JPH0522697A - Video recorder - Google Patents

Abstract

PURPOSE:To minimize an image memory with a camera incorporated video recorder. CONSTITUTION:A camera signal processing circuit 26 performs the image stabilizing processing of hand shake correction besides the gamma correction, etc., with an image memory 28. That is, in accordance with an action vector, a displaying area is selected in a photographing screen. An interpolation expanding circuit 32 expands the image of the displaying area selected by the image stabilization to the size of a TV screen. The interpolation expanding circuit 32 simultaneously compresses the video signal of 1 field period Tf to a shorter period Tc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video recording device, and more particularly to a video recording device having a camera integrated therein.

[0002]

2. Description of the Related Art A camera-integrated video recording apparatus as described above basically comprises a camera section for taking an image and a recording section for recording a video image signal taken by the camera on a magnetic tape.

In recent years, a camera shake correction circuit has been put into practical use, which detects a motion of an object by an output signal of an image pickup device of a camera and detects and corrects a camera shake by digital image signal processing.

As the recording section, a method of compressing a video signal and recording it on a magnetic tape is known. For example,
Let θ be the winding angle of the magnetic tape on the rotating drum equipped with the double azimuth head, and set the rotating drum to 1
Drum mechanisms are known which rotate once in the field, i.e. at 3,600 rpm. FIG. 5 shows its plan view.
Reference numeral 10 is a rotary drum, 12 is a magnetic tape, 14a is a plus-azimuth magnetic head, and 14b is a minus-azimuth magnetic head. When using this drum mechanism,
Since one rotation of the rotary drum corresponds to one field period, the short contact angle (360-θ) results in a non-contact period, and the video signal to be recorded is 360 / (3).
60-θ) must be compressed. In the conventional example,
This compression is realized using an image memory. FIG. 6 is a timing diagram of the image memory for compression.
(A) is a writing period, and (b) is a reading period. That is, Tf / Tc = 360 / θ.

[0005]

When a camera having a camera shake correction function as described above and a recording circuit for compression recording are integrated to form a camera-integrated video recording device, the camera section and the recording circuit are integrated. Both require image memory. The image memory still has a drawback that it consumes a large area and not only hinders miniaturization, but also consumes a large amount of power. Normally, the camera-integrated video recording device is used in a battery drive, and therefore it is not preferable to increase power consumption.

SUMMARY OF THE INVENTION It is an object of the present invention to solve these problems and provide a compact and low power consumption video recording apparatus.

[0007]

A video recording apparatus according to the present invention comprises a camera section for digitally processing a captured image signal and a recording section for time-axis converting the video signal and recording it on a recording medium. The apparatus is characterized in that an image memory shared by the digital signal processing of the camera section and the time axis conversion processing of the recording section is provided.

[0008]

By the above means, the image memory can be reduced. As a result, it is possible to prevent an increase in circuit scale and an increase in power consumption and reduce the load on the battery.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. The image sensor 22 converts the subject image from the taking lens 20 into an electric signal, and the A / D converter 24 converts the analog output of the image sensor 22 into a digital signal. The camera signal processing circuit 26 comprises a so-called digital signal processor (DSP) and performs various camera signal processing. For camera signal processing, nonlinear processing such as gamma correction and knee correction, level adjustment such as AGC and clamp,
Chroma-based processing such as white balance and false color removal,
It also includes image quality improvement processing such as noise removal and aperture control. On the other hand, in this embodiment, the image memory 28
Is used to perform the image stabilization processing for the above-described camera shake correction.

The image stabilizing process is specifically composed of a motion vector detecting process and an image moving process for canceling the detected motion vector. For example, as shown in FIG. 2, when the size of the imaging area of the image sensor 22 is Ho × Vo, h × v narrower than this is set as the display area, and the imaging area Ho is set.
The display area h in the direction of canceling the motion vector in × Vo
By moving xv, the camera shake is reduced and eliminated. The motion vector detection circuit 25 detects a motion vector from the digital video signal output from the A / D converter 24. Information on the detected motion vector is input to the memory control circuit 30, and the read address of the image memory 28 is controlled.

Since the shooting area Ho × Vo of the image pickup device 22, that is, the size of the TV screen, determines the cut-out range (read-out range from the image memory 28) of the display area h × v, and then the standard television signal. Therefore, the interpolation enlargement process needs to be performed, and the interpolation enlargement circuit 32 executes the interpolation enlargement process. Specifically, the expansion ratio Ho / h, Vo
Each pixel value is calculated by enlarging according to / v and performing weighted averaging by a coefficient inversely proportional to the distance between horizontal pixels and horizontal scanning lines.

However, when recording on a magnetic tape by the method described with reference to FIGS. 5 and 6, as described above,
The video signal of one field must be compressed into a period Tc shorter than the one-field period Tf. In the present embodiment,
The interpolation enlargement circuit 32 is designed to output a digital video signal compressed during the period Tc. Therefore, the interpolation enlarging circuit 32 has the horizontal direction Tf / Tc · Ho / h and the vertical direction Tf / Tc · Vo at the timing shown in FIG.
Data is read from the image memory 28 at a ratio of / v, data is interpolated at a ratio of h / Ho and v / Vo, respectively, and output at the timing shown in FIG. As a result, the interpolation expansion circuit 32 outputs the digital signal obtained by compressing the video data of the one-field period Tf into the period Tc to the D / A converter 34.

Needless to say, when the image stabilization is not performed, the image pickup area Ho × Vo of the image pickup element 22 becomes the display area as it is, and the interpolation enlarging circuit 32 only compresses Tf / Tc.

The user instructs the system control circuit 52 with the key 53 whether or not to perform image stabilization, and the system control circuit 52 controls the memory control circuit 30 and the interpolation enlarging circuit 32 in accordance with the instruction.

The D / A converter 34 converts the video data from the interpolation enlargement circuit 32 into an analog signal, and the recording processing circuit 3
6 performs recording processing such as FM modulation. Recording processing circuit 36
The output of is alternately applied to the double azimuth heads 42a and 42b of the rotary drum 40 for each field by the head changeover switch 38, and is recorded on the magnetic tape 44. The magnetic tape 44 is wound around the rotary drum over 300 °.

A drum motor 46 rotates the rotary drum 40, and a capstan motor 48 drives the magnetic tape 44 to run. The servo circuit 50 controls the rotation speeds and phases of the motors 46 and 48 to predetermined values.

FIG. 4 shows a block diagram of a reproducing system corresponding to the recording system shown in FIG. The same components as those in FIG. 1 are designated by the same reference numerals. The reproducing operation will be briefly described with reference to FIG.

Under the control of the servo circuit 50, the drum motor 46 rotates the rotary drum 40 at a predetermined speed and a predetermined phase, and the capstan motor 48 runs the magnetic tape 44 at a predetermined speed. The head changeover switch 38 alternately switches the outputs of the magnetic heads 42a and 42b of different azimuths and supplies them to the reproduction processing circuit 54.
The reproduction processing circuit 54 performs reproduction processing such as FM demodulation,
The compressed reproduced video signal is output during the period Tc shown in FIG. The A / D converter 56 converts the output of the reproduction processing circuit 54 into a digital signal. The output of the A / D converter 56 is written in the image memory 38 under the control of the memory control circuit 30. The video data written in the image memory 38 is expanded and read during the period shown in FIG.
The analog signal is converted by the D / A converter 58 and output to the output terminal 60.

The tape winding angle on the rotating drum is 3
Although the case of 00 ° has been described as an example, it is obvious that the present invention is not limited to this. Further, it is needless to say that the present invention can also be applied to the case where the time axis conversion process is performed by the VTR using the 180 ° opposite two-head type rotary drum or the four-head type rotary drum (270 ° winding) which is currently used in the commercial product. Absent.

An example has been described in which the image memory used for the image stabilization process for camera shake correction is also used for the compression process during recording.
Even an image memory for freeze recording of simple still image shooting and other image memories can be shared in the same manner.

[0022]

As can be easily understood from the above description, according to the present invention, since the image memory is shared, it is possible to prevent an increase in circuit scale and an increase in power consumption and reduce a load on the battery. Further, since the camera unit and the recording unit are directly connected by a digital signal, the D / A converter of the camera unit and the A / D converter of the recording unit can be omitted, and the quantization error, that is, the image quality deterioration can be reduced. There are also advantages.

[Brief description of drawings]

FIG. 1 is a configuration block diagram of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of camera shake correction.

FIG. 3 is a timing chart of compression / expansion according to the present embodiment.

FIG. 4 is a configuration block diagram of a reproduction system corresponding to the present embodiment.

FIG. 5 is a plan view of a rotary drum.

FIG. 6 is a compression timing diagram of a video recording apparatus using the rotary drum of FIG.

[Explanation of symbols]

10: rotating drum 12: magnetic tape 14a: plus azimuth magnetic head 14b: minus azimuth magnetic head 20: taking lens 22: image sensor 24: A / D converter 25: motion vector detection circuit 2
6: Camera signal processing circuit 28: Image memory 30: Memory control circuit 32: Interpolation enlargement circuit 34: D / A converter 36: Recording processing circuit
38: Head changeover switch 40: Rotating drum 4042a, 42b: Magnetic head 44: Magnetic tape
46: Drum motor 48: Capstan motor
50: Servo circuit 52: System control circuit 53: Key 54: Reproduction processing circuit 56: A / D converter 58: D / A converter 60: Output terminal

Claims (1)

Claim: What is claimed is: 1. A video recording apparatus comprising: a camera unit for digitally processing a captured image signal; and a recording unit for time-axis-converting a video signal and recording the video signal on a recording medium. An image recording device provided with an image memory shared between a digital signal processing of a recording section and a time base conversion processing of the recording section.