JP3960140B2 - Video camera - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a video camera equipped with an optical camera shake correction device, and more particularly to camera shake correction when a conversion lens is mounted.
[0002]
[Prior art]
Conventionally, in order to prevent image shake due to camera shake or the like that is likely to occur during hand-held shooting, the shake information of the video camera is detected by the shake detection means, and the shake is optically or electronically canceled according to the detection result. Various devices for realizing camera shake correction have been proposed.
The most common optical correction process as a camera shake correction apparatus for a video camera will be described. FIG. 6 is a schematic configuration diagram of a video camera for explaining this. In FIG. 6, the image of the subject 1 passes through a lens group 2 consisting of a zoom lens and a focus lens, and is converted into an electrical signal by the CCD 4, so Then, a known signal processing is performed and output to the monitor 6. An apparatus that realizes camera shake correction includes a camera shake sensor 7 including an X-axis camera shake sensor and a Y-axis camera shake sensor, and a shift lens 3 that corrects camera shake. The shift lens 3 is attached to an X-axis actuator and a Y-axis actuator (not shown) so as to be able to move in the respective directions, and moves in the X-axis direction and the Y-axis direction in a plane perpendicular to the optical axis. It is held by a driving device (not shown) so that it can be made.
The microcomputer 8 calculates the movement control amount of the shift lens 3 from the detection result of the camera shake amount in the X-axis direction and the Y-direction from the camera shake sensor 7 and the zoom magnification of the lens group 2 and outputs the movement control amount to the drive device of the shift lens 3 for camera shake correction. Like to do.
[0003]
[Problems to be solved by the invention]
When the amount of camera shake given to the video camera is constant, the relationship between the zoom magnification of the lens group 2 and the movement control amount of the shift lens 3 for correcting camera shake is inversely proportional to the zoom magnification as shown in FIG. is doing. Therefore, the relationship shown in the figure is set in advance in the microcomputer 8 of the video camera, and the movement control amount according to the zoom magnification of the lens group 2 and the output of the camera shake sensor 7 is controlled.
By the way, if an attempt is made to shoot with a conversion lens attached to a video camera, the magnification of the lens provided as a standard and the magnification of the lens in actual use change, so the relationship of FIG. The movement control amount of the shift lens 3 becomes incompatible. When the magnification of the conversion lens to be attached is larger than 1, the correction amount is too large. Conversely, when the magnification is smaller than 1, the correction amount is small.
That is, when a conversion lens is attached to a video camera equipped with an optical camera shake correction device, there is a problem that the camera shake correction function cannot be used.
The present invention has been made in view of the above points, and it is an object of the present invention to provide a video camera that performs optimal camera shake correction even when a conversion lens is attached to a video camera equipped with an optical camera shake correction device.
[0004]
[Means for Solving the Problems]
The present invention, in order to solve the above problem, consists of means described in below.
That is,
In a video camera with a conversion lens detachable and equipped with an optical image stabilization device,
Means for detecting motion vectors from incoming image information;
Means for detecting attachment of the conversion lens;
Based on the conversion lens mounting information, the image taken by driving the optical camera shake correction device is vibrated, the motion vector of the incoming image is detected by the vibration, and the conversion lens corresponding to the motion vector is detected. Means for detecting the magnification of
Based on the detected magnification of the conversion lens, means for calculating a camera shake correction amount when the conversion lens is mounted from a preset camera shake correction amount table, and controlling the optical camera shake correction device;
A video camera characterized by comprising:
[0005]
DETAILED DESCRIPTION OF THE INVENTION
The preferred embodiments of the present invention will be described below. FIG. 1 is a schematic block diagram of a video camera according to the embodiment. The same components as those of the conventional optical camera shake correction apparatus shown in FIG.
FIG. 1 shows a state in which a detachable conversion lens 11 is attached to a lens system originally provided as a standard. The imaging light of the subject 1 is converted into an electrical signal by the CCD 4 through the conversion lens 11, the lens group 2, and the shift lens 3 in order, and further processed into a video signal by the camera circuit 12 and output to the monitor 6.
[0006]
The camera circuit 12 will be described in more detail with reference to FIG. As shown in the figure, the imaging signal converted into an electrical signal by the CCD 4 is digitized by an A / D converter 52, and this digitally processed signal passes through a signal processing circuit 53 and a D / A converter 54. It is output to the monitor 6. On the other hand, a luminance signal is extracted by the signal processing circuit 53, and a hand shake component is detected by the motion vector detection circuit 55 based on the luminance signal and output to the microcomputer 18.
[0007]
In the original camera shake correction apparatus, the camera shake image is stopped when the video camera vibrates at the time of shooting. In this embodiment, the shift lens 3 is used to detect the magnification of the lens mounted on the video camera. The drive device is operated so as to vibrate the captured image. Hereinafter, this operation is referred to as reverse camera shake correction. In order to realize the reverse camera shake correction, the driving device of the shift lens 3 may be intentionally controlled by the microcomputer 18, and the relationship between the vibration of the image at that time and the magnification of the zoom lens provided as a standard is as follows: The proportional relationship shown in FIG. 3 is obtained.
As shown in the figure, when both the subject and the video camera are fixed and the zoom magnification of the lens is changed with the shift lens 3 generating a constant vibration, it is taken into the video camera and displayed on the monitor. The amount of vibration of an image increases as the zoom magnification increases.
[0008]
Next, FIG. 4 shows a state of reverse camera shake correction when the conversion lens 11 is attached to the video camera. In the figure, a conversion lens having a magnification of 2 is assumed. Before the conversion lens 11 is mounted, the amount of shake of the monitor image at the 1 × zoom position is the same amount of shake as the double position before mounting after mounting, and the double position before mounting is 4 × after mounting. This indicates that the inclination of the graph changes before and after the attachment.
[0009]
Here, the shake amount of the monitor image is the vibration of the image signal, and is equivalent to a motion vector obtained by processing the image taken from the video camera by the vector detection circuit 55.
Therefore, the microcomputer 18 can determine the magnification of the mounted conversion lens 11 by detecting the motion vector when the conversion lens 11 is not mounted and the motion vector when the conversion lens 11 is mounted.
As described in the above-mentioned optical camera shake device, the zoom lens magnification and the current zoom position information provided as standard in the video camera, the corresponding camera shake correction amount, that is, the movement control amount of the shift lens 3 Is made to be recognized by the microcomputer 18 in advance. Therefore, the magnification of the mounted conversion lens 11 can be obtained by detecting only the motion vector when the conversion lens 11 is mounted and calculating the value of the standard lens that has been set.
[0010]
In this embodiment, whether or not the conversion lens 11 is mounted is detected by the conversion lens lens mounting sensor 19, and the lens magnification is detected immediately after starting recording or immediately after canceling the recording pause. I try to let them. For this reason, it can be set as the structure which always always provides the exact camera-shake correction amount irrespective of the presence or absence of the conversion lens 11 mounting | wearing.
In this embodiment, several types of conversion lens devices are assumed in advance, and a movement control amount table is provided in the microcomputer 18 for correcting camera shake when the conversion lens 11 is mounted. The conversion lens is identified from the obtained magnification, and the table is switched.
[0011]
Next, a method for obtaining the magnification when the conversion lens 11 is mounted, which is executed in the microcomputer 18, will be described with reference to the schematic block diagram of FIG. 1 and the flowchart of FIG.
When the conversion lens mounting sensor 19 detects that the conversion lens 11 is mounted, the information is supplied to the microcomputer 18. In this state, magnification measurement is started immediately after starting REC (recording) or immediately after releasing REC pause (step 500).
When measurement is started by the microcomputer 18, first, the shift lens 3 is vibrated with a predetermined amplitude A (step 501). The lens group 2 is set to a zoom magnification of 1 (step 502). The motion vector VK1 in the zoom magnification 1 state is detected by the motion vector detection circuit 55 (step 503).
If these are detected, the vibration of the shift lens 3 is terminated (step 504). The magnification P of the conversion lens 11 is obtained by calculating the detected VK1 and the motion vector V1 that is provided as a standard and the lens group 2 has a zoom magnification of 1 (step 505).
[0012]
Based on the obtained magnification P of the conversion lens 11, the type of the conversion lens is specified, and a movement control amount table for camera shake correction corresponding thereto is selected (step 506). Then, the selected table is output to the movement control amount table of the microcomputer 18 (step 507). After performing the above steps, the measurement is terminated.
[0013]
Further, not only in the above embodiment, when the conversion lens 11 is mounted, the correction amount in FIG. 7 set for the lens group that is standardly provided in the video camera is set as described above. The obtained magnification P of the conversion lens 11 may be multiplied to perform control as a correction amount that matches the actual use state.
With this configuration, even when a conversion lens that is not set in the movement control amount table of the microcomputer 18 is mounted, a movement control amount that is an accurate camera shake correction amount can be given to the drive device of the shift lens 3. it can.
[0014]
In addition, when a lens that does not correspond to the conversion lens mounting sensor 19 is attached and used as shown in FIG. 1, a mode input button for performing measurement for detecting magnification is set in the video camera input operation button 20, By detecting the magnification of the mounted lens by manual operation, it is possible to accurately correct camera shake regardless of which additional lens is mounted.
[0015]
【The invention's effect】
According to the video camera of the present invention, on the basis of the conversion lens mounting information, the image taken by driving the optical camera shake correction device is vibrated, and the motion vector of the incoming image is detected by this vibration. By detecting the magnification of the conversion lens corresponding to, the amount of camera shake changes before and after the conversion lens is attached. When the conversion lens is installed, the magnification after the conversion lens is installed is detected as standard. Since it is reflected in the magnification of the photographic lens provided, the correction amount of the optical camera shake correction device can be optimally controlled even when the conversion lens is mounted.
[Brief description of the drawings]
FIG. 1 is a schematic block diagram of a video camera equipped with an optical camera shake correction apparatus applied to the present embodiment.
FIG. 2 is a diagram for explaining a camera circuit applied to the present embodiment.
FIG. 3 is a diagram for explaining a relationship between reverse camera shake correction and zoom magnification applied to the present embodiment;
FIG. 4 is a diagram for explaining a state of reverse camera shake correction when the conversion lens applied to the present embodiment is mounted.
FIG. 5 is an example of a flowchart for explaining processing for obtaining a magnification of a conversion lens applied to the present embodiment.
FIG. 6 is a schematic block diagram of a video camera equipped with a conventional optical image stabilizer.
FIG. 7 is a diagram for explaining a shift amount of a shift lens in a conventional optical image stabilization device.
[Explanation of symbols]
4, 21 ... CCD (solid-state image sensor)
3 ... Shift lens 11 ... Conversion lens 2 ... Lens group 5, 12 ... Camera circuit 24 ... Memory 26, 55 ... Motion vector detection circuit 7 ... Camera shake sensor 18, 8 ... Microcomputer 19 ... Conversion lens mounting sensor 20 ... Input operation button

Claims (1)

In a video camera with a conversion lens detachable and equipped with an optical image stabilization device,
Means for detecting motion vectors from incoming image information;
Means for detecting attachment of the conversion lens;
Based on the conversion lens mounting information, the image taken by driving the optical camera shake correction device is vibrated, the motion vector of the incoming image is detected by the vibration, and the conversion lens corresponding to the motion vector is detected. Means for detecting the magnification of
Based on the detected magnification of the conversion lens, means for calculating a camera shake correction amount when the conversion lens is mounted from a preset camera shake correction amount table, and controlling the optical camera shake correction device;
A video camera characterized by comprising:

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