JPS639716B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a television receiver that receives a television signal, converts the horizontal scanning period to 1/n (n is an integer of 2 or more), and displays the signal.

Current standard television formats, such as NTSC
The system requires 525 scanning lines and 30 images per second, so as the screen size increases, the spacing between the scanning lines becomes wider and the scanning lines become more noticeable. In order to improve this problem of subjective resolution reduction, a method of displaying by increasing the horizontal scanning frequency and increasing the number of scanning lines, so-called scan conversion means, has been proposed. There are also proposals that take special consideration to the scan line arrangement in order to realize interlaced scanning. In other words, Tokukai Sho
No. 51-110914 discloses a method for driving a vertical deflection coil by superimposing a pulse with a horizontal period of 50% duty cycle on a vertical sawtooth wave signal, and Japanese Patent Application Laid-open No. 55-42418 discloses discloses means for superimposing a horizontally periodic pulse voltage on a sawtooth voltage for vertical deflection and applying the same to a vertical deflection yoke, and causing a horizontally periodic sawtooth current to flow through the deflection yoke using the inductance of the deflection yoke.

However, Japanese Patent Application Laid-Open No. 110914/1983 has a drawback in that the horizontally periodic pulses are integrated by the inductance of the vertical deflection yoke, distorting the waveform and appearing on the screen as a curved scanning line.

In addition, in JP-A No. 55-42418, since the method is to flow a sawtooth wave current with a horizontal period through the vertical deflection yoke, there is a limit to the operating range of the scanning line spacing (from the end point of one horizontal scan to the vertical cannot move back in the scanning direction and start the next horizontal scan). Therefore, if you try to faithfully reproduce the original signal by increasing the scanning frequency by n times the received signal before the change and keeping the number of scanning lines as it is, in other words, the original signal will be faithfully reproduced. Although it is necessary to overlap the 2mth scanning line with the scanning line of (integer), this cannot be realized in the above-mentioned Japanese Patent Application Laid-Open No. 55-42418.

In view of the above points, the present invention provides a television receiver that converts the horizontal scanning period of a received television signal to 1/n and displays the same, by having means for arbitrarily adjusting the scanning line interval. To provide a television receiver capable of reliably realizing interlaced scanning and faithfully reproducing the original signal.

An embodiment of the present invention is shown in FIG. A video signal from a tuner, VTR, camera, etc. is supplied to the input end 1. The demodulation circuit 2 converts the video signal into signals corresponding to three primary colors, such as R, G, B signals,
Alternatively, it is demodulated into Y, I, and Q signals. The demodulated signal is supplied to the signal conversion circuit 3. The signal conversion circuit 3 has, for example, a memory that stores a signal of one horizontal period of the demodulated signal, and performs horizontal scanning by repeatedly reading out the stored signal twice at twice the speed at which it was stored. Obtain a signal whose period has been converted to 1/2. Alternatively, one of the demodulated signals
It has a memory that stores signals for frames, and may convert signals using methods such as interpolation and extrapolation.
Since these are not the main focus of the present invention, they will be omitted. The signal converted by the signal conversion circuit 3 is
The signal is amplified by an amplifier circuit 4 and drives a picture tube or projection tube (not shown).

On the other hand, the synchronization signal obtained by the demodulation circuit 2 is supplied to a synchronization separation circuit 5, and the synchronization separation circuit 5 separates the synchronization signal into a vertical synchronization signal and a horizontal synchronization signal. The vertical synchronization signal obtained by the synchronization separation circuit 5 is
The signal is supplied to a vertical deflection circuit 6, which drives a vertical deflection yoke (not shown). Further, the horizontal synchronization signal obtained by the synchronization separation circuit 5 is supplied to a multiplier circuit 7 and a signal generation circuit 9. The multiplier circuit 7 is constituted by a phase-locked loop or the like, and generates a horizontal synchronizing signal having twice the frequency of the horizontal synchronizing signal. The double frequency horizontal synchronizing signal obtained by the multiplier circuit 7 is supplied to the horizontal deflection circuit 8, and the horizontal deflection circuit operates at a horizontal scanning frequency twice that of the input video signal. and drives a horizontal deflection yoke (not shown).

On the other hand, the signal generation circuit 9 generates a signal with a duty cycle of 50% from the horizontal synchronization signal obtained by the synchronization separation circuit 5.
Generates a pulse voltage of This pulse voltage waveform is shown in FIG. 2c. 2a shows the horizontal synchronizing signal obtained by the synchronization separation circuit 5, and FIG. 2b shows the horizontal synchronizing signal obtained by the multiplier 7 and feeding it to the horizontal deflection circuit 8. The pulse voltage generated by the signal generation circuit 9 is supplied to the drive circuit 10. The drive circuit 10 amplifies the pulse voltage and drives the auxiliary deflection means 11.

One embodiment of the auxiliary deflection means is shown in FIG. 3, and another embodiment is shown in FIG. In FIG. 3, the coil device 1
2. A convergence magnet device 13 and a deflection yoke 14 are installed on the picture tube 15. The coil device 12 is configured to generate a horizontal magnetic field and deflect the electron beam vertically when current flows through the coil. In FIG. 4, an electrostatic deflection electrode 16 is incorporated into a projection tube 17. Note that the illustration of the electron gun portion is omitted. When a voltage is applied to the electrostatic deflection electrode 16, a vertical electric field is generated to deflect the electron beam in the vertical direction.

Therefore, when the auxiliary deflection means 11 is driven by the drive circuit 10 with a pulse voltage, the electron beam is oriented vertically in synchronization with the cycle of the pulse voltage according to the magnitude and polarity of the pulse voltage. be deflected.

Next, how the scanning line interval is changed by the auxiliary deflection means will be explained with reference to FIG. Figure 5a is
FIG. 7 is a diagram showing the arrangement of scanning lines when the horizontal scanning frequency is doubled and displayed when there is no auxiliary deflection means according to the present invention. The numbers written in the figure indicate the numbers of the scanning lines, and the scanning lines of even and odd fields are indicated by solid lines and broken lines, respectively. However, since the scanning lines of the even field and the odd field overlap, a is shown as a representative solid line.

Now, the signal generation circuit 9, drive circuit 10, and
The scanning line arrangement without the auxiliary deflection means 11 has an even number of 1050 scanning lines, so as shown in FIG. cannot be reproduced either. FIG. 5b shows the arrangement of scanning lines according to an embodiment of the present invention, and the position of the 2m-th scanning line (m is an integer of 1 or more) is divided between the 2m-1st scanning line and the 2m-th scanning line. It is adjusted so that it is at the midpoint between the original position of the scanning line. This is realized by applying the pulse voltage shown in FIG. 2c generated by the signal generating circuit 9 from the horizontal synchronizing signal shown in FIG. 2a to the auxiliary deflection means 11 by the drive circuit 10. That is, the polarity of the pulse voltage is selected to be a polarity that provides a deflection direction opposite to the vertical scanning signal, and the magnitude of the pulse voltage is changed by the drive circuit 10 to move the scanning line by 1/2 of the scanning line interval. The swing width is adjusted to . As a result, the number of scanning lines can be doubled while maintaining the interlaced scanning relationship.

FIG. 5c shows the arrangement of scanning lines according to another embodiment of the present invention, where the position of the 2mth scanning line is
It is adjusted so that it is on the 2m-1st scanning line, and the number of visible scanning lines is equivalently the same as the number of scanning lines of the original video signal. This is realized by the signal generating circuit 9, the driving circuit 10, and the auxiliary deflection means 11, as in the case of FIG. 5b. The amplitude of the pulse voltage (shown in FIG. 2c) is adjusted by the drive circuit 10 to an amplitude sufficient to move the scanning line by the distance between the scanning lines.
This makes it possible to double the horizontal scanning frequency while keeping the number of scanning lines and signal arrangement of the original signal the same.

In this way, by adjusting the amplitude of the pulse voltage generated by the signal generating circuit 9 using the driving circuit 10, the scanning line interval can be adjusted as desired.

By the way, in the present invention, as shown in FIGS. 3 and 4, auxiliary deflection means such as a coil device and an electrostatic deflection electrode are used. Deflection magnetic field and deflection electric field can be realized. This is because the amount of movement of the scanning line is small, and therefore the power required for this is also small, so the inductance of the coil can be selected to be small, compared to the conventional method in which the integral action of the coil superimposes a pulse voltage on the deflection yoke. This is because it becomes extremely small. Further, in the case of electrostatic deflection means, it can be made even smaller.

As described above, the present invention provides a television receiver that converts the horizontal scanning period of a received television signal to 1/n for display, and has means for arbitrarily adjusting the scanning line interval. It is possible to convert the number of scanning lines and horizontal scanning frequency by n times while maintaining the interlaced scanning relationship of the received television signal, and to convert the horizontal scanning frequency while maintaining the number of scanning lines and signal arrangement of the received television signal. Since it is possible to increase the scanning frequency by n times,
It has great industrial utility value.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a television receiver according to an embodiment of the present invention, Fig. 2 a, b, and c are waveform diagrams for explaining the receiver, and Fig. 3 is a cathode ray tube section of the receiver. 4 is a diagram showing the principle of the cathode ray tube, and FIGS. 5a, b, and c are diagrams showing the arrangement of scanning lines for explaining the operation of the embodiment shown in FIG. 1. 9... Signal generation circuit, 10... Drive circuit, 11... Auxiliary deflection means, 12... Coil device, 16... Electrostatic deflection electrode.

Claims (1)

[Claims] 1. In a television receiver that converts the horizontal scanning period of a received television signal to 1/n (n is an integer of 2 or more) and displays the signal, a signal generating means for generating a signal synchronized with the television signal; and a driving means for amplifying the output of the signal generating means and supplying it to the auxiliary deflecting means; Therefore, by adjusting the magnitude of the signal synchronized with the television signal supplied to the auxiliary deflection means, the horizontal scanning period can be converted to 1/n and the interval between the displayed scanning lines can be arbitrarily adjusted. A television receiver characterized by: 2. The television receiver according to claim 1, wherein the auxiliary deflection means comprises a coil device. 3. The television receiver according to claim 1, wherein said auxiliary deflection means comprises electrostatic deflection electrode means.