JP3182176B2 - Camera-integrated video tape recorder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera-integrated video tape recorder, and more particularly to a camera-integrated video tape recorder having a camera shake correction function and an electronic zoom function using an image memory in a camera mode.

[0002]

[Prior Art] Magazine "Television Technology", August 1990, p
17 to 26 describe a camera-integrated VTR equipped with a digital camera with a camera shake correction function. FIG. 3 is a modified block diagram of the digital camera section of the camera-integrated VTR. The principle of camera shake correction is that a motion detection IC compares a video signal of one field before and a video signal of the current field to obtain a motion vector, and according to the motion vector, an image memory and an IC for interpolation processing use This is to correct the shaking by moving the cutout frame of the output screen in parallel in the direction opposite to the movement.

[0003]

When a VTR head is composed of two or four heads and does not have a special reproduction head, the VTR head is compared with normal reproduction during a special reproduction such as slow reproduction or still reproduction. Therefore, there is a problem that noise appearing on the reproduction screen increases. Hence,
A main object of the present invention is to provide a camera-integrated video tape recorder that greatly reduces noise on a playback screen during special playback by using an image memory that has been conventionally used for camera shake correction and the like. .

[0004]

According to the present invention, a first switching means for switching between a first video signal obtained from an image sensor in a camera mode and a second video signal obtained by reproducing a video tape in a reproduction mode, An analog-to-digital converter for converting the video signal selected by the first switching means from analog to digital to output video data; an image memory for storing video data output from the analog / digital converter for one frame period; A second switch for switching between video data read from the memory and video data output from the analog / digital converter, a delay for delaying the video data selected by the second switch by one line period, and a camera mode. Video data and delay means selected by the second switching means A camera comprising: first processing means for performing at least Y / C separation processing using passed video data; and second processing means for processing video data read from an image memory and outputting a video signal during special reproduction in a reproduction mode. It is an integrated video tape recorder.

[0005]

The camera mode and the reproduction mode or the VTR mode are switched by the first switching means. In the VTR mode, a second video signal obtained by reproducing a video tape is selected by a first switching means and supplied to an analog / digital converter. The video data of the second video signal from the analog / digital converter is written to the image memory. Video data read from the image memory is selected by the second switching means. In normal reproduction, writing and reading to and from the image memory are performed every frame, but a video signal based on the second video signal is output to the video output terminal instead of the image memory output. And in the case of special reproduction, for example, in still reproduction,
Stop writing to the image memory for a period from immediately after the user presses the still play button until the still is released,
In each frame, the same data, that is, the last written data is continuously read and output to the video output terminal through the second processing means. For example, during slow playback, writing to the image memory is performed at a rate of one frame every several frame periods from immediately after the user presses the slow playback button until the slow playback is released, and reading from the image memory is performed. The video data read every frame is sent to the second processing means and output to the video output terminal. In other words, using the video data written in the image memory, the camera operates as a digital camera having a camera shake correction function and an electronic zoom function in the camera mode,
In the reproduction mode or the VTR mode, digital still reproduction and digital slow reproduction are performed.

[0006]

According to the present invention, the image memory used for camera shake correction and the like is also used for special reproduction. Therefore, even without a special reproduction head, a simple circuit change and a large increase in cost are possible. The noise that appears during special reproduction can be greatly reduced. The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

[0007]

Referring to FIG. 1, a camera-integrated VTR 10 of this embodiment includes a switch 12 for switching or selecting a video signal. CC is connected to one input of the switch 12.
An imaging video signal obtained from D14 is input, and a reproduction video signal is input to the other input of the switch 12. The switch 12 is switched by a camera / VTR switching signal. The output of the CCD 14 is selected in the camera mode, and the reproduced video signal is selected in the reproduction mode or the VTR mode.

[0008] The video signal selected by the switch 12 is input to an analog / digital converter 16 and converted into video data. Analog / digital converter 16
Is supplied to the camera shake detection circuit 18 and the frame memory 20, and is also input to one input of the switch 22. Video data read from the frame memory 20 is input to the other input of the switch 22. The switch 22 is switched by the camera / VTR
This is performed by the output of the gate 24 to which the switching signal and the camera shake correction on / off switching signal are input. That is, the output of the analog / digital converter 16 is selected in the camera mode when the camera shake correction is off, and the output from the frame memory 20 is selected when the camera shake correction is on or in the VTR mode.

The video data (V0) selected by the switch 22 is a one-line delay line (1HTL) 26a-2.
6c, the output from each of the delay lines 26a to 26c (V1
To V3) and V0 are electronic zoom, gamma correction, Y / C
The signal is input to a signal processing circuit 28 that performs separation, aperture control, white balance, synchronous mixed modulation, burst mixed modulation, and the like. The video data V0 and V1 are input to the Y / C separation circuit 30. In the Y / C separation circuit 30, Y = (V0 + V1) / 2 and C = (V0-V1)
By performing the operation of / 2, Y signal data and C signal data are obtained.

The Y signal data and C signal data obtained by the Y / C separation circuit 30 are supplied to one input of a switch 32 and a switch 34, respectively. Data and C signal data are input, respectively. Switch 32 and Switch 3
4 is performed by a camera / VTR switching signal.
In the camera mode, Y signal data and C signal data obtained by the signal processing circuit 28 are selected, and in normal reproduction, Y signal data and C signal data obtained by the Y / C separation circuit 30 are selected.

The Y signal data selected by the switch 32 is input to a digital / analog converter 36 to become an analog signal, and is sent to a VTR circuit (not shown) by a low-pass filter 38 excluding unnecessary high frequency components. Also,
The C signal data selected by the switch 34 is input to the digital / analog converter 40 to become an analog signal, which is band-limited by the band-pass filter 42 and sent to the VTR circuit.

In the camera mode, such a camera-integrated VTR 10 operates as a digital camera having a camera shake correction function or an electronic zoom function, as in the prior art described above. On the other hand, in the VTR mode, a reproduced video signal obtained by reproducing a video tape is converted into video data by the analog / digital converter 16 and then written into the frame memory 20. The output of the frame memory 20 is provided to the Y / C separation circuit 30 via the switch 22 and the delay line 26a.

At the time of normal reproduction, the frame memory 20
Writing to the VRAM and reading from the frame memory 20 are performed every frame, but the VTR circuit is supplied with normal reproduced video signal data instead of the memory output by the instruction of the memory control circuit 44. Then, a normal reproduction video signal is output from a video output terminal (not shown). On the other hand, in the case of the still reproduction, the writing to the memory is stopped by the instruction of the memory control circuit 44 during a period from immediately after the user presses the still reproduction switch 46 until the still reproduction is released. The same data as the frame, that is, the last written playback video data of one frame is continuously read. The read reproduced video data is V
It is given to the TR circuit. That is, in the case of still playback, video data stored in the frame memory 20 is repeatedly read, so that still playback with greatly reduced noise can be performed.

In the case of slow reproduction, writing to the memory is performed for several frame periods by the instruction of the memory control circuit 44 during a period from immediately after the user presses the slow reproduction switch 48 until the slow reproduction is released. Is performed regularly at a rate of one frame, and memory data is read out for each frame. That is, in the case of slow reproduction, since the signal processing circuit 28 generates a video signal based on the intermittently stored reproduced video data from the frame memory 20, still reproduction in which noise is significantly reduced becomes possible.

In the above-described embodiment, Y / C separation is performed by passing the reproduced video data once through the camera delay line. In particular, in the camera circuit, the delay of one line period and the Y / C separation are performed.
There is no need to perform C separation. For example, as in a camera-integrated VTR 50 shown in FIG. 2, the output of a low-pass filter 52 (Y signal) and the output of a band-pass filter 54 (C signal)
May be mixed in the Y / C mixing circuit 56, and may be switched to the video data V0 by the switch 58 and output, and V0 may be delayed by one line period and Y / C separated by the VTR circuit. However, in the case of the embodiment of FIG.
Since the one-line period delay and Y / C separation required for the line noise canceller, dropout compensation, and Y / C separation processing in the TR can be performed by the camera-side circuit, there is an advantage that the circuit configuration can be reduced in scale. .

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is a block diagram showing another embodiment of the present invention.

FIG. 3 is a block diagram showing a conventional technique.

[Explanation of symbols]

 10, 50 camera-integrated VTR 12, 22, 32, 34 switch 20 frame memory 26a, 26b, 26c one-line delay line 28 signal processing circuit 30 Y / C separation circuit 44 memory control circuit 46 Still playback switch 48… Slow playback switch

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04N 5/232 G11C 11/401 H04N 5/21 H04N 5/228

Claims (1)

(57) [Claims] 1. A first mode obtained from an image sensor in a camera mode.
First switching means for switching between a video signal and a second video signal obtained by reproducing a video tape in a reproduction mode; analog / digital conversion of the video signal selected by the first switching means to output video data; An analog / digital converter, an image memory for storing video data output from the analog / digital converter for one frame period, video data read from the image memory and video data output from the analog / digital converter. Switching means for switching the video data selected by the second switching means.
Delay means for delaying a line period, and first processing means for performing at least Y / C separation processing using the video data selected by the second switching means and the video data passed through the delay means in the camera mode,
And a camera-integrated video tape recorder, comprising: a second processing unit that processes the video data read from the image memory and outputs a video signal during special playback in the playback mode.