JPH033590A - Color television receiver - Google Patents

Abstract

PURPOSE:To attain low power consumption by outputting a video signal only when an electron beam strikes on a phosphor face of a CRT in the case of deflecting the electron beam. CONSTITUTION:The color television receiver is provided with a pitch detection means 28 detecting a pitch of a prescribed phosphor PC and sampling means 13, 20 sampling a video signal based on a detection signal of the pitch detection means 28 to drive an electron beam with an output signal of the sampling means 13, 20. That is, the electron beam 1 outputs a video signal only while the phosphor face is irradiated with the electron beam 1 through an aperture of an aperture grill and no video signal is outputted while the aperture grill is irradiated with the electron beam. Thus, the power consumption is remarkably reduced.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a color television receiver.

[Summary of the invention]

The present invention provides a color television receiver that projects an image by irradiating an electron beam onto a predetermined phosphor.
Low power consumption is achieved by providing pitch detection means for detecting the pitch of a predetermined phosphor and sampling means for sampling a video signal based on the detection signal of the pitch detection means, and driving the electron beam by the output signal of the sampling means. The system was designed to provide a color television receiver.

[Conventional technology]

FIG. 4 shows the configuration of a CRT electron gun using an aperture grill. In the figure, Gml is a beam emission source and a first grid that modulates the beam, and
B is arranged inline. Gt and G are prefocus electrodes and are the second and third grids, G4 is a cylindrical focus electrode and is the fourth grid, high voltage is supplied to the third and fifth grids C, and C6; The third to fifth grids G, , G, , G5 form a unipotential lens. The electrode CE disposed in front of the fifth grid G5 is a convergence electrode for electrostatic concentration deflection, and the electron beams emitted from the electron guns R, G, and B are focused at the fourth grid G4, and the convergence electrode CB
The beam is concentrated and deflected by the aperture grille AG.

The aperture grille AC is a metal plate with vertically striped slit holes (4) etched therein, and the electrons emitted from the electron guns R, G, and B that have passed through the slit holes (4) of the aperture grille AG. The R, G, and B beams are irradiated onto the phosphor surfaces R, , G, and B of the phosphor PC formed on the inner surface of the CRT to emit light in the three primary colors of red, green, and blue. This aperture grill AC slit hole (
The electron beam (1) passing through step 4) must be made to accurately hit, for example, the red phosphor surface R1 of the corresponding phosphor PC, as shown in FIG.

That is, in FIG. 5, only the electron beam (1) passing through the striped slit hole (4) is, for example, the phosphor R9.
However, the electron beam (1) hitting the inner surface (2) of the aperture grille AG does not contribute to the light emission. This state is illustrated in terms of time as shown in FIG. Figure 6 is a straight line graph with time on the horizontal axis and electron beam position on the vertical axis (7
), this electron beam (1) hits the phosphor surfaces R,,G,,B of the phosphor PC.

The section (6) where the electron beam is emitted is extremely short, and the other section (5) does not contribute to light emission at all, but this section (5) is extremely long and more than 70% of the electron beam is wasted. has been done. For example, in an HDTV, the electron beam transmittance is about 20% for a shadow mask type, and about 27% for an aperture grill type.

[Problem to be solved by the invention]

As seen on the ridges, more than 70% of the electron beams (1) hit areas other than the aperture grille AC or the slit holes or dots of the shadow mask in conventional CRTs, and during this time the video signal is continuously transmitted to the CRT. Since the current is supplied to the cathode of the high-voltage regulator, unnecessary current also flows through the high-voltage regulator, leading to the problem of wasted power consumption.

The color television receiver of the present invention has been developed in view of the problem of ridges, and its purpose is to provide a color television receiver with low power consumption.

[Means to solve the problem]

An example of the color television receiver of the present invention is as shown in FIG.
In a color television receiver configured to project an image by irradiating light onto a PC, a pitch detecting means (28) for detecting the pitch of a predetermined phosphor PC, and a pitch detecting means (28)
) sampling means (13) and (20) for sampling video signals based on the detection signals of the sampling means (13) and (20) are provided, and the electron beam is driven by the output signals of the sampling means (13) and (20).

[Effect]

According to the color television receiver of the present invention, the CRT (
16) A video signal is output only while the electron beam (1) emitted from the electron gun is irradiated onto the phosphor surface through the aperture of the aperture grill, and no video signal is output while it is hitting the aperture grill. As a result, power consumption can be significantly reduced.

〔Example〕

Hereinafter, the color television receiver of the present invention will be explained with reference to FIGS. 1 to 3.

FIG. 1 is a system diagram showing one embodiment of the color television receiver of the present invention. Before explaining this system diagram, FIG.
I will explain in detail. FIG. 2 is a conceptual diagram for explaining the electrode structure and beam position sensor of the CRT used in the color television receiver of the present invention. However, the electron beam passing through the fifth grid G5 and the convergence electrode CE is focused by the aperture grill AC.
In (16), a fluorescent material (27) with extremely low afterglow characteristics is applied to the upper end of this aperture grille AG at a position that is not visible from the surface of the CRT screen on the back side.

In addition, a sensor (28) for detecting the aperture grill position is disposed opposite to the surface coated with the fluorescent material, and the surface coated with the fluorescent material is scanned before scanning the first scanning line. 28) is configured to detect the fluorescent material reflected light and extract the position data of the aperture grille AG.

FIG. 1 will be explained below. In the figure, T is an input terminal into which HDTV signals and the like are input. This composite video signal is supplied to a video signal processing circuit (10) and a synchronous separation circuit (17). Video signal processing is performed in a video signal processing circuit (10), and the video signal is passed through an analog-to-digital conversion circuit (hereinafter referred to as A).
/D) (11) is digitized and A/D (11
) The video data digitized by the image memory (12)
The stored data read out from the image memory (12) is sampled by a switching circuit (13) and then converted into analog data by a digital-to-analog conversion circuit (hereinafter referred to as D/A) (14). is supplied to the cathode of the first grid G1 of the CRT. Synchronous separation circuit (17
), the vertical and horizontal synchronizing signals ■ and H are generated, and these synchronizing signals V and H are sent to the vertical deflection circuit (1
8) and horizontal deflection circuit (19).
The vertical deflection coil VDC and the horizontal deflection coil HDC of the main deflection yoke (15) arranged near the neck section and funnel section of 6) are driven to deflect the electron beam (1) in the horizontal and vertical directions.

The vertical and horizontal synchronization signals V and H generated by the synchronization separation circuit (17) are supplied to the position detection data memory (21) in the control circuit (20), and are further supplied to a sensor for detecting the position of the aperture grille AC. The position detection output signal from (28) is supplied to the position detection data memory (21) via the amplifier (26). This position detection output signal is generated by scanning the fluorescent material (27) coated surface of the aperture grill AG with an electron beam before scanning the first horizontal scanning line, and detecting the reflected light emitted from the fluorescent material (27) surface by the sensor ( 28) is detected. During this scanning, the sensor is illuminated with white data, which will be described later. In this way, the position information data of the aperture grill AC is output as serial timing data, stored in the position detection data memory (21), and when the image enters the first horizontal scanning line where the image can be seen from the front of the screen of the CRT (16). obtains a select signal for selecting a video signal when the electron beam (1) is hitting the phosphor surface RI+GI+BI etc. based on the interval data of the aperture grille AC of the timing data stored in the position detection data memory (21). For this purpose, the position detection data memory (21) is equipped with a crystal oscillator X-
A reference clock from a reference signal generator (23) having Ta1 is supplied, and data corresponding to the aperture grill interval read from the position detection data memory (21) is supplied to a select signal generation circuit (22). The select signal generation circuit (22) first outputs to the output terminal T3 a select signal that selects video data for sampling the video signal at a predetermined timing, and supplies this select signal to the switching circuit (13), for example, an image memory. (12)
A switching circuit (1
3) Control.

In addition, an electron beam (
Aperture grilles other than 1) where the video signal is outputted and supplied to the D/A (14) at the timing when the electron beam (1) hits the phosphor PC, and the electron beam (1) passes through the slit hole (4) of the aperture grille AG. While hitting surface AG, black data is supplied from the select signal generation circuit (22) to the output terminal T4 of the control circuit (20), and the output terminal T4
The black data from is supplied to the switching circuit (13). This black data is the data that serves as the black level reference, and at the timing when this black data is output, the reading of the video data written in the image memory (Step 2) is stopped, and the black data is
/A (14). This reading clock is transmitted from the output terminal T2 of the control circuit (20) to the A/D (
11), image memory (12), and D/A (14). In addition, the white data mentioned above is sent from the select signal generation circuit (22) to the switching circuit (22) via the output terminal T4.
13) immediately after the vertical synchronization signal, and the electron beam (
1) is scanned at the white level to obtain pitch information of the aperture grille AC.

FIGS. 3A and 3B are waveform explanatory diagrams showing the sampling state of the video signal in this example. In Figures 3A and 3B, (33) shows the synchronization signal, (3) shows the video signal, and in Figure 3A, (32) shows the phosphor surface RIICII of the phosphor PC of the CRT (16).
It represents the time that the electron beam hits B+ etc. When the read address of this section image memory (12) is read out, sampling is performed at the timings of T I, T + . . . as shown in FIG.
32) is output to the D/A (14).

Since the present invention is structured like a ridge, the electron beam (1)
Since the video signal is not supplied to the video drive circuit during the period when it is not contributing to light emission while it is hitting the aperture grill AC, it is possible to save the power that was wasted during this period, so it is a low power consumption type. A color television receiver is obtained. Furthermore, the commonly used A B L (A
The automatic BeamLimiter (BeamLimiter) circuit automatically limits the maximum amount of electron beam to, for example, 0.9mA to protect the CRT and other parts, but if the electron beam (1) hits the aperture grill AC During this time, no video signal is supplied to the CRTO cathode, so the electron beam current can be used effectively, resulting in a brighter screen.

Although the present invention has been described with respect to a CRT having an aperture grill, a shadow mask type CRT may also be constructed in the same manner. Furthermore, it is clear that the electron gun configuration is not limited to the unipotential type, but may also be of the pipotential type, and it goes without saying that various changes can be made without departing from the gist of the present invention.

〔Effect of the invention〕

According to the color television receiver of the present invention, a video signal is output only when the electron beam is hitting the phosphor surface of the CRT when deflecting the electron beam, so that a color television receiver with low power consumption can be obtained. It has the characteristics of being able to

[Brief explanation of drawings]

FIG. 1 is a system diagram showing an embodiment of the color television receiver of the present invention, FIG. 2 is an explanatory diagram of the CRT electron beam position sensor used in the present invention, and FIG. 3 is a sampling waveform diagram of the present invention. Figure 4 is a diagram of the electrode configuration of a conventional CRT, Figure 5 is a schematic diagram of the electron beam near the aperture grill, and Figure 6 is a schematic diagram of the electron beam near the aperture grill.
The figure is an explanatory diagram of a state in which a conventional phosphor is irradiated with an electron beam. (10) is a video signal processing circuit, (11) is an A/D, (1
2) is the image memory, (13) is the switching circuit, (14) is D
/A, (20) is a control circuit, (21) is a position detection data memory, and (22) is a select signal generation circuit.

Claims (1)

[Scope of Claims] A color television receiver configured to project an image by irradiating an electron beam onto a predetermined phosphor, comprising pitch detection means for detecting the pitch of the predetermined phosphor; A color television receiver comprising: a sampling means for sampling a video signal based on a detection signal of the pitch detecting means, and the electron beam is driven by an output signal of the sampling means.