JP2013083772A - Camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To photograph a focused still image, during moving image photographing or live view operation.SOLUTION: A camera includes control means executing a moving image photographing mode in which a moving image for recording is generated by image generation means, while range-finding, calculation, and driving are repeatedly executed by focus adjustment means or a live view mode in which an image for displaying is generated by the image generation means. While the moving image photographing mode or the live view mode is executed and when a still image photographing operation is performed during the execution of the calculation or the driving by the focus adjustment means, the control means allows the focus adjustment means to execute the range-finding, the calculation, and the driving and then, the image generation means to generate a still image.

Description

  The present invention relates to a camera.

  There are known cameras that perform still image shooting during movie shooting.

JP 2001-111878 A

  However, in the above-described conventional camera, if a still image shooting command is input during moving image shooting, the moving image shooting sequence is not changed and the process proceeds to the still image shooting sequence as it is, and therefore distance measurement is performed at an optimal timing for still image shooting. However, it is not always possible to shoot still images in focus.

  An imaging device in which imaging pixels and focus detection pixels are arranged, a photographing optical system that forms a subject image on the imaging device, and a distance measurement that detects a signal indicating the focus state of the photographing optical system by the focus detection pixels A focus adjusting unit that sequentially executes a calculation for detecting a focus state of the photographing optical system based on a signal of the distance measurement result, and a drive for performing a focus adjustment of the photographing optical system based on the focus state of the calculation result; Image generation means for generating an image based on the output of the pixel for use, and a moving image shooting mode for generating a moving image for recording by the image generation means while repeatedly performing distance measurement, calculation and driving by the focus adjustment means, or image generation Control means for executing a live view mode for generating a display image by the means, and the control means is executing the moving image shooting mode or the live view mode, and the focus adjustment means. When the calculation or the still image photographing operation during the execution of the drive is made by the distance measurement by the focus adjusting means, to generate a still image by the image generating means after executing the operation and driving.

  According to the present invention, it is possible to shoot a still image in focus during moving image shooting or live view operation.

The figure which shows the structure of the camera of one Embodiment. The figure which shows the cross-shaped focus detection area set to the imaging | photography screen of the camera of one Embodiment. FIG. 2 is a partially enlarged view showing the arrangement of the light receiving regions of the imaging pixels R, G, B and the focus detection pixels S1, S2 in the horizontal region (long side direction of the photographing screen 4a) in the cross-shaped focus detection region shown in FIG. 2 is a partially enlarged view showing the arrangement of the light receiving areas of the imaging pixels R, G, B and the focus detection pixels S3, S4 in the vertical (short-side direction of the photographing screen 4a) area of the cross-shaped focus detection area shown in FIG. Timing chart showing AF (Auto Focus) operation during movie shooting or live view operation with a conventional camera Timing chart showing still image shooting operation during movie shooting or live view operation with a conventional camera Timing chart showing still image shooting operation during moving image shooting or live view operation in camera of one embodiment Timing chart showing another still image shooting operation during moving image shooting or live view operation in the camera of one embodiment The figure which shows the light-shielding timing of the focus detection area | regions a and k by the driving | running | working of the trailing curtain in the focal plane shutter of an up-down traveling system

  FIG. 1 is a block diagram illustrating a configuration of a camera according to an embodiment. In FIG. 1, illustration and description of camera devices and circuits not directly related to the present invention are omitted. In FIG. 1, a camera 1 includes a photographing lens 2, a shutter 3, an image sensor 4, an AFE (Analog Front End) circuit 5, an image processing circuit 6, a phase difference AF circuit 7, a shutter driving circuit 8, a lens driving circuit 9, and an operation member. 10, a memory 11, a monitor 12, a memory card 13, an interface 14, a controller 15, and the like.

  Although the photographing lens 2 is illustrated as a single lens, it is composed of a plurality of lens groups including a zooming lens and a focusing lens, and forms a subject image on the imaging surface of the image sensor 4 via the shutter 3. The shutter 3 is a focal plane shutter and has a front curtain and a rear curtain (not shown). The image pickup device 4 is composed of a CMOS image sensor or the like in which a plurality of pixels are two-dimensionally arranged on the light receiving surface, and photoelectrically converts a subject image formed by the photographing lens 2 and outputs an analog image signal.

  FIG. 2 is a view showing the photographing screen 4a of the camera 1. A plurality of imaging pixels and focus detection pixels are two-dimensionally arranged on the imaging surface of the imaging element 4 corresponding to the imaging screen 4a, and each of these pixels includes a microlens and a light receiving unit. In this embodiment, cross-shaped focus detection areas a to k are set at 11 positions in the center of the photographing screen 4a.

  The imaging pixels are arranged in a Bayer array throughout the imaging screen 4a, and receive light passing through the exit pupil of the imaging lens 2 (see FIG. 1) and output an image signal corresponding to the subject image. On the other hand, the focus detection pixel is arranged in a cross-shaped area corresponding to each of the focus detection areas a to k at the center of the imaging screen 4a, and receives light passing through a partial area of the imaging lens 2 to receive the imaging lens. A focus detection signal indicating the second focus adjustment state is output.

  FIG. 3 is a partially enlarged view showing the arrangement of the light receiving areas of the imaging pixels R, G, B and the focus detection pixels S1, S2 in the horizontal (long-side direction of the photographing screen 4a) area of the cross-shaped focus detection area. It is. FIG. 4 shows the arrangement of the light receiving areas of the imaging pixels R, G, B and the focus detection pixels S3, S4 in the vertical (short-side direction of the shooting screen 4a) area of the cross-shaped focus detection area. It is an enlarged view. In FIG. 3 and FIG. 4, each “mass” surrounded by vertical and horizontal lines indicates an area of imaging pixels or focus detection pixels. Squares and rectangles indicated by solid lines in each square indicate mask openings, and light reaches the light receiving portions of the imaging pixels and the focus detection pixels through these mask openings. R, G, and B represent an imaging red pixel, an imaging green pixel, and an imaging blue pixel, respectively. 3 and 4, illustration of the microlens and the light receiving unit of each pixel is omitted.

  In this embodiment, the shape of the light receiving regions (mask openings) of the imaging pixels R, G, and B is a regular square. However, the shape of the light receiving regions of the imaging pixels R, G, and B is a regular square. For example, it may be circular.

  Further, in this embodiment, the shape of the light receiving area (mask opening) of the focus detection pixels S1 to S4 is substantially bisected in the vertical or horizontal direction of the light receiving area (mask opening) of the imaging pixels R, G, and B. An example of a rectangular shape is shown. Furthermore, in the pair of focus detection pixels S1 and S2 in the horizontal direction shown in FIG. Similarly, in the pair of focus detection pixels S3 and S4 in the vertical direction shown in FIG.

  The shape of the light receiving region of the focus detection pixel is not limited to a rectangle. For example, when the light receiving region (mask opening) of the imaging pixel is circular, the light receiving region (mask opening) of the focus detection pixel is The light receiving area of the imaging pixel may be a semicircular shape that is substantially bisected.

  In the horizontal region of the cross-shaped focus detection region, a pair of focus detection pixels S1 and S2 receive light that has passed through the pair of regions of the exit pupil of the photographing lens 2, and the lateral direction of the photographing lens 2 (the photographing screen 4a). The focus detection signal indicating the focus adjustment state in the long side direction) is output. Further, in the vertical region of the cross-shaped focus detection region, the focus detection pixels S3 and S4 are paired, and a focus detection signal indicating the focus adjustment state in the vertical direction of the photographing lens 2 (the short side direction of the photographing screen 4a) is output. To do.

  Note that the focus detection area of the shooting screen 4a is not limited to the arrangement of this embodiment as long as it is set at the center of the shooting screen 4a. Further, the number and shape of the focus detection regions are not limited to the number and shape of this embodiment. Furthermore, the arrangement of the focus detection pixels arranged corresponding to each focus detection area is not limited to the arrangement of this embodiment.

  Returning to FIG. 1, the AFE circuit 5 performs analog processing such as correlated double sampling and gain adjustment on the analog image signal, and converts the image signal after the analog processing into digital image data. The image processing circuit 6 performs various types of image processing (color interpolation processing, gradation conversion processing, contour enhancement processing, white balance adjustment processing, image compression processing, image expansion processing, etc.) on the digital image data.

  The phase difference AF circuit 7 calculates a defocus amount indicating a focus adjustment state of the focusing lens based on focus detection signals output from the pair of focus detection pixels (S1, S2) and (S3, S4). A shutter drive circuit 8 controls driving and charging of the front curtain and rear curtain of the shutter 3. The lens driving circuit 9 drives the focusing lens of the photographing lens 2 to adjust the focus, and also drives the zooming lens to change the focal length.

  The operation member 10 includes various switches such as a release half-press and full-press switch, a zoom switch, a mode switch, a menu switch, a cross switch, and an OK switch.

  The memory 11 is a storage element such as a ROM or a RAM that stores various programs and various information. The monitor 12 is an LCD that displays a through image captured by the image sensor 3, a captured image, and various types of information. The interface 14 writes an image and various information data to the memory card 13 and reads an image and various information data from the memory card 13. The controller 15 includes a CPU and its peripheral components, and controls various operations of the camera 1 such as imaging, exposure, focus adjustment (AF), and image display.

  FIG. 5 is a timing chart showing an AF (Auto Focus) operation during moving image shooting or live view operation in a conventional camera. During moving image shooting or live view operation, the front curtain of the shutter 3 is completed and the shutter 3 is in an open state, and imaging by the image sensor 4 is repeatedly performed. The image signal repeatedly read from the image sensor 4 is processed by the AFE circuit 5 and the image processing circuit 6 to generate a recording image or a display image. The recording image is recorded as a moving image on the memory card 13, and the display image is displayed on the monitor 12 as a live view image.

  During moving image shooting or live view operation, focus detection signals are repeatedly read out from the focus detection pixels S1 to S4 (see FIGS. 3 and 4) of the image sensor 4 via the AFE circuit 5 to measure the distance. Is done. The phase difference AF circuit 7 performs focus detection calculation based on the focus detection signal, and detects the focus adjustment state (defocus amount) of the photographic lens 2 in the focus detection region (see FIG. 2) designated in advance (this amount). In the specification, this operation is called “distance measurement”), and the driving amount of the photographing lens 2 is calculated based on the focus adjustment state (in this specification, simply “calculation”). The lens driving circuit 9 drives the photographic lens 2 according to the driving amount of the photographic lens 2 and performs focus adjustment (simply referred to as “drive” in this specification).

  During moving image shooting or live view operation, one AF cycle consisting of the above-mentioned distance measurement, calculation, and driving is repeatedly executed. Note that the time required for ranging, calculation, and driving varies depending on the photographing conditions, and therefore the time of one AF cycle also varies depending on the photographing conditions.

  FIG. 6 is a timing chart showing still image shooting operation during moving image shooting or live view operation in a conventional camera. When the release SW (release full-press switch) is operated at time t1 during movie shooting or live view operation, the AF cycle consisting of distance measurement, calculation, and driving shown in FIG. 5 is stopped, and then the shutter 3 at time t2. The rear curtain travels to close the shutter 3, and the shutter charge is performed after the rear curtain travel is completed. Shooting is started at time t3 after the shutter charge is completed, and first the front curtain of the shutter 3 is run, then the rear curtain of the shutter 3 is run after the set shutter time, and the shooting is completed at time t4.

  As described above, in the still image shooting operation during the moving image shooting or the live view operation in the conventional camera, when the shutter is released, the AF cycle operation including distance measurement, calculation, and driving is stopped, and the rear curtain running and the shutter charge are performed. A still image is picked up by the image pickup device 4 after the shooting preparation time including In the example shown in FIG. 6, since the calculation and driving based on the distance measurement result immediately before the release are not executed, still image shooting is performed in the focus adjustment state in the previous AF cycle. That is, since the focus adjustment is not performed after the lens driving in the AF cycle is completed until the actual still image shooting is started, for example, as shown in FIG. 6, the shutter is released at the end of the calculation of the AF cycle. Then, the time from the focus adjustment in the AF cycle to the still image shooting becomes longer. Therefore, there is a high possibility that the subject will move, the angle of view changes, camera shake, etc. during this time, and the intended main subject may be out of focus.

  Even if there is a shutter release during lens driving in the AF cycle, the lens driving is immediately stopped and preparations for still image shooting are made, so still image shooting is performed with the main subject completely out of focus. The focus on the intended main subject will shift.

  FIG. 7 is a timing chart showing still image shooting operation during moving image shooting or live view operation in the camera of the embodiment. When the release SW (release full-press switch) is operated at time t1 during movie shooting or live view operation, the operation of the AF cycle being executed (calculation in the example shown in FIG. 7) is stopped, and the AF cycle is started again. Start ranging, calculating and driving. At the time t2 after the distance measurement, the calculation and driving of the AF cycle are started, the rear curtain of the shutter 3 is run, and the shutter charge is performed after the rear curtain run is completed. Then, at time t3 after completion of lens driving and shutter charging, still image shooting is started. First, the front curtain of shutter 3 is run, then the rear curtain of shutter 3 is run after the set shutter time, and at time t4. Complete shooting.

  In FIG. 7, the case where the release SW is operated during movie shooting or live view operation and during the “calculation” of the AF cycle has been illustrated and described, but the release is performed during “driving” of the AF cycle. Similarly, when the SW is operated, the driving of the AF cycle being executed is stopped, and the AF cycle is started again to perform distance measurement, calculation, and driving.

  As described above, in the still image shooting operation during the moving image shooting or the live view operation in the camera of the embodiment, when the shutter is released during the calculation or driving of the AF cycle, the AF cycle operation being executed is stopped, AF cycle operation consisting of distance measurement, calculation, and drive is started again, and shooting preparation including shutter rear curtain travel and shutter charge is performed in parallel with new AF cycle calculation and drive operation. A still image is captured by the element 4. For this reason, still image shooting is performed immediately after the focus adjustment for the main subject by the AF cycle is performed, and a still image in focus can be shot during moving image shooting or live view operation.

  In the still image shooting operation of the camera of the embodiment shown in FIG. 7, if the shutter is released during the distance measurement in the AF cycle or immediately after the distance measurement is completed, the AF cycle is not started again from the distance measurement. In addition, calculation and driving are performed using the distance measurement result, and the shutter trailing curtain travels and the shutter charge is performed in parallel with these operations, and still image shooting is performed after the lens driving and shutter charging are completed. Compared to stopping AF range measurement in progress and starting AF cycle after ranging again after shutter release, the distance measurement operation becomes unnecessary and the release time lag is reduced. During movie shooting or live view operation You can shoot still images that are in focus.

<< Modification of Embodiment >>
FIG. 8 is a timing chart showing a still image shooting operation of a modified example during moving image shooting or live view operation in the camera of the embodiment. In the embodiment described above, an example in which the AF cycle operation is forcibly executed from the beginning after the shutter release is shown. However, in this modified example, if there is a shutter release during the repeated AF cycle operation, A shooting preparation operation is performed in parallel with the next AF cycle operation after the AF cycle operation, and still image shooting is performed after the completion of the next AF cycle operation and the shooting preparation operation.

  As shown in FIG. 8, when the release SW (release full press switch) is operated at time t1 during the calculation of the AF cycle, the AF cycle operation being executed is continued as it is, and after the distance measurement of the next AF cycle. At time t2, the calculation and driving of the AF cycle is started, the rear curtain of the shutter 3 is run, and the shutter charge is performed after the rear curtain run is completed. Then, at time t3 after completion of lens driving and shutter charging, still image shooting is started. First, the front curtain of shutter 3 is run, then the rear curtain of shutter 3 is run after the set shutter time, and at time t4. Complete shooting.

  Although FIG. 8 illustrates and describes the case where there is a shutter release during the calculation of the AF cycle, the AF cycle operation being executed is also performed as it is when there is a shutter release during the driving of the AF cycle. Continuing, a shooting preparation operation is performed in parallel with the next AF cycle operation, and still image shooting is performed after the completion of the next AF cycle operation and the shooting preparation operation.

  On the other hand, in the still image shooting operation of the modified example of the camera shown in FIG. 8, if the shutter is released during the distance measurement in the AF cycle or immediately after the distance measurement is completed, the distance measurement result is displayed without waiting for the next AF cycle. In addition to performing computation and driving using them, in parallel with these operations, running of the shutter rear curtain and shutter charging are performed, and still image shooting is performed after completion of lens driving and shutter charging. Compared to the case of taking a still image after executing the next AF cycle, one AF cycle operation is omitted and the release time lag is reduced, and a still image in focus is shot during movie shooting or live view operation. can do.

  As described above, in the still image shooting operation of the modified example during moving image shooting or live view operation, when the shutter is released during the calculation or driving of the AF cycle, the AF cycle operation being executed is continued as it is, and the next AF In parallel with the calculation of the cycle and the driving operation, preparation for shooting including shutter rear curtain travel and shutter charge is performed, and a still image is captured by the image sensor 4 after the completion of these operations. For this reason, still image shooting is performed immediately after the focus adjustment for the main subject by the AF cycle is performed, and a still image in focus can be shot during moving image shooting or live view operation.

<< Other Variations of One Embodiment >>
In the above-described embodiment and its modification shown in FIGS. 7 and 8, the distance measurement is performed after the shutter release, and the timing for moving the rear curtain of the shutter 3 at the distance measurement completion time t2 is set. As shown in FIG. 2, when a plurality of focus detection areas a to k are developed over a wide range of the photographing screen 4a, the timing at which light is blocked by the shutter rear curtain differs for each focus detection area.

  FIG. 9 shows the light blocking timing of the focus detection areas a and k due to the travel of the rear curtain 3a in the vertical travel type focal plane shutter 3. Since the focus detection area a at the top of the photographing screen 4a shown in FIG. 2 is close to the locking position of the shutter rear curtain 3a, the shutter is immediately shielded after the shutter rear curtain 3a is released and the vehicle starts running. . On the other hand, the focus detection area k at the lower part of the photographing screen 4a shown in FIG. 2 is located far from the position where the shutter rear curtain 3a is locked. It takes time to shield from light.

  Therefore, the timing of starting the trailing curtain, that is, the time t2 in FIGS. 7 and 8 may be varied in accordance with the position of the focus detection area designated by the camera or the photographer within the shooting screen. In other words, the shutter curtain that travels to shield the image sensor prior to still image shooting (the shutter rear curtain in this embodiment) only takes the time from when the lock is released until the focus detection pixels in the focus detection area are shielded. The time t2 may be advanced earlier. If a focus detection area that is far from the shutter curtain locking position is designated for focus detection, the designated focus detection area is specified when the shutter curtain starts running, even if the shutter curtain travel timing is increased. Since it takes time to reach, ranging can be completed in the focus detection area before reaching the designated focus detection area.

  In this way, by changing the shutter curtain travel start timing in accordance with the position of the focus detection area to be used, it is possible to set an optimum shooting preparation time for still image shooting in accordance with the focus detection area to be used. it can.

<< Other Variations of One Embodiment >>
In the above-described embodiment and its modification, an example using a mechanical focal plane shutter having a front curtain and a rear curtain and an electronic global shutter that simultaneously captures all pixels on the image sensor is shown. The present invention can also be applied to a camera using a rolling shutter (electronic shutter) that captures an image every one or several rows on the image sensor. Even when this rolling shutter is used, a mechanical shutter consisting of a single curtain is used instead of a focal plane shutter with a front curtain and a rear curtain. To do. For example, in the example shown in FIGS. 7 and 8, instead of the trailing curtain running from time t2, the single curtain is run, the light incident on the imaging device is once blocked, and the imaging device is reset. Thereafter, immediately before the start of shooting at time t3, the one-screen curtain is opened to guide subject light to the image pickup device, and image pickup is performed by the image pickup device.

  In the above-described embodiments and their modifications, all combinations of the embodiments and the modifications are possible. In the above-described embodiment and its modification, an example in which a release full-push switch is used as an operation member for instructing the camera to take a still image is shown. However, for example, a dedicated switch other than the release full-push switch may be provided. Good. Further, in the above-described embodiment and its modification, an example in which the moving image shooting or the live view operation is stopped after the still image shooting has been described, but the moving image shooting or the live view operation may be restarted after the still image shooting. Good.

DESCRIPTION OF SYMBOLS 1; Camera, 2; Shooting lens, 3; Shutter, 3a; Rear curtain, 4; Image pick-up element, 5; AFE circuit, 6; Image processing circuit, 7: Phase difference AF circuit, 8: Shutter drive circuit, 9; Drive circuit, 10; operation member, 15; controller

Claims (5)

An imaging device in which imaging pixels and focus detection pixels are arranged;
A photographing optical system for forming a subject image on the image sensor;
Distance measurement for detecting a signal indicating the focus state of the photographing optical system by the focus detection pixel, calculation for detecting the focus state of the photographing optical system based on the signal of the distance measurement result, Focus adjusting means for sequentially executing driving for adjusting the focus of the photographing optical system based on the focus state;
Image generating means for generating an image based on the output of the imaging pixels;
A moving image shooting mode in which a moving image for recording is generated by the image generating unit or a live view in which a display image is generated by the image generating unit while the focus adjustment unit repeatedly executes the distance measurement, the calculation, and the driving. Control means for executing the mode,
When the moving image shooting mode or the live view mode is being executed, and the still image shooting operation is performed during the calculation or driving by the focus adjusting unit, the control unit is configured to perform the focus adjusting unit. A still image is generated by the image generation means after the distance measurement, the calculation and the driving are executed by the camera. The camera of claim 1,
The control unit stops the calculation or the drive being executed by the focus adjustment unit, and after the focus adjustment unit performs the distance measurement, the calculation, and the drive again, the image generation unit generates a still image. A camera characterized by generating. The camera of claim 1,
The control means terminates the calculation and the drive or the drive being executed by the focus adjustment means, and executes the next distance measurement, the calculation and the drive by the focus adjustment means, and then the image generation means. A camera characterized in that it generates a still image. The camera of claim 1,
The control means is executed by the focus adjustment means when the moving image shooting mode or the live view mode is being executed and a still image shooting operation is performed during the distance measurement by the focus adjustment means. A still image is generated by the image generation means after the distance measurement is completed and the calculation and the drive are executed. In the camera according to any one of claims 1 to 4,
A shutter is provided between the imaging optical system and the image sensor, and the focus detection pixels are arranged in each of a plurality of focus detection areas set on the imaging screen,
The control means shields the image sensor with the shutter before the still image shooting according to the position in the shooting screen of the focus detection area designated for focus detection among the plurality of focus detection areas. A camera characterized by changing timing.

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