JPH0623107Y2 - Video signal storage - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a video signal storage device for storing a composite video signal used in various video equipment such as a TV or a VTR, and in particular, converting a video signal into a digital signal. The present invention relates to a video signal storage device capable of obtaining a still image of these video devices by writing and reading in a memory.

[Conventional technology]

In recent years, in the consumer VTR industry, a technique for obtaining a still image by applying a memory has received attention because it can form a still image without a noise bar.

This technology uses 1152K (= 64K x 18) as a memory
This is a method for storing 1-field information of a video signal by using a bit capacity and performing 6-bit composite coding of the video signal at a sampling frequency of 3 _SC ( _SC : color subcarrier frequency).

With this method, one field (262.5
H) image data is stored. At the time of reading, by adding a signal read continuously and a pseudo vertical sync pulse which is several lines ahead of the vertical sync signal, 262 lines and 263 lines are provided for each field. Is a method of correcting the occurrence of 0.5H skew by generating a signal that repeats.

A VTR equipped with a conventional video signal storage device having this video signal storage system can realize a still image without a noise bar without changing the tape running speed or using a special head, and the effect is great. Also, the conventional video signal storage device has a higher function and more versatility because the conventional video signal storage device has a gate array of a digital controller and a general-purpose DRAM is used as a memory. It has many advantages.

[Problems to be solved by the invention]

However, the above-mentioned video signal storage system of the conventional video signal storage device is constructed by adding a signal continuously read at the time of reading the memory and a pseudo vertical synchronization pulse which is advanced by several lines from the vertical synchronization signal. 2 for each
Since the signal of repeating 62 lines and 263 lines, the vertical synchronizing signal of this still video signal becomes a pseudo signal, and it is standard when this still video signal is to be stored in another VTR, for example. There was a problem in its operation because it does not have the sync signal of.

[Means for solving problems]

The video signal storage device of the present invention is a video signal storage device for storing one field of a composite video signal, the information of the first field including vertical synchronization signal information and horizontal synchronization signal information, and at least the first field. A field memory for storing information of a second field including vertical synchronization signal information of vertical synchronization 9 lines;
The write control to the field memory is performed, and after reading all the information of the first field, reading of the vertical synchronizing signal information of the second field and reading of information other than the vertical synchronizing signal information of the first field are performed. After that, a pulse generator for controlling so as to return to the reading of all information in the first field.

[Action]

According to the present invention, as information to be stored in the memory, all of one field (provisionally A field) and the other field (provisionally B field, A + B = 2n−
1, B-A = 1 (n is a natural number). 9) in the vertical synchronization period of FIG. 3), the signal C other than the vertical synchronization signal of the A field is read twice when reading, and the vertical synchronization signal of the A field and the vertical synchronization signal of the B field are used as the vertical synchronization signals. And are read alternately and this is signal C
By combining with, one frame is configured to form a still image.

〔Example〕

Hereinafter, a video signal storage device according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of essential parts showing an embodiment of a video signal storage device according to the present invention.

Referring to FIG. 1, a video signal storage device according to an embodiment of the present invention includes a composite sync signal S from a composite video signal 1 input thereto by a sync signal / burst signal separation circuit 2.
y and the color burst signal _SC are separated by horizontal sync and vertical sync clock generating circuit 9, a horizontal synchronizing signal H _D, a vertical synchronizing signal V _D, the sampling clock signal 3
_SC is configured to output a 40 multiplying signal 40 _H (color burst signal _SC synchronized) and a horizontal synchronizing signal _{H D.}

Further, the pulse generator circuit 10 of the video signal storage device according to one embodiment of the present invention includes a horizontal synchronizing signal H _D , a vertical synchronizing signal V _D , a sampling clock signal 3 _SC, and a 40-fold signal 40 _H of the horizontal synchronizing signal H _D. The required timing is created in the field memory 5 by each.

On the other hand, the video signal 1 is sync-tip clamped by the sync signal / burst signal separation circuit 2 and is A by the sampling clock SC ₁ generated by the pulse generator circuit 10.
It is converted into a digital signal 4 by the / D converter 3.

Field memory 5 of the video signal storage device of this embodiment
Is continuously supplied with the digital signal 4 and continues to write data until the read / write control circuit 11 enters the read mode (corresponding to the still image output mode). During data writing, digital signal 4
Passes through the field memory 5, is converted into an analog signal by the D / A converter 7 by the sampling lock SC ₂ generated by the pulse generator circuit 10, and becomes the output video signal 8.

In the data read mode, the field memory 5
Is stopped, the data written immediately before that is read, and the read data becomes a still image.

Next, a second conceptual diagram of storing and reading a video signal
Referring also to the drawing, when the field memory 5 of the video signal storage device of this embodiment is stored, for example, the vertical sync signal of the odd field, which is the period A from 1 line to 272 line, and the even field that follows it. Are stored in the field memory 5. At the time of reading the field memory 5 of the video signal storage device of this embodiment, the period B from line 273 to line 525 is not stored in the field memory 5, so this period B is 11 of period A.
Substituting from line to 262 line. Where 27
The reason why 11 lines are used instead of 3 lines is to provide continuity in the transfer of color subcarriers.

As a result, one frame of the video signal 1 can be read continuously, and a still image can be formed.

Next, the configuration of the field memory 5 of the video signal storage device according to the embodiment of the present invention will be described with reference to FIG.

Since the levels of the sync signals of the video signals of the video signal storage device of this embodiment are all constant as sync-chap levels, the field memory 5 does not need to store the sync signals of this video signal and the period D shown in FIG. Corresponds to this.

The field memory 5 has memory cells 12 of 272 rows × 66.
The number of columns is 0, and one row corresponds to a horizontal scanning line. The information C for one line of the video signal is stored in one row of the memory cell 12, but this period D requires a minimum time of 63.556-2.2 = 61.356 (μsec). D is sampling clock 3
_{Since it corresponds} to 658.9 _SC cycles, 659 bits are required in the column direction of the memory cell 12.

By storing the synchronization signal information and the video information in the memory cell 12 of the field memory 5 of this configuration and designating a row at the time of reading, it becomes possible to read an arbitrary line.
It is possible to easily specify a signal to substitute for the period B shown in the figure.

[Effect of device]

According to the video signal storage device of the present invention described in detail above, it is possible to give a still video signal a standard synchronizing signal, and it is possible to apply such as interlaced output to a TV monitor or recording to a VTR. effective.

In addition, as the memory capacity, 272 × per 1-bit encoding
659 = 179,248 bits are required, which is the memory capacity of the memory used in the conventional method ((3 × 455 /
2) × (525/2) = 179156 bits), there is no difference, and there is an effect that it is possible to easily achieve that the still video signal has a standard synchronizing signal.

[Brief description of drawings]

FIG. 1 is a block diagram of a main part of a video signal storage device according to an embodiment of the present invention, FIG. 2 is a conceptual diagram of storage and reading of a video signal, and FIG. 3 is a video signal storage device according to an embodiment of the present invention. It is a block diagram of a field memory of. 1 ... Composite video signal, 2 ... Sync signal / burst signal separation circuit, 3 ... A / D converter, 4, 6 ... Digital signal, 5 ... Field memory, 7 ... D / A converter, 8 ... Output video signal, 9 ... Horizontal synchronization / vertical synchronization / clock generation circuit, 10 ... Pulse generator circuit, 11 ... Read / write control circuit, 12 ... Memory cell.

Claims (1)

[Scope of utility model registration request] 1. A video signal storage device for storing one field of a composite video signal, wherein information of a first field including vertical sync signal information and horizontal sync signal information, and at least 9 sync lines of vertical sync following the first field. Field memory for storing the information of the second field including the vertical synchronization signal information of the second field, and writing control to the field memory and reading of all the information of the first field, and then the vertical synchronization of the second field. Readout of signal information Further, a video signal comprising a pulse generator for controlling to return to reading of all information of the first field after reading information other than the vertical synchronizing signal information of the first field Storage device.