JPS58151791A - Reproducer of video signal - Google Patents

Abstract

PURPOSE:To obtain a character screen with high resolution, even in case of a black-and-white character picture, by discriminating whether a reproducing video signal is a composite color video signal or the black-and-white video signal and transmitting the signal after eliminating a color burst signal, in latter case. CONSTITUTION:A reflected light on a disc 22 is separated at a half mirror 24, applied to a photodetector 26. An output signal from the detector 26 is applied to an FM detector 27, where it is demodulated as a reproduced video signal and applied to a time axis correction circuit 28. The reproducing video signal corrected at the circuit 28 without jitter is applied to a black-and-white signal discriminating circuit 29 and a burst eliminating circuit 30. When the signal from the circuit 28 is a composite color video signal, the output signal of the circuit 29 controls the circuit 30, and the composite color video signal is transmitted to an output terminal 31 as it is. Further, when the signal from the circuit 28 is the black-and-white video signal, the circuit 29 controls the circuit 30, the added color burst signal is eliminated and the black-and-white video signal only is transmitted to the terminal 31.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a video signal reproducing apparatus suitable for use in a video disk layer or the like for reproducing signals recorded on a recording medium such as a video disk.

Recently, video discs are expected to develop in many fields as a storage medium for all kinds of information, and one example of its application is the attempt to store the contents of encyclopedias on video discs. be. In this case, the luminance signal of the character screen generally includes high-frequency components and extends to around 3.58 MH1, so it is natural to extract and process the color components with a normal band-pass filter. When the luminance signal component jumps into the color signal system, a so-called cross-color phenomenon occurs, causing color blurring and making characters very difficult to read on a color monitor due to color noise.

This invention was made in view of these points, and it is possible to improve the clarity of character screens by removing color noise, and also to make it easier to apply video discs to encyclopedias, etc. The present invention provides a signal reproducing device.

Hereinafter, some embodiments of this invention will be described in detail in Figs. 1 to 5. Fig. 1 shows the configuration of the recording system used in this device. For example, the 1-e-no is divided into a predetermined number of frames, for example, 15 frames, and the contents are firstly photographed with a video camera and recorded on a magnetic recording medium. Then, this recording medium is loaded into the m collector (1), and the horizontal synchronizing signal generator (2) and vertical synchronizing signal generator (3)
A composite video signal is obtained on the output side in response to horizontal synchronization signals and vertical synchronization signals from. The output signal from the editing machine (1) is supplied to the FM modulator (5) via the switch circuit (4), which FM modulates the carrier wave signal supplied from the terminal (6) and supplies it to the optical system (7). be done. This FM
The changed signal is sent to the optical converter iS1# (8) of the optical system (7).
This @i sound wave signal is mutually interfered with the laser light from the radar light source (9) and undergoes optical modulation. The output signal from this optical modulator (8) is reflected by the reflecting mirror (g) and converged by the optical lens (0)) onto the disk (s) rotating around the rotation axis (s). recorded in

In addition, 04 is a code (g number generator). In this invention, as will be described later, as a method for determining whether the reproduced video signal is a composite color video signal or an incandescent video signal, the recording side uses a special code in the video signal. In other words, at the leading edge of the signal format for each field of the distribution signal, for example, for each V!, 21st H, a 24-bit code is inserted, depending on whether it is a composite color video signal or a black and white video signal. Discrimination code expressed as a pinary code, FFFFF
Enter F' (color) and 8FOF80 (black and white). Therefore, this discrimination code is generated by the code signal generator α♦ during recording. The color signal code and monochrome signal code from the code signal generator α♦ are respectively supplied to a switch circuit (G) K, and are switched by a color/black and white discrimination signal from the editing machine (1).

That is, when the switch circuit () is connected to the terminal 1 side, the color signal code is taken out, and when it is switched to the contact side, the black and white signal code is taken out. And the output signal from this switch circuit (c) is the switch circuit (
4) is supplied to the terminal side. Switch circuit (4) is 2
It is switched every 21st H of each field by a signal from the 1Hr-) signal generator (G). 21H) 1'-G signal generator (G) outputs its output #JK each field in response to the horizontal synchronization signal from the horizontal synchronization signal generator (2) and the vertical synchronization signal from the vertical synchronization signal generator (3). 21H of
A signal for switching the switch circuit (4) is output for each eye. Therefore, when the switch circuit (4) is at the contact a@, the image signal from the editing machine (1) is taken out, but when it is at the contact b@, the code signal generator a
Code from 4 is supplied. That is, a code signal for color/black and white discrimination is inserted for each field 211 in the Eirin signal.And these code signals are also recorded on the disk (1) in the same manner as the Eirin I and No. 1 mentioned above. Ru.

Figure 2 shows the reproduction system of this device, in which the beam from the laser light source (C) is placed on the 8-7 mirror (H) on a disk that rotates around the rotation axis t2η in the optical system (E). ) and a converging lens (c), and is imaged as a spot on the disk. And this spot V
The reflected light is reflected on the optical disc) and returns to the half mirror (c) via the converging lens (c), where the reflected light is separated and supplied to the photodetector (c). When the condensation spot hits the flat reflective surface on the disk (2), the reflected light is approximately 1
The light returns to 00, giving information to the photodetector that it is on. On the other hand, if the imaging spot just hits a concave or convex part of the reflective surface on the disk (2), the light will be scattered and the original path difference w'i will be absorbed. ) and the portion that returns to the photodetector (c) through the mirror (c) is drastically reduced and turns off. In this way, signals can be read without contact with light beams using a very simple optical imaging system.

The output signal from the photodetector (c) thus read is F
After being supplied to the M demodulator and demodulated as a reproduced video signal, it is supplied to the time axis correction circuit. Normally, in a video disc player, time axis correction is performed using a color burst signal, so it is not possible to remove the color burst signal at the video disc editing stage. In other words, a color burst signal is always required, regardless of whether it is a full-color image signal or a black-and-white video signal.

This time axis correction circuit (c) has a configuration as shown in FIG. 3. In FIG. 3, the horizontal synchronization signal is extracted from the reproduced video signal in the horizontal synchronization separation circuit (28m) and supplied to the phase comparator (28b).
After comparing the phase with the horizontal synchronizing signal which becomes s, and converting the comparison error signal to 1ljlEi No. 8 by a low/9 filter (28e), this DC signal is passed through an adder (28d) to a clock generator (28s ) K is supplied, and the clock signal from the clock generator (28) is changed to 1 according to the difference, and this clock is supplied to a delay circuit (28f) consisting of, for example, a CCD or BBD, and its delay 11 ' is changed by oJ, thereby increasing the coarse adjustment I) of time axis error correction. In addition, a color burst signal is extracted from the output signal of the delay circuit (28f) in the burst r-) circuit (28g), and is supplied to the phase comparator (28h) to be compared with the basic carrier signal, and the comparison error signal is is converted into a DC signal by a low/mother filter (281), and then sent to a clock generator (28e) via a compensator (28d).
) K is supplied, and the delay of the delay circuit (28f) is changed by 1 degree by changing the number of 0's that occur as described above. This K allows further fine adjustment of the time axis error correction. Therefore, at the output side of the delay circuit (2sr), a reproduced video signal corrected with no jitter is taken out.

The reproduced video signal whose jitter has been corrected in this manner is supplied to a color/monochrome signal discrimination circuit (e) and a burst removal circuit (to). If the reproduced video signal from the time axis correction circuit is a composite color video signal, the discrimination circuit controls the burst removal circuit (to) using the output signal and sends the composite color video signal as it is to the output terminal 0p. On the other hand, if the reproduced video signal from the time axis correction circuit (c) is a black-and-white video signal, the discrimination circuit controls the color burst removal circuit (g) with its output signal to add it to the black-and-white video signal. Remove the color burst signal that is
Send only black and white video signals to output terminal 0.

The signal from this output terminal 01 is supplied to a monitor, etc. (not shown), and even if the screen on the monitor is text and trenches, color noise disappears, the text on the screen becomes glossier, and its resolution increases. . In addition, 2) is equipped with a KN' modulator, which modulates the carrier signal of an empty television channel, such as channel I@2, supplied from the terminal (to) to FM using the output signal from the burst removal circuit (1), and outputs it. Terminal-
In this way, the same signal as the radio waves tuned to the second channel described above is obtained.

Figure 4 shows an example of a specific circuit configuration of the color and black and white signal discrimination circuit. This is a case where it is determined whether the reproduced video signal is a composite color video signal or a monochrome video signal. That is, in FIG. 4, the synchronization separation circuit←p separates the horizontal synchronization signal from the reproduced video signal from the time axis correction circuit, and converts this horizontal synchronization signal into the 21H87'''-to signal generator aQ similar to the above-mentioned 21H87''-to signal generator aQ.
-) supplying a signal generator to the 21
) 1st and Kr-totes, and also supplies the reproduced video signal from the time axis correction circuit (c) to the date circuit, and generates the 21st h of each field according to the r- signal from the generator (14). The reproduced video signal is extracted every time and is fed to the code signal sequence yilj (is4).Then, it is determined from the code whether the input reproduced video signal is a composite color code or a black and white video signal. After that, this discrimination signal is sent to the burst removal circuit (
Supplied to the - input terminal of 1). On the other hand, the horizontal synchronization signal from the synchronization separation circuit α is supplied to the burst f-) signal generator, and the pulse input synchronized with the horizontal synchronization signal is
-) signal and feed it to the other input of the burst removal circuit (to). If the output signal of the code signal discriminator indicates a composite color video signal, parse) r-
) The burst removal circuit (1) is controlled by the burst dirt signal from the signal generator (-) so that the reproduced video signal from the time axis correction circuit (c) is output as is. on the other hand,
When the output signal from the code signal discriminator specifies a black and white video signal, the parse) f-) signal from the generator Sakaki controls the ruburst removal circuit (1) and outputs the f-) signal only during the color burst period. In other words, the color burst signal added to the black and white video signal from the time axis correction circuit is removed from the black and white video signal.

FIG. 5 shows another example of the specific circuit configuration of the color and monochrome signal discrimination circuit 4 in FIG. 2. That is,
Figure 5 shows the IH delay circuit (46m) and the L unit (46m).
A comb-type filter consisting of b) is provided, and the filter detects the combined color signal sound, and the output signal of this filter is passed through a gradation filter @1j and supplied to a level detector.

In this level detector, when the level of the output signal from the band/mother filter is higher than the reference value, it is regarded as a composite color image signal, and the time axis correction circuit The 11# signal from (c) is output as is from the burst removal circuit (to), while when the level of the output signal from the parallel filter nl> is below the reference value, it is output as a black and white video signal. Consider,
Burst removal circuit (to) K, burst r-) Parse from Ig generator -) f-) Try to remove the burst signal gold.

According to the above v(4), it is determined whether the reproduced video signal is a composite color video signal or a monochrome video signal, and if it is a chalk video signal, the color/4-st signal is removed and sent. Therefore, even in the case of a character image that is normally transmitted as a black and white video signal, a character screen with good resolution and color noise can be removed.

In addition, the color burst signal added to the black and white video signal for time axis error correction can be easily and reliably removed, making it easy to remove information such as encyclopedias that are printed with a mixture of color photographs and text. It can be recorded and stored on a recording medium such as a video disc, and played back and viewed as needed.

In the above-mentioned embodiment, the case where such an electrical appliance is integrated into the recording/reproduction system has been explained as an example, but it may be added as an adapter. This eliminates the need for any modification of the main unit, such as the player.

Further, the disc may be a master disc, a copy may be made based on the master disc, or the disc may be reproduced as it is.

[Brief explanation of the drawing]

@Figure 1 is a configuration diagram showing a recording system of an embodiment of this invention, @
Figure 2 is a configuration diagram showing a reproduction system according to an embodiment of the present invention.
The configuration diagram showing a specific example of the time axis correction circuit (to) in Figure 2 of Zushasha, and Figure 4 of this invention! ! FIG. 5 is a block diagram showing another example of the essential parts of the present invention. (7) is the optical system on the reproduction side, (b) is the FM demodulator, @ is the time axis correction circuit, 4 is the color and monochrome signal discrimination circuit, Cl
) is a burst removal circuit. 450

Claims (1)

[Claims] A composite color video signal containing a carrier color signal component and a black and white video signal to which a color burst signal included in the skeleton composite color video signal are mixed are reproduced by reproducing the interposed signal from a recording medium on which the composite color video signal is recorded. In a video signal reproducing device configured to compare a color burst signal in a reproduced video signal with a reference signal and correct a time axis difference in the reproduced video signal using the comparison output, the reproduced video signal is a composite color video signal. A discriminating means for discriminating whether the lacquer signal is a black and white video signal, and a discriminating means for discriminating whether the reproduced video signal is a lacquer signal or a black and white video signal;
9. A video signal reproducing device comprising: a burst gate means for controlling transmission of a video signal; and a color burst signal is removed when the reproduced video signal is a monochrome video signal.