JPH0377249A - Image display device - Google Patents

Abstract

PURPOSE:To make illuminating sizes of rasters of RGB colors by a method wherein fluorescent bodies to be applied on a screen are applied to right and left ends by several pixels more respectively while the order of pulse width modulation signals to be added to a beam current control electrode is varied. CONSTITUTION:Fluorescent bodies to be applied to a screen are applied to right and left ends by several pixels more respectively. A switch 32 is a 3-input triple switch wherein input RGB signals can be converted by switching into three kinds of RGB, GBR and BRG respectively with respect to 33a, 33b, 33c of an A/D converter 33 in the next stage. The switched RGB signals are made to be digital signals by the converter 33 and further pulse-width-modulated by a PWM signal output circuit 34 according to the order of inputs of 33a, 33b, 33c to be a PWM output signal 35 to have a beam current control electrode driven. when the order of the RGB signals is changed by the switch 32 so that horizontal deflection amount is minimum, illumination sizes of rasters of RGB colors can be uniform thereby obtaining uniform rasters on the whole.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention generates an electron beam for each division when a screen on a screen is vertically divided into a plurality of divisions, and generates an electron beam for each division. The present invention relates to an apparatus for displaying a plurality of lines by vertically deflecting a beam to display a televised image as a whole.

Conventional technology Traditionally, cathode ray tubes have been mainly used as display elements for displaying color television images, but conventional cathode ray tubes have a very long depth compared to the screen size, making it difficult to use for thin TVs. It was impossible to create a Gillan receiver. In addition, although EL display elements, plasma display devices, liquid crystal display devices, and the like have recently been developed as flat display devices, all of them are insufficient in terms of performance such as brightness, contrast, and color display.

Therefore, as a means to achieve a flat display device using electron beams, we proposed a method for achieving a flat display device using an electron beam.
135590), a new display device was proposed.

This method generates an electron beam for each section when both sides of the screen are vertically divided into multiple sections, and displays multiple lines by deflecting each electron beam vertically for each section. However, it displays the TV set image as a whole.

However, the above-mentioned image display device has a complicated structure, and it has been difficult to put it into practical use due to the high precision required in the assembly process, high material cost, and basic performance. Therefore, the present applicant proposed an image display device with a new structure in order to solve the above problems.

This is superior in that it has a simpler electrode structure than the previous image display device, and each electrode works very well for its own purpose and does not have much effect on other things.

This will be briefly explained below using figures.

FIG. 3 shows a basic configuration example of the Wi imitation display element used in the present invention, in which 1 is a back electrode, 2 is a line cathode as a beam source, and 3 is a beam extraction electrode. The electron beam is guided to the front by the potential relationship of the three electrodes. Reference numeral 4 denotes a beam flow control aS pole, which is divided into a plurality of parts in the horizontal direction so that the amount of light emitted from each picture element can be controlled. The electron beam whose emission amount is controlled by the beam flow control electrode 4 is focused to a desired beam size by the focusing electrode 5, and is then focused to the desired beam size by the horizontal deflection electrode 6. The phosphor 20 on the screen plate 8 is deflected horizontally and vertically by the vertical deflection [i7, respectively.
It is irradiated to create a raster image. The above raster is successfully displayed on the screen board 8 by each control signal generated from the video signal.
They are lined up on top of each other and project a single image as a whole.

Problems to be Solved by the Invention However, in the above configuration, the screen plate 8
Considering the light emission size, horizontal and vertical deflection amounts, etc. of the raster above, it is necessary to provide a sufficient distance from the vertical deflection electrode 7 to the screen plate 8 relative to the distance from the back electrode 1 to the vertical deflection electrode 7. There is. Furthermore, unlike other electrodes, the screen plate 8 has phosphor (RGB) 20 on the glass plate 21.
are arranged in a stripe pattern, and since the horizontal position could not be precisely aligned with other electrodes because it was more than 0, the emitting size of the raster of each RGB color on the screen plate 8 was made uniform. However, there was a problem in that brightness unevenness was noticeable on the screen as a whole.

The above-mentioned problems will be explained below with reference to the drawings.

FIG. 2 is a schematic top view of the image display element used in the present invention. In FIG. 2, unnecessary electrodes are omitted in order to explain the Lascou's emission size with respect to the amount of horizontal deflection.

In FIG. 2, (a) shows the case where the position of the screen plate 8 and other electrodes is normal, and (b) shows the case where the position of the screen plate 8 and other electrodes shifts in the horizontal direction, respectively. The beam flow trajectory 30 is the trajectory of the electron beam guided from the line cathode 2 as a beam source to the front, and is deflected in several stages (three stages in the figure) by the horizontal deflection electrode 6, and is reflected by the fluorescent light on the screen plate 8. The body 20 is irradiated to form a raster 31.

Now, if the position of the screen plate 8 and other electrodes is shifted in the horizontal direction as shown in (b), the deflection will be biased to either the left or the right, so the raster (B in the figure) where the amount of deflection is maximum is The emitted light size becomes significantly large, and the emitted light size of the raster of each RGB color cannot be made uniform, and uneven brightness is noticeable on both sides.Furthermore, since the amount of deflection becomes large, the voltage applied to the horizontal deflection electrode 6 must also be increased. There must be.

In view of the above-mentioned problems, the present invention provides an image display device in which the emission sizes of rasters of each RGB color are made uniform, and a -like raster can be obtained on the entire screen.

Means for Solving the Problems In order to solve the above problems, the image display device of the present invention includes:
The phosphor to be applied on the screen is applied in large numbers on both the left and right ends, and the order of the pulse width modulation signals (RGB) applied to the beam flow control electrodes can be changed. The light emitting size is made uniform, and a -like raster can be obtained for the entire screen.

Effect of the Invention With the above-described configuration, the present invention changes the emission size of the raster of each RGB color by changing the order (RGB) of the pulse width modulation signals applied to the beam flow control electrode so that the amount of horizontal deflection is the smallest (for example, to BRG). By arranging them uniformly and applying a few more pixels of phosphor to both the left and right ends, the number of picture elements will not be reduced, and a -like raster can be obtained as a whole.

Embodiment Hereinafter, an image display device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a pulse width modulation signal output circuit of an image display device according to an embodiment of the present invention.

In the figure, 32 is a switch, 33 is an analog-to-digital converter (A/D converter), 34 is a pulse width modulation signal output circuit (PWM signal output circuit), and 35 is a pulse width modulation output signal (PWM output signal). Also, in consideration of the misalignment between the screen plate and other electrodes, although not shown, the phosphor applied to the screen plate is applied to the left and right ends of the screen by several picture elements.

Now, the switch 32 is a triple switch operated by three people, and the input RGB signal is transferred to the next stage A/D by switching the switch 32.
Each of the converters 33a, 33b, and 33c can be switched in three ways: RGB, GBR, and BRG. The switched RGB signals are converted into digital signals by the A/D converter 33, and then converted into digital signals by the PWM signal output circuit 3.
4 by 33a, 33b.

33c, the pulse width is modulated according to the input order of PW
As the M output signal 35, the beam flow control electrode 4 is driven.

By first changing the order of the RGB signals using the switch 32 so that the amount of horizontal deflection is the smallest, it is possible to make the emission sizes of the rasters of each RGB color uniform and to obtain a uniform raster as a whole.

Note that it is also possible to switch the first ROB signal by wiring, etc., instead of switching by a switch.

Effects of the Invention As described above, the present invention coats the phosphor on the screen by several pixels on both the left and right ends, and furthermore, changes the order (RGB) of pulse width variable All signals applied to the beam flow control electrodes.
By changing the order of the RGB signals so that the amount of horizontal deflection is minimized, the emitted light size of the raster of each RGB color can be made uniform without damaging the picture elements, and the overall screen can be improved. You can get a raster.

[Brief explanation of drawings]

FIG. 1 is a block diagram of essential parts of an image display device according to an embodiment of the present invention, FIGS. 2a and b are schematic diagrams of an image display element used in the present invention viewed from above, and FIG. FIG. 2 is an exploded perspective view of an image display element used in FIG. 1... Back IT pole, 2... Line cathode, 3
...Beam extraction electrode, 4...Beam flow control electrode, 5...Focusing electrode, 6...
Horizontal deflection electrode, 7... Vertical deflection electrode, 8...
... Screen plate, 20 ... Phosphor, 21.
...Glass plate, 31...Beam flow trajectory,
32... Switch, 33... A/D converter, 34... PWM signal output circuit.

Claims (1)

[Claims] A screen coated with a phosphor that emits light when irradiated with an electron beam; an electron beam source that generates an electron beam for each vertical division of the screen on the screen; separation means for separating the electron beam generated by the beam source into each horizontal section and irradiating the separated electron beams onto the screen; a deflection electrode that deflects in stages; a beam flow control electrode that controls the amount of light emitted from each pixel on the screen by controlling the amount of irradiation of the screen with the electron beam separated for each horizontal section; Each picture element includes a focusing electrode that controls the size of light emitted by the electron beam on the phosphor surface, a back electrode that controls the amount of electron beam from the electron beam source, and a beam extraction electrode that controls the total amount of the electron beam. In preparation, the phosphor to be coated on the screen is coated on both the left and right ends by several picture elements, and the order of pulse width modulation signals (RGB) to be applied to the beam flow control electrode is determined.
An image display device characterized in that it is configured to be able to change the image display device.