cause the imaging interface circuit 217 to pass through the image processing controller 218. The imaging operation of the imaging image sensor 212a is started. Then, based on the exposure amount calculated in step S4, the shutter control circuit 210 is caused to open and close the shutter unit 208. Thereafter, the shutter control circuit 210 closes the shutter unit 208 and stops the photographing operation of the photographing image sensor 212a.

  Note that the electrical signal (image signal) obtained by the imaging element 212a for photography is read out and digitized via the imaging interface circuit 217 at every predetermined timing. Further, the image data obtained by digitization by the imaging interface circuit 217 is subjected to known image processing such as white balance correction, gradation correction, and color correction by the image processing controller 218.

  Thereafter, the diaphragm 104 is opened, and the first reflecting mirror 202a is moved to the DOWN position (step S12). Then, the image data is stored in the buffer memory 219 (step S13). Note that the buffer memory 219 has a capacity sufficient to temporarily store a large number of image data shot by, for example, high-speed continuous shooting. Thereafter, it is determined whether or not the user has performed an operation for changing the shooting mode using the cross button 424 and the OK button 425 (step S15). If it is determined that an operation for changing the shooting mode has been performed, the process returns to the main process (not shown). On the other hand, if it is determined that the operation for changing the shooting mode has not been performed, the process returns to step S3.

  Hereinafter, the above-described step S5, which is a process unique to the present embodiment, that is, the subroutine of distance measurement and focus adjustment step will be described with reference to the flowchart shown in FIG. 5 and the time charts shown in FIGS. Here, FIG. 6 is a time chart when the auxiliary illumination light is not used, and FIG. 7 is a time chart when the auxiliary illumination light is used.

  The frame rate for live view display is set to (1/30) seconds. That is, the image processing controller 218 captures live view display image data every 30 ms on the live view display imaging element 212b as shown in the “live view display: imaging” time chart shown in FIGS. Let The image data thus captured is displayed in live view on the liquid crystal monitor 222.

  The image data once displayed continues to be displayed on the liquid crystal monitor 222 until the next image data is updated and displayed as shown in the “live view display: display” time chart shown in FIGS. Therefore, the live view display displayed on the liquid crystal monitor 222 is recognized as a moving image for human vision.

  When the release button 402 is half-pressed by the user, that is, when the first release switch is turned on (see the “first release switch” time chart shown in FIGS. 6 and 7), as shown in the “distance measurement” time chart. First, distance measurement is performed without auxiliary illumination light (corresponding to the first distance measurement in the “distance measurement” time chart) (step S21). Specifically, a signal detected by the AF sensor unit 205 is transmitted to the Bucom 201 via the AF sensor driving circuit 206. In response to this, the Bucom 201 performs distance measurement processing.

  Next, based on the result of the distance measuring process in step S21, it is determined whether or not the subject has low luminance (step S22). The criterion for this determination is whether or not the charge accumulation (integration) in the AF sensor unit 205 has reached a predetermined level in the distance measurement without auxiliary illumination light in step S21. The predetermined level may be set as a default value or may be set by the user. If it is determined in step S22 that the subject does not have low brightness, the process proceeds to step S26 described later.

  If it is determined in step S22 that the subject has low brightness, the image processing controller 218 is instructed to prohibit display updating in live view display when the auxiliary illumination light is emitted (step S23). Then, the light emission is controlled through the flash control circuit 301 and the charging and light emitting circuit 303, and the distance measuring operation is performed again while the light emitting unit 307 emits light (refer to the “auxiliary light flash” time chart shown in FIG. 7) ( Step S24).

  That is, distance measurement is performed while irradiating the subject with auxiliary illumination light (flash pre-emission) using the flash device 300, and during that time, live view display is performed as shown in the “live view display: display” time chart of FIG. The image processing controller 218 is controlled so as not to update the display of the image data.Specifically, the image data acquired by the live view display imaging device 212b during execution of flash pre-flash is discarded, and instead, immediately before the flash pre-flash is emitted. Continue to display image data.

  Then, after completing the distance measurement by irradiating the auxiliary illumination light in step S24, the image processing controller 218 is instructed to permit display updating in the live view display (step S25).

  Subsequently, with reference to the distance measurement result, it is determined whether or not the position of the photographing optical system 102 is within the in-focus range (step S26). If it is determined in step S26 that the position of the photographing optical system 102 is within the in-focus range, the process returns to the flowchart shown in FIG. 4 and proceeds to the in-focus display step in step S6. In this focus display step, the LED light from the focus display superimpose LED 240 is projected onto the subject screen in the viewfinder field of view, and a display to the effect that the focus operation has been completed is displayed in the viewfinder field of view.

  This focus display is performed by the focus display superimpose LED 240 after the focus is confirmed by the last distance measurement as shown in the “focus display” time charts of FIGS. 6 and 7.

  On the other hand, if it is determined in step S26 that the position of the photographing optical system 102 is not within the in-focus range, the driving amount of the photographing optical system 102 necessary for focus adjustment is calculated based on the distance measurement result. (Step S27). Then, the calculation result is transmitted to the Lucom 101, and the drive control of the photographing optical system 102 (see the “lens drive” time chart shown in FIGS. 6 and 7) is performed by the Lucom 101 based on the drive amount notified by the Bucom 201 (steps shown in FIGS. 6 and 7). S28).

  Thereafter, it is determined whether or not the auxiliary illumination light has been irradiated in the previous distance measurement (step S29). If it is determined that the auxiliary illumination light has been irradiated in the previous distance measurement, the process returns to step S23, and the distance measurement is performed again using the auxiliary illumination light. If it is determined in the previous distance measurement that the auxiliary illumination light is not irradiated, the process returns to step S21 and the subsequent steps are repeated.

  When focusing is completed without using any auxiliary illumination light, a ranging operation is performed while performing normal live view display as shown in the time chart of FIG.

  As described above, according to the present embodiment, it is possible to provide a camera in which the display screen of an image display device that is executing live view display does not cause overexposure when flash pre-flash is performed. .

  Specifically, in the present embodiment, while flash pre-light emission is performed as auxiliary illumination light, the display update of the live view display is prohibited by prohibiting the display update of the live view display. Prevent overexposure of the screen.

  In addition, for several frames of image data immediately after permission to update the display of the live view display, display update is prohibited, and the subsequent image data is used to update the display of the live view display, thereby preventing whiteout. Of course you can go to.

[Second Embodiment]
Hereinafter, a camera according to a second embodiment of the present invention will be described with reference to the drawings. Note that portions that are the same as those in the first embodiment in terms of device configuration and operation control are omitted here, and differences from the camera according to the first embodiment will be mainly described.

  The difference in the device configuration from the camera according to the first embodiment is that an auxiliary light lamp 500 is used in this embodiment instead of the flash device 300 in the first embodiment as shown in FIG. is there. The auxiliary light lamp 500 is a light emitting diode (LED) or a light bulb. Further, the auxiliary light lamp 500 is not an indispensable constituent element in the present embodiment, and the flash device 300 may be used as in the first embodiment. Further, on the contrary, in the first embodiment, the auxiliary light lamp 500 may of course be used instead of the flash device 300. Note that the auxiliary light lamp 500 is communicably connected to the Bucom 201, and light emission is controlled by the Bucom 201.

  The difference in operation control between the first embodiment and the present embodiment is that, in the first embodiment, the live view display is displayed when the auxiliary illumination light is irradiated (flash pre-light emission; the same applies hereinafter). Although the update is prohibited, in the present embodiment, the imaging operation itself of the live view display imaging element 212b is prohibited when the auxiliary illumination light is irradiated. This point is a major difference between the first embodiment and the present embodiment.

  That is, the distance measurement and focus adjustment subroutine that is step S5 in the flowchart shown in FIG. 4 is different from that of the first embodiment. Therefore, the subroutine of distance measurement and focus adjustment step under the control of Bucom 201 will be described below with reference to the flowchart shown in FIG. 9 and the time chart shown in FIG.

  Steps S21 and S22 are the same as those in the first embodiment, and are as described with reference to the flowchart of FIG.

  If it is determined in step S22 that the subject has low luminance, the live view display imaging device is irradiated to the imaging interface circuit 217 via the image processing controller 218 while the auxiliary illumination lamp 500 emits auxiliary illumination light. An instruction to prohibit the imaging operation 212b is issued (step S33). Then, distance measurement is performed again while controlling the auxiliary light lamp 500 to emit light (step S34). That is, distance measurement is performed using the auxiliary light lamp 500 while irradiating the subject with auxiliary illumination light, and during that time, the live view display imaging device 212b is as shown in the “live view display: imaging” time chart shown in FIG. The image processing controller 218 and the imaging interface circuit 217 are controlled so that the imaging operation is not performed. Specifically, the imaging operation of the live view display imaging element 212b is not performed during the irradiation of the auxiliary illumination light, but instead, the image data immediately before the irradiation of the auxiliary illumination light is continuously displayed as the live view display.

  Thereafter, an instruction is given to the image processing controller 218 to permit the imaging operation of the live view display imaging element 212b (step S35). Thereafter, the operation control in steps S26 to S29 is the same as that in the first embodiment.

  As described above, according to the present embodiment, the camera having the same effect as that of the first embodiment is provided by prohibiting the imaging operation itself of the live view display imaging element 212b when the auxiliary illumination light is irradiated. be able to.

  Further, the above-described embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and the effect described in the column of the effect of the invention Can be extracted as an invention.

  As mentioned above, although embodiment of this invention was described, in the range which does not deviate from the summary of this invention other than embodiment mentioned above, this invention can be variously modified.

1 is a diagram illustrating a configuration of a camera according to a first embodiment of the present invention. 1 is a diagram illustrating a configuration of a finder optical system in a camera according to a first embodiment of the present invention. 2A and 2B are views showing the appearance (upper surface and rear surface) of the camera according to the first embodiment of the present invention. 6 is a flowchart showing operation control during shooting when the camera according to the first embodiment of the present invention is set in a live view display mode. 5 is a flowchart of distance measurement and focus adjustment steps in the camera according to the first embodiment of the present invention. 3 is a time chart of distance measurement and focus adjustment steps (when auxiliary illumination light is not used) in the camera according to the first embodiment of the present invention. The time chart of the ranging and the focus adjustment step (at the time of auxiliary illumination light use) in the camera which concerns on 1st Embodiment of this invention. The figure which shows the structure of the camera which concerns on 2nd Embodiment of this invention. The flowchart of the ranging and the focus adjustment step in the camera which concerns on 2nd Embodiment of this invention. The time chart of the ranging and focus adjustment step (at the time of auxiliary illumination light use) in the camera which concerns on 2nd Embodiment of this invention.

Explanation of symbols

    DESCRIPTION OF SYMBOLS 1 ... Camera, 100 ... Lens barrel, 101 ... Microcomputer for lens control, 102 ... Shooting optical system, 200 ... Camera body, 201 ... Microcomputer for body control, 202a ... First reflection mirror, 202b ... Focusing screen, 202c Finder optical system 202c2 second reflecting mirror 202c3 third reflecting mirror 202c4 fourth reflecting mirror 202c5 imaging lens 204a photometric sensor 205 AF sensor unit 207 mirror driving mechanism 210 DESCRIPTION OF SYMBOLS ... Shutter control circuit, 212b ... Live view display imaging device, 212a ... Shooting imaging device, 217 ... Imaging interface circuit, 218 ... Image processing controller, 222 ... Liquid crystal monitor, 227 ... Camera operation SW, 240 ... Superimpose LED for focus display, 300 ... Flash device, 301 ... Flash control circuit, 307 ... Light emitting unit, 500 ... Auxiliary light lamp

Claims (3)

A distance measuring means for detecting a defocus amount of the photographing lens;
Live view display imaging means for imaging a subject at a predetermined cycle;
Display means for sequentially updating and displaying the image data acquired by the live view display imaging means;
An auxiliary illumination light irradiating means for projecting auxiliary illumination light to the object at the time of distance measurement by the distance measuring means when the subject has low brightness;
Control means for prohibiting image display data acquired by the live view display imaging means from being updated on the display means while the auxiliary illumination light irradiating means irradiates the subject with auxiliary illumination light; ,
A camera comprising: A distance measuring means for detecting a defocus amount of the photographing lens;
Live view display imaging means for imaging a subject at a predetermined cycle;
Display means for sequentially updating and displaying the image data acquired by the live view display imaging means;
An auxiliary illumination light irradiating means for projecting auxiliary illumination light to the object at the time of distance measurement by the distance measuring means when the subject has low brightness;
Control means for prohibiting the imaging operation of the imaging means for live view display while the auxiliary illumination light irradiating means irradiates the subject with auxiliary illumination light;
A camera comprising:   The control means updates the display means to display at least the acquired first frame image data among the image data acquired by the live view display imaging means after the auxiliary illumination light irradiation by the auxiliary illumination light irradiation means is completed. 3. The camera according to claim 1, wherein control is performed so that the camera is not controlled.

Images