JPS6226977A - Television receiver - Google Patents

Abstract

PURPOSE:To improve the picture quality of a reproduced picture without deteriorating the horizontal resolution by making the shape of cross section of an electron beam subject to sub scanning for plural times during the main scanning period just after the irradiation from an electron gun as a shape where the width in the main scanning direction is larger than the width in the sub scanning direction. CONSTITUTION:The cross section shape of the 4th grid G4 being a focusing electrode is selected as an elliptic shape longer vertically so that the cross section shape of the electron beam EB just after the irradiation from electron guns 10R, 10G, 10B is a shape where the vertical width is larger than the horizontal width. Thus, the luminous part on a fluorescence screen 14 onto which the electron beam EB is irradiated through a hole 16 of a shadow mask 13 shows a nearly elliptic shape longer vertically, and the raster is broad vertically, then the rasters at odd and even number fields are overlapped mutually at upper and lower ridges. Thus, the apparent raster interval is almost eliminated and the coarseness on the reproduced pattern is made unremarkable.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to television receivers, particularly CRTs.
The cross-sectional shape of the electron beam that deflects and scans inside the (Catliode Ray Tube), that is, the spot shape, is made such that the width in the main scanning direction (generally vertical direction) is larger than the width in the sub-scanning direction (generally horizontal direction). The image quality of the reproduced m-image is improved by deforming the m-image.

(Prior Art) Generally, in a television receiver, as shown in FIG. 7, an electron beam FB emitted from an electron gun 2 disposed within < Cr By avoiding scanning, for example, it is possible to
A pre-vision receiver with a 30-second frame rate (-30 frames per second)
6 [field)] is played back.

(A shortcoming to be solved by the invention) By the way, in a television receiver that complies with the NTSC system, the horizontal trajectory of the double electron beam FB, that is, the number of rasters, depends on the size of the CRT. Relationship A [(There are 525 lines per frame.

Further, FIG. 8 is a schematic diagram of the main part of a general shadow mask type CRT, and as shown in this figure, the spot shape of the electron beam Ef3 formed on the shadow mask 4 in this CRT is is always a perfect circle.

The spot diameter of this electron beam [Mi[3] is expanded or contracted as appropriate depending on the level of the 4J luminescent signal in the television signal, so that this 01 <King's fluorescent surface; There are 41 light emitting areas (light 9 dots 1 - number) so that it can be illuminated. In addition, in this way, the electron beam "1
3 Spora I~(Y is appropriately variable b17)Ct.

1, but if the diameter is expanded 4 without limit, there will be problems such as the appropriate brightness of the fluorescent surface 3 or the prevention of water deterioration. I'm coming. For this reason, the above
The diameter is not limited to 0, but there are certain limits.

In this way, conventionally, in a general television receiver, the number of rasters per room and the diameter of the electron beam F B are 1, regardless of the size of
'□+1 was there.

Therefore, the recent increase in the size of television receivers:
As a result, the raster spacing inevitably becomes larger - ((]
Mau.

The roughness of the raster is noticeable as shown in Figure 9 of this/q.
The quality of the reproduced image is degraded]! - is the cause of
,Z,.

(Means for solving and solving the problem of interpolation) The present invention has been developed in view of the actual situation such as 1-). !
Reduce raster roughness in the sub-scanning direction without
Excellent image quality/: 'rl
Realize T'I! The purpose of the present invention is to provide a high-revision receiver.

Therefore, in order to achieve this goal, the present invention conducts multiple scans during the 10-scan interval as shown in FIG. 1. In [[3, cross-sectional shape 1 immediately after emission from the electron gun 10] 1, the width W1 in the main scanning direction is narrower than the width W2 in the sub-scanning direction LJ. Niunishita.

(Function) According to the present invention as described above, as shown in FIG. 2, the scanning line in the sub-scanning direction becomes -1- broad in the scanning direction. For this reason, it is possible to apply the present invention to a particularly large-sized digital engine receiver to fill in the raster interval of the sub-scan lth t+1 raster. The same effect can be obtained by narrowing the interval between (2 and 2).

J, ·) improves the image quality ()°l of +IJ/1 imageJ
I can do that.

-, 5- (Embodiments) Hereinafter, preferred embodiments of the present invention will be described in detail using FIGS. 1 to 6.

This embodiment is an example in which the present invention is applied to a color television receiver equipped with a general CRT 11 of the NTSC type and conforming to the NTSC system.
-811CRT'i1 is small in size as shown in FIG.
B, a light mask 13, and a fluorescent surface 14 are provided, and a deflection number 15 is attached with the mounting number -J.

I think J3 is in this CRTII, and each of the above electron guns 10
R, 1 (IG, 1013 Ni LJ, Illustrated E Neu C Ian T sl'J 7 [1 N], 121 parts, etc. 1 No. Red (lj>, Green (G).

A signal and a luminance signal are supplied to each of the ports 1 and 15 in FIG. It has become.

Also, l-n+F! 'Wi Koji On the first page, each [with,
G, B's fluorescence! Dots 14R and 14G coated with paint
, 14f3 are arranged in a certain regular arrangement 41.

In this case ct<-rii, as shown in Fig. 4, tN
[J row electron gun 101, qJ from 100.10B
The electron beams modulated by the 8-color fd of R, G, and n respectively [nee Bn, Ellq, and EBti are recessed in the ζ7 screen 13, If, and color sorted in the hole 16. Been E 81! 140 predetermined dora t-
14R, 14 (run-r' (run to 2, 14B).

Each of these Dora T-14R, 14G, 1413 LJ
, attenuated beam with headnote 1 as described above] 2F3 scale, E
Rq.

[ ] 3B is emitted and a predetermined image is reproduced 1J.

In addition, the above 8 Denryo B 8 F ['3 +<, [Bq
.

The EBs are arranged so that the recording surface 141- is deflected and scanned in the -1-scanning direction and the sub-scanning direction in the deflection field formed by the deflection field 15. (C-C is here,
.

In addition, in this embodiment, -1-u+F IE scan lj
Direction refers to both horizontal and vertical directions, and sub-scanning direction 1~ refers to the water pattern direction (
Assume that the horizontal deflection is performed 262 times and 5 times during the - vertical scanning period.

On the other hand, each of the ten electron guns 10R110G in this example
, 1013 is approximately small in size as shown in FIG.
+ 03 *') 41 G! ] are arranged in sequence.

MaI, Ko, -1: R+! 1st Nogane 33rd Grid G
+ + 02103 and 5th grid G 54i are each formed into a cylindrical shape with a circular cross-sectional shape and / (. , l/Niwa b11i+1 It is formed into a substantially elliptical shape that is elongated in the eight directions indicated by the arrows in the figure.

Electron guns like I(ノ'(, lho) HIR, 10G, IO
iJ at B, emitted from the cathode 21 heated by the heater 22 (the broken electrons (thermoelectrons) are
1;,:'r bundle (3-collected to form a beam; then this same beam 1.i, in crossover, constituted by the second and third grids 02103)A- Nonos [Nonos can suppress the divergence of B. Then, after being focused by the 11th red-colored Nonzu formed at the 4th grid G4 of -11, the 5th grid G! , through this electron gun 10R, 10G
.

It is emitted from 1013.

Here, in this example, the fourth electrode is the Toshu electrode.
By making the cross-sectional shape of the grid G4 substantially elliptical long in the vertical direction, this electron gun 1on) is formed.

HIG, 1(l [The cross-sectional shape of the electron beam immediately after being emitted from
1 method W1 is lit in horizontal width Ij direction w2 1. / gives a larger shape.

Here, the optimal ratio of Tokidai width and width W1 and w2 is CR
It varies depending on the type of T, for example, for a 26-inch telezig 1)-domain tube, a linen about 1.5 times W + <Y2 is appropriate, and for the same <26 inch high-definition tube If so, about 3 times (about 3 times was appropriate).

Isagi-oh, 1-The telejiri 1-node tube (1, the pitch (pixel pitch) of each hole in g stages on the Shitodo mask is 0.6
The quasi-beam diameter is 1.2 m and 1 degree, and the above-mentioned high-definition polishing tube has a hip of each hole of 0.311P as described above.
i! One standard beam diameter is approximately 0.6 degrees.

Therefore, in the television receiver of this embodiment,
The spot shape D2 of the electron beam E Fl formed on the spot mask 13 [of CRl' +1] is approximately elliptical in the vertical direction as shown in FIG. In addition, the electron beam [ ] 3 is passed through the hole 16 of this Shitodo mask 13.
The light-emitting portion on the fluorescent surface 14 that is irradiated has a substantially elliptical shape that is elongated in the vertical direction.

Therefore, in the television receiver according to this embodiment, since the raster becomes broad in the vertical direction, as shown in FIG. The edge and the lower edge overlap in a U-shaped manner.

Therefore, as shown in FIG. 2, in this embodiment, compared to the conventional one, the raster spacing on htt) can be almost eliminated, and the roughness on the reproduced image can be reduced by 1). can do.

Further, by making the width W2 in the horizontal direction of the cross-sectional shape D1 of the electron distribution beam EB the same as that of the prior art, the horizontal resolution is not particularly degraded.

In this way, in the television receiver according to this embodiment, J
It is possible to reduce the roughness of the raster in the horizontal direction of the moon, thereby significantly improving the quality of the reproduced image.

In the present invention, the means ( ) for improving the cross-sectional shape of the electronic gun EB in the vertical direction is not limited to this embodiment, and for example, the means for improving the cross-sectional shape of the electronic gun EB are
The grid G 21 G 3r G 41 G5 may be formed into a substantially elliptical shape, or the convergence control of the electron beam EB may be performed separately horizontally and vertically.

Further, the cross-sectional shape of the electron beam E8 is not limited to a substantially elliptical shape as in this embodiment, but may be, for example, substantially rectangular or oval in the vertical direction.

(Effect of Brightness) As is clear from the above description, according to the present invention, it is possible to improve the image quality of a reproduced image without degrading the horizontal resolution.

This effect is particularly noticeable when the present invention is applied to a large-sized television receiver.

[Brief explanation of the drawing]

Fig. 1 is a characteristic diagram showing the features of the present invention, Fig. 2 is a diagram schematically showing a =10- reproduced image of a preview receiver to which the invention is applied, and Fig. 3 is a diagram showing the present embodiment. Fig. 4 is a perspective view of the main parts of the electron gun, Fig. 5 is an enlarged cross-sectional view of the electron gun, and Fig. 6 is a raster of the reproduced image. FIG. 7 is a schematic diagram showing the CR of a general television receiver, and FIG.
(A perspective view of the concave part of [, FIG. 9 is a schematic diagram showing a reproduced image of the J television receiver shown in FIG. 7. ...Cross-sectional shape of the electron beam, Wl...Width dimension of the electron beam in the main scanning direction, W2...
・Width in scanning direction of electron beam -> l method. Figure 3 [4-day 1oR (lOcIX108) Figure 5 Figure 7 Doo No. 81! ! ,,． 15X9- Figure 9

Claims (1)

[Claims] The cross-sectional shape of the electron beam that is sub-scanned multiple times during one main-scanning period immediately after exiting from the electron gun is such that the width in the main-scanning direction is larger than the width in the sub-scanning direction. A television receiver characterized by: