JPH0584109B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a disc-shaped information recording medium reproducing method,
Provided is a disc-shaped information recording medium reproducing method capable of reproducing frame programs with good vertical resolution using a reproducing device provided with two field memories as memories when reproducing a disc-shaped information recording medium in which a field program and a frame program are mixed. The purpose is to

The present applicant previously applied for a patent application in Japanese Patent Application No. 57-67816 titled "Digital Signal Recording System" and Japanese Patent Application No. 57-67816.
No. 67818 patent application ``Digital Video Signal Recording System,'' etc., involves digital pulse modulation of an analog video signal to generate a digital video signal, which is pixel data for each pixel arranged in a matrix on the screen, and to record this signal on a recording medium. We proposed a method for recording data.

In this method, a digital video signal related to color still image information is added as additional information to a digital audio signal and recorded as changes in a series of intermittent pits on the same track on a disk. On the other hand, this pit row is detected as, for example, a change in capacitance, and the recorded signal is read and reproduced.
The structure of one frame of a digital video signal recorded on a disk using this recording method is as shown in _FIG .
H ₂ , . . . and 16-bit, 684-word encoded video signal portions V ₁ , V ₂ , . . . are alternately synthesized in time series.

In particular, the configuration of the header sections H ₁ , H ₂ , . . . is as shown in FIG. 2, including a synchronization signal section S for indicating the start of the header signal, various identification code sections F, and an address signal section for pixel data memory. F etc. are synthesized.
The identification code section E contains an image information amount identification code "FR/
FL” (one frame when the value is “1”, one field when the value is “0”), a memory that specifies the write and read modes of the two memories provided in the playback device. Mode designation code "B19W""B19R" (When both values are "0" (or "1"), write pixel data of the digital video signal to the first (or second) memory,
Then, the stored data is read out and displayed on the screen. On the other hand, when "B19W" is "0" and "B19R" is "1", pixel data is written to the first memory, pixel data read from the second memory is displayed, and the pixel data read from the second memory is displayed. After the write operation is completed, the front screen is switched from the second memory to the first memory by the EOD signal.
Further, when "B19W" is "1" and "B19R" is "0", the pixel data read from the first memory is displayed while writing the pixel data to the second memory, contrary to the above. ) etc.

Here, as shown in FIG. 3A, for example, video signal program A for one field, program B for one frame (program B ₁ for one field),
and program B ₂ for one field),
There is a disk in which frame information and field information are mixedly recorded on one disk, such as one field's worth of program C being intermittently recorded. In such a disk, as shown in Figure B, the code "FR/" in the header section for program A is "0", the code "FR/" for program B is "1", and the code "FR/" for program C is "0". is recorded as "0", while the code for program A is "B19R"
is "1", "B19W" is "0", code "B19R" for program B is "0", "B19W" is "0", code "B19R" for program C is "1", "B19W" is "0" is recorded.

When playing back a disc on which video programs A, B, C and each code are recorded in this way,
A playback device shown in FIG. 4 is used. Since the method of the present invention is intended for an inexpensive playback device having two field memories as memories, the description will be made using the cheap playback device in this case as well. The reproduced signal taken out from disk 1 is demodulated by FM demodulation circuit 2, and the demodulated digital signal is sent to decoder 3.
After MFM decoding, the digital audio signal is converted into an analog audio signal by the DA converter in the decoder 3 and taken out from the output terminal 4.

On the other hand, the digital video signal taken out from the decoder 3 is supplied to a scanning line number exchange circuit 5, where the number of scanning lines is converted from 625 to 525. Further, the output signal of the decoder 3 is supplied to a header section detection circuit 6, where each code in the header signal is discriminated and supplied to a control circuit 7.
The output of the scanning line number conversion circuit 5, memory write controller 8, switch circuit 9, and switching circuit 10
is controlled.

The output signal of the scanning line number conversion circuit 5 selectively outputted by the switch circuit 9 is supplied to either the field memory 11 or the field memory 12, and here, according to the write control signal from the memory write controller 8, the Data is sequentially written to addresses specified by address signal B.
Field memories 11 and 12 have the code “B19R”,
Playback pixel data is written alternately one field at a time according to "B19W".

The digital video signals written in the field memories 11 and 12 are sent to the memory read controller 1.
3 are simultaneously read out based on the readout control signals from 3 and supplied to the switching circuit 10. Switching circuit 10
selects and outputs the read output of one of the field memories 11 and 12 according to a switching control signal from the control circuit 7, and the selected output signal is output to the DA converter 1.
4 and converted into an analog video signal. The analog video signal is supplied to an encoder 15,
Here, a color video signal conforming to the NTSC system is generated using horizontal and vertical synchronization signals, a color burst signal, etc., and is outputted from an output terminal 16.

By the way, this disk has the period "B19R" of field programs B ₁ and B ₂ as shown in Figure 3B.
Since the value of "B19W" does not change for each field and does not change over one frame, if played as is using the playback method proposed earlier by the applicant, the memory 1
1 continuously writes programs B ₁ and B ₂ for one frame, while memory 12 only reads them continuously, and as a result, the field program
By writing _B2 , the field program _B1 one field before is erased. That is, as shown in FIG. 3C, program A is program B.
and program C is repeatedly played back for each field until the next program is reached and displayed on the screen (in this case, the display of program A is the field program written in the memory 11 at time _t1 ). A is displayed by repeatedly reading each field from the memory 11 using the code "FR/" of "0", while program C is displayed using the field program C written to the memory 11 at time _t3. (This is done by repeatedly reading each field from the memory 11 using the code "0" of the code "FR/"), and for the program B, the field program B _{2 is}
only is played repeatedly for each field (in this case, the display of program B ₂ is the same as that of field program B ₂ written to memory 12 at time t ₂
is memory 12 due to “1” of code “FR/”
(This is done by repeatedly reading out each field over one frame.)

In this way, in the playback method proposed earlier by the applicant, even though there is frame program B,
The problem is that only half of the frame information can be reproduced and the vertical resolution is poor.

The present invention solves the above problems, and one embodiment thereof will be described below with reference to the drawings.

The reproducing method of the present invention alternately reproduces field programs B ₁ and B ₂ one field at a time, especially when reproducing frame program B, when reproducing a disc on which each signal as shown in FIG. 3A and B is recorded. .

During playback, as shown in FIG. 3E, during playback of each field of field program A, at time _t2 , the header section detection circuit 6 in FIG. 1" is played, and at the same time, "1" of the code "FR/" is played. As a result, a predetermined control signal is taken out from the control circuit 7 to control the memory write controller 8, and the outputs of the memory write controller 8 and the memory read controller 13 cause the memory 1
1 and 12 are controlled so that one of them is in the write mode and the other is in the read mode so that they are inverted for each field.

That is, as shown in FIG. 3D, the code "B19R" is "0" in program _B1 , as if it were written on the disk.
"B19W" is "1", and in program B ₂ , code "B19R" is "1", and "B19W" is "0" (that is, frame program B is recorded as field program B ₁ and field program B and ₂ and are controlled as if separate memory mode designation codes were recorded in each field program).

First, in the first field, program B ₁ is written to memory 12 and at the same time program A is read by memory 11, and in the next field, program B ₂ is written to memory 11 and program B ₁ is read out by memory 11 at the same time. It is read out by memory 12. In this case, at time _t2 , reading of program A from memory 11 ends, and reading of program _B1 from memory 12 begins. This results in
As shown in FIG. 3E, this period is a period during which the reproduction screen of program A is transferred to the reproduction screen of program _B1 , and this generally takes about 2.2 seconds.

When this screen transition period ends, the memory 11,
12 is repeated by reversing the write mode and the read mode for each field, and as a result, the third
As shown in Figure E, field program B ₁ and field program B ₂ are displayed alternately on the screen,
As shown in FIG. 3C, the frame information can be completely reproduced compared to the reproduction method in which the field programs B ₁ and B ₂ do not change at all over one frame.

“1” and “B19W” of code “B19R” at time t ₃
With "0", the program _B2 written in the memory 12 is read out and displayed on the screen.

As described above, similar reproduction may be performed not only when transitioning from a field program to a frame program but also when transitioning from a frame program to another frame program.

By the way, pixel data can be pixel data of two adjacent scanning lines (that is, pixel data of two rows of pixel groups arranged horizontally) (horizontal feed method), or pixel data of about 2 to 10 columns arranged vertically. It may be pixel data of adjacent pixel groups (vertical feed method). In this case, according to the former method, the reproduced image gradually appears from the top to the bottom of the screen, while according to the latter method, the reproduced image gradually appears from the left to the right side of the screen.

Note that the pixel data of frame program B may be divided as in the above embodiment, in which program B ₁ is the data of the first field and program B ₂ is _the data of the second field. The data on the left half of the screen and program B ₂ may be the data on the right half of the screen.
In such a vertical feed method, the transition from program A to program B at time _t2 may be configured such that program B appears so as to spread from the center of the screen to both left and right sides. Generally, the main image is often located near the center of the screen, and if this is done, the main image portion of program B will appear quickly and naturally.

As described above, the disc-shaped information recording medium reproducing method according to the present invention digitally pulse-modulates an analog video signal of image information to reproduce one field, which is a time-series signal of pixel data corresponding to each pixel constituting one screen. The digital video signal of 1 frame and the pixel data constituting one screen are essentially divided into two, and the digital video signal of 1 frame is recorded in chronological order for each of a plurality of different programs. Image information that records a memory mode designation code that designates the field memory in pixel data write mode or pixel data read mode, and identifies whether the digital video signal to be transmitted is for one frame or one field. When playing back a disc-shaped information recording medium on which a quantity identification code is recorded, if a memory mode designation code and an image information quantity identification code for one frame are detected, playback from one frame's worth of program to the next program is performed. During the period, one of the two field memories is in the write mode and the other is in the read mode, so that they are alternately inverted every field, and the program for one frame and the digital video signal for one frame constituting one screen are controlled. Since pixel data that is essentially divided into two parts is reproduced by alternately reading each field, a low-cost reproduction device equipped with two field memories can store, for example, two fields' worth of data on a disk. It is possible to completely reproduce one frame of a frame program recorded as pixel data, and even though the program for two fields has been recorded, only one
Compared to the case where the frame period memory mode designation code is not changed, this method has the advantage of being able to reproduce images with higher vertical resolution and of higher quality.

[Brief explanation of the drawing]

1 and 2 are diagrams schematically showing the structure of one frame of a digital video signal recorded using the method previously proposed by the applicant, and the main part of the header signal in FIG. 1, respectively. A diagram showing the format,
Figures 3A and 3B show the programs, various identification codes, and
Figure C is a diagram schematically showing a program reproduced by the reproduction method previously proposed by the applicant, and Figure D is a diagram for illustrating a pseudo code of a disc reproduced by the reproduction method of the present invention. Figure E is a diagram schematically showing a program reproduced by the method of the present invention.
FIG. 4 is a block system diagram of a reproducing apparatus used in the reproducing method previously proposed by the present applicant and the reproducing method of the present invention. 1...Disk, 3...Decoder, 6...Header section, 7...Control circuit, 8...Memory write controller, 11, 12...Field memory, 1
3...Memory read controller, 14...DA
Converter, 16...Output terminal, FR/...Image information amount identification code, B19R, B19W...Memory mode specification code, A, C, _B1 , _B2 ...Field program, B...Frame program.

Claims (1)

[Claims] 1 Digital pulse modulation is applied to an analog video signal of image information to generate one field's worth of digital video signal, which is a time-series signal of pixel data corresponding to each pixel constituting one screen, and pixel data constituting one screen. The divided one-frame digital video signal is recorded chronologically for each different program, while the two field memories provided in the playback device are designated as pixel data write mode and pixel data read mode. A disc-shaped information recording medium having a memory mode designation code recorded thereon and an image information amount identification code identifying whether the transmitted digital video signal is for one frame or one field is played back. When doing so, the memory mode designation code and the 1
When an image information amount identification code for a frame is detected, one of the two field memories is in write mode and the other is in read mode, alternately for each field during the playback period from the program for one frame to the next program. Control so that it is reversed, and
A disc-shaped information recording medium reproducing method characterized in that a program for a frame is reproduced by alternately reading out the pixel data divided into two for each field.