JP2008042405A - Digital camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digital camera which provides an animation without a strange feeling even by using a lens the field angle of which is changed in response to focusing. <P>SOLUTION: The digital camera includes: a photographing lens 101 the photographing field angle of which is changed in response to focus adjustment; and a CCD 27 for receiving the luminous flux of an object which passes through the photographing lens 101 and outputting an object image signal. Trimming is performed (S177, S179), so as to allow the object images 461, 463, 465 whose field angles are changed due to the focus adjustment, to be the object images 481, 483, 485 having fixed field angles. The animation of the object is recorded in a recording medium 245, based on the trimmed object image signal. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a digital camera having a moving image shooting function.

Many digital cameras can record not only still images but also moving images. For example, Patent Document 1 discloses a digital single-lens reflex camera that takes a moving image by retracting a quick return mirror (movable mirror) out of the photographing optical path and maintaining the focal plane shutter in a bulb state.
JP 59-201029 A

By the way, in order to realize a small and high-performance lens, a type in which the angle of view (focal length) changes depending on the focus position may be used as a photographing lens for a digital camera. Since this type of lens can provide a high-performance lens in a small size and at low cost, it has a great merit for the user. However, this change in the angle of view does not stand out when shooting a still image, so there is no problem. However, in the case of moving image shooting, a change in the angle of view due to focusing is recorded, resulting in an uncomfortable image.

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 acquiring a moving image without a sense of incongruity even when using a lens that changes the angle of view by focusing.

In order to achieve the above object, a digital camera according to a first aspect of the present invention is a photographing lens whose photographing angle of view changes in accordance with focus adjustment, and an imaging device that receives a subject luminous flux that has passed through the photographing lens and outputs a subject image signal. Means, trimming means for trimming the subject image signal in accordance with a change in the angle of view of the photographing lens, and recording means for recording a moving image of the subject based on the subject image signal subjected to the trimming process.

In the digital camera according to the second invention, in the first invention, the photographing lens is detachable.
According to a third aspect of the present invention, in the digital camera according to the second aspect, the photographing lens includes an output unit that outputs information corresponding to the change in the angle of view.
Furthermore, in the digital camera according to the fourth invention, in the third invention, the output means includes storage means for storing a plurality of field angle information corresponding to the focal length and the focal position of the photographing lens.

According to a fifth aspect of the present invention, in the digital camera according to the first aspect, the trimming means prevents the change in the angle of view of the recorded moving image even when focus adjustment is performed during recording of the moving image. Then, the subject image signal is trimmed.
According to a sixth aspect of the present invention, in the digital camera according to the first aspect, the trimming means performs a trimming process on the basis of the narrowest field angle within the field angle change range.

In order to achieve the above object, a digital camera according to a seventh aspect of the present invention is a photographic lens whose photographic angle of view changes according to focus adjustment, and an imaging device that receives a subject luminous flux that has passed through the photographic lens and outputs a subject image signal. Means for obtaining an amount of change in angle of view in accordance with the focus adjustment, trimming means for performing trimming processing of the subject image signal so as to obtain a constant angle of view based on the amount of change in angle of view, and the trimming Recording means for recording a moving image of the subject based on the processed subject image signal is provided.

According to an eighth aspect of the present invention, in the seventh aspect of the invention, the means for obtaining the view angle change amount includes a storage means for storing the view angle change amount corresponding to the focal position.
According to a ninth aspect of the present invention, in the digital camera according to the eighth aspect, the photographic lens is a zoom lens having a variable focal length, and the storage means includes an image corresponding to the focal length in addition to the focal position. The amount of angular change is memorized.
Further, the digital camera according to the tenth invention is the selection means for selecting a still image mode for recording a still image of a subject and a moving image mode for recording a moving image based on the subject image signal in the seventh invention. The trimming means performs the trimming process when the moving image mode is selected.

Furthermore, a digital camera according to an eleventh aspect of the present invention is the digital camera according to the seventh aspect, wherein the amount of focus shift and the direction of shift are detected by the phase difference method using the subject light flux that has passed through the photographing lens. There is provided an automatic focus adjusting means for driving the photographing lens based on the shift direction.
Further, a digital camera according to a twelfth aspect of the present invention is the digital camera according to the eleventh aspect of the invention, further comprising a half mirror that can be moved back and forth between the photographic lens and the imaging means, and the automatic focus adjustment means is reflected by the half mirror. Distance measurement is performed by the phase difference method using the subject light flux.

According to the present invention, since the subject image signal is trimmed in accordance with the change in the angle of view of the photographing lens, a digital image capable of acquiring a moving image without any sense of incongruity using a lens that changes the angle of view by focusing. A camera can be provided.

Hereinafter, a preferred embodiment using a digital camera to which the present invention is applied will be described with reference to the drawings. This digital camera forms a subject image formed by a photographing lens on an image sensor and displays a moving image on a display device such as a liquid crystal monitor for observing the subject image based on the output of the image sensor. It has a display function (also called a live view display function or an electronic viewfinder function). Further, a still image can be acquired and recorded on a recording medium in accordance with a shooting instruction from the photographer. Furthermore, it is possible to acquire a moving image in accordance with a shooting instruction from the photographer and record it on a recording medium.

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 lens CPU 111 controls the inside of the lens barrel 10 and controls the optical system driving mechanism 107 to perform focusing and zoom driving, and also controls the diaphragm driving mechanism 109 to perform aperture control. The focal length is adjusted (zooming) by a manual operation member (not shown).

Various unique data of the lens barrel 10, such as wide-side focal length, tele-side focal length, close-up distance, open aperture value, minimum aperture value, field angle change Δkt, Δkw information (see FIG. 7) described later, and the like. A lens data storage circuit 112 that stores various data is connected to the lens CPU 111. The lens CPU 111 transmits the lens data read from the lens data storage circuit 112 to the body CPU 229.

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 the CCD 221.

When the movable half mirror 201 is substantially parallel to the optical paths of the lenses 101a and 101b and is in a retracted position (a position indicated by a two-dot chain line in FIG. 1) that does not block the subject light beam, the entire subject light beam is guided to the CCD 221. The structure of the movable half mirror 201 will be described later with reference to FIG. 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. Moreover, although the rotation center of the movable half mirror 201 is arranged on the CCD 221 side, it is not limited to this and may be arranged on the mount opening side. Furthermore, in this 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 exposure time control and light shielding of the CCD 221 is disposed behind the movable reflecting mirror 201 and on the optical axis of the lenses 101a and 101b and on the photographing optical path. Is driven and controlled by a shutter drive mechanism 213. A dustproof filter 205 is disposed behind the shutter 203. This is because dust generated in the mount opening of the camera body 20 and inside the body adheres to the CCD 221 and the optical element, and the shadow of the dust is reflected in the subject image. It is a filter to prevent it from becoming unsightly.

A piezoelectric element 207 is fixed to the entire periphery or a part of the periphery of the dustproof filter 205, and this piezoelectric element 207 is connected to the dustproof filter drive circuit 211 and driven by this circuit. The piezoelectric element 207 is driven by the dust filter driving circuit 211 so that the dust filter 205 vibrates with a predetermined ultrasonic wave, and the dust attached to the front surface of the dust filter 205 is removed using the vibration. In addition, as long as dust attached to the image pickup device itself such as a CCD or an optical element disposed on the front side of the image pickup device can be removed, it is not limited to one using ultrasonic vibration as in the present embodiment. Of course, it may be appropriately replaced with various methods such as a method of blowing off by an air flow using an air pump or a method of collecting and removing dust using static electricity.

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

The CCD 221 is connected to the image sensor driving circuit 223 and is driven and controlled by a control signal from the input / output circuit 239. A photoelectric analog signal output from the CCD 221 is amplified and analog-digital converted (AD converted) by the image sensor driving circuit 223. The image sensor driving circuit 223 is connected to an image processing circuit 227 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 image processing such as correction, gamma (γ) correction, contrast correction, monochrome / color mode processing, through image processing, moving image processing for recording medium recording, and trimming 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 the image data stored in the SDRAM 238 in a compression format for still images such as JPEG and MJPEG and for moving images. Note that image compression is not limited to JPEG or MJPEG, 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. The input / output circuit 239 connected to the above-described dustproof filter drive circuit 211, shutter drive mechanism 213, movable mirror drive circuit 215, distance measurement / photometry processing circuit 219, and image sensor drive circuit 223 is connected to the body CPU 229 via the data bus 261. Control input / output of data with each circuit. The communication circuit 241 connected to the lens CPU 111 via the communication contact 300 is connected to the data bus 261, and exchanges data with the body CPU 229 and the like and communicates control commands.

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

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

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 driving means and retracting means of the movable half mirror 201 will be described with reference to FIG. A half mirror 401 that transmits part of the subject luminous flux and reflects part of it is held by a mirror frame 403. The mirror frame 403 is rotatable around a shaft 411 inserted in the hole 403 a, and the rotation shaft 201 a in FIG. 1 is a central axis of the shaft 411. Both ends of an opening spring 407 are engaged between a pin 409 fixed to the camera body 20 and a driving pin 405 implanted in the mirror frame 403, and a coil portion of the opening spring 407 is wound around a shaft 411. It is disguised. Due to the spring force of the opening spring 407, the mirror frame 403 receives a biasing force in the counterclockwise direction (arrow A direction) in the figure. One end of the drive pin 405 and the locking lever 413 are engaged, and the cam pin 415 implanted at the other end of the locking lever 413 is engaged with the mirror cam 417.

The locking lever 413 is pivotally supported by a mirror box (not shown), and receives a biasing force counterclockwise (arrow B direction) in the figure by the spring force of the opening spring 407 via the drive pin 405. Yes. Therefore, the cam pin 415 of the locking lever 413 is in pressure contact with the cam surface of the mirror cam 417. The cam surface of the mirror cam 417 is formed so that the length in the radial direction from the center of rotation changes. That is, the locking position 417a on the cam surface is formed so that the distance from the rotation center is longer, and the locking release position 417b is formed so that the distance from the rotation center is shorter than the locking position 417a. ing. A cam surface is formed with a step 417c from the locking position 417a to the locking release position 417b in the counterclockwise direction in the drawing, and the cam surface is smoothly displaced from the locking release position 417b to the locking position 417a. It is formed.

When the locking position 417a of the mirror cam 417 is in a position where it abuts on the cam pin 415, the locking lever 413 is restricted from rotating in the direction of arrow B by the mirror cam 417. Hold on. From this state, when the mirror cam 417 is rotated clockwise in the drawing to a position where the unlocking position 417b contacts the cam pin 415 through the step 417c, the locking lever 413 is rotated in the arrow B direction. It becomes possible. Therefore, the mirror frame 403 is rotated in the direction of arrow A by the urging force of the opening spring 407 and displaced to the retracted position. The mirror cam 417 is rotationally driven by a motor (not shown).

The driving means for driving the movable half mirror 201 to the reflection position (the position indicated by the solid line in FIG. 2) in the imaging optical path includes a mirror cam 417, a locking lever 413, and the like. Further, the retracting means for driving the movable half mirror 201 to the retracted position (the position indicated by the two-dot chain line in FIG. 2) outside the imaging optical path includes an opening spring 407. The driving unit and the retracting unit are not limited to such a configuration, and other configurations may be used as long as the movable half mirror 201 can be driven.

Since the movable half mirror 201 is configured in this way, when the cam pin 415 is driven to a position in contact with the locking release position 417b by a motor (not shown), the mirror frame 403 and the locking lever 413 are opened and the spring 407 is attached. The mirror frame 403 is moved to the retracted position as shown by a two-dot chain line in the figure by the force. In this state, when the mirror cam 417 is rotated by the motor and the locking position 417a comes into contact with the cam pin 415, the locking lever 413 is rotated in the clockwise direction (the direction opposite to the arrow B direction), and the opening spring 407 is rotated. The mirror frame 403 is rotated clockwise (opposite to the direction of the arrow A) via the drive pin 405 against the urging force, and is positioned at a reflection position as shown by a solid line in the drawing.

Next, the operation of the digital camera in one embodiment of the present invention will be described using the flowcharts shown in FIGS. In the power-on reset flow shown in FIG. 3, 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 S5 to enter a sleep state that is a state of low power consumption. 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 S7 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, when the power switch 257 is on, the process proceeds to step S3, 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 S67 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 S3 that the attach / detach switch 259 is on, the process proceeds to step S7 and subsequent steps to perform processing for turning on the power switch.

In step S7, 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 subject luminous flux from the lens barrel 10 is measured / photometrically measured. This is for guiding to the sensor 217 and performing photometry and distance measurement as necessary. In step S9, the dust removal operation in the dustproof filter 205 is performed. This is an operation in which a driving voltage is applied from the dustproof filter driving circuit 211 to the piezoelectric element 207 fixed to the dustproof filter 205, and dust and the like are removed by ultrasonic vibration as described above. Subsequently, the shutter driving circuit 213 performs an opening operation of the shutter 203 (S11).

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 through image conditions are initially set in order to start the through image display in which the subject image is displayed as a moving image on the rear liquid crystal monitor 26 (S13). The initial setting of the through image conditions is to set default values of the electronic shutter speed TV and ISO sensitivity SV of the CCD 221. In addition, the frame rate for displaying the through image is set (in this embodiment, 30 fps). 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 the image is displayed on the rear liquid crystal monitor 26 and the like according to the set frame rate. Since the through image display is now ready, the start of the through image is instructed (S15). The through image display operation is controlled by the image processing circuit 227 in response to the start instruction.

Next, information such as a shooting mode for still image shooting such as a program shooting mode set by a mode dial (not shown) or a shooting mode such as a movie shooting mode, ISO sensitivity, a manually set shutter speed, an aperture value, etc. If there are, the photographing conditions are read (S17). Then, it communicates with the lens CPU 111, and various lens data stored in the lens data storage circuit 112, for example, wide-side focal length, tele-side focal length, close distance, full aperture value, field angle change Δkt, Δkw information The information such as (see FIG. 7) and the state of the optical system driving mechanism 107 are detected, and various lens data such as the currently set focal length and the current set focus position are read (S19).

Subsequently, the image data of the moving image can be acquired with the exposure value EV that is the target appropriate exposure amount, and an image with appropriate brightness (lightness) is displayed on the rear liquid crystal monitor 26 and / or the liquid crystal 29 in the viewfinder. The through image condition is set (S21). In this step, conditions for the electronic shutter speed TV and sensitivity SV for driving the CCD 221 are set. Initially, the values initially set in step S13 are used, and the electronic shutter speed is set so that the target image brightness is obtained. Adjust TV and sensitivity SV.

Next, it progresses to step S23 and it is determined whether it is a reproduction | regeneration mode. This playback mode is a mode in which 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 when the playback button is operated. If the reproduction mode is set as a result of the determination, the process proceeds to step S41 to instruct the image processing circuit 227 to stop the through image display. Thereafter, after the shutter 203 is closed (S43), the image data recorded on the recording medium 245 is read, the image data is expanded by the compression / decompression circuit 231, and the video signal output circuit 233 and the liquid crystal monitor are driven. A still image or a moving image is reproduced and displayed on the rear liquid crystal monitor 26 and / or the viewfinder liquid crystal 29 via the circuit 235 (S45). If another manual operation such as half-pressing the release button is performed during the reproduction operation, the reproduction operation is terminated and the process returns to step S9 to repeat the above operation.

Returning to step S23, if the playback mode has not been set, the process proceeds to step S25 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 (S47) and a close command is output to the shutter 203 (S49) as in the case where the playback mode is set. Thereafter, a menu setting operation is performed (S51). When the menu setting operation is completed, the process returns to step S9, and the above operation is repeated.

Returning to step S25, if the result of determination is that the menu mode has not been set, processing proceeds to step S27, where it is determined whether the release button has been pressed halfway, that is, whether the 1R switch is on. As a result of the determination, if 1R is on, the process proceeds to step S53, and it is determined whether or not the shooting mode read in step S17 is the moving image mode. If the result of determination is that it is in moving image mode, the flow proceeds to step S55 to execute a moving image shooting operation subroutine. If it is not in moving image mode, that is, if it is still image mode, the flow proceeds to step S57. A shooting operation subroutine is executed. The subroutine for the moving image shooting operation will be described later using FIG. 6, and the subroutine for the still image shooting operation will be described later with reference to FIG. When the subroutine for moving image shooting operation ends, the process returns to step S17. When the subroutine for still image shooting operation ends, the process returns to step S9, and the above steps are repeated.

Returning to step S27, if the result of determination is that the 1R switch is off, processing proceeds to step S29, where it is determined whether the attachment / detachment detection switch 259 is off, as in step S3. When the lens barrel 10 is detached, a through image stop instruction is output (S61) and the shutter 203 is closed (S63), as in steps S41 and S43 in the reproduction mode. Thereafter, the retracting operation of the movable half mirror 201 is performed (S65). As described above, the retracting operation is performed by driving the motor to rotate the mirror cam 417 and rotating the mirror frame 403 to the position retracted from the photographing optical path by the biasing force of the opening spring 407 (FIG. 1). And the position of the chain double-dashed line in FIG.

When the retracting operation of the movable half mirror 201 is completed, or when it is determined in step S3 that the attachment / detachment detection switch 259 is off (that is, when the lens barrel 10 is detached), the process proceeds to step S67. It is determined whether the attachment / detachment detection switch 259 is on. In step S29, after detecting that the lens barrel 10 is detached, it is determined whether or not the lens barrel 10 is mounted again. As a result of the determination, if it is mounted, the process proceeds to step S71, and the movable half mirror 201 is returned. As described above, the mirror cam 417 is rotated by driving the motor, the locking lever 413 is rotated clockwise by the cam surface against the urging force of the opening spring 407, and the mirror frame. 403 is inserted in the optical path of the lenses 101a and 101b. When the return of the movable half mirror 201 is completed, the process returns to step S9 and the above-described steps are repeated.

Returning to step S67, if the attachment / detachment detection switch 259 is off, the process proceeds to step S69 to determine whether or not 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 S67, the lens barrel 10 is mounted, and in step S69, the standby state in which the determination of the operation state of the power switch lever is repeated. If it is determined in step S67 that the power switch 257 is off, the process returns to step S5 and enters a sleep state. If it is detected in step S67 that the lens barrel 10 remains detached, the determination in step S69 may be omitted, and the process may proceed to step S5 to enter the sleep state, or the process may proceed to step S9. Modifications such as performing an operation based on an operation by the operation button are possible.

Returning to step S29, if the result of determination is that the attachment / detachment detection switch 259 is on, that is, if the lens barrel 10 is mounted on the camera body, the routine proceeds to step 31, 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 S17 and the above steps are repeated. After the through image display is started in step S15, the subject luminous flux transmitted through the movable half mirror 201 is not blocked by the shutter 203 unless various operation buttons are operated in step S23 and the subsequent steps. The image data picked up by the CCD 221 is displayed as a moving image on the rear liquid crystal monitor 26 and / or the finder liquid crystal 29 as a moving image.

If it is determined in step S31 that the power switch 257 is off, as in steps S41 and S43, the image processing circuit 227 is instructed to stop the live view display (S33), and the shutter 203 is closed. (S35). Thereafter, similarly to step S65 described above, after the retracting operation of the movable half mirror 201 is performed (S37), the process returns to step S5 and enters the sleep state.

Next, the subroutine for the still image shooting operation in step S57 will be described with reference to FIG. As described above, this subroutine is executed when the release button is pressed halfway when a still image shooting mode such as a normal program shooting mode is selected. First, the image processing circuit 227, the compression / decompression circuit 231 and the like are instructed to be in the still image mode (S91). As a result, these circuits perform processing suitable for still images.

When the still image mode instruction is completed, the image size and compression ratio are instructed to the image processing circuit 227 and compression / decompression circuit 231 based on the image size and compression ratio set by the user in the menu mode (S93). Here, the image size is, for example, 3200 * 2400, 1600 * 1200, 640 * 480, and the compression rate is automatically determined according to the image size, but may be arbitrarily set by the user. Of course.

Subsequently, a subroutine of phase difference AF1 for driving the photographing lens to the in-focus position based on the distance measurement operation and the distance measurement result is executed (S95). In the distance measurement, the subject light flux reflected by the movable half mirror 201 is received by the distance measurement sensor in the distance measurement / photometry sensor 217, and the distance measurement / photometry processing circuit 219 and the body CPU 229 are output using the output of the distance measurement sensor. And the like detect the focal shift amounts of the lenses 101a and 101b by the TTL phase difference method, and the lenses 101a and 101b are brought into focus by the optical system driving mechanism 107 via the lens CPU 111 based on the detected focal shift amounts. To drive. This phase difference AF1 performs AF with higher accuracy than the subroutine of phase difference AF2 in step S175 described later. The subroutine for the phase difference AF1 will be described later with reference to FIG.

Next, photometry / exposure amount calculation is performed (S97). The subject luminous flux reflected by the movable half mirror 201 is also received by the photometry sensor of 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.

When the photometry / exposure amount calculation is finished, it is next determined whether or not the release button has been fully pressed, that is, whether or not 2R is on (S99). As a result of the determination, if it is off, the process proceeds to step S101 to determine whether 1R is on. If the release button is half-pressed to jump to the still image shooting operation subroutine, and the release button remains half-pressed, a standby state is made in which repeat determination is made in steps S99 to S101. When the hand is released from the release button and 1R is turned off, the process returns to the power-on reset step S9.

Returning to step S99, 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 S103, an instruction to stop the through image is output to the image processing circuit 227. This is because when moving the movable reflecting mirror 201 to the retracted position, a subject image incident on the CCD 221 is disturbed and a through image becomes unsightly on the rear liquid crystal monitor 26 and / or the liquid crystal 29 in the viewfinder. This is to prevent it.

Thereafter, similarly to step S65, the retracting operation of the movable half mirror 201 is performed (S109). In general, when acquiring / recording a still image, it is desirable to acquire / record high-quality image data. Therefore, the movable half mirror 201 is retracted in order to avoid degradation in image quality due to the movable half mirror 201.

When the retracting of the movable half mirror 201 is completed, the lens CPU 111 is instructed to perform the aperture operation of the aperture 103 to the set aperture value or the aperture value calculated in S97, and is performed by the aperture drive mechanism 109 (S111). When the narrowing-down operation is completed, the CCD 221 performs an exposure operation for acquiring a still image (S113). At the start of this exposure operation, the movable half mirror 201 has moved to the retracted position, so that 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 S113, 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.

Next, the shutter 203 is closed (S115), and an instruction to open the aperture 103 is output to the lens CPU 111 (S117). Further, the image signal stored in the CCD 221 is read, the image processing circuit 227 performs image processing in accordance with the image size and compression rate specified in step S93, and the compression / decompression circuit 231 performs processing such as signal compression. To generate a still image file (S119). Subsequently, the generated still image file is recorded on the recording medium 245 (S121). When the recording of the image data ends, it is determined in step S123 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 S127, and the return operation of the movable half mirror 201 is performed in the same manner as in step S7. When the return operation is completed, the process returns to the power-on reset routine.

In the still image shooting operation subroutine of the present embodiment, the movable half mirror 201 is retracted from the shooting optical path during the shooting operation for acquiring a still image. For this reason, it is possible to avoid image degradation caused by the refractive index, thickness, etc. of the half mirror that occurs when passing through the movable half mirror 201. Further, the half mirror does not attenuate the subject light amount, and the subject light amount can be increased when acquiring a still image, so that shooting at a high shutter speed is possible.

Further, in the present embodiment, since the movable half mirror 201 has entered the photographing optical path in step S7, automatic focus adjustment by phase difference AF can be performed immediately when the release button is half-pressed. That is, distance measurement can be started more quickly than when the movable half mirror 201 is entered into the photographing optical path when the release button is half-pressed.

Next, the moving image shooting operation subroutine in step S55 will be described with reference to FIG. As described above, this subroutine is executed when the release button is pressed halfway while the moving image shooting mode is selected. In this subroutine, when shooting a movie, the angle of view of the display image is not changed in accordance with the change of the focus adjustment position (focus position). Before explaining the operation of each step, this constant angle of view display will be explained. To do.

In order to realize a small and high-performance lens for a single lens reflex lens, there is a type in which the angle of view (focal length) varies depending on the focus position. When a moving image is shot using such a type of lens, a moving image in which the angle of view varies due to focusing is recorded, and a sense of incongruity occurs. Therefore, in the present embodiment, the cut-out position of the image data is changed using the view angle change Δkt, Δkw information (see FIG. 7) and the like so that the view angle change does not occur due to focusing.

FIG. 7 is a diagram showing the relationship between the angle of view (focal length) and the focus adjustment position (focus position). When there is no change in the angle of view even if the focal length changes on the tele side, the reference angle of view line 451 is shown. As described above, even if the focus adjustment position (focus position) changes, the angle of view (focal length) is constant. Similarly, when the angle of view does not change even when the focal length changes on the wide side, the angle of view (focal length) is constant even if the focus adjustment position changes as in the reference angle of view line 455. . On the other hand, in practice, when the focus adjustment position changes, the angle of view (focal length) also changes, and on the tele side, the angle of view change Δkt relative to the reference angle of view is as shown by the angle of view change Δkt line 453. There is a lens whose angle of view changes. Similarly, on the wide side, there is a lens in which the angle of view changes by the angle of view change Δkw with respect to the reference angle of view, such as an angle of view change Δkw line 457 (for the sake of schematic illustration, the angle of view change Δkt is actually larger than the actual angle). , Delta kw is displayed larger).

Since the optical characteristics shown in FIG. 7 are obtained in this way, even if the focal length adjusting member of the lens barrel 10 is not operated, the acquired image changes as shown in the upper part of FIG. 8 when the focus position is changed. To do. In other words, the long-distance acquisition image 461 acquired by focusing on the subject 471 located far away has a narrower angle of view than the image 463 acquired by focusing on the medium-distance subject 473, and the medium-distance acquisition image 463 of the medium-distance subject. Is narrower than the short-range acquired image 465 acquired by focusing on the short-distance subject 475.

If the focal position is changed without changing the focal length adjusting member, a strange feeling will occur if the angle of view changes accordingly. Therefore, in this embodiment, the trimming range is determined so as to have a constant angle of view. That is, when the trimming range 467 for the intermediate distance acquired image 463 and the trimming range 469 for the short distance acquired image 465 are determined and the images are cut out in the trimming ranges 467 and 369, the display images 481, 483, and 485 at a certain angle of view are obtained. Can be obtained.

Therefore, in the present embodiment, the setting is made based on the currently set focal length information, the focus position information, and the view angle change Δkt and the view angle change Δkw stored in the lens data storage circuit 112 sent from the lens CPU 111. The angle-of-view change Δk corresponding to the focal length and the focus position is obtained. Then, the trimming range is determined based on the obtained angle-of-view change Δk, the image processing circuit 227 is instructed to cut out the image data corresponding to the trimming range, and the moving image is displayed at a constant angle of view regardless of the focus position. To record video. At this time, the trimming process is performed on the basis of the narrowest field angle within the field angle change range. The angle-of-view change data stored in the lens data storage circuit 112 are Δkt and Δkw, and the intermediate focal length is obtained by an interpolation method as appropriate, and Δkt and Δkw are also skipped values. Interpolate as appropriate. Of course, the angle-of-view change data Δk may be stored for different numbers of lines other than two lines as in the present embodiment.

Next, the subroutine of the moving image shooting operation in FIG. 5 will be described. First, the image processing circuit 227, the compression / decompression circuit 231 and the like are instructed to be in the moving image mode (S131). Thus, the image processing circuit 227 performs image processing suitable for moving images, and the compression / decompression circuit 231 performs compression suitable for moving images. Subsequently, the phase difference AF1 is performed in the same manner as in step S95, and focusing is performed with high accuracy (S133). When the distance measurement / focusing driving is finished, as described above, the angle-of-view change Δk is determined, trimming information is read based on the angle-of-view change Δk (S135), and a trimming instruction is sent to the image processing circuit 227. An instruction is given (S137).

When the trimming instruction is finished, next, as in step S99, it is determined whether or not the release button has been fully pressed, that is, whether or not 2R is on (S139). As a result of the determination, if it is off, the process proceeds to step S141 to determine whether 1R is on. If the release button is half-pressed to jump to this moving image shooting operation subroutine and the release button remains half-pressed, steps S133 to S141 are looped to enter a standby state for repeated determination. During this time, the phase difference AF1, trimming information reading and trimming instructions are performed.

Since the phase difference AF1 is repeatedly performed in this way, focusing is automatically performed even when the framing is changed or the subject moves. Even if the focus changes, the trimming information is read and a trimming instruction is issued, so that a constant angle of view can be maintained. When the release button is released and 1R is turned off, the process returns from step S141 to power-on reset step S9.

If it is determined in step S137 that the 2R switch is on, that is, if the release button is fully pressed, the process proceeds to an imaging operation for moving image acquisition, and the process proceeds to step S145, where the image size and compression rate are set. Is issued to the image processing circuit 227 and the compression / decompression circuit 231 as in step S93. When displaying a through image, image processing for display is performed with a predetermined image size, regardless of the image size. In the case of moving image shooting, the image size and compression rate specified in this step are used. Image processing is performed so as to be recorded.

When the instruction in step S145 ends, the process proceeds to step S147 to issue an instruction to start moving image recording. When the moving image recording is started, the CCD 221 captures an image at the set electronic shutter speed TV, and the subject image signal output from the CCD 221 is processed by the image processing circuit 227 and compressed by JPEG for each frame by the compression / expansion circuit 231. The processed image data is stored in the SDRAM 238. Note that the movable half mirror 201 is retracted from the photographing optical path during still image shooting, but is not retracted during moving image shooting. In order to activate the automatic focus adjustment operation during moving image shooting, the subject light flux is guided to the distance / photometry sensor 217 by the movable half mirror 201. For this reason, even when the subject distance changes during moving image shooting, it is possible to always perform shooting with focus.

In step S149, it is determined whether the storage capacity of the SDRAM 238 used as the buffer memory is full. As a result of the determination, if it is not full, the process proceeds to step S171, and it is determined whether or not the 2R switch is turned on, that is, whether or not the release button is fully pressed by the photographer and movie shooting is continued. If the 2R switch is on as a result of the determination, the process proceeds to step S173, and the moving image condition is set. In step S21, the electronic shutter speed TV and the ISO sensitivity SV are adjusted so that the image can be displayed with the targeted brightness. However, the subject brightness may change due to a change in framing during moving image shooting. In addition to being able to display at the target lightness even during shooting, the image data can be recorded at a constant lightness.

Unlike the still image shooting, the aperture 103 is not narrowed down when shooting in the moving image mode. This is because phase difference AF2, which will be described later, is performed during operation shooting, and the aperture value is opened to ensure distance measurement accuracy. Therefore, the exposure amount at the time of moving image shooting is performed by the electronic shutter speed TV, and when the exposure amount is insufficient, it is compensated by the ISO sensitivity SV.

When the movie condition setting is completed, the process proceeds to step S175, and the phase difference AF2 is executed. This phase difference AF2 is less focused than the phase difference AF1 in step S133. If the focusing accuracy is set to a high accuracy, tracking is performed according to changes in the subject image during moving body shooting, and the shooting lens is driven in small steps, so that the feeling of use is not necessarily good. Details of the phase difference AF2 will be described later with reference to FIG.

After the phase difference AF2, the trimming information is taken in similarly to step S135 (S177), and the trimming instruction is issued as in step S137 (S179). As a result, while recording a moving image, trimming is performed based on the view angle change Δk unless the zooming operation is performed, and the view angle is kept constant even if the focus position of the subject changes. When the trimming instruction is issued, the process returns to step S149, and the above steps are repeated.

Returning to steps S149 and S171, when the storage capacity of the SDRAM 238 in which the image data is recorded is full, or when the 2R switch is turned off, that is, when the photographer releases the release button and stops shooting, the process proceeds to step S151. Instruct to stop. Subsequently, a moving image file in MJPEG (Motion JPEG) format for moving images is generated based on the JPEG format image data for each frame stored in the SDRAM 238 (S153). The generated moving image file is recorded on the recording medium 245 via the recording medium control circuit 243 (S155). When the recording of the moving image file ends, the process returns to step S9 in the power-on reset routine, and the above steps are repeated.

In the moving image shooting operation subroutine of the present embodiment, the movable half mirror 201 is allowed to enter the shooting optical path, so that the reflected light of the subject light beam from the movable half mirror 201 is used to perform phase difference AF. A focused moving image can be obtained by performing ranging or focusing drive. In particular, the TTL phase difference AF has an advantage of excellent tracking even when the subject distance changes greatly.

Next, the phase difference AF1 subroutine in steps S95 and S133 and the phase difference AF2 subroutine in step S175 will be described with reference to FIG. In this subroutine, the focus determination value is changed according to shooting conditions such as still image shooting and moving image shooting, and the lens driving speed for focus adjustment is changed.

When the subroutine for phase difference AF1 is entered, first, an allowable focus value s is calculated (S201). The focus allowable value s is obtained by multiplying the open aperture value F and the allowable confusion circle ε. That is,
s = ε · F
Ask more. In the present embodiment, the allowable confusion circle is 30 μm, but may be a value that can be allowed according to the design concept. The focus allowable value s obtained in this step is set as the focus determination value r as it is (S203). The focus determination value r is a value used for determining whether or not the defocus amount (focus shift amount) δ obtained by the phase difference AF is within the focus range, as will be described later. Subsequently, the high-speed lens driving mode is set as the lens driving mode (S205). The high-speed lens driving mode is a mode for determining the lens driving speed for focus adjustment. In the present embodiment, a high-speed lens driving mode and a low-speed lens driving mode are prepared.

When the setting of the high-speed driving mode is completed, next, ranging integration is started (S207). Since the subject luminous flux that has passed through the periphery of the photographing lens via the movable half mirror 201 is incident on the distance measuring sensor of the distance measuring / photometric sensor 217, the distance measuring integration operation in this distance measuring sensor is started. . The level of the distance measurement integration is detected (S211), and when the predetermined level is reached, the integration is completed. Subsequently, ranging data is read from the ranging sensor (S213), and the defocus amount δ is calculated according to a known phase difference ranging calculation (S215).

Next, the calculated defocus amount δ is compared with the focus determination value r set in step S203 or step S231 described later (S217). As a result of the comparison, when the defocus amount δ is smaller than the focus determination value r, that is, when the defocus amount of the photographic lens is smaller than the focus determination value and the photographic lens can be regarded as being in focus, The automatic focus adjustment by the phase difference AF1 is finished and the process returns to the original routine.

In step S217, when the defocus amount δ is larger than the focus determination value r, the amount of defocus of the photographic lens is large, and the photographic lens is not in focus. A drive amount LD for driving the lens is calculated. Subsequently, a driving instruction such as a driving mode of the photographing lens is output to the lens CPU 111 (S221). Here, the high-speed lens drive mode set in step S205 (or the low-speed lens drive mode set in step S233 described later), the defocus direction (drive direction) obtained by the defocus amount δ calculation, and the calculation in step S219. The drive amount LD thus transmitted is transmitted to the lens CPU 111.

Here, the flow of signals for driving the photographing lens will be described with reference to FIG. In step 221, the body CPU 229 sends the lens driving direction, the driving amount LD, and the lens driving mode to the lens CPU 111. The lens CPU 111 converts the received information into a drive control signal for the motor driver 107b that drives the motor 107a in the optical system drive mechanism 107 based on the transmitted information. Based on the converted drive control signal, the motor 107a controls the drive of the lens 101 toward the focal point.

In this drive control, when a high-speed lens drive mode is sent, the lens CPU 111 performs drive control at a drive speed according to the drive curve 491 shown in FIG. That is, the lens is driven at a high speed, and after temporarily stopping, the distance is measured again, and minute driving is performed based on the distance measurement result. The focus drive is suitable for still images. On the other hand, when the low-speed lens drive mode is sent, the lens CPU 111 performs drive control at a drive speed according to the drive curve 493. That is, the drive control is performed at low speed and slowly toward the in-focus position without driving at high speed. Since it can be smoothly driven toward the focal point, the drive control is suitable for moving objects. Note that the high-speed drive mode of the drive curve 491 is drive control suitable for still image shooting, but also in the moving image shooting operation subroutine of FIG. 5, it is used for focusing before moving object shooting is started in step S133.

Returning to step S221, when the instruction of the driving mode is finished to the lens CPU 111, the process returns to step S207 again, and the above steps are repeated. In this way, ranging from step S207 to step S221 is repeated until the photographic lens enters the in-focus range, and distance measurement by phase difference AF and photographic lens driving are repeated.

Next, when the subroutine for phase difference AF2 is entered, first, 2s, which is twice the focusing allowable value s, is set as the focusing determination value r (S231). This phase difference AF2 is loosened by about twice as much as the focus permissible value that determines the focusing accuracy compared to the phase difference AF1. This is because if the focusing accuracy is set to a high accuracy, the photographic lens is driven in small increments as described above, causing a hunting phenomenon, and the usability is not always good. In the present embodiment, the focus determination value is 2s, which is twice the focus allowable value s. However, the present invention is not limited to this, and any accuracy that is looser than the phase difference AF1 may be used.

Once the in-focus determination value is set, next, the low-speed lens driving mode is set as the lens driving mode (S233). As described above, when driving in the high-speed lens driving mode at the time of moving image shooting, driving and stopping are repeated little by little, and hunting is likely to occur. Therefore, in the present embodiment, at the time of moving image shooting, acceleration / deceleration is reduced as shown in FIG. For this reason, it can be smoothly driven toward the focal point, and an image having no sense of incongruity can be obtained when reproducing a moving image.

When the setting of the low-speed lens driving mode is completed, the above steps S207 to S221 are repeated, and the CPU 111 focuses the subject by driving the lens at a low speed based on the defocus direction and the defocus amount δ obtained by the phase difference AF. If the subject is moving, focusing can be performed following this movement. In step S217, when the in-focus range is entered, the process returns to the moving object photographing operation subroutine.

Next, the flow of data processing relating to images in the present embodiment will be described. The image signal output from the CCD 221 is subjected to various image processing (301) by the image processing circuit 227. The image processing circuit 227 performs an image size changing process (302) using the processed image signal. This change process is performed according to the image size specified in steps S93 and S145.

Next, the image data that has been subjected to the image size change processing is distributed according to the shooting mode (303). This distribution corresponds to step S53, but even in the moving image mode, the phase difference AF1 is executed in step S133 before moving body shooting is started. In the moving image mode, trimming processing is performed based on the trimming range information (304). As described above, when the focal length is not changed, the image is cut out so that the angle of view remains constant even if the focus adjustment position (focus position) changes.

The image data of the moving image that has been subjected to the trimming process or the image data of the still image that has been subjected to the image size changing process is then sent to the compression / decompression circuit 231 and JPEG compression process (305) is performed. The compression ratio here is performed at the ratio specified in steps S93 and S145. The image data subjected to JPEG compression processing is stored in the SDRAM 238 by single data accumulation (307) when still image shooting is selected. Then, the sequence controller creates a JPEG file based on the JPEG data stored in the SDRAM 238 (311).

On the other hand, when the moving image shooting is selected, the image data subjected to the JPEG compression process (305) is sequentially stored in the SDRAM 238 in accordance with the start of moving image recording in step S147. Then, in response to the stop of moving image recording in step S151, storage of the image data in JPEG format is stopped, and the sequence controller performs moving image compression according to MJPEG (Motion JPEG), which is a compression format for moving images, and creates an MJPEG file ( 313). Next, in accordance with the file recording in steps S121 and S155, the MJPEG file or JPEG file is recorded on the recording medium 245 (315).

Thus, in the present embodiment, the focus determination value r is changed between still image shooting and moving image shooting (see S203, S231, and S217 in FIG. 6). For this reason, during still image shooting, the focus of the subject can be adjusted with high accuracy, and during moving body shooting, the shooting lens can be smoothly driven to perform focus adjustment without any sense of incongruity. In the present embodiment, distance measurement is performed by phase difference AF. However, the present invention is not limited to this, and the present invention can also be applied to contrast AF performed by extracting a high-frequency component of a subject image signal from an image sensor. In this case, the threshold value that is regarded as in-focus by contrast AF may be changed between still image shooting and moving object shooting, that is, the threshold value may be relaxed during moving object shooting.

In the present embodiment, the driving speed of the taking lens is changed during still image shooting and during moving image shooting (see S205, S233, and S221 in FIG. 6). For this reason, when taking a still image, the taking lens can be quickly driven to the in-focus point, and when taking a moving object, the taking lens can be smoothly driven to adjust the focus without any sense of incongruity. In the present embodiment, since the distance measurement is performed by the phase difference AF, the defocus amount δ is calculated. However, even if the defocus amount δ is not calculated as in contrast AF, The effect similar to that of the present embodiment can be obtained by changing the driving speed of the taking lens according to still image shooting and moving object shooting.

Furthermore, in the present embodiment, image trimming processing is performed in accordance with the change in the angle of view of the photographing lens (see S135, S137, S177, and S179 in FIG. 5). For this reason, even when the focus position of the subject changes during moving image shooting, a constant angle of view can be maintained, and an image without a sense of incongruity can be obtained. In the present embodiment, the trimming is performed only by the moving image shooting operation. However, the trimming process may be performed also in a through image display during still image shooting.

Furthermore, in the present embodiment, since the target image quality is different between still image shooting and moving image shooting, the position of the movable half mirror 201 is changed. That is, since it is generally required to have a high image quality at the time of still image shooting, the movable half mirror 201 is retracted from the shooting optical path to prevent image degradation caused by the movable half mirror 201. On the other hand, since moving images are not required to have the same high image quality as still image shooting, the movable half mirror 201 remains in the shooting optical path, eliminating the time for moving forward and backward, and the time lag until shooting starts. Is shortened.

Furthermore, in the present embodiment, the movable half mirror 201 is inserted in the photographing optical path when the camera is operated, and a part of the subject light beam is reflected to the distance measuring / photometric sensor 217, so that the release button is displayed during the through image display. When 21 is pressed halfway and 1R is turned on, photometry and distance measurement can be performed immediately in parallel with the live view display.

In the present embodiment, the CCD 221 serving as the 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. In addition, the CCD 221 may receive reflected light, and the distance measuring / photometric sensor 217 may receive transmitted light.

In the present embodiment, the present invention is applied to a general digital camera. However, the present invention is not limited thereto, and may be a digital camera in various devices such as a portable device, and may be attached to various devices such as a microscope and binoculars. Of course, the present invention can also be applied to a dedicated digital camera. The present invention can be applied to any camera that can record a shooting target as a moving image.

It is a block diagram which shows the whole structure of the electric system of the digital camera in one Embodiment to which this invention is applied. It is a disassembled perspective view which shows the structure of the movable half mirror in one Embodiment to which this invention is applied. It is a flowchart which shows the operation | movement of the power-on reset in one Embodiment of this invention. It is a flowchart of the still image shooting operation in one embodiment of the present invention. It is a flowchart of the moving image shooting operation in one embodiment of the present invention. It is a flowchart of phase difference AF1 and phase difference AF2 in one embodiment of the present invention. It is a figure which shows the relationship between an angle of view (focal distance) and a focus adjustment position (focus position) in one Embodiment of this invention. It is a figure explaining the trimming process in one Embodiment of this invention. It is a figure which shows the drive state of the imaging lens in one Embodiment of this invention. It is a block diagram which shows the flow of the signal for the drive of the imaging lens in one Embodiment of this invention. It is a flowchart which shows the process of the data in one 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 107 Optical system drive mechanism 107a Motor 111 Lens CPU
112 Lens data storage circuit 201 Movable half mirror 203 Shutter 215 Movable mirror drive mechanism 217 Distance / photometric sensor 221 CCD
223 Image sensor driving circuit 227 Image processing circuit 229 Body CPU
231 Compression / decompression circuit 238 SDRAM
241 Communication circuit 243 Recording medium control circuit 245 Recording medium 257 Power switch

Claims (12)

A photographic lens whose shooting angle of view changes according to the focus adjustment;
Imaging means for receiving a subject luminous flux that has passed through the photographing lens and outputting a subject image signal;
Trimming means for trimming the subject image signal in accordance with a change in the angle of view of the photographing lens;
Recording means for recording a moving image of the subject based on the subject image signal subjected to the trimming process;
A digital camera comprising:   The digital camera according to claim 1, wherein the photographing lens is detachable.   3. The digital camera according to claim 2, wherein the photographing lens includes an output unit that outputs information corresponding to the change in the angle of view. 4. The digital camera according to claim 3, wherein the output means includes storage means for storing a plurality of field angle information corresponding to a focal length and a focal position of the photographing lens. 2. The trimming means trims the subject image signal so that the angle of view of the recorded moving image does not change even when focus adjustment is performed during recording of the moving image. The digital camera described in 1. 6. The digital camera according to claim 5, wherein the trimming means performs a trimming process on the basis of the narrowest angle of view within the angle of view change range. A photographic lens whose shooting angle of view changes according to the focus adjustment;
Imaging means for receiving a subject luminous flux that has passed through the photographing lens and outputting a subject image signal;
Means for determining the amount of change in angle of view in accordance with the focus adjustment;
Trimming means for performing trimming processing of the subject image signal so as to obtain a constant angle of view based on the amount of change in the angle of view;
Recording means for recording a moving image of the subject based on the subject image signal subjected to the trimming process;
A digital camera comprising:   8. The digital camera according to claim 7, wherein the means for obtaining the angle-of-view change includes storage means for storing the angle-of-view change according to the focal position.   9. The zoom lens according to claim 8, wherein the photographic lens is a zoom lens having a variable focal length, and the storage means stores an angle of view change corresponding to a focal length in addition to the focal position. Digital camera.   A selection unit that selects a still image mode for recording a still image of a subject based on the subject image signal and a moving image mode for recording a moving image; and the trimming unit is configured to select the moving image mode when the moving image mode is selected. The digital camera according to claim 7, wherein the trimming process is performed.   A focus shift amount and a shift direction are detected by a phase difference method using the subject luminous flux that has passed through the shooting lens, and an automatic focus adjustment unit that drives the shooting lens based on the focus shift amount and the shift direction is provided. The digital camera according to claim 7, wherein:   A half mirror which can be moved back and forth between the photographing lens and the image pickup means; and the automatic focus adjustment means performs distance measurement by the phase difference method using a subject light beam reflected by the half mirror. The digital camera according to claim 11.