JP2007336388A - Image pickup device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image pickup device which is capable of performing appropriate monitor display according to a use situation, in a photographing apparatus capable of performing slew picture display. <P>SOLUTION: The image pickup device comprises: a CCD 221 for capturing video information; a back liquid crystal monitor 26 for displaying video information obtained by the CCD 221; and a shake sensor 216 for detecting a camera shake. It is discriminated from an output of the shake sensor 216 whether a photographing direction is changed or not (S103, S109) and in a case that it is discriminated that the photographing direction is changed, a frame rate for the display of video information is set higher than an ordinary one (S107, S113). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

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

In a conventional imaging device, image data is acquired from an imaging element for displaying and recording a subject image, and the frame rate at the time of acquiring the image is generally constant. However, it has been proposed to change the frame rate under various conditions. For example, Patent Document 1 discloses that when a blur amount is detected and the blur amount is large, an image with less blur is obtained by increasing the frame rate and combining a plurality of image data. Patent Document 2 discloses that the rotational speed of a turntable to which a network camera is fixed is detected, and that the frame rate of video information is increased when the rotational speed is high.
JP 2006-33123 A JP 2004-253904 A

In addition, panning photography, that is, a photography method in which the camera is shaken from right to left or from left to right and tilting photography, that is, a photography method in which the camera is shaken in the vertical direction are well known. This method is often used when photographing a wide landscape, a vertically long building, or chasing a moving person.

However, in a portable photographing device, when performing panning photographing or the like in which the subject image changes every moment, sufficient observation image display cannot be obtained even if the above-described prior art is applied. That is, in the technique disclosed in Patent Document 1, a frame rate of the imaging unit is increased in accordance with the amount of blur, and a plurality of images are combined to obtain one frame image, which is recorded or displayed. For this reason, the frame rate of the monitor image becomes constant, and there is a problem that the image data cannot be sufficiently followed when the subject image changes every moment in panning photography or the like. Further, the technique disclosed in Patent Document 2 is a network camera fixed to a turntable, and detects the shooting direction of the camera based on the rotation speed of the turntable that supports the camera. There is a problem of end. For this reason, handheld shooting is not applicable to general digital cameras.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a digital camera capable of displaying an appropriate monitor in accordance with a use situation.

In order to achieve the above object, an imaging apparatus according to a first invention includes an imaging unit that acquires video information, a display unit that displays video information obtained by the imaging unit, and a blur detection unit that detects camera shake. Determining means for determining whether or not the shooting direction is changed from the output of the blur detection means; and when the determination means determines that the shooting direction is changed, the video by the display unit Set the frame rate for displaying information higher than normal.

An imaging apparatus according to a second invention further includes a switch for instructing a shooting preparation operation in the first invention, and when the switch is input, a frame for displaying the video information by the display unit. Set the rate lower than normal.
An image pickup apparatus according to a third invention is the image display device according to the second invention, when the input of the switch is made and the determination unit determines that the shooting direction is changed. The frame rate for displaying the video information is set higher than the normal time.

In order to achieve the above object, an imaging device according to a fourth aspect of the present invention is an imaging unit that acquires video information, a display unit that displays video information obtained by the imaging unit, and whether or not the shooting direction is changed. A frame rate of display of the video information by the display unit when the shooting direction is not changed when the determination unit determines that the shooting direction has been changed. Set higher than.

An image pickup apparatus according to a fifth aspect of the present invention further includes a switch for instructing a shooting preparation operation in the fourth aspect of the invention. The frame rate of display by the display unit can be set to a low value, and if the determination unit determines that the shooting direction has been changed regardless of whether the switch is input, the display unit The frame rate for displaying the video information is set higher than when there is no change in the shooting direction.
An imaging apparatus according to a sixth invention further includes a switch for instructing a shooting preparation operation in the fourth invention, and when the determination unit determines that the shooting direction is changed, The frame rate for displaying the video information by the display unit is set higher when the switch is being input than when the switch is not being input.
Furthermore, in the image pickup apparatus according to a seventh aspect based on the fourth aspect, the determination means determines whether or not the shooting direction has been changed based on the output of the blur sensor or video information.
Furthermore, in the image pickup apparatus according to the eighth invention, in the fourth invention, when it is determined by the determination means that the shooting direction is changed, the frame rate at which pixel information is read by the image pickup unit is also changed To do.

According to the present invention, when the determination unit determines that the shooting direction is changed, the frame rate for displaying the video information by the display unit is set higher than when the shooting direction is not changed. Therefore, it is possible to provide a digital camera capable of displaying an appropriate monitor according to the usage situation.

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

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

In a mirror box in the camera body 20, a movable reflecting mirror 201 (referred to as a movable half mirror for convenience) having a characteristic of transmitting a part of the light beam that has passed through the lenses 101a and 101b is disposed. The movable half mirror 201 is driven by a movable mirror drive mechanism 215 and can rotate along an axis in a direction perpendicular to the paper surface around a rotation shaft 201a. When the movable half mirror 201 is at a position inclined by 45 degrees with respect to the optical paths of the lenses 101a and 101b (the position indicated by the solid line in FIG. 1), a part (for example, 30%) of the subject luminous flux is reflected, and the camera body 20 Is guided to a distance measuring / photometric sensor 217 provided at the bottom. Further, the remainder (for example, 70%) of the subject luminous flux passes through the movable half mirror 201 and is guided in the direction of a CCD (Charge Coupled Devices) 221. When the movable half mirror 201 is substantially parallel to the optical paths of the lenses 101a and 101b and is at a retracted position (a position indicated by a two-dot chain line in FIG. 1) that does not block the subject light flux, all of the subject light flux is guided to the CCD 221. In the present embodiment, the center of rotation of the movable half mirror 201 is the lower side in the mirror box, but is not limited to this, and may be the upper side or parallel to the paper surface on either the left or right side. Of course, the center of rotation may be used. In the present embodiment, the reflectance and transmittance of the half mirror are 30% and 70%, respectively, but are not limited to this ratio and can be changed as appropriate.

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

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

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

The unit including the CCD 221 is held in a known camera shake correction mechanism that is driven in a direction that cancels the movement of camera shake, and this camera shake correction mechanism is driven and controlled by a camera shake correction mechanism drive circuit 212. In addition to the method of mechanically driving the unit including the image sensor as in this embodiment, the image stabilization method acquires image data from which camera shake has been removed by image processing based on the output of the image sensor. Of course, it does not matter if the method is used. A shake sensor 216 for detecting the shake amount for correcting camera shake is disposed in the camera body 20 and is connected to an input / output circuit 239 described later. The blur sensor 216 measures the blur amount of the camera body 20 in a two-dimensional or three-dimensional manner, such as a known gyro, an angular velocity sensor, or an angular acceleration sensor.

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

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

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

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

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

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

Next, the operation of the digital camera according to the first embodiment of the present invention will be described with reference to the flowcharts shown in FIGS. In the power-on reset flow shown in FIG. 2, it is determined whether the power switch 257 of the camera body 20 is turned on (S1). As a result of the determination, if the power switch 257 is off, the process proceeds to step S3 to enter a sleep state that is a low power consumption state. In this sleep state, interrupt processing is performed only when the power switch 257 is turned on, and processing for turning on the power switch is performed in step S5 and subsequent steps. Until the power switch is turned on, operations other than power switch interrupt processing are stopped to prevent the power battery from being consumed. In step S1, if the power switch 257 is on, the process proceeds to step S2, and it is determined whether the attach / detach switch 259 is off. As described above, the attachment / detachment detection switch 259 is a switch that is turned off when the lens barrel 10 is removed from the camera body 20. If it is off, that is, if the lens barrel 10 is detached, the process proceeds to step S51 described later. This is because when the power switch lever of the camera body 20 is operated and the power is turned on with the lens barrel 10 detached, the same processing as when the lens is detached is performed. If it is determined in step S2 that the detachable switch 259 is on, the process proceeds to step S5 and subsequent steps, and processing for turning on the power switch is performed.

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

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

Next, if there is information such as the shooting mode set by a mode dial (not shown), ISO sensitivity, manually set shutter speed, aperture value, etc., those shooting conditions are read (S13). Then, the subject brightness is measured by the distance measuring / photometric sensor 217, the exposure amount is calculated, and exposure control values such as a shutter speed and an aperture value are calculated according to the shooting mode and shooting conditions using the exposure amount (S15). . Further, through image display setting is performed using a photometric value, an exposure amount, and the like (S17). In this step, in order to set the electronic shutter speed and sensitivity conditions for driving the CCD 221, using the photometry / exposure calculation result obtained in step S15 or the previous display image, the rear liquid crystal monitor 26 and / or Alternatively, calculation and setting for displaying an image of appropriate brightness (brightness) on the liquid crystal 29 in the finder is performed. Also, the frame rate is set for through image display. Here, reading by the CCD 221 and processing of the image processing circuit 227, the video signal output circuit 233, the liquid crystal monitor driving circuit 235, and the like are performed so that they are displayed on the rear liquid crystal monitor 26 and the like according to the set frame rate. The setting of the frame rate will be described later with reference to FIG.

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

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

Returning to step S21, if the result of determination is that the menu mode has not been set, processing proceeds to step S23, where it is determined whether the release button has been pressed halfway, that is, whether the 1R switch is on. If the result of determination is that 1R is on, processing advances to step S43, and a shooting operation subroutine for shooting preparation and shooting is executed. Details of this subroutine will be described later with reference to FIG. When the photographing operation subroutine ends, the process returns to step S7 and the above-described steps are repeated.

Returning to step S23, if the result of determination is that the 1R switch is off, processing proceeds to step S25, where it is determined whether the attachment / detachment detection switch 259 is off, as in step S2. When the lens barrel 10 is detached, a through image stop instruction is output (S45) and the shutter 203 is closed (S47), as in steps S31 and S33 in the reproduction mode. Thereafter, the retracting operation of the movable half mirror 201 is performed (S49). The retracting operation is performed by rotating the movable half mirror 201 to a position retracted from the photographing optical path (the position of the two-dot chain line in FIG. 1).

When the retracting of the movable half mirror 201 is completed, or when it is determined in step S2 that the attachment / detachment detection switch 259 is off (that is, when the lens barrel 10 is detached), the process proceeds to step S51. It is determined whether or not the detection switch 259 is on. In step S25, after detecting that the lens barrel 10 is detached, it is determined whether or not the lens barrel 10 is attached again. As a result of the determination, if it is mounted, the process proceeds to step S55, and the movable half mirror 201 is returned. This is because the movable half mirror 201 is inserted into the optical path of the lenses 101a and 101b by driving the motor. When the return of the movable half mirror 201 is completed, the process returns to step S7, and the above steps are repeated.

Returning to step S51, if the attachment / detachment detection switch 259 is off, the process proceeds to step S53 to determine whether the power switch 257 is on. When the lens barrel 10 is detached and the power switch 257 is on, the mount opening remains open even when various operation buttons are operated. Therefore, from the viewpoint of preventing malfunction, the camera operation should not be performed. Yes. For this reason, in step S51, the lens barrel 10 is mounted, and in step S53, the standby state in which the determination of the operation state of the power switch lever is repeated. If it is determined in step S53 that the power switch 257 is off, the process returns to step S3 to enter a sleep state. In step S51, when it is detected that the lens barrel 10 remains detached, the determination in step S53 may be omitted, and the process may proceed to step S3 to enter the sleep state, or the process may proceed to step S13. Modifications such as performing an operation based on an operation by the operation button are possible.

Returning to step S25, if the result of determination is that the attachment / detachment detection switch 259 is on, that is, if the lens barrel 10 is attached to the camera body, the routine proceeds to step S27, where it is determined whether or not the power switch 257 is on. If the result of determination is that it is on, processing returns to step S13 and the above steps are repeated. In step S11, after the through image display is started, the subject light flux that has passed through the movable half mirror 201 is not blocked by the shutter 203 unless various operation buttons are operated in step S19 and subsequent steps. The image data picked up by the CCD 221 is displayed as a moving image on the rear liquid crystal monitor 26 and / or the finder liquid crystal 29 as a moving image. Then, when it is detected in step S17 that the panning operation or the like has been performed during the live view display, the frame rate for display on the rear liquid crystal monitor 26 or the like is changed. If it is determined in step S27 that the power switch 257 is off, as in steps S31 and S33, the image processing circuit 227 is instructed to stop displaying the through image (S28), and the shutter 203 is closed. (S29). Thereafter, similarly to step S49 described above, after the retracting operation of the movable half mirror 201 is performed (S30), the process returns to step S3 and enters the sleep state.

Next, the subroutine of the photographing operation in step S43 will be described with reference to FIG. As described above, this subroutine is executed when the release button is half-pressed. First, distance measurement and automatic focus adjustment are performed (S71). This is because the movable half mirror 201 is inserted in the photographing optical path, and a part of the subject luminous flux is reflected toward the distance measuring / photometric sensor 217, and therefore the distance measuring / photometric processing circuit 219 using the subject luminous flux. The body CPU 229 and the like detect the focus shift amounts of the lenses 101a and 101b by the TTL phase difference method, and the lens 101a is brought into focus by the optical system driving mechanism 107 via the lens CPU 111 based on the detected focus shift amounts. , 101b are driven.

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

Next, through image display setting is performed in the same manner as in step S17 (S74), and it is determined whether or not the release button is fully pressed, that is, whether 2R is on (S75). If the result of determination is that it is off, processing advances to step S77 to determine whether 1R is on. When the release button is half-pressed, the process jumps to the shooting operation subroutine, and when the release button remains half-pressed, a standby state is made in which the determination is repeated in steps S74 to S77. When the release button is released and 1R is turned off, the process returns to the power-on reset step S7. As described above, while the release button is half-pressed, the through image display setting is repeatedly performed, and the through image display at an appropriate frame rate according to the state of the camera such as the panning operation can be performed.

Returning to step S75, if the result of determination is that the 2R switch is on, that is, if the release button is fully pressed, the operation moves to an imaging operation for acquiring a still image. First, in step S79, a through image stop instruction is output to the image processing circuit 227. This is due to the movement of the movable half mirror 201 to the retracted position and the opening / closing operation of the shutter 203 during the acquisition of the still image, causing the subject image incident on the CCD 221 to be disturbed, and in the rear liquid crystal monitor 26 and / or the liquid crystal 29 in the viewfinder. This is to prevent the through image from becoming unsightly. Subsequently, the retracting operation of the movable half mirror 201 is performed in the same manner as in step S49 (S81).

Subsequently, the aperture driving mechanism 109 performs the aperture operation of the aperture 103 to the set aperture value or the aperture value calculated in S73 (S83). When the narrowing-down operation is completed, an exposure operation by the CCD 221 is then performed (S85). That is, since the movable half mirror 201 has moved to the retracted position, all of the subject luminous flux that has passed through the lenses 101 a and 101 b forms an image on the CCD 221. In this state, the reset of the electronic shutter of the CCD 221 is released, and charge accumulation of the photoelectric conversion current of the subject image is started. When the exposure time set in advance or set in step S73 has elapsed, the electronic shutter of the CCD 221 stops the charge accumulation of the photoelectric conversion signal. In the exposure operation in step S85, the exposure time is controlled by the electronic shutter of the CCD 221. However, the present invention is not limited to this, and the exposure time can also be controlled by the shutter 203. In this case, it is necessary to once move the front and rear curtains of the shutter 203 to the initial positions before the start of the exposure operation.

Subsequently, the shutter 203 is closed (S87), and an instruction to open the aperture 103 is output to the lens CPU 111 (S89). Further, the image signal stored in the CCD 221 is read (S91), and image processing is performed by the image processing circuit 227 or the like (S93). After processing such as signal compression in the compression / decompression circuit 231, image data is recorded on the recording medium 245 (S95). When the recording of the image data is finished, it is determined in step S97 whether the 1R switch is on, that is, whether the release button is half pressed. When the 1R switch is turned off, the process proceeds to step S99, and the return operation of the movable half mirror 201 is performed in the same manner as in step S55. When the return operation is completed, the routine returns to the power-on reset routine.

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

Next, the through image display setting subroutine of steps S17 and S74 will be described with reference to FIG. When this subroutine is entered, a 1R switch that is turned on by half-pressing the release button is detected, and it is determined whether or not it is on (S101). As a result of the determination, if it is on, the process proceeds to step S103 to determine whether or not a panning operation or the like is being performed. This is based on the output of the blur sensor 216, where the subject image is sequentially shaken horizontally from right to left or from left to right, or from the bottom to the top or from the top to the bottom in the vertical direction. Determine whether you are being shaken. The determination of the panning operation may be made by performing image processing based on the image data output from the CCD 221 in addition to the determination based on the output of the blur sensor 216. Further, the detection is not limited to the two-dimensional direction, but may be only the one-dimensional direction as in the horizontal direction.

If it is determined that the panning operation has been performed, the process proceeds to step S107, and the frame rate is set to a high value, for example, 60 fps. When a panning operation is performed, the number of images per unit time is increased and the frame rate is increased to follow the change in the subject image. That is, even if the user shakes the camera from right to left or the like, the display on the rear liquid crystal monitor 26 can follow the change in the subject image. On the other hand, if it is determined in step S103 that the panning operation is not performed, the process proceeds to step S105, and the frame rate is set lower than the standard, for example, 15 fps. When the panning operation is not performed, the change in the subject image is small, and it is not necessary to increase the number of images per unit time. Furthermore, since the 1R switch is on in this state, it is estimated that the framing operation for shooting is completed and the shooting composition is almost determined. At this time, the influence of camera shake does not stand out. Therefore, the frame rate is set lower than the standard.

Returning to step S101, if the 1R switch is OFF, the process proceeds to step S109, and it is determined whether a panning operation is performed as in step S103. As a result of the determination, if the panning operation is performed, the process proceeds to step S113, and the frame rate is set to a high rate, for example, 60 fps. This is because the release button is not half-pressed but the panning operation is performed, so that the change in the subject image is followed. On the other hand, if it is determined in step S109 that the panning operation is not performed, the frame rate is set to the standard, for example, 30 fps. In this embodiment, the frame rate is 60 fps as the high frame rate, 30 fps as the standard frame rate, and 15 fps as the low frame rate. However, this is an example, and the high, standard, and low frame rates are set as appropriate. But of course.

Thus, in the first embodiment, the setting of the frame rate is changed from the viewpoint of the followability of the monitor image in the panning operation. That is, when there is a panning operation, a high frame rate is set (see S107 and S113). As a result, the monitor image does not become discontinuous, and the display on the rear liquid crystal monitor 26 can follow the change in the subject image.

In the first embodiment, when the panning operation is not performed, the frame rate is lowered from the high frame rate (see S105 and S111). Since a photographing device such as a digital camera has a limited number of built-in power supply batteries, it is not preferable to continuously display a monitor image at a high frame rate because it causes short-term consumption of the power supply battery. In this embodiment, since the frame rate is lowered when the panning operation is not performed, such a problem can be solved.

Furthermore, in the shooting preparation state in which the release button is half-pressed, if the panning operation is not performed, the composition has already been determined or the shooting direction has been determined. If camera shake occurs in this state, camera shake will occur. There is a problem that the monitor image shakes following the above and the monitor image becomes difficult to see. In this embodiment, in such a case, since the low frame rate is set (see S105), the influence of camera shake can be made difficult to appear.

Furthermore, in an imaging apparatus such as a digital camera, a shooting technique called panning is known when shooting a moving object. Even in such panning, the monitor image can follow by determining that the panning operation is performed and setting a high frame rate in this embodiment. Thus, in the present embodiment, it is possible to perform appropriate monitor display according to the usage status of the imaging device.

Next, a second embodiment of the present invention will be described. In the first embodiment, when it is determined that the panning operation is performed, a high frame rate is set. However, in the second embodiment, the frame rate is changed in consideration of whether the camera is in a shooting preparation state. Yes. That is, if the monitor image is continuously displayed at a high frame rate, the battery will be consumed short-term, which is not preferable. Therefore, the shooting preparation state is also used as a determination factor in determining whether to set a high frame rate. Since the configuration of the second embodiment is the same as that of the first embodiment except for the through image display setting subroutine shown in FIG. 5, a different through image display setting subroutine will be described.

When this subroutine is entered, a 1R switch that is turned on by half-pressing the release button is detected, and it is determined whether or not it is on (S121). As a result of the determination, if it is on, the process proceeds to step S123, and it is determined whether or not the panning operation is performed as in step S103. As a result of the determination, if the panning operation has been performed, the process proceeds to step S127, and the frame rate is set to a high value, for example, 60 fps. This is because, similarly to the case of step S107, when the panning operation is performed, the display on the rear liquid crystal monitor 26 is made to follow the change in the subject image by increasing the frame rate. On the other hand, if it is determined in step S123 that the panning operation is not performed, the process proceeds to step S125, and the frame rate is set to the standard, for example, 30 fps. Although the panning operation is not performed, the standard frame rate is set from the viewpoint that the user is also paying attention to the monitor screen because it is a shooting preparation operation.

Returning to step S121, if the 1R switch is off, the process proceeds to step S129, and it is determined whether a panning operation is performed as in step S103. As a result of the determination, if the panning operation is performed, the process proceeds to step S131, and the frame rate is set to the standard, for example, 30 fps. This is because the release button is not half-pressed but the panning operation is performed, so that the change in the subject image is followed. On the other hand, if it is determined in step S129 that the panning operation is not performed, the frame rate is set to a low value, for example, 15 fps. This is because the panning operation is not performed and the shooting preparation operation is not performed, so that the display is not performed with the number of frames more than necessary. As in the first embodiment, this is an example of the frame rate, and it is of course possible to appropriately set the high, standard, and low frame rates.

As described above, in the second embodiment, the setting of the frame rate is changed from the viewpoint of the followability of the monitor image in the panning operation and the reduction of power consumption. That is, when the panning operation is performed, the frame rate is set higher than when the panning operation is not performed. In this case, the frame rate is changed depending on whether the photographing preparation state (when 1R is on). In the shooting preparation state, it is highly possible that the photographer is gazing at the monitor screen, so the follow-up is improved by increasing the frame rate. Therefore, the power consumption is prevented by lowering the frame rate and reducing the power consumption. Although the release switch is used to detect the shooting preparation operation, other sensors that detect whether or not the camera is held by the photographer and whether or not the photographer is looking through the viewfinder are detected. A sensor may be used. That is, the case where the camera is gripped or the case where the photographer is looking through the viewfinder can be determined as the photographing preparation operation. In these cases, the determination in step S101 in FIG. 4 and step S121 in FIG. 5 may be performed according to the output of the sensor. Further, if the outputs of these sensors and switches are used, it is possible to detect the shooting preparation operation with higher accuracy.

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

In the first and second embodiments, the image pickup device is only the CCD 221. However, the image pickup device is not limited to this, and is separately arranged in the viewfinder optical system, and the image pickup device for recording and the image pickup device in the viewfinder optical system are used. It can also be applied to those that display through images by switching either or both of the outputs.

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

It is a block diagram which shows the whole structure of the electric system of the digital camera in 1st Embodiment to which this invention is applied. It is a flowchart which shows the operation | movement of the power-on reset in 1st Embodiment of this invention. It is a flowchart of the imaging | photography operation | movement in 1st Embodiment of this invention. It is a flowchart of the through image display setting in 1st Embodiment of this invention. It is a flowchart of the through image display setting in 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Lens barrel 20 Camera main body 26 Back surface liquid crystal monitor 29 Liquid crystal monitor 101a, 101b in finder Lens 103 Diaphragm 111 Lens CPU
201 Movable Half Mirror 203 Shutter 205 Dustproof Filter 207 Piezoelectric Element 212 Camera Shake Correction Mechanism Drive Circuit 215 Movable Mirror Drive Mechanism 216 Shake Sensor 217 Distance / Photometric Sensor 219 Distance / Photometric Processing Circuit 221 CCD
227 Image processing circuit 229 Body CPU
253 Switch detection circuit 255 Various switches 257 Power switch 259 Detachment detection switch

Claims (8)

An imaging unit for acquiring video information;
A display unit for displaying video information obtained by the imaging unit;
Blur detection means for detecting camera shake;
Determination means for determining whether or not the shooting direction is changed from the output of the blur detection means;
Comprising
An image pickup apparatus, wherein the frame rate of display of the video information by the display unit is set higher than normal when the determination unit determines that the shooting direction is changed. A switch for instructing a shooting preparation operation;
The imaging apparatus according to claim 1, wherein when the switch is input, a frame rate for displaying the video information by the display unit is set lower than normal.   The frame rate for displaying the video information by the display unit is set to be higher than normal when the switch is input and the determination unit determines that the shooting direction is changed. The imaging apparatus according to claim 2. An imaging unit for acquiring video information;
A display unit for displaying video information obtained by the imaging unit;
Determination means for determining whether or not the shooting direction is changed;
Comprising
When it is determined by the determination means that the shooting direction has been changed, the frame rate for displaying the video information by the display unit is set higher than when the shooting direction has not been changed. Imaging device. A switch for instructing a shooting preparation operation is further provided. When this switch is input, the frame rate of display by the display unit can be set lower than when no switch is input, and the switch Regardless of whether or not the input is made, if it is determined by the determining means that the shooting direction has been changed, the frame rate of the display of the video information by the display unit is higher than when the shooting direction is not changed. The imaging device according to claim 4, wherein the imaging device is set to a higher value. A switch for instructing a shooting preparation operation, and when the determination unit determines that the shooting direction is changed, the switch is input as the frame rate for displaying the video information by the display unit. The imaging apparatus according to claim 4, wherein the image pickup apparatus is set to be higher when the switch is input than when the switch is not in use.   The imaging apparatus according to claim 4, wherein the determination unit determines whether or not the shooting direction is changed based on an output of a blur sensor or video information.   The imaging apparatus according to claim 4, wherein when the imaging unit determines that the imaging direction is changed, the frame rate at which pixel information is read out by the imaging unit is also changed.