JPS58201467A - Television receiver - Google Patents

Abstract

PURPOSE:To improve the vertical sharpness especially, by converting a television signal in the standard system into a signal having the n-times horizontal frequency with a storage element. CONSTITUTION:R,G,B or Y,I,Q signals demodulated at a demodulating circuit 3 are applied to a signal converting circuit 4, which converts the input signals into television signals having the horizontal frequency two times that of the standard system. The horizontal synchronizing signal from a synchronizing separating circuit is applied to a PLL circuit 8. The PLL circuit 8 generates a clock signal of the signal converting circuit 4 and converts the horizontal synchronizing signal converting circuit 4 and converts the horizontal synchronizing signal into the signal having double frequency through scanning frequency conversion. Further, a special deflection pulse having the standard horizontal scanning period and 50% of duty cycle is applied to an auxiliary deflection coil 14 via a special deflectin circuit 10 from the PLL circuit 8. Thus, the vertical scanning speed is modulated with a signal from an LPF17 delayed by 1H, allowing to improve the vertical sharpness.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a television receiver that uses a storage element to convert a standard television signal into a signal having a horizontal scanning frequency n times higher for display.

Current standard television systems include NTSCPA
There are methods such as L, SECAM, etc., but it cannot be said that the resolution of any of them is necessarily sufficient. Especially today, when there is a demand for larger screens, higher resolution broadcasting is required. Therefore, in the near future, high-definition broadcasting will be implemented in which the number of scanning lines is about 2 to 3 times that of the current standard system, and the bandwidth is about 5 to 10 times as large. In fact, NHK has 1126 scanning lines and 20 M jl Z , E in the brightness band.
I A (E 10 Ctr On l CIndu
The number of scanning lines is 1023 and the brightness bandwidth is 21.1 from the American Electronics Industries Association.
MHz.

From the BBC, the number of scanning lines is 16o1, and the brightness band is 50M [
Various lz methods have been proposed. During the transitional period of commercialization of these new television formats, it is necessary to realize what is called a compatible television receiver so that the receivers that receive signals of these formats can also receive television signals of standard formats. It is thought that the spread will be faster.

In addition, in the recent information age, character displays that display alphanumeric characters and characters as converter terminals,
Demand for graphic displays that display charts, patterns, etc. is increasing. In order to improve the amount of information, these devices have come to be used with increased resolution and the number of scanning lines, and with a scanning frequency set to about twice that of the standard television system. If these displays are configured to receive standard television signals, they will also be able to receive signals from VTRs and cameras, expanding the range of applications for displays9, and it is hoped that this will become a reality.

In order to create a compatible television receiver, both the standard system and the new system must share all circuits, not only the signal circuit, but also the deflection circuit, due to the large difference in horizontal scanning frequency. It was difficult to operate the circuit, and it was necessary to switch the circuit using a changeover switch, relay, etc. This not only made the circuit more complex, but also caused problems in terms of reliability since parts with high potential were switched. Furthermore, conventionally used conversion devices between systems with different scanning frequencies have a conversion method that exactly matches the scanning frequency to be converted, so one scan frequency is converted for every few scanning lines. The configuration was extremely complicated, requiring operations such as dropping or adding 9 signals.

For this reason, a method of converting the standard television signal into a signal having a horizontal scanning frequency close to the horizontal scanning frequency of the new television system and displaying the signal was proposed in Japanese Patent Application No. 1986-
It is proposed in No. 141201.

Generally, in television images, when the brightness is high, the beam current of the picture tube increases, so the beam spot size increases and the sharpness decreases.

In view of the above points, the present invention relates to a television receiver that converts and displays signals having a horizontal frequency n times higher by using a standard television signal total storage element, and relates to a television receiver that uses a standard television signal total storage element to convert and display a signal having a horizontal frequency n times higher. The object of the present invention is to provide a circuit that can be utilized to improve sharpness, especially in the vertical direction.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIG. 2 is a diagram for explaining the entire signal conversion thereof. This embodiment will be described for the case where n=2.

Radio waves emitted from a broadcasting station are received by an antenna 1, converted to an intermediate frequency by a TV station 2, amplified, and then detected to become a composite video signal.

This composite video signal is supplied to a demodulation circuit 3, which converts it into signals corresponding to the three primary colors, for example R and G.

It is demodulated into a B signal or a Y, I, Q signal and supplied to a signal conversion circuit 4vζ. In the signal conversion circuit 4, the second
The signal f is converted into a television signal having a horizontal set frequency twice that of the standard television signal shown in FIG. Then, the image is amplified by the video signal amplification circuit 5 and the picture tube 16 is driven. Next, the synchronization separation circuit 6 separates the horizontal synchronization signal and the vertical synchronization signal from the synchronization signal obtained by the demodulation circuit 3. The vertical synchronization signal is supplied to the vertical deflection circuit 7, and the vertical deflection circuit 7 is connected to the deflection yoke 16.
to drive vertical deflection coils. A horizontal synchronization signal is supplied to a PLL (phase locked loop) circuit 8. The PLL circuit 8 generates the tarlock signal of the signal conversion circuit and converts the scanning frequency into a horizontal synchronizing signal having a frequency twice that of the horizontal synchronizing signal. The horizontal synchronizing signal converted into a double mantissa is supplied to the horizontal deflection circuit 9, and the horizontal deflection circuit 9 fully drives the horizontal deflection coils of the deflection yoke 16.

In order to display the entire pseudo-interlaced image, the PLL circuit 8 outputs a special deflection pulse with a duty cycle of 50% in standard horizontal scanning synchronization. The special deflection pulse is supplied to a special deflection circuit 1o, which drives an auxiliary coil 14. As a means of improving the sharpness especially in the vertical direction, the signal from the signal conversion circuit 4 The converted signal is passed through the low-pass filter 17 and supplied to the 1H delay circuit 11, and the 1H-delayed signal conversion signal and the undelayed signal V=multiple signal are supplied to the subtraction circuit 12 for subtraction.This difference signal is The vertical scanning velocity modulation signal is supplied to the vertical set meal velocity modulation circuit 13, and the vertical scanning velocity modulation circuit 13 drives the auxiliary coil 14 to produce a special deflection waveform on which the vertical scanning velocity modulation waveform is superimposed, and the vertical scanning velocity modulation It's all done.

As mentioned above, standard video signals are converted into signals.

Displayed after fixed frequency conversion.

Next, in order to explain the incrace relationship, an explanatory diagram showing the state of scanning lines on the screen in FIG. 3 will be used.

The numbers written in the figure indicate the numbers of the scanning edges, and the scanning lines of even and odd fields are indicated by solid lines and broken lines, respectively. Also in the figure are (a) and (b).

The symbols shown as 1→... are the signals for each scanning line of the standard television signal before signal conversion shown in Figure 3a, and the even and odd fields are shown in the symbols. They are distinguished by adding ``'''. After signal conversion, the number of scanning lines is 1060, and since it is an even number, interlaced scanning is not performed, and as shown in Figure 3, the even field signal and the odd field signal overlap, resulting in a normal screen. Can't reproduce.

Therefore, as shown in Fig. 3C, the position of the (2m)th (m is an integer of 1 or more) scanning edge is the original position of the (2m-1)th scan line and the 11th (2m)th scanning line. This is a screen shot when the magnitude of the special deflection pulse signal applied to the special deflection circuit 10 is adjusted so that the special deflection pulse signal is at the midpoint. Figure 3 d
is the screen when the magnitude of the special deflection pulse signal applied to the special deflection circuit 1o is adjusted so that the position of the (2N11)th scanning edge is on the (2m-1)th scanning line -. be. From the above, the screens shown in FIGS. 3c and 3d realize a signal arrangement according to interlaced scanning, and can faithfully reproduce the original signal.

The means for realizing the scanning edge appearance as shown in FIG. 3C will be explained using the waveform diagram in FIG. 4.

In Figure 4, a is the standard horizontal synchronization signal, b is the horizontal synchronization signal converted to twice the set frequency, and C is the P in Figure 1.
The special deflection pulse voltage waveform outputted from the LL circuit 8 and having a signal amplitude v1 at a data cycle of 60% in the standard horizontal scanning period, d is the special deflection pulse voltage waveform of the special deflection shown in FIG. supplying circuit 10 and auxiliary coil 14
This is a special deflection signal shaping when driven. The numbers written in FIG. 4d correspond to the scanning line numbers shown in FIG. 3. Further, FIG. 4 θ shows the vertical deflection I= waveform. The position of the (2m)th scanning line from Figure 4d is the midpoint between the (2m-1)th scanning line and the original position of the (2m)th scanning, and is shown in Figure 3a. It can be seen that the original signal is faithfully reproduced.

The means to realize the fixed line appearance as shown in Fig. 3 (d) is to have a standard horizontal scanning period with a duty cycle of 50% and a double signal amplitude vl as shown in Fig. 4 (f). Special deflection circuit 1 shown in Figure 1
FIG. 4-q shows the special deflection waveform when the auxiliary coil 14 is driven. The numbers written in FIG. 4q correspond to the numbers of the run fd already shown in FIG. The position of the (2m)th scanning line from q in Figure 4 is (
It can be seen that the original signal located on the 2nd)th scanning line and shown in FIG. 3a is faithfully reproduced.

As described above, it can be seen that the pseudo-interlacing shown in FIGS. 3C and 3D can be easily realized by setting the amplitude of the special deflection pulse signal to 1:2.

Next, vertical scanning velocity modulation will be explained using the waveform diagram shown in FIG.

The maximum frequency of the vertical scanning speed modulation signal is 31.5K [Iz], twice that of the standard method, and the maximum frequency of the correction signal to improve vertical sharpness is about 200K [Iz]. .

The vertical scanning velocity modulation signal generating means supplies the signal conversion signal from the first symbol conversion circuit 4 to the 1H delay circuit 11 through a band-limited 200K[]Z LPF 17. The 1H delayed signal conversion signal and the undelayed signal conversion signal are supplied to a subtraction circuit 12 for subtraction. This difference signal is used as a vertical scanning velocity modulation signal and is supplied to the vertical scanning velocity modulation circuit 13. The vertical scanning velocity modulation circuit 13 drives the auxiliary coil 14 to create a special deflection waveform on which the vertical scanning velocity modulation waveform is superimposed, and performs pseudo incline,
Vertical scanning speed modulation is performed to improve vertical sharpness.

As shown in FIG. 5a, when the signal conversion circuit has a bright wind butter 7 in the center, each horizontal scanning period TiHi++,
The scanning line corresponding to Hi+2...Hi+m is Ll
...Lion, the signal S for the period H1 to H+m
1 is shown in Figure 5. Furthermore, the signal S2 for the period Hi-Hi+m delayed by one horizontal synchronization due to the 1H delay circuit 11 is shown in FIG.
becomes. Therefore, from the subtraction circuit 12, the period H1 to Hi
The vertical scanning velocity modulation signal S3 of +m is shown in FIG. 5d. This vertical scanning speed modulation signal S3 is transmitted to the vertical scanning speed modulation circuit 1.
3, drive the auxiliary coil 14.

Therefore, in the period H1, since the signal VVM o is at 0 level, normal vertical scanning is performed as shown in the 51st section e.
By M + , the vertical scanning speed of the beam is increased by the period of pulse VVMiρ of C, and the portion of scanning line L1+1 corresponding to pulse VVMi is shifted downward from the normal position. Then, in the continuation (Hi+2 to H1+(m-2)), the signal VVM2 is at the O level, so normal vertical scanning is performed, but in the period Hi+(m-1), the negative polarity pulse VVM3 of the signal VVM1 causes the VVMs to The vertical scanning speed of the period-distance beam is slowed down so that the scanning line Li+(m−
The portion corresponding to pulse VVM3 VC in 1) is shifted upward from the normal position.

Therefore, the part corresponding to the scanning line L1+1 is brought close to the part corresponding to the next scanning line Li+2, and the part corresponding to the scanning line Li+
(m-1) is also the previous scanning line Li+(m-2)
), thus improving vertical sharpness.

Further, a detailed explanation will be provided using the waveform diagram in FIG. 6.7. FIG. 6a shows a standard video signal. b indicates a signal conversion signal converted by the signal conversion circuit 4 in FIG. 1, C indicates a signal conversion signal delayed by 1H in the 1H delay circuit 11 in FIG. 1, and f indicates the signal conversion signal described above. and the 1H delayed signal conversion signal of C are subtracted by the subtraction circuit 12 of FIG. Indicates an inexpensive special deflection pulse waveform. q indicates a waveform in which the vertical scanning velocity modulation waveform f is superimposed on the special deflection pulse waveform e. By driving the auxiliary coil 14 shown in FIG. 1 with a waveform in which a vertical scanning speed modulation waveform is superimposed on the special deflection pulse waveform, vertical scanning speed modulation is performed together with pseudo interlacing, and the sharpness in the vertical direction can be improved. . The situation is shown in FIG. 7a.

The numbers written in FIG. 7 correspond to the numbers of the scanning lines shown in FIG.

As shown in FIG. 7, when the image 1 original has a bright wind pattern in the center, when vertical scanning speed modulation is performed using the vertical scanning speed modulation waveform shown in FIG. The vertical scanning speed of the beam during the period is increased, and the portion of the scanning line L3 corresponding to the Noculus period is shifted downward from the normal position. Further, the negative polarity pulse in the period L9 slows down the vertical scanning speed of the beam only during this period, and the portion of the scanning line L9 corresponding to the pulse period is shifted upward from the normal position.

Therefore, the portion corresponding to scanning line L3 is the opposite scanning line L4.
The portion corresponding to the scan line L9V is also placed close to the portion corresponding to the cutting scan line L8, so that the sharpness in the vertical direction is improved.

Next, the pseudo-interlace shown in FIG. 3(d) will be described. In this case, the position of the (2m)th scanning line is on the (2m-1)th scanning line, so in this case, the 2H delay circuit 11 is used instead of the 1H delay circuit 11 in FIG. A delay circuit having a delay time serves as the casing. Figure 6 shows the signal conversion signal delayed by 2H by this 2H delay circuit. l
1 shows the difference signal, that is, the vertical scanning velocity modulation waveform, obtained by subtracting the 2H delayed signal conversion signal of 1 and the 2H delayed signal conversion signal of 1. A waveform in which one vertical scanning velocity modulation means is superimposed on a pulse waveform is shown. At this time, when compared with the pseudo-interlace shown in FIG. 3C, the ratio of signal magnitudes between q and
: Set so that it becomes 2.

By driving the auxiliary coil AA4 of FIG. 1 with a waveform in which a vertical scanning speed modulation waveform is superimposed on the special deflection pulse waveform, vertical scanning speed modulation is performed together with pseudo interlacing, and the sharpness in the vertical direction can be improved.

The situation is shown in Figure 7.

When vertical scanning velocity modulation is performed using the vertical scanning velocity modulation waveform shown in FIG.
The vertical scanning speed of the beam during this period is increased, and the portions corresponding to the scanning at the same position and the pulse periods 11, 3 and L4 are shifted downward from the normal position. Discarded period L9 and L
The vertical scanning speed of the beam during this period is slowed down by the negative polarity pulse lo, and the scanning lines L9 and Ll at the same position are
The portion corresponding to the pulse period o is shifted above the normal position.

Therefore, the parts corresponding to the scanning lines L3 and L4 at the same position are brought close to the parts corresponding to the next scanning lines L6 and L6 at the same position, and the parts corresponding to the scanning lines L9 and Llo at the same position are also brought close to the part corresponding to the scanning lines L9 and Llo at the same position. The positions corresponding to scan lines L7 and L8 are brought closer, thus improving vertical sharpness.

By the way, in this embodiment, the case of n22 has been described, but the same applies to other cases.

As described above, according to the present invention, a standard television signal is converted into a signal having a horizontal scanning frequency close to n times (n is an integer of 2 or more) using a storage element, and
In a television receiver that displays a pseudo-interlaced image using an auxiliary coil, a signal converting means for storing a signal of one horizontal period of a standard method and reading it out n times at a speed n times the time of storage, and a signal converting means. a delay means for delaying the signal conversion signal by one horizontal period corresponding to the horizontal scanning frequency multiplied by n, which is output from the signal conversion signal; and a subtraction means for obtaining a difference signal between the signal conversion signal and the signal delayed by -horizontal period; Since the auxiliary coil is used both as a difference signal and a vertical scanning velocity modulation means for modulating the vertical scanning velocity, the auxiliary coil for special deflection and the auxiliary coil for vertical scanning velocity modulation that performs pseudo-interlacing are In addition, since the vertical scanning speed modulation multiplier has a narrow band, a narrow band can be used as a -horizontal period (1H) delay circuit, eliminating the need for special parts or circuits and improving vertical sharpness. Therefore, it can be realized with a simple configuration and has great industrial utility value.

In particular, the position of the (2m)th scanning line is (2m-1
When the pseudo-interlacing means is located at the midpoint between the )th scanning line and the original position of the (2m)th scanning line, the sharpness in the vertical direction can be improved as the number of scanning lines increases. Image quality is further improved.

1) In the case of a pseudo-interlacing method that is placed on the th scanning line, the sharpness in the vertical direction in particular can be improved by suppressing the deterioration in sharpness due to high brightness, which is caused by the same signal scanning the same scanning line n times at the same position. can be improved.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the configuration of a television receiver according to an embodiment of the present invention, Fig. 2 is a waveform diagram for explaining its operation, and Fig. 3 shows the state of scanning lines on the screen. Figure 4 is a waveform diagram to explain the pseudo-interlace, Figure 6 is a waveform diagram to explain the vertical scanning velocity modulation, and Figure 6 is a waveform diagram to explain the overall operation. The waveform diagram in FIG. 7 is an explanatory diagram showing the state of the scanning lines on the screen in FIG. 6. 3... Demodulation circuit, 4... Signal conversion circuit,
8...PLL circuit, 17...LPF,
11...1H delay circuit, 12...subtraction circuit, 13...vertical scanning speed modulation circuit, 10.
...Special deflection circuit, 14...Auxiliary coil. Name of agent Patent attorney Toshio Nakao and one other person Cd Figure 4 Cl-1--J--1-1■--1. =,,f-ko-J--],-"-11-1"-""-m-""-un-
2l and 1・f+river, -Yo and ``-1m2Vl Figure 5Figure 5-J N'%I 1J--11,
; ゝ ゝN NNsaeh-≧ N \ ~

Claims (3)

[Claims] (1) Convert a standard television signal to a signal with a horizontal scanning frequency close to n times (n is an integer of 2 or more) using a storage element, and display a pseudo-interlaced image using an auxiliary coil. At the same time, the signal converting means stores the signal of one horizontal period of the standard method and reads it out n times at a speed n times that of storage, and the signal conversion output signal outputted from the signal converting means is delayed. a delay means;
It is characterized by comprising subtraction means for obtaining a difference signal between the delayed signal obtained from the delay means and the signal conversion output signal, and vertical scanning speed modulation means for superimposing this difference signal on the auxiliary coil. television receiver. (2) As a pseudo-interlacing means, set the position of the 2mth scanning line (m is an integer greater than or equal to 1) to the midpoint between the (2m-1)th scanning line and the original position of the 2mth scanning line. Claim 1, characterized in that the delay means delays the signal conversion output signal by one horizontal period to create a difference signal and perform vertical scanning velocity modulation.
The television receiver described in Section 1. (3) Using pseudo-interlacing means that positions the 2mth scanning line on the (2m-1)th scanning line,
2. The television receiver according to claim 1, wherein the delay means delays the signal conversion output signal by n horizontal periods to create a difference signal and perform vertical scanning speed modulation.