JP2009267894A - Camera shake detecting apparatus, imaging apparatus, and program - Google Patents

Abstract

An image pickup apparatus that effectively detects camera shake based on a range of a shooting angle of view is provided.
A digital camera has an optical system for setting a shooting angle of view, a gyro sensor for detecting camera shake, and a detection accuracy to be detected by the gyro sensor based on the shooting angle of view set by the optical system. And a control unit 7 configured to control the gyro sensor 18 to detect camera shake with the set detection accuracy. According to the present invention, camera shake can be detected more effectively based on the setting of the shooting angle of view.
[Selection] Figure 3

Description

  The present invention relates to a camera shake detection device, an imaging device having a camera shake detection function, and a program.

2. Description of the Related Art Conventionally, imaging devices such as a digital camera and a digital video camera that image a subject using a CCD or MOS type solid-state imaging device are known.
As this imaging apparatus, for example, there is an apparatus that performs camera shake detection using a gyro sensor (see Patent Document 1).
Specifically, a camera shake detection circuit such as a gyro sensor or an A / D converter is built in the imaging apparatus. According to this imaging apparatus, the angular velocity is detected by the gyro sensor in accordance with the fluctuation width of the imaging apparatus due to camera shake, and the detected angular velocity is output as an analog signal in a predetermined range centered on the reference voltage. Next, the A / D converter encodes the analog signal output from the gyro sensor with a predetermined number of bits and outputs it as a digital signal. Then, camera shake detection is performed based on the digital signal.

JP 2007-274207 A

  However, in telephoto shooting, the field angle of view is narrower than that of wide-angle shooting, and the influence of camera shake is increased. Therefore, it is required to improve the detection accuracy of camera shake.

  An object of the present invention is to provide a camera shake detection device, an imaging device, and a program that can detect camera shake more effectively based on the setting of a shooting field angle.

  The camera shake detection apparatus according to the first aspect of the present invention is based on a shooting field angle setting unit that sets a shooting field angle, a detection unit that detects a camera shake, and a shooting field angle set by the shooting field angle setting unit. Detection accuracy setting means for setting the detection accuracy of camera shake to be detected by the detection means, and detection control means for controlling the detection means to detect camera shake with the detection accuracy set by the detection accuracy setting means; It is characterized by providing.

  A camera shake detection apparatus according to a second aspect of the present invention is the camera shake detection apparatus according to the first aspect, wherein the detection unit includes a gyro sensor that detects a camera shake and outputs a detection signal, and the detection accuracy setting unit includes: And a means for setting a range for converting the output signal from the gyro sensor.

  A camera shake detection apparatus according to a third aspect of the present invention is the camera shake detection apparatus according to the first aspect, wherein the detection unit includes a gyro sensor that detects a camera shake and outputs a detection signal, and the detection accuracy setting unit includes: And a means for setting a reference voltage to be supplied to the gyro sensor.

  A camera shake detection apparatus according to a fourth aspect of the present invention is the camera shake detection apparatus according to any one of the first to third aspects, wherein the photographing field angle setting means sets an aspect ratio of the optical image of the subject. Setting means is included.

  A camera shake detection apparatus according to a fifth aspect of the present invention is the camera shake detection apparatus according to any one of the first to fourth aspects, wherein the photographing field angle setting means includes a zoom lens and the zoom lens along the optical axis. It is characterized by comprising a lens moving means for moving, and a lens position detector for detecting the position of the zoom lens.

  A camera shake detection apparatus according to a sixth aspect of the present invention is the camera shake detection apparatus according to any one of the first to fifth aspects, wherein the shooting angle-of-view setting means photoelectrically converts an optical image of a subject and outputs it as an imaging signal. Signal output means and range setting means for setting a range of an optical image to be output from the signal output means in accordance with a user operation.

  A camera shake detection device according to a seventh aspect of the present invention is the camera shake detection device according to any one of the first to sixth aspects, wherein the camera shake amount output means outputs the camera shake amount detected by the detection means, and The camera further comprises shooting field angle correction means for correcting the position of the shooting field angle based on the camera shake amount output from the camera shake amount output means.

  The camera shake detection apparatus according to the invention described in claim 8 is the camera shake detection apparatus according to any one of claims 1 to 7, wherein the detection accuracy setting means is at least a photographed image set by the photographing field angle setting means. One of increasing the camera shake detection accuracy as the angle becomes narrower or decreasing the camera shake detection accuracy as the shooting field angle set by the shooting field angle setting unit becomes wider is set. To do.

  An image pickup apparatus according to a ninth aspect of the present invention includes a camera shake detection device according to any one of the first to eighth aspects, an image pickup unit, and an image picked up by the image pickup unit. And a recording means for recording the fact.

  According to a ninth aspect of the present invention, there is provided a program according to a ninth aspect of the present invention, in which a computer included in an image pickup apparatus including a camera shake detection unit includes a photographing field angle setting unit that sets a photographing field angle and a photographing field angle set by the photographing field angle setting unit. Based on the detection accuracy setting means for setting the detection accuracy of the camera shake to be detected by the camera shake detection unit, and controls the camera shake detection unit to detect the camera shake with the detection accuracy set by the detection accuracy setting unit. It functions as a detection control means.

  According to the present invention, it is possible to effectively detect camera shake based on the range of the shooting angle of view.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a schematic configuration of a digital camera 1 as an imaging apparatus according to an embodiment of the present invention.
The digital camera 1 has functions of automatic exposure adjustment (AE) control, automatic focusing (AF) control in telephoto shooting and wide-angle shooting, and mainly includes the following units.

  That is, the digital camera includes an optical system 16 as a photographing field angle setting unit, a CCD 2 as a signal output unit, a timing generator (TG) 3, a CCD driving circuit 4, an A / D converter 5, an image processing unit 6, a photographed image. Control unit 7, lens driving circuit 8, SDRAM 9, display unit 10, JPEG conversion unit 11, external memory I / F 12, external memory 13, key as angle setting unit, detection accuracy setting unit, detection control unit, and range setting unit An input block 14, a flash memory 17, a gyro sensor 18 as detection means, and a CCD moving unit 19 are provided.

The optical system 16 forms an optical image of the subject. The optical system 16 includes a zoom lens, a focus lens, a lens motor as a lens moving unit that moves these lenses along the optical axis, and a lens position detector that acquires the positions of these lenses.
The lens driving circuit 8 drives the lens motor in accordance with the command from the control unit 7, thereby controlling the position of the focus lens on the optical axis.

The timing generator 3 generates a timing signal, and the CCD driving circuit 4 generates a driving signal based on the timing signal.
Based on the timing signal output from the CCD drive circuit 4, the CCD 2 photoelectrically converts the optical image of the subject and outputs it as an imaging signal.
The A / D converter 5 converts the imaging signal output from the CCD 2 into a digital signal and outputs the digital signal to the image processing unit 6.

The image processing unit 6 performs RGB interpolation processing for generating R, G, and B color component data (RGB data) for each pixel, and luminance signals (Y) from the RGB data. YUV conversion processing for generating YUV data consisting of color difference signals (U, V) for each pixel, and digital signal processing for improving image quality such as auto white balance and edge enhancement are performed.
The image processing unit 6 sequentially stores the generated YUV data in the SDRAM 9.

The key input block 14 includes a plurality of keys such as a power key, a mode switching key for switching between a recording mode and a playback mode, which are basic operation modes of the digital camera 1, a MENU key, and a shutter key.
The shutter key has a so-called half shutter function that allows a two-step operation of a half-pressed position for a user to make a shooting advance notice and a full-pressed position for instructing an actual shooting operation.
The operation state of each key of the key input block 14 is scanned by the control unit 7 as needed.

The display unit 10 includes a liquid crystal monitor and a drive circuit for the liquid crystal monitor. In the recording mode, whenever one frame of YUV data is stored in the SDRAM 9, the YUV data is converted into a video signal by the image processing unit 6 and displayed as a through image on the display unit 10.
When shooting in the recording mode, the image data temporarily stored in the SDRAM 9 is compressed and encoded by the JPEG conversion unit 11 using the JPEG method, and then configured by, for example, various memory cards via the external memory I / F 12. It is recorded in the external memory 13 as a still image file.

  In the reproduction mode, the still image file recorded in the external memory 13 is appropriately read in accordance with the user's selection operation, decompressed by the JPEG conversion unit 11 and expanded on the SDRAM 9 as YUV data, and is statically displayed on the display unit 10. Displayed as an image.

  The flash memory 17 is a nonvolatile memory capable of rewriting stored data, and stores various programs executed by the control unit 7 and various data necessary for control by the control unit 7. The flash memory 17 also stores setting information regarding various functions of the digital camera 1 set by the user.

The gyro sensor 18 detects the angular velocity in a predetermined range centered on the reference voltage according to the shake width of the digital camera 1 due to camera shake. That is, the gyro sensor 18 detects camera shake by outputting an angular velocity due to camera shake as a detection signal.
The CCD moving unit 19 moves the CCD 2 in a predetermined direction.

  The control unit 7 includes a CPU and its peripheral circuits and the like, reads out data stored in the flash memory 17, controls each unit of the digital camera 1, AE control based on luminance information included in the imaging signal, phase difference AF control using a detection method or contrast detection method, aspect ratio setting processing, electronic zoom processing, camera shake correction processing using an image sensor shift method, and the like are performed.

That is, in the electronic zoom process, the control unit 7 sets a range of an optical image to be output from the CCD 2 according to a user operation.
In the aspect ratio setting process, when the aspect ratio is designated by a user operation, the control unit 7 sets the aspect ratio of the optical image based on the imaging signal output from the CCD 2 to the designated aspect ratio.

  In addition, in the camera shake correction process, the control unit 7 sets the camera shake detection accuracy to be detected by the gyro sensor 18 based on the shooting angle of view set by at least one of the optical system 16 and the electronic zoom process. An angular velocity is detected by the gyro sensor 18 with the set detection accuracy, and the CCD moving unit 19 is driven based on the detected angular velocity to move the CCD 2.

By the way, there are the following differences between telephoto shooting and wide-angle shooting.
FIG. 2 is a diagram showing the difference between telephoto shooting and wide-angle shooting.
As shown in FIG. 2, in wide-angle shooting, the focal length is shortened and the shooting angle of view is widened. Therefore, the amount of movement of the CCD 2 per unit angular velocity is small with respect to the angular velocity detected during camera shake correction. Accordingly, since the maximum movable speed is a predetermined value, the range of angular speeds that can be followed is widened in wide-angle shooting.
In this way, in wide-angle shooting, the effect of hand-shake correction errors on the image is reduced, so the resolution may be low.

On the other hand, in telephoto shooting, the focal length becomes long and the shooting angle of view becomes narrow. Therefore, the amount of movement of the CCD 2 per unit angular velocity increases with respect to the angular velocity detected at the time of camera shake correction. Therefore, since the maximum movable speed of the CCD moving unit 19 is a predetermined value, the range of the angular speed that can be followed is narrowed in telephoto shooting.
As described above, in telephoto shooting, the influence of the image stabilization resolution on the image becomes large, and therefore it is necessary to increase the resolution.
When the resolution of camera shake correction is large, there is a problem that the effect of the camera shake correction error on the image becomes large.
In telephoto shooting, it is natural that the shooting angle of view becomes narrower and the movement amount of the shooting angle of view per unit angular velocity of the detected camera shake increases.Therefore, electronic camera shake correction is used instead of optical camera shake correction. Even if it is used, the influence of the camera shake correction resolution on the image is similarly increased, so it can be said that improving the camera shake detection resolution is advantageous for camera shake correction.

From the above, it is known that the telephoto shooting requires a higher resolution than the wide-angle shooting, but the range of the angular velocity that can be followed is narrowed.
Therefore, a camera shake correction circuit for executing the camera shake correction process is configured as follows.

FIG. 3 is a block diagram of the above-described camera shake correction circuit.
The control unit 7 includes a lens control unit 71, a camera shake control unit 72 as a photographing field angle correction unit, a voltage control unit 73, an A / D control unit 74 as a camera shake amount output unit, and a D / A control unit 75. Prepare.

  The lens control unit 71 detects the focal length based on the focus position of the lens detected by the optical system 16 and outputs the detected focal length.

The camera shake control unit 72 determines the angular velocity range A ₁ , the supply voltage V ₁ , and the sensitivity G based on the focal length and the result of the electronic zoom process, and outputs the supply voltage V ₁ . Here, the angular velocity range A ₁ is a range in which an output signal from the gyro sensor 18 is converted, and the supply voltage V ₁ is a voltage value for setting a reference voltage supplied to the gyro sensor 18.
Hand shake control section 72, a telephoto shot, to increase the detection accuracy by narrowing the angular range A _1, in the wide-angle shooting, reducing the detection accuracy by a wide speed range A _1. That is, the camera shake detection accuracy is increased as the set shooting angle of view becomes narrower, or the camera shake detection accuracy is lowered as the set shooting angle of view becomes wider.

Further, the camera shake control unit 72 drives the CCD moving unit 19 based on the sensitivity G and the angular velocity signal. That is, the position of the shooting angle of view is corrected based on the amount of camera shake output from the A / D control unit 74.
Voltage control unit 73 sets the supply voltage _{V 1,} and outputs the supply voltage _{V 1.}
The D / A control unit 75 calculates the gyro setting voltage V ₂ based on the supply voltage V ₁ and outputs the calculated gyro setting voltage V ₂ .

When the gyro set voltage V ₂ is input, the gyro sensor 18 sets the gyro set voltage V ₂ as the reference voltage V _ref . Then, the angular velocity is detected in a predetermined range A centered on the reference voltage _Vref , and this angular velocity is output as an analog signal.
A / D control unit 74 outputs the amount of hand-shake digital signal only speed range A ₁ encoded a predetermined number of bits of the analog signal output from the gyro sensor 18.

The camera shake correction process of the digital camera 1 will be described with reference to the flowchart of FIG.
In step ST1, the zoom lens is operated by the user to set the shooting angle of view, the lens position at this shooting angle of view is detected by the optical system 16, and the lens controller 71 determines the focal length based on this in-focus position. , And the detected focal length is output to the camera shake controller 72.
In step ST2, the camera shake control unit 72 determines the supply voltage V ₁ , the angular velocity range A ₁ , and the sensitivity G based on the focal length and the result of the electronic zoom processing. Among these, the angular velocity range A ₁ and the supply voltage are determined. V ₁ is output to the voltage control unit 73. Here, the supply voltage V _1, determined based on the following equation (1).
V ₁ = A ₁ (1)

At step ST3, the the voltage control unit 73 sets the speed range _{A 1} and the supply voltages _{V 1,} the speed range _{A 1} and the supply voltages _{V 1} that this setting, A / D controller 74 and D / A controller 75 Output to.

In step ST4, the D / A control unit 75, based on the supply voltage _{V 1,} seeking gyro set voltage _{V 2,} and outputs the gyro set voltage _{V 2} to the gyro sensor 18. Specifically, the gyro set voltage V _2, determined based on the following equation (2).
V ₂ = V _1/2 (2)

In step ST5, the gyro sensor 18, to set the gyro set voltage _{V 2} as a reference voltage _{V ref.}
In step ST6, the angular velocity is detected by the gyro sensor 18 based on the reference voltage _Vref . Specifically, the gyro sensor 18 detects the angular velocity as an analog signal in a predetermined range A centered on the reference voltage V _ref .

In step ST7, the A / D control unit 74 converts the output analog signal into an angular velocity range A ₁ centered on the reference voltage V _ref , that is, a range from zero to the supply voltage V ₁ into a digital signal. .

For example, as shown in FIG. 5, it is assumed that the angular velocity is output as an analog signal by the gyro sensor 18 within a predetermined range A centered on the reference voltage V _ref .
The wide-angle imaging, speed range A ₁ is equal to the predetermined range A, A / D controller 74 converts all of the analog signal into a digital signal. On the other hand, in the telephoto shooting speed range A ₁ is narrower than the predetermined range A, only a portion of the analog signal into a digital signal. Thereby, the resolution per unit of the digital signal is improved.

  In step ST8, the camera shake control unit 72 drives the CCD moving unit 19 based on the sensitivity G and the angular velocity as a digital signal, and performs a process for correcting the range of the shooting angle of view, that is, a camera shake correction process.

According to this embodiment, there are the following effects.
(1) According to the present invention, A / D controller 74 outputs a digital signal by encoding only speed range A ₁ of the output analog signal from the gyro sensor 18 with a predetermined number of bits.
Here, in the telephoto shooting, as compared to the wide-angle shooting, by reducing the speed range A _1, along with narrowing the range of digital conversion, enhanced resolution. Therefore, it is possible to effectively detect camera shake based on the range of the shooting angle of view.

  When the digital conversion range is narrowed in this way, a portion of the analog signal that is not digitally converted is generated. However, since the portion that is not digitally converted is an angular velocity that the digital camera 1 cannot actually follow, the camera shake correction function does not deteriorate.

  It should be noted that the present invention is not limited to the above-described embodiment, and modifications, improvements, etc. within a scope that can achieve the object of the present invention are included in the present invention.

Further, the change of the shooting angle of view related to the present invention may be a change of the aspect ratio.
As aspect ratios for recording, 4: 3 (standard display aspect ratio), 16: 9 (aspect ratio applied to high-quality displays such as HDTV), and 3: 2 (suitable for printing) Aspect ratio) is prepared in the digital camera 1 so as to be selectable in advance, this aspect ratio change means that a predetermined aspect ratio among the above aspect ratios is detected by detecting an operation to the key input block 14. Is selected and set, the range of the optical image formed on the CCD 2 is changed, and as a result, the shooting angle of view is set.
Therefore, the detection content of the angular velocity is changed according to the setting of the aspect ratio.

In the above embodiment, the camera shake correction is performed based on the detected camera shake. However, the present invention is not limited to this.
For example, the detected camera shake may be simply recorded in time series so that camera shake data at the time of shooting can be confirmed after shooting, or by displaying the detected camera shake on the display unit 10 simultaneously with the through image, It may be configured to be able to shoot while paying attention to camera shake while checking the state of camera shake, or may be configured to execute all of the above-described camera shake correction, camera shake recording, and camera shake display simultaneously. Good.

In this embodiment, the image sensor shift method for moving the CCD 2 is adopted as the camera shake correction method. However, the present invention is not limited to this, and a lens shift method for moving the lens may be adopted, or image processing is used. An electronic method may be adopted.
In the present embodiment, the gyro set voltage V ₂ is obtained based on the supply voltage V _1. However, the present invention is not limited thereto, and the supply voltage V ₁ and the gyro set voltage V ₂ may be set separately. .

1 is a block diagram illustrating a schematic configuration of an imaging apparatus according to an embodiment of the present invention. It is a figure which shows the difference between the telephoto photography and wide-angle photography of the imaging device which concerns on the said embodiment. It is a block diagram of a camera shake correction circuit of the imaging apparatus according to the embodiment. 4 is a flowchart of camera shake correction processing of the imaging apparatus according to the embodiment. It is a figure which shows the specific example of the camera-shake correction process of the imaging device which concerns on the said embodiment.

Explanation of symbols

1 Digital camera 2 CCD
7 Control Unit 16 Optical System 18 Gyro Sensor 72 Camera Shake Control Unit 74 A / D Control Unit

Claims (10)

A shooting angle setting means for setting a shooting angle of view;
Detection means for detecting camera shake;
Detection accuracy setting means for setting the detection accuracy of camera shake to be detected by the detection means based on the shooting angle of view set by the shooting angle of view setting means;
Detection control means for controlling the detection means to detect camera shake with the detection precision set by the detection precision setting means;
A camera shake detection device comprising: The detection means includes a gyro sensor that detects a camera shake and outputs a detection signal,
2. The camera shake detection apparatus according to claim 1, wherein the detection accuracy setting means includes means for setting a range for converting an output signal from the gyro sensor. The detection means includes a gyro sensor that detects a camera shake and outputs a detection signal,
2. The camera shake detection apparatus according to claim 1, wherein the detection accuracy setting means includes means for setting a reference voltage to be supplied to the gyro sensor.   4. The camera shake detection apparatus according to claim 1, wherein the photographing field angle setting unit includes an aspect ratio setting unit that sets an aspect ratio of the optical image of the subject. The photographing field angle setting means includes a zoom lens,
Lens moving means for moving the zoom lens along the optical axis;
A lens position detector for detecting the position of the zoom lens;
The camera shake detection device according to claim 1, further comprising: The shooting field angle setting means includes a signal output means for photoelectrically converting an optical image of a subject and outputting as an imaging signal;
Range setting means for setting a range of an optical image to be output from the signal output means according to a user operation;
The camera shake detection apparatus according to claim 1, further comprising: Camera shake output means for outputting the amount of camera shake detected by the detection means;
Shooting angle of view correction means for correcting the position of the shooting angle of view based on the amount of camera shake output from the shake amount output means;
The camera shake detection device according to claim 1, further comprising:   The detection accuracy setting unit increases the detection accuracy of the camera shake as the shooting field angle set by the shooting field angle setting unit becomes narrower, or the shooting field angle set by the shooting field angle setting unit. 8. The camera shake detection apparatus according to claim 1, wherein one of the lowering of the camera shake detection accuracy is set as the image becomes wider. 9. The camera shake detection device according to any one of claims 1 to 8,
Imaging means;
Recording means for recording, together with the image taken by the imaging means, that the camera shake is detected by the detection means;
An imaging apparatus comprising: A computer included in an imaging apparatus including a camera shake detection unit,
Shooting angle setting means for setting the shooting angle of view,
Detection accuracy setting means for setting the detection accuracy of camera shake to be detected by the camera shake detection unit based on the shooting angle of view set by the shooting field angle setting means;
Detection control means for controlling the camera shake detection unit to detect camera shake with the detection accuracy set by the detection accuracy setting means;
A program characterized by functioning as

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