JP2010287926A - Image capturing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image capturing apparatus for necessarily displaying information for assisting a user to capture images. <P>SOLUTION: The image capturing apparatus includes: an optical system; an image sensor for capturing an image of a subject formed by the optical system; a correcting means for correcting the burr of the subject image formed on the image sensor; a reduction degree detecting means for detecting the degree at which the burr of the subject image can be reduced by the correcting means; a decision means for determining a threshold on the basis of results of detection by the reduction degree detecting means; a speed detecting means for detecting the speed of degree of burr of its own device; a comparing means for comparing results of detection by the speed detecting means with the threshold determined by the decision means; and a display means. The display means switches as to whether an alarm should be displayed for the operation method for the own device in response to results of comparison by the comparing means. <P>COPYRIGHT: (C)2011,JPO&INPIT

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 has a new power source for a shake detection sensor in addition to the camera power source. Therefore, even when the voltage of the camera power supply fluctuates, it is possible to supply power to the shake detection sensor with a stable voltage, and accurate shake detection can be performed.

  Accordingly, the camera can perform a camera shake warning and a camera shake amount display, and can obtain a clear photographed image without camera shake by accurate camera shake correction.

JP-A-4-181929

  However, Patent Document 1 does not disclose a method for determining whether or not to display a camera shake warning. It is inconvenient if the camera shake warning is displayed too frequently, and it is inconvenient if the camera shake warning is displayed too much.

  An object of the present invention is to provide an imaging apparatus that displays information that assists a user in photographing when necessary.

  In order to solve the above-described problems, an imaging apparatus according to the present invention reduces an optical system, an imaging element that captures a subject image formed by the optical system, and blurring of the subject image formed on the imaging element. A correction means, a reduction degree detection means for detecting the degree of reduction in blurring of the subject image by the correction means, a determination means for determining a threshold based on the detection result by the reduction degree detection means, and the blur speed of the own device A speed detecting means for detecting, a comparing means for comparing a detection result by the speed detecting means with a threshold value determined by the determining means, and a display means. The display means automatically determines according to the comparison result by the comparing means. Switches whether or not to display a warning regarding the operation method of the machine.

  In the imaging apparatus according to the present invention, the display unit determines that the comparison unit includes the speed detected by the speed detection unit within a range including a value larger than the threshold value determined by the determination unit as a minimum value. When a warning is displayed regarding the operation method of the own device, and the speed detected by the speed detecting means is determined to be included in the range including a value smaller than the threshold value determined by the determining means as the maximum value. The warning display regarding the operation method of the own device may not be performed.

  Further, in the imaging apparatus according to the present invention, the display means warns about the operation method of the own device when the comparing means determines that the speed detected by the speed detecting means is larger than the threshold value determined by the determining means. When the display is performed and it is determined that the speed detected by the speed detection unit is smaller than the threshold value determined by the determination unit, the warning display regarding the operation method of the own device may not be performed.

  Further, the imaging apparatus according to the present invention further includes a measuring unit that measures a time elapsed after the warning display related to the operation method of the own device by the display unit is turned off. The warning display regarding the operation method of the own device may not be performed until it is measured by the measuring means that the predetermined time has elapsed.

  ADVANTAGE OF THE INVENTION According to this invention, the imaging device which displays the information which assists imaging | photography by a user when needed can be provided.

The block diagram which shows the structure of the digital camera 100 Schematic diagram for explaining OIS140 Schematic diagram for explaining the correction angle Schematic diagram for explaining the relationship between focal length and maximum correction angle Flowchart for explaining shooting assistance The figure which shows the relationship between the threshold value in each maximum correction angle, and continuous blurring time Schematic diagram showing shooting assistance information

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

[1-1. Overview〕
The digital camera 100 according to the present embodiment can capture a moving image. The digital camera 100 displays shooting assist information on the liquid crystal monitor 270 when shooting a moving image. Here, the photographing assist information is information indicating advice regarding the photographing method. The digital camera 100 assists the user in shooting by displaying shooting assist information on the liquid crystal monitor 270. For example, the digital camera 100 displays a warning that the pan operation is too early when the user shakes left and right at high speed.

  The digital camera 100 according to the present embodiment displays shooting assist information only when necessary.

[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 will be described with reference to FIG. FIG. 2 is a schematic diagram for explaining the OIS 140. As shown in FIG. 2, 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. As shown in FIG. 2B, the correction lens can be moved from the center by a maximum L in the OIS 140.

  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. Here, the movement amount of the correction lens is an absolute value of the deviation amount from the center of the OIS 140. For example, in FIG. 2B, L is the movement amount of the correction lens.

  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 processes 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 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 image data generated by the CCD image sensor 180. Further, 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 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 the correction lens in the OIS in a direction to cancel out the shaking, the camera shake given to the digital video camera 100 by the user is corrected.

  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 configuration including the zoom lens 110, the OIS 140, and the focus lens 170 is an example of the optical system of the present invention. The CCD image sensor 180 is an example of an image sensor of the present invention. The configuration including the OIS 140, the OIS actuator 150, and the controller 210 is an example of the correction unit of the present invention. The configuration including the detector 120 and the controller 210 is an example of a mitigation degree detection unit of the present invention. The controller 210 is an example of a determination unit of the present invention. The configuration composed of the gyro sensor 220 and the controller 210 is an example of the speed detection means of the present invention. The controller 210 is an example of a comparison unit of the present invention. The liquid crystal monitor 270 is an example of the display means of the present invention. The controller 210 is an example of a measuring unit of the present invention.

[1-3. Correction angle and maximum correction angle)
In the digital camera 100 according to the present embodiment, information related to the maximum correction angle is used in order not to display the photographing assist information too much. Therefore, the correction angle and the maximum correction angle will be described with reference to FIGS. FIG. 3 is a schematic diagram for explaining the correction angle. FIG. 4 is a schematic diagram for explaining the relationship between the focal length and the maximum correction angle.

  In FIG. 3A, the digital camera 100 captures a subject in a state where there is no camera shake by the user. In this state, the correction lens is located at the center of the OIS 140. When camera shake by the user occurs from this state, the digital camera 100 is in a state as shown in FIG. 3 (B) or FIG. 3 (C).

  FIG. 3B shows a state in which the digital camera 100 is shaken upward due to camera shake of the user. In this state, the correction lens is positioned below the OIS 140. When the digital camera 100 is shaken upward, the correction lens is moved downward in the OIS 140, so that the point X formed at the center of the CCD image sensor 180 in FIG. In B), an image is formed at the center of the CCD image sensor 180.

  FIG. 3C shows a state in which the digital camera 100 is shaken downward due to camera shake of the user. In this state, the correction lens is positioned above the OIS 140. When the digital camera 100 shakes downward, the correction lens is moved upward in the OIS 140, so that the point X formed at the center of the CCD image sensor 180 in FIG. In C), an image is formed at the center of the CCD image sensor 180.

  In this way, by driving the correction lens in a direction that cancels the influence of camera shake, the digital camera 100 can reduce the blur of the image formed on the CCD image sensor 180. Here, as shown in FIG. 3, the correction angle refers to a shake angle that is eliminated by driving the OIS 140 when the digital camera 100 is shaken by the user. The maximum correction angle refers to a camera shake angle that can be corrected by moving the correction lens within the OIS 140 to the maximum extent. As shown in FIG. 2B, in the digital camera 100 according to the present embodiment, the correction lens can move within the OIS 140 with the range of the radius L being maximized. Therefore, the maximum correction angle is a camera shake angle that can be canceled when the correction lens is moved within the OIS 140 by the size of the radius L.

  Here, the maximum correction angle varies depending on the focal length. The relationship between the focal length and the maximum correction angle will be described with reference to FIG. Note that the digital camera 100 according to the present embodiment stores information about the relationship between the focal length and the maximum correction angle in the internal memory 280.

  The zoom lens 110 is movable on the optical axis from the wide angle end (W) to the telephoto end (T). Consider a case where the correction lens is moved the same length in the OIS 140. In this case, when the zoom lens 110 is at the wide-angle end and the telephoto end is compared, the maximum correction angle is larger when the zoom lens 110 is at the wide-angle end. The reason for this will be described below.

  When the digital camera 100 receives the same amount of camera shake, the angle of view is greatly changed when the zoom lens 110 is closer to the telephoto than when it is closer to the wide angle. If the angle of view is greatly changed, it is necessary to move the correction lens greatly in the OIS 140 in order to correct the fluctuation of the angle of view. In short, even if the correction lens is moved in the OIS 140 by the same amount, a larger angle of blurring can be corrected when the zoom lens 110 is closer to the wide angle than when the zoom lens 110 is closer to the telephoto. In short, the maximum correction angle becomes larger when the zoom lens 110 is at the wide-angle end.

[1-4. Shooting assist)
The digital camera 100 causes the liquid crystal monitor 270 to display that the pan operation is too early when the user shakes it left and right at high speed. A photographing assist function in the digital camera 100 will be described with reference to FIGS. FIG. 5 is a flowchart for explaining the photographing assist function. FIG. 6 is a table showing the relationship between the threshold value and the continuous blur time at each maximum correction angle. FIG. 7 is a schematic diagram showing photographing assist information.

  The user can set the digital camera 100 to the photographing mode by operating the mode selection dial of the operation member 250 (S100). When the photographing mode is set, the controller 210 acquires focal length information from the detector 120 (S110). When the focal length information is acquired, the controller 210 refers to the information on the relationship between the focal length and the maximum correction angle stored in the internal memory 280, and acquires the information on the maximum correction angle (S120).

  When the information about the maximum correction angle is acquired, the controller 210 obtains the threshold value and the continuous blur time associated with the acquired maximum correction angle (S130). Here, the digital camera 100 displays the photographing assistance information on the liquid crystal monitor 270 when the state in which the user is shaking at an angular acceleration larger than the threshold exceeds the continuous blur time. The threshold value and the continuous blur time will be described with reference to FIG. Note that the digital camera 100 according to the present embodiment stores, in the internal memory 280, information related to the relationship between the threshold value and the continuous blur time at each maximum correction angle as shown in FIG.

  As shown in FIG. 6, the digital camera 100 does not display the photographing assist information on the liquid crystal monitor 270 unless the angular acceleration increases as the maximum correction angle increases. The reason for this will be described below. The digital camera 100 does not limit the movable range of the correction lens in the OIS 140 even if the focal length is changed. Therefore, in the digital camera 100, the maximum correction angle varies depending on the focal length. Even if the maximum correction angle is different, if the threshold value is set to a constant value, the following adverse effects occur. For example, it is assumed that the threshold is determined based on the point where the maximum correction angle is 0.5 °. In this case, if the zoom lens 110 is at the wide-angle end, a situation occurs in which the photographing assist display is displayed on the liquid crystal monitor 270 even though the influence of camera shake is actually corrected. On the other hand, it is assumed that the threshold is determined based on the point where the maximum correction angle is 4 °. In this case, if the zoom lens 110 is at the telephoto end, the influence of camera shake cannot be corrected, and the liquid crystal monitor 270 is essentially a scene in which the photographing assist display is displayed on the liquid crystal monitor 270. In some cases, the shooting assist display may not be displayed. Therefore, the digital camera 100 determines the threshold value to be variable according to the focal length. Thereby, an appropriate threshold value can be set for each maximum correction angle, and photographing assist information can be displayed only when necessary.

  Next, the description returns to step S140 in the flowchart of FIG. When the threshold and the continuous blur time associated with the maximum correction angle are obtained (S130), the controller 210 determines whether or not the angular acceleration of the own device detected by the gyro sensor 220 is larger than the threshold (S140). ).

  If it is determined that the angular acceleration is smaller than the threshold value, the controller 210 acquires focal length information from the detector 120 again (S110).

  On the other hand, if it is determined that the angular acceleration is greater than the threshold, the controller 210 determines whether or not the continuous blur time has elapsed since the angular acceleration of the own device is greater than the threshold (S150). If it is determined that the continuous blur time has not elapsed, the controller 210 starts measuring the elapsed time when the angular acceleration of the own device exceeds the threshold, and acquires the focal length information again (S110). On the other hand, when determining that the continuous blur time has elapsed, the controller 210 causes the liquid crystal monitor 270 to display shooting assist information (S160). For example, if the right pan operation by the user is too early, the controller 210 causes the liquid crystal monitor 270 to display warning information (shooting assist information) as shown in FIG.

  When the photographing assist information is displayed on the liquid crystal monitor 270, the controller 210 determines whether or not a predetermined time has elapsed since the photographing assist information was displayed on the liquid crystal monitor 270 (S170). If it is determined that the predetermined time has elapsed, the controller 210 erases the photographing assist information displayed on the liquid crystal monitor 270 (S180).

As described above, in the digital camera 100 according to the present embodiment, the threshold for displaying the photographing assist information on the liquid crystal monitor 270 is variable according to the maximum correction angle. Thereby, an appropriate threshold value can be set for each maximum correction angle, and photographing assist information can be displayed only when necessary.
[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 digital camera 100 according to the present embodiment turns off the display of the shooting assistance information when the continuous camera shake time elapses again after the angular acceleration of the own device exceeds the threshold after the display of the shooting assistance information is turned off. The shooting assist information is displayed again regardless of the elapsed time from However, such a configuration is not necessarily required. For example, after the display of the shooting assistance information has been turned off, the digital camera 100 can display a predetermined amount of time after the display of the shooting assistance information has been turned off even if the continuous blur time has elapsed with the angular acceleration of the device exceeding the threshold again. If the time has not elapsed, the photographing assist information may not be displayed. Thus, when the user wants to shoot the subject by shaking the digital camera 100 at a high speed in the first place, it is possible to prevent a situation in which the shooting assistance information is continuously displayed many times.

  Further, in the digital camera 100 according to the present embodiment, the camera shake angle by the user that can be reduced when the correction lens is moved to the maximum movable range of the OIS 140 is set as the maximum correction angle. It is not necessary to. For example, in consideration of vignetting caused by moving the correction lens within the OIS 140, the angle of camera shake caused by the user that can be reduced by moving the correction lens within the maximum range in which vignetting does not occur may be set as the maximum correction angle. . As a result, the digital camera 100 can capture an image with no vignetting even when camera shake by the user is corrected.

  Further, the optical system and drive system of the digital video 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.

  The present invention can be applied to an imaging apparatus such as a digital still 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 (4)

Optical system,
An image sensor that captures a subject image formed by the optical system;
Correction means for reducing blurring of a subject image formed on the image sensor;
A reduction degree detection means for detecting a degree by which blurring of the subject image by the correction means can be reduced;
Determining means for determining a threshold based on a detection result by the reduction degree detecting means;
Speed detection means for detecting the speed of shake of the aircraft,
A comparison means for comparing a detection result by the speed detection means with a threshold value determined by the determination means;
Display means,
The display means switches whether or not to display a warning regarding the operation method of the own machine according to the comparison result by the comparison means.
Imaging device. The display means includes
The comparing means is
When it is determined that the speed detected by the speed detecting means is included in a range including a value larger than the threshold value determined by the determining means as a minimum value, a warning display regarding the operation method of the own machine is performed,
When it is determined that the speed detected by the speed detecting means is included in a range including a value smaller than the threshold determined by the determining means as a maximum value, a warning display regarding the operation method of the own machine is not performed.
The imaging device according to claim 1. The display means includes
The comparing means is
When it is determined that the speed detected by the speed detecting means is larger than the threshold value determined by the determining means, a warning display regarding the operation method of the own machine is performed,
When it is determined that the speed detected by the speed detecting means is smaller than the threshold value determined by the determining means, warning display regarding the operation method of the own machine is not performed.
The imaging device according to claim 1. A measuring means for measuring the time elapsed after the warning display on the operation method of the own machine by the display means is turned off;
The display means does not display a warning regarding the operation method of the own machine until it is measured by the measuring means that a predetermined time has passed, regardless of the comparison result by the comparing means.
The imaging device according to claim 1.

Images