JPS5830280A - High quality television set - Google Patents

Abstract

PURPOSE:To change a wide band video signal into a narrow band video signal without giving any damage on the video information, by using an image receiving tube of multi beam type and, at the same time, by delaying the reading out speed from a memory more than the writing speed in the memory. CONSTITUTION:A multiple beam type image receiving tube which is arranged in such a way that N (>=2) pieces of electron beams make simultaneous scannings on different horizontal lines, is used as an image receiving tube 1. Then, a video signal S1 is written in a memory 6 after it is A/D converted by an A/D converter 4 and the data is read out at a frequency which is 1/N of the frequency at the time of writing. The read out data are D/A converted by D/A converters 7A and 7B which are corresponded to the N pieces horizontal lines and, at the same time, supplied to the image receiving tube 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a television receiver that reproduces a high-definition, high-resolution angle of view using a wideband video signal.

The provisional values of the standard method for obtaining such high-quality image quality include, for example, the number of horizontal twins of 112 seconds and 60 fields per second, and the horizontal frequency of 33.7! 1, the required bandwidth of the video signal is 39M1h (20Mm for the luminance signal, 6.5Mm for the chrominance signal). Even the scumbag's television receivers must be designed to receive television signals based on this provisional standard.

However, since the required bandwidth of the video signal is an ultra-wide band, it is extremely difficult to implement k using existing electronic components. In particular, a video output circuit that drives a picture tube handles large amplitude signals, but it is difficult to construct a video output circuit that is suitable for large amplitudes and has wideband characteristics.

Therefore, the present invention proposes a television receiver that is devised so that it can fully reproduce the performance of the electronic components used in current monitor television receivers. Therefore, in the invention of %Jin, a plurality of narrowband transmission systems are provided to transmit wideband video signals.

An example of the present invention will now be described in detail with reference to the drawings.

In the present invention, a multi-beam type picture tube is used in which N (N22) electron beams simultaneously scan different horizontal lines. In the embodiment described below, two narrowband transmission systems are provided to transmit a wideband video signal, so a picture tube that scans simultaneously with two electron beams is used as the picture tube. By the way, in the case of color picture tubes, there are two types: single electron gun 3-beam system, %3 electron gun 3-beam system, and single electron gun 1-beam system (beam index type), so in this case, a multi-beam color picture tube is used. A plurality of sets of these electron guns are provided in the K constituting the electron gun. Therefore, for example, in a three-beam single electron gun system, a plurality of single electron guns are housed to form a multi-beam color picture tube. Similarly, in the case of a 3-beam 3-electron gun type, a plurality of 3-electron guns are provided as one set to form a multi-beam type 2-picture tube. Therefore, in a multi-beam type picture tube, the number of pairs of the above-mentioned electron guns forming two-images is N.

Although this invention is based on a color screen, in the following description, for convenience of explanation, a monochrome multi-beam picture tube will be used instead.

In Fig. 1, (1) shows a multi-beam picture tube;
Two electron beams B1 and Bb are simultaneously emitted from two independent cathodes, M and KB, and in an odd field, one electron beam Ba and an odd horizontal line 11 from K are emitted as shown in Figure 2. 2 stars are formed, and even horizontal lines 12, 4... are formed by the electron beam Bb.
tester is formed.

In the even field, the electron beam Ba generates a raster of odd horizontal lines h', i, / , , , and the electron beam Bb generates a raster of even horizontal lines h', i, / , , , 2 even horizontal lines i 2/ , t 4/ .
... ° tester is formed. When scanning an even field, the deflection system is controlled so that an interlaced relationship as shown in the figure is obtained.

Now, in FIG. 1, a wideband video signal 8i supplied to a terminal (2)K is supplied to a digital converter (4)K via a wideband amplifier (3) and converted into a digital video signal 8D. (5) is a clock signal generator and sequence controller to which pulse CKW is supplied as a sampling pulse.

A digital video signal 8D is supplied to a memory device (6)K. As shown in FIG. 3, this memory device (6) is provided with four memories (c memory Ml to M4), each having a memory capacity of 1*horizontal twin, and the first memory M1 is (41m+1). )-th (n=0.1..., same hereafter) horizontal line digital video signal is stored in the memory device, second memory M2 stores the (4n+2)-th horizontal twin digital video signal, and so on. The third memory Ms Vc stores the digital video signal of the (411+3)th horizontal line, and the fourth memory M4 stores the digital video signal of the (4n+4)th horizontal line. An example is shown in Fig. 3. Its analog waveform is shown in Fig. 4.

Write clock CKW for this memory device (6)
The frequency is selected to be 60 MHz or more depending on the bandwidth of the video signal. The frequency of the read clock CKR is selected to be 1/NK of the frequency of the write clock CKW. N is the number of narrowband transmission systems mentioned above, and in the embodiment, N, 2
(Figure 4 B%C).

In this way, if the read speed is reduced to the write speed of 4 and the data is read, the read time will take twice the write time (K), so the data in one horizontal period TRI will be read once in two horizontal periods. become.

Of the data read out at low speed, 'data SO corresponding to odd-numbered horizontal lines is supplied to the first DA converter (7A) K constituting the first narrowband transmission system (10 people). The analog video signal S is converted into OK, and the data Se corresponding to even-numbered horizontal lines is sent to the second narrowband transmission system (l
The signal is supplied to the second D-back unit (7B) constituting the video signal 0B) and converted into an analog video signal 81H.

Here, since the read speed is h of the write speed, D-
The signal bandwidth of the A-converted analog video signal SA0°8A]C is . Therefore, as mentioned above, K 3QMH
If the bandwidth is z, then the bandwidth of the narrowband transmission system is 15
MHz.

Note that the reading of the signal 81 (originally a digital signal, but shown as an analog signal for convenience) written to the first memory MtVc is performed using the signal 81 written to the second memory M2.
! After the writing of the signal 8 is completed, it is carried out at the same time as the reading of the signal 8 (the fourth diagram).

B). Similarly, the signal S3 written in the third memory MsK is read out at the same time as the signal 84 is read out after the writing of the signal 84 in the fourth memory M4 is completed.

The video signal SA0.8AΣ converted from analog to 4G by the first and second D-A converters (7 people) and (7B) is sent to the narrowband first and second video output circuits (8 people), respectively. The picture tube (1)k is supplied via (8B). Therefore, electron beam B
A is simultaneously density-modulated by the video signal Sm0, and the other electron beam Bb is density-modulated by the video signal 8mE, thereby reproducing an image.

5. By slowing down the readout speed, a wideband video signal can be made into a narrowband signal without losing video information.
Based on this narrowband video signal 810% 8AΣ, the picture tube (
Even when driving 1), the image does not deteriorate, a high-resolution image is reproduced like an image by a wideband video signal, and the signal transmission system can have narrowband characteristics.

Note that the video signal 8AO18 supplied to the picture tube (1)k
Since the signal bandwidth of AI is 101510l5,
Horizontal deflection circuit, (not shown) horizontal deflection 1 supplying K
33.75 The frequency of the direction signal is also lowered to 2KHz (2KHz).

In addition, in the above example, the picture tube (1) is driven by supplying the video signals 8 and 0.8 AI to the pair of cathodes, but the drive method for the picture tube (1) is a cathode drive method. is not limited.

As explained above, in this invention, a multi-beam type picture tube (1) is used and the reading speed is slower than the writing speed to the memory, so that the wideband video signal can be processed without loss of video information. It is possible to narrow the band without any problem. Therefore, while it is possible to reproduce an image with the same high resolution and high quality as when the picture tube (1) is driven by a wideband video signal, the signal transmission system can have narrowband characteristics.

Therefore, this high-definition television receiver can be realized as long as the video output circuit has substantially the same performance as the video output circuit used in the monitor receiver. Because '6
This is because the receiver aircraft for monitors generally handles video signals of 10- or more.

Since the horizontal frequency can also be lower than the normal h, the horizontal deflection system can be configured relatively easily.

In the above embodiment, two narrowband transmission systems were used to configure the high-definition television receiver, but the number of narrowband transmission systems is arbitrary. The larger the number N, the slower the speed of successive output to the memory device (6), so the transmission band becomes 1/N, and accordingly, the horizontal deflection frequency also becomes 1/N.
NK becomes.

However, a multi-beam type picture tube (1) is also used depending on the NK.

[Brief explanation of the drawing]

Figure 181 is a system diagram of essential parts showing an example of a high-definition television receiver according to the present invention, Figure 2 is an explanatory diagram of horizontal scanning of a two-beam tube, and Figure 3 is an example of a memory device. The configuration diagram and FIG. 4 are explanatory diagrams of its operation. (4) is an A-D converter, (6) is a memory device 1M1~
M4 is memory, (7 people), (7B) is D-A converter,
(IOA) and (IOB) are narrowband transmission systems, and (1) is a picture tube.

Claims (1)

[Claims] In a 5K television receiver that supplies a wideband video signal to a picture tube to obtain a high-quality image, the picture tube uses N (N22) electron beams to simultaneously scan a horizontal line called h14. A multi-beam type picture tube is used, and when the above video signal is written to the memory capacity after MuD conversion, the data is output one after another at the supporting frequency at the time of writing, and N horizontal The high-definition television receiver is configured such that the video signal after analog-to-digital conversion corresponding to the line is simultaneously supplied to the picture tube to obtain a high-quality viewing angle.