JP2011091520A - Imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus which performs appropriate blur corrections, even in a macro photographing mode. <P>SOLUTION: The imaging apparatus can be set to a normal photographing mode and the macro photographing mode and includes: an imaging device for imaging a subject image; a correction lens moved in a plane perpendicular to an optical axis to correct blurs of the subject image formed on the imaging device; a driving means for moving the correction lens; and a determination means for determining a photographic mode to which a video camera is set. The driving means changes the amount of movement of the correction lens between the case, in which the determination means determines the video camera as being in the normal photographing mode and the case in which the determination means determines it as being in the macro photographing mode. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a digital video camera, and more particularly to a digital video camera having a camera shake correction function.

  Patent Document 1 discloses a digital camera having a camera shake correction function. This digital camera further has a macro shooting mode as a shooting mode. This digital camera cancels the camera shake correction function when the macro shooting mode is set.

JP 2008-244939 A

  However, some digital cameras disclosed in Patent Document 1 cannot reduce the influence of camera shake by the user in the macro shooting mode.

  It is an object of the present invention to provide an imaging apparatus that performs appropriate camera shake correction even in the macro shooting mode.

  In order to solve the above-described problems, an imaging apparatus according to the present invention is an imaging apparatus that can be set in a normal shooting mode and a macro shooting mode, and is formed on an imaging element that captures a subject image. A correction lens that corrects a blur of the subject image by moving in a plane perpendicular to the optical axis, a driving unit that moves the correction lens, and a determination unit that determines a shooting mode in which the video camera is set. The driving unit changes the amount by which the correction lens is moved depending on whether the determination unit determines that the normal shooting mode is set or the macro shooting mode.

  According to the present invention, it is possible to provide an imaging apparatus that performs appropriate camera shake correction even in the macro shooting mode.

The block diagram which shows the structure of the digital camera 100 Flow chart for determining flow amount of OIS 140 Relationship diagram showing the relationship between subject distance and OIS 140 shake amount Relationship diagram showing the relationship between the subject distance and the ideal shake amount of the OIS 140 Schematic diagram for explaining the relationship between the subject distance and the ideal shake amount of the OIS 140

[1. Embodiment 1]
Hereinafter, an example in which the present invention is applied to a digital video camera will be described with reference to the drawings.

[1-1. Overview〕
The digital video camera 100 has an OIS 140. The digital video camera 100 reduces the influence of its own shake on the captured image by moving the correction lens in the OIS 140. Hereinafter, the amount of movement of the correction lens in the OIS 140 is referred to as the amount of shake of the OIS 140.

  The digital video camera 100 performs appropriate camera shake correction in various scenes by changing the shake amount of the OIS 140.

[1-2. Constitution〕
[1-2-1. Electrical configuration)
The electrical configuration of the digital video camera 100 according to the present embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing a configuration of the digital video camera 100. The digital video camera 100 captures a subject image formed by an optical system including a zoom lens 110 and the like with a CCD image sensor 180. The image data generated by the CCD image sensor 180 is subjected to various processes by the image processing unit 190 and stored in the memory card 240. The image data stored in the memory card 240 can be displayed on the liquid crystal monitor 270. Hereinafter, the configuration of the digital video camera 100 will be described in detail.

  The optical system of the digital video camera 100 includes a zoom lens 110, an OIS 140, and a focus lens 170. The zoom lens 110 can enlarge or reduce the subject image by moving along the optical axis of the optical system. The focus lens 170 adjusts the focus of the subject image by moving along the optical axis of the optical system.

  The OIS 140 includes a correction lens that can move in a plane perpendicular to the optical axis. The OIS 140 reduces the shake of the subject image by driving the correction lens in a direction that cancels the shake of the digital video camera 100.

  The zoom motor 130 drives the zoom lens 110. The zoom motor 130 may be realized by a pulse motor, a DC motor, a linear motor, a servo motor, or the like. The zoom motor 130 may drive the zoom lens 110 via a mechanism such as a cam mechanism or a ball screw. The detector 120 detects where the zoom lens 110 exists on the optical axis. The detector 120 outputs a signal related to the position of the zoom lens by a switch such as a brush in accordance with the movement of the zoom lens 110 in the optical axis direction.

  The OIS actuator 150 drives the correction lens in the OIS 140 in a plane perpendicular to the optical axis. The OIS actuator 150 can be realized by a planar coil or an ultrasonic motor. The detector 160 detects the amount of movement of the correction lens in the OIS 140.

  The CCD image sensor 180 captures a subject image formed by an optical system including the zoom lens 110 and generates image data. The CCD image sensor 180 performs various operations such as exposure, transfer, and electronic shutter.

  The image processing unit 190 performs various processes on the image data generated by the CCD image sensor 180. The image processing unit 190 performs processing on the image data generated by the CCD image sensor 180 to generate image data to be displayed on the liquid crystal monitor 270 or to store image data to be stored in the memory card 240 again. Or generate. For example, the image processing unit 190 performs various processes such as gamma correction, white balance correction, and flaw correction on the image data generated by the CCD image sensor 180. In addition, the image processing unit 190 compresses the image data with respect to the image data generated by the CCD image sensor 180 by a compression format or the like conforming to the JPEG standard. The image processing unit 190 can be realized by a DSP or a microcomputer.

  The controller 210 is a control means for controlling the whole. The controller 210 can be realized by a semiconductor element or the like. The controller 210 may be configured only by hardware, or may be realized by combining hardware and software. The controller 210 can be realized by a microcomputer or the like. The digital video camera 100 holds data in the internal memory 280 that can roughly determine the subject distance according to the position of the zoom lens 110 and the position of the focus lens 170. The controller 210 determines the distance between the subject and the subject device (subject distance) based on the data held in the internal memory 280, the position information of the zoom lens 110, and the position information of the focus lens 170. The controller 210 determines an optimal shake amount of the OIS 140 based on the determined subject distance.

  The memory 200 functions as a work memory for the image processing unit 190 and the controller 210. The memory 200 can be realized by, for example, a DRAM or a ferroelectric memory.

  The liquid crystal monitor 270 can display an image indicated by image data generated by the CCD image sensor 180 and an image indicated by image data read from the memory card 240.

  The gyro sensor 220 is composed of a vibration material such as a piezoelectric element. The gyro sensor 220 vibrates a vibration material such as a piezoelectric element at a constant frequency, converts a force generated by the Coriolis force into a voltage, and obtains angular velocity information. By obtaining angular velocity information from the gyro sensor 220 and driving a correction lens in the OIS in a direction to cancel out the shaking, the digital video camera 100 corrects camera shake by the user.

  The card slot 230 is detachable from the memory card 240. The card slot 230 can be mechanically and electrically connected to the memory card 240. The memory card 240 includes a flash memory, a ferroelectric memory, and the like, and can store data.

  The internal memory 280 is configured by a flash memory, a ferroelectric low memory, or the like. The internal memory 280 stores a control program for controlling the entire digital video camera 100 and the like.

  The operation member 250 is a member that receives an image capturing instruction from the user. The zoom lever 260 is a member that receives a zoom magnification change instruction from the user.

[1-2-2. Correspondence with the present invention)
The CCD image sensor 180 is an example of an image sensor of the present invention. The correction lens in the OIS 140 is an example of the correction lens of the present invention. The configuration including the OIS actuator 150 and the OIS 140 is an example of the driving means of the present invention. The controller 210 is an example of a determination unit of the present invention.

[1-3. Operation)
FIG. 2 is a flowchart showing the flow of processing of the present invention. First, the user of the camera can set the digital video camera 100 to an automatic shooting mode (a shooting mode that automatically provides a mode corresponding to a shooting situation) by operating a mode setting button of the operation member 250. (S100). The digital video camera 100 includes a focus lens 170 based on luminance information of a video signal photoelectrically converted by a CCD image sensor 180 and processed by an image processing unit 190 and position information of a zoom lens 110 via an imaging lens. Is moved to perform an autofocus operation (S110).

  The controller 210 determines the near / close position of the subject based on the data stored in the internal memory 280 in advance (S120).

  When it is determined that the position determination result is the far side, the controller 210 sets the shooting mode to the normal shooting mode (S130), and sets the shake amount of the OIS 140 in the normal state for the OIS actuator 150 (S140). .

  If it is determined by the near / close position determination of the subject (S120) that the distance is closer than the preset distance, the controller 210 sets the macro mode as the shooting mode (S150). When the macro mode is set, the controller 210 determines the subject distance in detail (S160), and determines the optimum shake amount according to the subject position (S170).

  Specifically, how the controller 210 determines the shake amount of the OIS 140 will be described with reference to FIG. FIG. 3 is a relationship diagram illustrating the relationship between the subject distance and the shake amount of the OIS 140 in the digital video camera 100. As shown in FIG. 3, the controller 210 changes the shake amount of the OIS 140 in accordance with the subject distance in the macro mode. On the other hand, in the normal mode, the controller 210 sets the shake amount of the OIS 140 to a constant value regardless of the subject distance.

  The reason for this will be described with reference to FIG. FIG. 4 is a relationship diagram showing the relationship between the subject distance and the amount of shake of the OIS 140 necessary for realizing the optimum camera shake correction. As shown in FIG. 4, in the range where the subject distance is short, the amount to which the OIS 140 should be shaken varies greatly due to a slight change in the subject distance. On the other hand, when the subject distance is longer than a certain length, the amount that the OIS 140 should be shaken hardly changes.

  Therefore, the digital video camera 100 changes the shake amount of the OIS 140 in accordance with the subject distance in the macro mode with a short subject distance, but the subject distance in the normal mode in which the subject distance is not so short. Accordingly, even if the shake amount of the OIS 140 is changed, the effect is hardly changed. Therefore, the shake amount of the OIS 140 is constant.

  The reason why the relationship between the subject distance and the shake amount of the OIS 140 necessary for realizing the optimum camera shake correction is as shown in FIG. 4 is as follows. FIG. 5 is a schematic diagram schematically illustrating the relationship between the OIS 140 and the CCD 180 in the imaging lens, and the distance between the optical axis and the subject. If the subject is far away from the imaging lens and the camera shakes upward or downward with respect to the optical axis due to camera shake, the image is taken upward to capture the subject at the same position as when there is no camera shake. It is necessary to change the angle A spectral axis with respect to the optical axis when the lens is shaken and the far-side subject. Similarly, when the imaging lens is moved downward, it is necessary to change the angle A ′ spectral axis. On the other hand, when the subject is on the near side with respect to the imaging lens, it is necessary to change the optical axis when the imaging lens is shaken on the upper side and the angle B spectral axis with respect to the near-side subject. Similarly, when the imaging lens is moved downward, it is necessary to change the angle B ′ spectral axis. A relationship of A <B and A ′ <B ′ is established between these angles, and when the subject distance is short, a larger swing amount is required than when the subject distance is long.

  Further, it is assumed that the subject has approached (or was far away from) the same amount of the digital video camera 100 in each of the case where the subject exists on the far side and the case where the subject exists on the near side. In each case, assuming that the same camera shake occurs, the amount of change in the angle at which the OIS 140 needs to change the optical axis is greater in the near side than in the far side. Therefore, when the subject distance is short, the amount that the OIS 140 should be shaken changes greatly due to a slight change in the subject distance. On the other hand, if the subject distance is longer than a certain length, the amount that the OIS 140 should be shaken hardly changes. It becomes.

As described above, the video camera according to the present invention changes the swing amount of the OIS 140 between the macro mode and the normal shooting mode, so that the swing amount of the OIS 140 in the normal mode with respect to the input from the conventional gyro sensor 220 is changed. Therefore, it is possible to provide a high correction effect even with respect to camera shake in the macro mode that cannot be corrected because it has been determined.
[2. Other Embodiments]
As described above, the first embodiment has been described as the embodiment of the present invention. However, the present invention is not limited to these. Therefore, other embodiments of the present invention will be described collectively in this section.

  The optical system and drive system of the digital camera 100 according to the present embodiment are not limited to those shown in FIG. For example, although FIG. 1 illustrates an optical system having a three-group configuration, a lens configuration having another group configuration may be used. In addition, each lens may be composed of one lens or a lens group composed of a plurality of lenses.

  In the first embodiment, the CCD image sensor 180 is exemplified as the imaging unit, but the present invention is not limited to this. For example, it may be composed of a CMOS image sensor or an NMOS image sensor.

  Moreover, the detector 120 and the detector 160 are not necessarily required if the controller can determine the zoom lens 110 and the OIS 140.

  Further, the controller 210, the detector 120, the detector 160, the zoom motor 130, and the OIS actuator 150 may be provided with means for controlling each of them.

  Further, the adjustment of the focus lens 170 is not necessarily performed automatically, and may be manually operated.

  Further, switching between the macro mode and the normal mode is not necessarily performed automatically, and may be switched manually.

  In FIG. 3, as an example, the swing amount is fixed in the normal area, but the swing amount may be changed continuously according to the subject distance.

  The present invention can be applied to an imaging apparatus such as a digital video camera or a digital still camera.

100 Digital Camera 110 Zoom Lens 120 Detector 130 Zoom Motor 140 OIS
150 OIS Actuator 160 Detector 170 Focus Lens 180 CCD Image Sensor 190 Image Processing Unit 200 Memory 210 Controller 220 Gyro Sensor 230 Card Slot 240 Memory Card 250 Operation Member 260 Zoom Lever 270 Liquid Crystal Monitor 280 Internal Memory

Claims (2)

An imaging device that can be set to a normal shooting mode and a macro shooting mode,
An image sensor for capturing a subject image;
A correction lens that corrects blurring of a subject image formed on the imaging element by moving in a plane perpendicular to the optical axis;
Driving means for moving the correction lens;
Determining means for determining a shooting mode in which the video camera is set,
The drive means changes the amount by which the correction lens is moved when it is determined that the determination means is in the normal shooting mode and when it is determined as the macro shooting mode.
Imaging device. The driving means sets the movable amount of the correction lens more when the determination means determines that the macro shooting mode is set than when the determination means is the normal shooting mode,
The imaging device according to claim 1.

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