JPS59139778A - Video disk player - Google Patents

Abstract

PURPOSE:To reproduce a video disk of an ES system or NTSC system by a TV receiver of an NTSC or PAL system by providing a circuit which shifts a reproduced carrier color signal by a pi/4 phase only in a burst period. CONSTITUTION:When a disk of NTSC system is reproduced, a switch 13 is fixed at the (a) side and a pi/4 phase shifter 12 is bypassed. While the switch 13 is turned to the (b) side only in a burst period and otherwise at the (a) side when a disk of ES system is reproduced. As a result, only the burst signal is shifted by a pi/4 phase to obtain an NTSC signal. In such a way, the phase shifter 12, a switch 13 and a synchronizing separator are added to the NTSC or ES system. Thus, the reproduction and conversion of systems is made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a video disc player that allows reproduction signals from discs of different formats to be played back on a television receiver of the same format.

[Prior art]

Conventional CED video disc player (hereinafter referred to as VDP)
), when using an NTSC television receiver, only MSC format discs can be played.
S format discs cannot be played. Furthermore, when using a PAL television receiver, only ES discs could be played, but NTSC discs could not be played.

[Purpose of the invention]

The present invention has been made in order to solve the above-mentioned disadvantages in the prior art, and therefore, the purpose of the present invention is to reproduce signals from discs of different formats.
An object of the present invention is to provide a video disc player that can be played on a television receiver of the same system.

[Summary of the invention]

In order to achieve the above object, the present invention improves the conventional NT, SC
In the VDP VC,t- system, a circuit for shifting the reproduced carrier color signal by π/4 only during the burst period is provided, and is operated only when the ES system disk is reproduced.

A similar phase shift circuit is also provided in the ES FDP, and is operated only when reproducing an NTSC disc.

[Embodiments of the invention]

The present invention will now be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention. In the figure, 1 is a disk drive motor, 2 is a turntable, 3 is a disk, 4 is a hiccup, and 5 is an FM
Demodulator, 6 is a comb filter, 7 is a multiplier, 8 is a band pass filter (BPF), 91d is a 3.58MHz reference oscillator, 1o is a phase detector, 11 is a 5.111dEzV
cXO (voltage variable oscillator), 12 a 7 phase shifter, 13 a switch, 14 a synchronous separator, 15 an adder, and 16 a video output terminal.

In FIG. 1, a disc 3 is mounted on a turntable 2 connected to a disc drive motor 1, and a set rotation speed (450 rpm F, s for an NTSC disc) is set.
In the case of a disk, it is rotated at 675γ7+yn). On the other hand, a cartridge (not shown) is installed in the pickup 4, and the change in capacitance between the stylus tip of the cartridge and the disk is detected by the pickup 4, which modulates the F with video and audio.
Detected as M signal. The detected FM signal is demodulated by the FM demodulator 5 and converted to Buried Sub carrier Vid.
The eo signal is obtained and separated into a luminance signal and a carrier color difference signal by a comb filter 6. The carrier wave of the color difference signal is i,5'',M
Since the signal is low, 3.58 kfEz carrier color difference signal is obtained by multiplying by the output of 511 MHz VC'XO11.

In conventional VDP, N
I am getting a TSC video signal. However, in the case of an ES type disc, the signal format encoded on the disc is different as described below, so that a satisfactory reproduced image cannot be obtained.

Second, regarding the differences between the E, S method and the AITSC method. This will be explained using FIG. FIG. 2 is a vector diagram of an ES system signal, and FIG. 3 is a vector diagram of an NTSC system signal. The difference between the two is the phase of the BILrst signal, and if it can be shifted and summed by π/4, the ES system can be converted to the A7SC system.

When reproducing an NTSC format disc, the switch 13 is fixed to the α side and the π/4 phase shifter 12 is bypassed. This is the same as the conventional VDP. In the case of an ES type disk, the switch 13 is turned to the b side only during the burst period, and to the a side at other times.

By doing so, only the burst signal can be phase-shifted, resulting in an NTSC signal.

The advantage of the present invention is that it is possible to play back ES format discs in addition to the NTSC format by simply adding the π/4 phase shifter 12, the switch 13o, and the sync separator 14.

The disadvantage is that the horizontal and vertical scanning lines are not converted (50 vertical scan lines/sec, 625 horizontal scan lines/sec for ES discs, NTSC Halo 01525), so the synchronization is disrupted when playing back the ES disc. This can be played back by adjusting the TV.

FIG. 4 is a block diagram showing another embodiment of the present invention.

In the figure, 21 is a disk drive motor, 22 is a turntable, 23 is a disk, 24 is a pickup, 25 is an FM demodulator, 26 is a comb filter, 27 is a delay element, 28.38 is a multiplier, 29.37 .3
9.40 is each band bus fee (BPF)
, 30 π/4 phase shifter, 31.41 each switch, 32 synchronous separator, 63 4.43MEz oscillator, 34 phase detector, 35 5.951rfEz V
CXo, 36 is a multiplier, 42 is a frt/2 generator, 4
3 is an adder, and 44 is a video output terminal.

In FIG. 4, a disk 23 is mounted on a turntable 22 connected to a disk drive motor 21 and rotated at a predetermined rotation speed (450 t-pm for an NTSC disk and 375 t-pm for an ES disk).

On the other hand, the backup 24 includes a cartridge (not shown).
is installed, and the pickup 24 detects changes in the capacitance between the stylus tip of the cartridge and the disk as an FM (i number) modulated by video and audio. The skewed Buγ1ectVidto signal is divided into a luminance signal and a chromaticity signal by a comb filter 26. . This chromaticity signal has a carrier frequency of 1.52MHz.
4.4 so that it can be received on a PAL TV.
This is a CED format video disc system that converts to 3kflz.1. -, then, RCA special public service 1973
-4414. It is described in detail in Special Publication No. 53-11804, etc. Although it is an NTSC system, the above CE
f) The system player and disc have been on the market in the United States since June 1981 and are well known. Figure 4 is NTSC
PA type discs and ES type discs also have
FIG. 2 is a block diagram of a VAP capable of outputting an L video signal.

Before explaining the present invention, the ES system disc 1 will be briefly described. FIG. 5 is a signal vector diagram of the PAL system, and FIG. 6 is a signal vector diagram of the cEn-'p,s system. Generally, a video signal can be expressed by equation (1).

E,=Ey+Eg sin w t+Ey cos w
t - (1) where EM: video signal EY: luminance component EU: (B-Y) component of color signal Ev': -(R-1') component W: 2πfsc fvc: subcarrier frequency, PAL system Then, the first and second fields of even lines and the third and fourth fields of odd lines are EHn,=Ey+EUsinwt+Eycoswt
-(21 The first and second fields of the odd line and the sixth and fourth fields of the even line are E)471+1-! y1E(lsinwt-Eycos
wt - (31. This means that in Figure 5, equation (2) shows the solid line, and (3)
The equations are shown with broken lines. This is for each line (RY)
This means that the polarity of the components is reversed. On the other hand, the ES signal does not invert line by line, and the signal is
4) The formula is consistent.

EM,,,=EMn+1=EY-J-E(1sinwt
+Eycoswt -(41 In order to convert this signal to the PAL system, it is sufficient to invert the (RY) component, ie, Ercoswt, for each line.

FIG. 7 shows the case of the NTSC system. The only difference from FIG. 6 is that the burst phase is shifted by 45°, ie, π/4. Therefore, in order to convert an NTSC system signal to a PAL system signal, it is only necessary to shift the phase by π/4 during the period in which the co-host is inserted. If you do that, BS
The signal υ of the system can be similarly converted to the PAL system.

The method will be explained below using FIG. 4.

The chroma signal separated by the comb filter 6 is Btbr
itd, 5tbb cαγrier, so the frequency is i, 52MEz. This is 5.95M11z
It is multiplied by the output of the VCXO 15, passed through the BPF 29, and rejects the upper side band and carrier, thereby obtaining a 4.45 MIIz chroma signal of the lower side band. If the signal recorded on the disk is in the NTSC system, it is necessary to shift the phase by π/4 only during the burst period as described above, so the switch 31 is operated by the output of the sync separator 62 only during the burst period. Make sure that ES disk drive 1 is not operated. In order to obtain a PAL signal, it is necessary to invert the K(RY) group 2 for each line.

In an example of the present invention, a signal whose (RY) component is inverted,
A signal other than that is always prepared, and a PAL signal is obtained by a switch 41 that is switched for each line. (R
In order to invert only the -)') component, it is obtained by multiplying the frequency twice the fsc by the chroma signal using the multiplier 38. This method is described in German patent No. 11939.
It is known from No. 86. The chroma signal whose (P-Y) component is inverted for each line of the switch 41 is added to the luminance signal by an adder 43 to become a PAL video signal. The delay caused by the chroma conversion circuit is adjusted by the delay element 27 to correct the difference between chroma and luminance. By the method described so far, it becomes possible to play back A'7'' SC discs, which conventionally could not be played in ES system FDPs.

However, the horizontal and vertical scanning lines are 7525 lines on 60 sheets for NTSC, 7625 lines for ES5o sheet,
When playing an h'rsc type disc on a general PALTV, although color is produced, vertical synchronization is disturbed and the vertical size becomes small. These can be played by adjusting the TV.

〔Effect of the invention〕

According to the present invention, video discs belonging to either the ES or NTSC system can be played back on an NTSC television receiver or a PAL television receiver, and the disadvantages of the prior art have been solved.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing one embodiment of the present invention, Fig. 2 is an ES system signal vector diagram, Fig. 3 is an NTSC system signal vector diagram, and Fig. 4 is a block diagram showing another embodiment of the invention. , Figure 5 is a PAL signal vector diagram, Figure 6 is a BS signal vector diagram.
FIG. 7 is an NTSC system signal vector diagram. Code explanation 1... Disc drive motor 2... Turntable 3... Disc 4...
Pickup 5... FM demodulator 6... Comb filter 7... Multiplier 8... Band pass filter 9... 558 MEZ reference oscillator 10... Phase detector 11... 5.11M11ZVCXO 12 ...π/4 phase shifter 13...Switch 1
4... Synchronous separator 15... Adder 16...
・Video output terminal 21...Disk drive motor 22...Turntable 23...Disc 24
...Pickup 2.5...FM demodulator 26
...Comb filter 27...Delay elements 28, 3
8... Multiplier 29, 57.39.40... Bandpass filter 30
...π/4 phase shifter 31.41...switch 320. , synchronous separator 33...4.473M
H2 oscillator-34...phase detector 35...
5.95MHz VCXO36...multiplier
42... fH/2 Generator 43... Adder
44... Video output terminal representative patent attorney Akio Takahashi * 1 Figure) 2 Figure 2 Paper 30 Hiroshi 4 Figure ! 5 times

Claims (1)

[Claims] 1) A video disc player that allows playback signals from discs of different formats to be played back on television receivers of the same format, and a phase shifter that shifts the reproduced carrier color signal by a predetermined phase and outputs it. When it is on, the color signal bypasses the phase shifting means during the burst period of the reproduced signal, and when it is off, the switch is always in a fixed position and does not switch, and the set disc is switched. A video disc player characterized by comprising means for turning the switch on or off depending on the type of system.