JPH0778580A - Color image tube - Google Patents

Abstract

PURPOSE:To accomplish a high brightness color image tube in the index system while color purity is well secured. CONSTITUTION:A metal back layer 6 is provide behind a number of sets of R, G, B phosphor stripes arranged repetitively one by one in the horizontal direction in a certain specified sequence where the three primary colors are provided as extending in the vertical direction, and further behind the effective image display plane, an index phosphor stripe group 7 is furnished in a specified relative positioning to the arrangement of the R, G, B phosphor stripes. In this beam index tube having a fluorescent screen 5, an electron gun 1 is installed so that a plurality of electron beams 2a, 2b are emitted in the same direction as the direction in which the R, G, B phosphor stripes exist.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color picture tube used in a color picture display device such as a television receiver, and more particularly to a beam index tube type color picture tube.

[0002]

6 and 7 are horizontal and vertical sectional views showing the structure of a conventional index type color picture tube. In the figure, 1 is an electron gun for emitting an electron beam 2, 3 is a deflection yoke, 4 is a glass bulb, 5 is blue and green,
Each of the red phosphor stripes extends in the vertical direction, and in the horizontal direction, the phosphor screen is arranged so that blue, green, and red are sequentially repeated. 6 is a metal back layer formed behind the fluorescent stripe group, and 7 is an index fluorescent stripe.

Next, the operation will be described. The electron beam 2 emitted from the electron gun 1 is deflected and scanned by the deflection yoke 3 over the entire screen. At this time, the position of the electron beam is detected by the light emission of the index phosphor stripe 7 formed on the back surface of the phosphor screen 5, and the beam current corresponding to the video signal is detected for the phosphor stripes of three colors of blue, green and red. The color image is reproduced by streaming.

[0004]

Since the conventional index type color picture tube is constructed as described above, as shown in FIG. 8, the beam spot diameter 8 is set to one fluorescence in order to secure color purity. Since it is necessary to limit the width of the body stripe and the black portions on both sides thereof to the total width or less, the beam current cannot be sufficiently increased, and high brightness cannot be obtained.

The present invention is intended to solve the above problems, and it is possible to improve the brightness while ensuring the color purity by making the electron beam and the phosphor correspond to each other without deteriorating the image quality. The aim is to get a color video tube that can.

[0006]

In a color picture tube according to the present invention, phosphors of three primary colors of red, green and blue are arranged in stripes in respective predetermined directions, and these phosphors are perpendicular to a predetermined direction. The fluorescent screens that are formed by repeatedly arranging them sequentially in a predetermined order in different directions, and the stripe-shaped index phosphors are arranged at predetermined relative positions with respect to the array of the three-primary-color phosphors in a stripe pattern on the fluorescent screen. In the color picture tube configured as described above, the electron gun is arranged so as to emit a plurality of electron beams in the same direction as the extending direction of the three primary color phosphor stripes.

[0007]

In the color picture tube according to the present invention, a plurality of electron guns for emitting electron beams are arranged and one spot is formed by a plurality of electron beams. The beam spot diameter can be reduced with the current, and the beam current amount can be increased with the same electron beam spot diameter.

[0008]

【Example】

Example 1. Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are a horizontal sectional view and a vertical sectional view of a color picture tube showing an embodiment of the present invention. In the figure, 1 is an electron gun that emits a plurality of (two in this embodiment) electron beams, 2a and 2b are two electron beams emitted from the electron gun 1, 3 is a deflection yoke, and 4 is a glass bulb. Reference numeral 5 denotes a phosphor screen in which blue, green, and red phosphor stripes extend in the vertical direction, and blue, green, and red are sequentially arranged in the horizontal direction. 6 is a metal back layer formed behind the phosphor stripe group, and 7 is an index phosphor stripe.

Next, the operation will be described. Two electron beams 2a emitted from the electron gun 1 arranged in the vertical direction,
As shown in FIG. 3, 2b is set so that two electron beam spots 8 overlap each other in the center of the screen. During operation, the electron beam deflection yoke 3 deflects and scans the entire area of the screen. At this time, the overlapping point of the two electron beams comes to the front of the fluorescent screen. Therefore, as shown in FIG. Although there is a vertical shift in the plane, the phosphor stripes of the three colors blue, green, and red are formed so as to extend in the vertical direction, so the color purity is not affected. Moreover, since the electron beam is composed of two lines, 2a and 2b, the amount of current per line is half that of the conventional one, and the brightness can be increased while keeping the electron beam diameter small.

Embodiment 2. In the first embodiment, the two electron beams are set in advance so that the beam spots overlap each other at the center of the screen. However, as shown in FIG.
The polar correction magnetic field 9 may be used to correct the trajectories of the two electron beams 2a and 2b, so that the beam spots can be optimally overlapped over the entire screen.

Embodiment 3. Further, in Example 2, the static magnetic field was used as the quadrupole correction magnetic field for correction, but as shown in FIG. 5, the dynamic correction magnetic field 10 is formed by the electromagnetic coil,
The optimum beam spot overlap may be obtained by changing the current flowing through the electromagnetic coil in accordance with the deflection position of the beam spot over the entire screen to correct the trajectory of the electron beam.

[0012]

As described above, according to the present invention, in a color picture tube of the index system or the like, a plurality of electron guns are arranged in the direction along the phosphor stripe and a spot is formed by a plurality of electron beams. Therefore, the spot diameter of the electron beam can be kept small even if the beam current increases,
There is an effect that luminance can be increased while ensuring color purity.

[Brief description of drawings]

FIG. 1 is a horizontal sectional view showing a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of FIG.

FIG. 3 is an explanatory diagram showing a trajectory of an electron beam according to the first embodiment.

FIG. 4 is an explanatory view showing the principle of Embodiment 2 of the present invention.

FIG. 5 is an explanatory view showing the principle of Embodiment 3 of the present invention.

FIG. 6 is a horizontal cross-sectional view showing a conventional index type color picture tube.

7 is a vertical cross-sectional view of FIG.

FIG. 8 is a diagram showing a positional relationship between a fluorescent screen and a beam spot in an index type color picture tube.

[Explanation of symbols]

 1 Electron Gun 2a Electron Beam 2b Electron Beam 3 Deflection Yoke 4 Glass Bulb 5 Fluorescent Surface 6 Metal Back Layer 7 Index Phosphor Stripe 8 Beam Spot 9 Static Quadrupole Correction Magnetic Field 10 Dynamic Correction Magnetic Field

Claims (3)

[Claims] 1. Red, green, and blue three-primary color phosphors are respectively arranged in a predetermined direction in a stripe shape, and these phosphors are repeatedly arranged in a predetermined order in a direction perpendicular to the predetermined direction. In the color picture tube having the above-mentioned three primary colors, the stripe-shaped index phosphor is arranged at a predetermined relative position with respect to the array of the three-primary-color phosphors in the stripe shape of the phosphor screen. A color picture tube characterized in that an electron gun is arranged so as to emit a plurality of electron beams in the same direction as the extending direction of the phosphor stripe. 2. The color picture tube according to claim 1, further comprising a static quadrupole correction magnetic field for correcting orbits of a plurality of electron beams emitted from the electron gun. 3. A dynamic correction magnetic field using an electromagnetic coil for correcting the orbits of a plurality of electron beams emitted from the electron gun in accordance with the deflection position of the electron beam over the entire screen. The color video tube according to claim 1.