JPH0646818B2 - High-quality still image playback system - Google Patents

Description

The present invention relates to a high-quality still image reproducing circuit for a video disc reproducing system.

(B) Conventional Technology In a conventional optical video disc player, a track for recording a video disc record having a constant angular velocity is repeatedly track-jumped by one track for each rotation, and one frame of one frame recorded on the same track is repeated. Continuous playback of video signals enables still image playback (Japanese Patent Publication No. 54-154).
See No. 85).

However, in the case of a video disc record with a constant linear velocity,
Although the same frame cannot be continuously reproduced and the recording / reproducing time can be lengthened, it is difficult to reproduce a still image.

(C) Object of the invention The present invention is a video disc player for reproducing a high-definition video signal, and a high-definition still image reproduction of a video disc reproduction system capable of reproducing a still image regardless of the disc record recording method. It proposes a circuit.

(D) Configuration of the Invention The present invention is characterized in that the storage operation of the field memory used for synthesizing a high-definition video signal is interrupted to repeatedly derive the same high-definition video signal with the same stored information. .

(E) Example Hereinafter, the present invention will be described with reference to an example.

First, the video disk recorder for creating a video disk record with a constant linear velocity used in this embodiment is provided with the circuit shown in FIG.

First, the high definition video signal is input to the TCI encoder (1). This TCI encoder converts a color signal into a line-sequential signal, precedes the luminance signal by 4H (H is a horizontal synchronization period), and compresses the time axis to ¼ to temporally compress the color component in the horizontal blanking period. Axial compression is multiplexed. (TEBS 91-5 “Technical Report on Television Science” issued on October 20, 1983) The encoded output is input to the sub-sample filter (2) and the phase is switched by π / 2 for each field 16.2MH
The encoded output is sampled by the z sampling pulse and the encoded frequency band of about 20 MHz is converted to about 8 MHz to realize a multiplexed sub-sample. (Showa 59
Part 6 of the encoded output is the motion vector detection circuit (3)
Is also input to detect the motion of the entire screen (panning or Telt) and vector-encodes the direction to derive the motion correction signal.

In addition, a part of the multiplexed sub-sample output is input to the motion block detection circuit (4) and is obtained by detecting the presence or absence of motion in each block obtained by dividing the screen in the horizontal direction 16 and the vertical direction 32. A troll signal is derived.

On the other hand, the audio signal is input to the audio encoding circuit (5), time-axis compressed within the vertical blanking period and then encoded into three values to be derived as a PCM audio signal.

When a stop command output is issued during the recording period, the stop code generation circuit (6) issues a stop code signal at a timing slightly preceding the PCM audio signal.

The wideband video signal, the motion correction signal, the block control signal, the PCM audio signal, and the stop code signal obtained by the multiplexed sub-sample are input to the multiplexing circuit (7).

The 8.1 MHz multiplexed signal is input to the FM modulation circuit (8) having a frequency shift range of 14 to 16 MHz. This FM modulated wave is recorded on the video disc as an information signal.
Only the band of 4 to 16 MHz including the frequency shift region and the first lower sideband (6 to 14 MHz), which is necessary for recording and reproducing without deterioration, is derived via the first band pass filter.

The high-definition video signal is limited in allowable residual jitter to 2 nsec or less as compared with a normal color video signal. Therefore, the residual jitter cannot be limited to 2 nsec or less even if the jitter correction is performed at the horizontal synchronization cycle of 1 / 33.75 × 10 ³ (= 1 / _H ) sec. Therefore, it becomes necessary to detect the jitter at the horizontal synchronization period or more.

Therefore, it becomes necessary to superimpose a pilot signal having a horizontal synchronization period or more on the information signal. However, if a frequency-multiplied output of the horizontal synchronization cycle or a frequency close to it is used as the pilot signal, striped beat noise becomes conspicuous. Therefore, in this embodiment, the pilot signal frequency _P and the horizontal synchronizing frequency _H are set to _P =
(N + 1/2) _H is selected as an interleave relation.

With this 1/2 interleave frequency, 1125 horizontal scanning lines make up one frame, and if one frame is recorded on one track of the apex recording track, as long as two tracks are jumped, the pilot signal will drop out during the jump period. However, the phase is continuous.

Therefore, in the present embodiment, in view of the fact that the fixed oscillator of the high-definition video camera is selected to 48.6 MHz, which is twice the color subcarrier 24.3 MHz, its fixed oscillation output is divided by 1/64 (10). Input the fundamental wave component 759.395KHz (45
_H 2/2) is taken out through the low pass filter (11).

The information signal and the pilot signal are input to the adding circuit (12), and the pilot signal level is set to -3 with respect to the information signal level.
Limiting to 5dB and adding.

The addition output is input to the limiter (13) and converted into a low and high binary signal.

This limit output is input to the optical modulation means (14) arranged in the optical system of the video disc recorder, and a recording track having a constant linear velocity is formed on the video disc record.

The signal recording system is the same as that of the well-known optical video disk recorder and will not be described.

Next, the circuit operation of the video disc player of this embodiment will be described.

The preamplifier (15) that inputs the pickup output outputs the amplified output to the high pass filter (16) and the second band pass filter.
You have entered in (17).

The reproduction pilot signal derived by the band-vest filter (17) is input to the jitter correction circuit (18). The jitter correction circuit (18) phase-compensates a jitter detection signal obtained by phase comparison with a reference signal and inputs it as a jitter correction output to a drive coil of a jitter correction mirror to realize jitter correction.

The playback pilot signal is sent to the disk servo circuit (19).
Also, the servo output obtained by comparing the phase of the divided output of the reproduction pilot signal with the reference signal is supplied to the disc motor to control the video disc record so that the linear velocity is constant.

On the other hand, the high-pass output separates the information signal including the first lower sideband and the frequency shift region, and is input to the FM demodulation circuit (20) and converted into the original wideband signal.

This wideband video signal is input to the wideband compression decoder described below.

First, this decoder inputs a wideband video signal into an AD conversion circuit and performs AD conversion.

The AD conversion output is normally input to the memory circuit (M). This memory circuit (M) has a capacity for accumulating 8 bits of AD conversion output for 4 fields, and updates old contents by AD conversion output that is sequentially input. In the figure, the memory circuit is divided into first to fourth memories (M1) to (M4) for convenience, the contents of the second memory (M1) are 4 fields before, the second memory (M2) is 3 fields before, It is assumed that the third memory (M3) stores the AD conversion outputs two fields before and the fourth memory (M4) stores the AD conversion outputs before the first field. A circuit for driving the memory is omitted in the drawing.

Each memory output is input to the synthesis circuit (22).

The synthesis circuit (22) inputs the detection output of the motion vector detection circuit (23) in order to store and store the motion correction signal for controlling the synthesis, and the first memory (M1)
And the output of the third memory (M3) are directly used, and complemented by the outputs of the second memory (M2) and the fourth memory (M4), the high-definition video signal of the field is stored in the first memory (M1). It is synthesized from past information separately from the (current) information being stored in. Therefore, when displaying a screen that does not move, this synthesized signal may be derived as it is.

However, there is movement in the actual screen, and it is necessary to adjust the mixture ratio of the current information being stored in the first memory (M1) and the accumulated information of four fields depending on the degree of the movement.

The past information, which is the criterion for judgment, is switched by the block control signal detected by the block control detection circuit (24), and in the case of a block having a large movement, the prediction circuit (25) which receives the third memory output as an input. The output is used, and in the case of a block having a small motion, the first memory output serves as a reference. That is, when the movement is large, the information two fields before is used as the reference, and when the movement is small, the information four fields before is used as the reference.

This switching is performed by the selection circuit (26) and compared with the current information in the mixing ratio setting circuit (27) to derive the mixing ratio setting output.

This mixing ratio setting output controls the mixing ratio of the present information in the mixing circuit (28) and the past high density composite information.

The mixed output is converted into an analog signal in the DA conversion circuit (29), converted into the original high-definition video signal in the TCI decoder (30) in the next stage, and is derived to obtain a high-definition television image. Input to the video input terminal of the machine.

The PCM audio signal is input to the audio synthesis circuit (31), time-axis expanded and DA converted, and then input to the audio input terminal of the high-definition television receiver.

The operation described above is the operation of a normal band compression decoder,
The features of this embodiment are as follows.

That is, when the stop code signal reproduced by being superimposed in the vertical blanking period is input to the stop code detection circuit (32), the detection output is input to the memory circuit (M) and a memory drive circuit (not shown). Discontinues the storage of the AD conversion output, and continuously reads out the same contents with each of the memories (M1) to (M4) being exclusively in the read state.
Continue to derive the high-definition video signal in the field immediately before the stop code is input.

Further, the detection output is input to the mixing ratio switching circuit (33), and the mixing ratio of the present information is defined as 0 in the mixing circuit (28). Therefore, the mixing circuit (28) will derive only the composite signal,
It is possible to project a clear, high-quality still image.

However, if the above-described operation is repeated every field, only one field can be combined, so that an interlace cannot be made on the screen and the screen becomes rough in the vertical direction.

Therefore, in this embodiment, one field and the other field are alternately formed at a field cycle to form an interlaced still screen, so that one of the fields mainly formed by the first memory output and the third memory output is formed. Field high-definition video signal, second memory output and fourth
The high-definition video signal of the other field mainly formed by the memory output is selectively derived for each field by an additional circuit provided in the synthesizing circuit (22).

Therefore, although it is not a perfect interlaced screen, it is possible to display a screen which is almost inferior to the perfect screen by the above-mentioned additional circuit.

(F) Effects of the Invention According to the present invention, still images can be reproduced even when reproducing a video disc record having a constant linear velocity as well as a constant angle, and the effect is great.

[Brief description of drawings]

FIG. 1 is a circuit block diagram of the video disc player of this embodiment, and FIG. 2 is a circuit block diagram of the video disc recorder. Description of main drawing numbers (M) …… Memory circuit, (22) …… Composite circuit, (32) …… Stop code detection circuit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Izumi ▲ Yoshi ▼ Nori 1-10-11 Kinuta, Setagaya-ku, Tokyo Inside the Japan Broadcasting Corporation Research Institute (72) Inventor Hideki Kokubun 1 Kinuta, Setagaya-ku, Tokyo Chome No. 10-11 Inside the Japan Broadcasting Corporation Research Institute (72) Inventor Yasuhiro Ishii 2-18 Keihan Hondori, Moriguchi City, Osaka Prefecture Sanyo Electric Co., Ltd. (72) Takeo Sotoyama 2 Keihan Hondori, Moriguchi City, Osaka Prefecture Chome 18 Sanyo Denki Co., Ltd. (72) Inventor Yoshihiko Morita 2-18 Keihan Hondori, Moriguchi City, Osaka Sanyo Denki Co., Ltd. (56) Reference JP-A-54-136806 (JP, A)

Claims (1)

[Claims] 1. A wideband video signal obtained by subjecting only a color signal of a high-definition video signal to time axis compression and band compression by a multiplexing sub-sampling method, and a stop code signal in advance during a vertical blanking period of the wideband video signal. And a wideband video signal is sequentially stored in a memory for four fields, and a high-definition video signal obtained by synthesizing read-out information from the memory is received by a high-definition television receiver. In a high-quality still image reproducing system to be input to a machine, a high-quality still image in which the storage operation of the memory is interrupted by detecting the stop code signal and the same read output continuously introduced from the memory is combined. A high-definition still image reproducing system, characterized in that an image signal is supplied to the high-definition television receiver.