JPH10154469A - Color display method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the resolution of an image, without increasing the number of three primary color-emitting points or lines of a color picture tube. SOLUTION: In a color display picture tube, in which three electron guns respectively radiation electron beam to RGB phosphor dots through-holes 30, 32 of a shadow mask or through-slits of aperture grill, the number of the holes or the slits are increased by three times at equal intervals and modulated RGB signals to be applied to respective electron guns are synchronously switched at the deflection angle of the electron beam. Detecting elements 36, 37 indexing the color which a phosphor emits at first at the time of scanning are arranged in vertical direction in the front glass in the left side of the picture tube.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color display method for a color CRT.

[0002]

2. Description of the Prior Art FIG. 1 is a schematic view of a round-hole type color cathode-ray tube of a shadow mask with a 3-electron gun delta arrangement, for example. In this figure, three electron guns 12 arranged in delta form:
The electron beams 14R, 14G, and 14B are focused through the shadow mask 16 onto the RGB phosphor dots 20 applied to the front glass 18 at regular intervals.

Further, each of the electron beams 14R, 14G, 14
B is scanned in the horizontal and vertical directions by the deflection coil 22 and collected by the metal back 24. FIG. 2 shows a light-emitting surface of the front glass 18, and R, G, and B indicate portions where red, green, and blue (the three primary colors of light) phosphors are applied, respectively.

[0004] In FIG. 2, in the prior art, each pixel is [R1
1, G12, B21], [R14, G15, B24]
Etc. [R22 / G23 / B33], [R25 / G26 /
B36].

Accordingly, since the arrangement of the three electron guns and the RGB color signals applied to each electron gun are fixed, for example, in one-line scanning, [R11, G12, B21] and [R14, G15, B24] are used. ] Phosphor [R22 · G]
23 · B13] is not effectively used, and there is a limit in obtaining a high-resolution image.

In a "color display device" disclosed in Japanese Patent Application Laid-Open No. 55-936, the beam spot is moved in the horizontal direction by about half the pitch of the shadow mask over the entire screen to increase the resolution. However, problems such as a change in the light emitting area ratio of each pixel and a change in color occur in the current television having 525 scanning lines. A similar problem occurs in a high definition television (HDTV) with 1125 scanning lines employing the same display method.

[0007]

SUMMARY OF THE INVENTION In view of the above problems, the present invention increases the number of pixels without increasing the number of light emitting points or light emitting lines (phosphors) and without changing the light emitting area ratio of each pixel. Accordingly, an object of the present invention is to provide a color display method for obtaining an image with improved resolution and brightness.

[0008]

A color display method according to the present invention is a color display in which three electron guns for irradiating an electron beam to RGB phosphors through holes of a shadow mask or slits of an aperture grille are arranged in a delta or inline manner. In a cathode ray tube, the number of the holes or slits is formed three times at equal intervals, and the modulation R applied to each electron gun is adjusted.
The GB signal is switched in synchronization with the deflection angle of the electron beam.

In the vicinity of the phosphor dots on the left side of the cathode ray tube, detection elements for indicating a color which is initially fluorescent at the time of scanning are arranged, for example, in a vertical direction. That is, the emission color of each electron beam is not fixed, and each electron beam is R
.., Or R → B → G → R..., And the number of pixels in the horizontal direction is particularly tripled. Therefore, the number of holes in the shadow mask or the number of slits in the aperture grille is three times as large as that in the related art.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS For example, in a conventional color display system, 3
Since each electron beam emitted from one of the electron guns emits one color, one pixel has, for example, [R11, G12, B21] and [R14, G15] for horizontal scanning as shown in FIG.
B24], R22G23B33, R25
G26 / B36].

In the color display method according to the present invention, for example, [R11, G12, B21] is set as one pixel, and [G12
[B13 · R22] as an additional pixel, and [B13 · R14]
G13] is the next additional pixel.

That is, when m is an odd number, [R _m , 3 <sub>n
+ 1 · G m, 3 n</sub> + 2 · B m + 1, 3 n + 1],
_{[G m, 3 n + 2} · B m, 3 n + 3 · R m + 1, 3 n +
_{2], [B m, 3} n + 3 · R m, 3 n + 4 · G m + 1,
_3n + ₃ ].

When m is an even number, [B _m , 3 _n + ₁ ·
_{R m, 3 n + 2 ·} G m + 1, 3 n + 2], [R m, 3 n
_{+ 2 · G m, 3 n} + 3 · B m + 1, 3 n + 3],
_{[G m, 3 n + 3} · B m, 3 n + 4 · R m + 1, 3 n +
₄ ], a pixel is formed. Here, m is a positive integer,
n is a positive integer including 0.

Accordingly, the holes formed in the shadow mask are three times as large in the horizontal direction as the solid holes 30 are formed in the same arrangement as in the prior art, and the dotted holes 32 are added corresponding to the additional pixels. To increase. In the case of an aperture grill,
Similarly, the number of slits increases three times in the horizontal direction as compared with the related art.

Also, the electron beams of the three electron guns 12 that have been responsible for each of the R, G, and B colors emit R → G, G →
B, B → R are switched to [G23 / B21 / R2
2] to obtain the next one pixel. Similarly, each electron beam is switched from G → B, B → R, R → G to [B13 · R
22 · G15] to constitute one pixel.

Similarly, pixels can be sequentially set in the vertical scanning. Thus, the hole 32 of the shadow mask
Alternatively, when the electron beam is scanned in the horizontal or vertical direction by increasing the slit of the aperture grill three times, the number of light emitting points or lines of the phosphor dots or lines is increased, and the light emitting area ratio of each pixel is changed. A high-resolution image can be obtained without any problem.

Of course, there is no occurrence of color change as in the prior art. For horizontal scanning, [R11 · G1
Even if the pixels are configured as [2 · B21] → [B13 · R22 · G15] →..., The resolution is improved about three times as compared with the conventional method.

FIG. 3 shows a "color display method" according to the present invention.
1 shows an embodiment of the video output circuit of FIG. In the figure, the red (R), green (G), and blue (B) luminance modulation signals are applied to the first grids g1a, g1b, and g1c of the electron guns (a), (b), and (c) by switches S1 to S9. Are applied in a time sharing manner.

For example, in the electron gun (a), S1 to S
3, the RGB modulated signals are sequentially selected and applied to the first grid g1a located in front of the cathode Ka. As a result, the intensity of the electron beam of the electron gun (a) is controlled based on the modulation signal of each color, and the color of light emission is changed in the order of red → green → blue → red →. Glow body dots.

When the assigned emission colors of the electron guns (b) and (c) are sequentially changed as in the above example, the electron guns (a), (b) and (c) are shown in FIG. Red, green, and blue light is emitted at such timing.

The operation timings of the switches S1 to S9 are as follows. At time t1, S1, S5, S9 are on (others are off) At time t2, S2, S6, S7 are on (others are off) At time t3, S3, S4, S8 are on (others are off) At time t4, S1, S5 S5 and S9 are on (others are off).

The switches S1 to S9 are, for example, L
ED, Photocoupler with output side composed of FET (Photo MOS relay AQV210S manufactured by Matsushita Electric Works or CM
A combination circuit of an OS switch “4066B” (bidirectional switch) and a level shift is used. Also, S1
Switching from S3 to S4 to S6 to S7 to S9 can be performed by a ring counter circuit or the like.

Next, it is necessary to recognize whether the arrangement of the three color phosphors corresponding to the holes of the first shadow mask is RGB or BRG (GBR). In the arrangement shown in FIG. 2, when the electron beam is scanned in the horizontal direction, the arrangement that appears first is RGB or BRG.

Accordingly, at least two index holes 34 are formed in the shadow mask on the left side of the holes of the shadow mask corresponding to the phosphors of the three colors arranged first.
On the other hand, current detecting elements or electron beam detecting elements 36 and 37 are decoded and arranged on the front glass (instead of the fluorescent material) irradiated with the electron beam through each index hole.
In the case of the aperture grille, one index slit is formed on the left side of the slit corresponding to the phosphors of the three colors arranged first, and the current detection element is formed on the glass surface irradiated with the electron beam through each index slit. Alternatively, an array of electron beam detection elements is arranged.

The first row of current detecting elements or electron beam detecting elements 36 are provided for synchronizing the scanning and the luminance modulation signal, and the second row of current detecting elements or electron beam detecting elements 37 are provided with the first RGB or electron beam detecting elements. It is provided every other row to identify phosphors in the BRG arrangement. These current detecting elements or electron beam detecting elements are arranged at regular intervals including holes in the shadow mask including the index holes 34, and scanning is performed at a constant speed. Therefore, they are connected in parallel and taken out by one signal line. . This signal is decoded into an initial value setting and start signal of the ring counter. Alternatively, in the case of an aperture grill, a current detection element or an electron beam detection element array is provided to synchronize scanning with a luminance modulation signal.

Therefore, according to the present invention, in the conventional cathode ray tube, the number of holes of the shadow mask or the number of slits of the aperture grill is increased by about three times, and the indicator area is provided on the left side on the back side of the front glass coated with the fluorescent material. By simply providing the same, it is possible to obtain three times the resolution as compared with the conventional case.

Although a three-electron gun delta-arranged shadow mask circular hole picture tube has been described above, a similar effect can be obtained with a three-electron gun in-line array picture tube having an aperture grille or a trinitron tube.

[0028]

As described above, according to the present invention, the resolution of an image can be increased without increasing the number of light emitting points or lines (phosphors) of the three primary colors of a color CRT.

In the color picture tube, since most of the electron beam flows to the shadow mask or the aperture grill, it is difficult for the color picture tube to shine the phosphor through the hole.
In the color display method of the present invention, since the number of holes in the shadow mask or the number of slits in the aperture grille also increases, the number of electron beams for illuminating the phosphor increases, and the brightness of the screen improves.

In the case of the HDTV, if the driving method as in the present invention is adopted, a higher definition and brighter image can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic view of a three-electron gun delta arrangement shadow mask round hole picture tube.

FIG. 2 is a view showing a luminous body applied to a front glass of the picture tube of FIG. 1;

FIG. 3 is an embodiment of a video output circuit of a “color display method” according to the present invention.

FIG. 4 is an irradiation timing chart of a color corresponding electron beam from a three-electron gun.

[Explanation of symbols]

 18 Front glass 20 Phosphor dot 32 Additional hole 34 Index hole

Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01J 31/20 H01J 31/20 E H04N 9/16 H04N 9/16

Claims (2)

[Claims] 1. A color display cathode-ray tube in which three electron guns for irradiating an RGB phosphor with electron beams through holes of a shadow mask or slits of an aperture grill are arranged in a delta or in-line manner, wherein the number of the holes or the slits is three. 2. A color display method comprising: increasing the modulated RGB signals applied to each electron gun in synchronism with the deflection angle of the electron beam. 2. In the vicinity of a phosphor on the left side of the cathode ray tube,
2. The method of claim 1, wherein the detection elements that indicate the color that is initially fluorescent when scanned are arranged in one direction.