JP2011164321A - Imaging apparatus - Google Patents

Abstract

To provide an imaging device capable of appropriately controlling the movement of a correction lens even if a magnet used for detecting the position of the correction lens in the camera shake correction unit generates magnetism having different strength depending on the region. With the goal.
An image pickup apparatus according to the present invention includes an image pickup device, a correction unit that corrects blurring of an image formed on the image pickup device, and a controller that controls the correction unit. When the correction lens moves, the correction lens that can move in the horizontal and vertical directions, a magnet that has different magnetic strengths in some areas and other areas in the predetermined axial direction, move together. A Hall element that detects magnetism generated by the magnet, and the controller moves the correction lens in an axial direction different from the axis depending on at least the position of the correction lens in the axial direction. Determine the command value.
[Selection] Figure 1

Description

  The present invention relates to an imaging apparatus, and more particularly to an imaging apparatus having a camera shake correction function.

  Patent Document 1 discloses a digital camera equipped with a camera shake correction function. This digital camera drives the camera shake correction function when the zoom magnification is larger than the reference magnification, and stops the camera shake correction function when the zoom magnification is smaller than the reference magnification.

  Accordingly, it is possible to perform camera shake correction with less shaking according to the zoom magnification.

JP 2005-195656 A

  However, in the digital camera disclosed in Patent Document 1, the shape of the magnet for detecting the position of the correction lens in the camera shake correction unit is not disclosed.

  The present invention provides an imaging apparatus capable of appropriately controlling the movement of a correction lens even if a magnet used for detecting the position of the correction lens in the camera shake correction unit generates magnetism having different intensity depending on the region. For the purpose.

  In order to solve the above-described problems, an imaging apparatus according to the present invention includes an imaging device, a correction unit that corrects blurring of an image formed on the imaging device, and a controller that controls the correction unit. The unit includes a correction lens that can move in the horizontal and vertical directions inside, a magnet that has different magnetic strengths in some areas and some other areas in a predetermined axial direction, and a correction lens that moves. And a Hall element that detects the magnetism generated by the magnet, and the controller has a correction lens in an axial direction different from the axis depending on at least the position of the correction lens in the axial direction. The command value for moving the is determined.

  According to the present invention, there is provided an imaging apparatus capable of appropriately controlling the movement of the correction lens even when the magnet used for detecting the position of the correction lens in the camera shake correction unit generates magnetism having different strength depending on the region. Can be provided.

The block diagram which shows the structure of the digital video camera 100 Schematic diagram showing the configuration of OIS140 Schematic diagram showing the configuration of the magnet 143 Schematic diagram showing the relationship between the position of the correction lens in the X direction and the Hall output Flow chart for explaining the operation of determining the driving amount of the correction lens 141

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

[1-1. Constitution〕
[1-1-1. 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 video 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 video 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 141 that can move in a plane perpendicular to the optical axis. The OIS 140 includes a hall element 142 that moves simultaneously with the correction lens 141. The OIS 140 reduces the shake of the subject image by driving the correction lens 141 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 141 in the OIS 140 in a plane perpendicular to the optical axis. The OIS actuator 150 applies servo so that the command value from the controller 210 matches the output value of the detector 160. The OIS actuator 150 can be realized by a planar coil, an ultrasonic motor, a control circuit, or the like. In addition, the detector 160 outputs the movement amount of the correction lens 141 in the OIS 140 to the controller 210. Specifically, the output of the Hall element 142 in the OIS 140 is amplified and output to the controller 210.

  The CCD image sensor 180 captures a subject image formed by an optical system including the zoom lens 110 and generates video 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 video data generated by the CCD image sensor 180. The image processing unit 190 processes the video data generated by the CCD image sensor 180 to generate video data to be displayed on the liquid crystal monitor 270 or to store video data to be re-stored in the memory card 240. Or generate. For example, the image processing unit 190 performs various processes such as gamma correction, white balance correction, and flaw correction on the video data generated by the CCD image sensor 180. Further, the image processing unit 190 applies H.264 to the video data generated by the CCD image sensor 180. The video data is compressed by a compression format compliant with the H.264 standard or the MPEG2 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 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 the video data generated by the CCD image sensor 180 and an image indicated by the video 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 the correction lens 141 in the OIS in a direction to cancel out the shaking, the digital video camera 100 corrects camera shake caused 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.

[1-1-2. Configuration of OIS140]
The configuration of the OIS 140 will be described with reference to FIG. FIG. 2 is a schematic diagram showing the configuration of the OIS 140. The OIS 140 includes a correction lens 141, a hall element 142, and a magnet 143 inside.

  When the correction lens 141 moves in the OIS 140, the hall element 142 is disposed at a position where the correction lens 141 moves simultaneously with the correction lens 140. When the correction lens 141 is present at the optical center, the magnet 143 is disposed at a position where the magnetic detection sensor of the Hall element 142 is a boundary between the N pole and the S pole. Therefore, when the correction lens 141 is driven, the Hall element 142 moves simultaneously, and the magnetic detection sensor of the Hall element 142 straddles the boundary between the N pole and the S pole of the magnet 143.

  The hall element 142 and the magnet 143 are arranged at two locations, respectively, in order to detect the movement amount of the correction lens 141 in the X direction and the Y direction. When the correction lens 141 moves, the magnetism received by the Hall element 142 from the magnet 143 changes. As a result, the output (Hall output) of the Hall element 142 changes.

  In the present embodiment, the magnet 143 has a special shape and will be described with reference to FIG. FIG. 3 is a schematic diagram showing the configuration of the magnet 143. The magnet 143 has a different thickness at a position in the X direction. The magnet 143 has an N pole and an S pole in the Y direction. Therefore, the strength of the magnetism generated from the magnet 143 varies depending on the position in the X direction. That is, the magnet 143 emits stronger magnetism at the thicker position than at the thinner position.

  FIG. 4 is a diagram showing how much the output of the Hall element changes according to the position in the X direction. FIG. 4 shows an example in which the correction lens 141 is moved from −x to + x in the X direction when the correction lens 141 is at the position moved y in the Y direction. As can be seen from FIGS. 3 and 4, the output of the Hall element 142 is larger at the position where the magnet 143 is thicker than at the thin position.

[1-2. Determination of drive amount of correction lens 141]
Next, the determination operation of the driving amount of the correction lens 141 in the digital video camera 100 according to the present embodiment will be described with reference to FIG. FIG. 5 is a flowchart for explaining the operation of determining the driving amount of the correction lens 141. In FIG. 5, the drive amount determination operation of the correction lens 141 when the correction lens 141 is moved in the Y direction will be described.

  The user can set the digital video camera 100 to the shooting mode by operating the operation member 250 (S100). When the photographing mode is set, the digital video camera 100 starts correction of camera shake by the user.

  First, the controller 210 acquires the output of the gyro sensor 220 (S110). In addition, the controller 210 acquires information regarding the position of the correction lens 141 in the X direction from the detector 160.

  When the output of the gyro sensor 220 and the position of the correction lens 141 in the X direction are acquired, the controller 210 determines the amount of movement of the correction lens 141 to cancel out the blur in the Y direction based on the acquired information ( S120).

  Specifically, first, the controller 210 determines the amount of movement of the correction lens 141 based on the output of the gyro sensor 220. When the movement amount of the correction lens 141 is determined, the controller 210 determines a command value for moving the determined movement amount from the position of the correction lens 141 in the X direction.

  As described above, the Hall element 142 outputs different values depending on the position of the correction lens 141 in the X direction even if the correction lens 141 is moved in the Y direction by the same amount. On the other hand, the OIS actuator 150 applies servo so that the command value matches the output of the Hall element 142. Accordingly, the determined movement amount is multiplied by (Hall output corresponding to the position in the X direction where the correction lens 141 is present) / (Hall output corresponding to the center in the X direction), and this value is used as a command value. If the command value is determined in this way, the correction lens 141 can be appropriately moved even if the magnet 143 having different magnetic strength is used according to the position of the correction lens 141 in the X direction.

  Returning again to the description of FIG. When the command value is determined in step S120, the controller 210 instructs the OIS actuator 150 to move the correction lens 141 by the amount indicated by the command value (S130). When receiving the instruction, the OIS actuator 150 drives the OIS 140 by applying a servo such that the hall output matches the command value to the received amount. When the OIS actuator 150 drives the OIS 140, the controller 210 repeats the control in steps S110 to S130.

  As described above, the digital video camera 100 according to the present embodiment instructs the OIS actuator 150 in accordance with the position of the correction lens 141 in the X direction when the correction lens 141 is moved by the same amount in the Y direction. The command value was changed. Thereby, the digital video camera 100 according to the present embodiment can appropriately move the correction lens 141 even if the magnet 143 having different magnetic strength is used according to the position of the correction lens 141 in the X direction.

In the present embodiment, the driving of the correction lens 141 in the Y direction has been described. However, the same effect can be obtained with the same processing for the driving in the X direction.
[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 first 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.

  In Embodiment 1, the shape of the correction lens 141 is illustrated in FIG. 2, but the present invention is not limited to this. Any configuration that can detect the movement amount of the correction lens 141 in the X direction and the Y direction may be used.

  In Embodiment 1, the shape of the magnet 143 is illustrated in FIG. 3 and the hall output is illustrated in FIG. 4, but the present invention is not limited to this. For example, you may comprise with the magnet which has an inclination and a situation.

  The present invention can be applied to an imaging apparatus such as a digital video camera or a digital video 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 (1)

An image sensor;
A correction unit for correcting blurring of an image formed on the image sensor;
A controller for controlling the correction unit,
The correction unit is
A correction lens that can move horizontally and vertically inside,
In a predetermined axial direction, magnets having different magnetic strengths in some regions and other regions,
When the correction lens moves, the Hall element that moves together and detects the magnetism generated by the magnet,
The controller is
A command value for moving the correction lens in an axial direction different from the axis is determined according to at least where the correction lens exists in the axial direction.
Imaging device.

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