JP3464707B2 - Color picture tube - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color picture tube having a shadow mask, and more particularly to a color picture tube having a large number of phosphor dots. The present invention relates to a color picture tube in which a shadow mask having a large number of round holes is arranged and an electron beam from an electron gun arranged in-line is projected on the phosphor screen. 2. Description of the Related Art Currently used color picture tubes are a combination of an in-line arranged electron gun and a striped phosphor screen, and an in-line arranged electron gun and a dot type phosphor screen. There is a combination with a phosphor screen. The former color picture tube is used for televisions mainly for home use, and the latter color picture tube is a computer terminal particularly required for high resolution. And the like. Generally, a color picture tube of the type in which a dot-type phosphor screen is projected with an electron beam from an electron gun arranged in-line is a type of color picture tube which uses an electron beam from an electron gun arranged in-line with a stripe-type phosphor screen. Compared to the projection type color picture tube, the dispersion of the horizontal and vertical landing characteristics is large,
Good color purity cannot be obtained, and if the arrangement pitch of the dot-type phosphors is formed small in order to obtain high resolution, the dispersion of the landing characteristics in the peripheral portion of the shadow mask becomes larger. As a result, the color purity is further deteriorated. [0004] In order to improve such a point, the horizontal and vertical pitches of the circular openings in the shadow mask are set to be larger in the peripheral portion than in the central portion of the shadow mask. A color picture tube having a shadow mask in which a so-called circular opening is formed at a variable arrangement pitch has been developed.
It is disclosed in JP-A-59-194329. [0005] The above-mentioned JP-A-59-19
The color picture tube disclosed in Japanese Patent No. 4329 (in which the round openings of the shadow mask are formed at a variable arrangement pitch) is three in comparison with the conventional one in which the round openings of the shadow mask are formed at a fixed arrangement pitch. It is possible to prevent the deterioration of the color purity due to the inclination of each of the electron guns arranged in-line and the three dot-shaped phosphors corresponding to the three electron guns. However, when the pitch of the circular openings of the shadow mask is configured to be variable in the vertical and / or horizontal directions of the shadow mask as in the color picture tube disclosed in the above disclosure, the phosphor is Screen
Because the arrangement of dot-type phosphors in the center and the arrangement of dot-type phosphors in the periphery are different in
The landing tolerance varies depending on the direction, and when a landing change occurs due to terrestrial magnetism, the degree of color purity degradation varies depending on the position of the phosphor screen (screen). FIGS. 6 to 8 show the arrangement of the circular apertures when the arrangement pitch of the circular apertures of the shadow mask is changed in the vertical and / or horizontal directions in the color picture tube disclosed above. FIG. 6 is an explanatory diagram showing the relationship with the landing tolerance of other colors, in which FIG. 6 shows a case where the arrangement pitch of the round openings is made variable only in the horizontal direction, and FIG. FIG. 8 shows a case where the arrangement pitch of the round openings is made variable in the horizontal and vertical directions. In FIGS. 6 to 8, reference numeral 21 denotes a round opening of a shadow mask, reference numeral 22 denotes a phosphor dot, reference numeral 23 denotes an electron beam landing area. Every time,
Is the horizontal other color hitting landing tolerance in the same portion, the horizontal other color hitting landing tolerance in the horizontal peripheral portion of the shadow mask is the horizontal other color hitting landing tolerance in the same portion, and the shadow is The other-color hitting landing tolerance in the oblique direction in the peripheral portion of the vertical portion of the mask, the other-color landing landing tolerance in the horizontal direction in the same portion, the other-color landing landing tolerance in the oblique direction at the corner portion of the shadow mask, and Is the horizontal landing tolerance for other colors in the same portion. As shown in FIG. 6, the arrangement pitch of the circular openings in the vertical direction of the shadow mask is a _0.
And the arrangement pitch b ₁ , b ₂ , b ₃ ,..., B _n of the round openings in the horizontal direction of the shadow mask is b ₁
> B ₂ > b ₃ >...> B _n , when the arrangement pitch increases from the central portion to the peripheral portion in the horizontal direction, the peripheral portion in the horizontal direction of the phosphor screen (screen) In addition, the horizontal other-color hitting landing margin at the corner portion is increased, but the diagonal other-color landing landing latitude is not increased and remains unchanged. Next, as shown in FIG. 7, the arrangement pitch of each round opening in the horizontal direction of the shadow mask is b ₀ , and the arrangement pitch a ₁ of each round opening in the vertical direction of the shadow mask. _{a 2, a 3, ... ...} , a n
_{There, a 1> a 2> a} 3>......> as a _n, when the arrangement pitch is spread toward the peripheral portion in the vertical direction from the central portion, fluorescers screen (screen) In the peripheral portion and the corner portion in the vertical direction, the landing tolerance for the other-color hitting in the oblique direction increases, but the landing tolerance for the other-color hitting in the horizontal direction remains unchanged. Further, as shown in FIG. 8, the arrangement pitches b ₁ , b ₂ , b ₃ ,..., B _n of the round openings in the horizontal direction of the shadow mask are b ₁ > b ₂ > b _3.
...,> _Bn , the arrangement pitches a ₁ , a ₂ , a ₃ ,... Of the circular openings in the vertical direction of the shadow mask.
..., if a _{n is, a 1> a 2> a} 3> ... ...> as a _n, has spread the arrangement pitch toward the peripheral portion from each center portion in the horizontal direction and the vertical direction, Imbalance between the horizontal other-color landing landing margin and the diagonal other-color landing landing margin at the horizontal and vertical peripheral and corner portions of the phosphor screen (screen). Will occur. As described above, Japanese Patent Application Laid-Open No. Sho 59-19432 discloses
The color picture tube disclosed in Japanese Patent No. 9 has a problem that the landing tolerance of the other color for each direction is different, and the degree of color purity deterioration at each position of the phosphor screen (screen) is different. The present invention has been made to eliminate the above problems,
An object of the present invention is to provide a color picture tube in which the landing tolerance of other colors is made uniform and the degree of color purity deterioration is reduced uniformly over the entire screen regardless of the arrangement pitch of each opening of the shadow mask. . [0014] In order to achieve the above object, the present invention provides at least a phosphor screen formed of a large number of phosphor dots and applied to an inner surface of a face plate; In a color picture tube provided with a shadow mask having a number of circular openings at positions corresponding to the number of phosphor dots and an electron gun arranged in-line at a neck portion, the shadow is arranged opposite to the body screen. The horizontal and / or vertical pitch at which the circular openings of the mask are arranged can be changed from the center of the shadow mask to the periphery.
With sequentially increasing toward the edge portion, corresponding to the increase of the arrangement pitch, successively increasing the diameter of the direction in which the arrangement pitch of the round opening slide into increasing the shadow mask, before
The shape of the circular opening should be changed horizontally and / or vertically.
A means for forming a non-circular opening that gradually extends in the direction . According to the above means, the horizontal and / or vertical arrangement pitch of the circular openings in the central portion of the shadow mask is different from the horizontal and / or vertical positions of the openings in the peripheral portion of the shadow mask. The arrangement pitch in the direction is sequentially increased, and in response to the increase in the arrangement pitch, the opening in the peripheral portion of the shadow mask is a non-circular opening having a longer diameter in the direction in which the arrangement pitch is increased. In the case where the horizontal landing allowance and the other color hitting landing allowance differ from each other in accordance with the variable pitch of the round openings, the round openings of the shadow mask are changed. While maintaining the diameter of the round opening in the direction with the smaller landing tolerance, the diameter of the round opening in the direction with the larger landing tolerance is increased. Since the openings are changed into substantially elliptical openings, the landing tolerances of other colors in each direction can be made substantially equal without reducing the opening area (electron beam transmittance) of each opening, and the entire screen can be obtained. Over time, the deterioration of color purity can be made uniform and small. Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a sectional view showing the overall structure of an embodiment of a color picture tube according to the present invention. In FIG. 1, 1 is a panel portion, 2 is a funnel portion, 3 is a neck portion, 4 is a phosphor screen, 5 is a shadow mask, 6 is a mask frame, 7 is a deflection yoke,
Reference numeral 8 denotes a purity adjustment magnet, 9 denotes a center beam static convergence adjustment magnet, 10 denotes a side beam static convergence adjustment magnet, 11 denotes an electron gun, and 12 denotes an electron beam. The tube constituting the color picture tube is
A panel unit 1 arranged on the front side, a neck unit 3 containing three electron guns 11 arranged inline, and a funnel unit 2 arranged between the panel unit 1 and the neck unit 3
It consists of The panel unit 1 has a face plate on the front surface, and a phosphor screen 4 is arranged and formed on the inner surface of the face plate. The phosphor screen 4 has a large number of regularly arranged three-color dot-shaped phosphors. It is composed of light bodies. A mask frame 6 is fixedly arranged inside the peripheral portion of the panel portion 1, and the mask frame 6 is attached so that the shadow mask 5 is opposed to the phosphor screen 4. The deflection yoke 7 includes the funnel 2
And the neck portion 3
A magnet 8 for adjusting the purity, a magnet 9 for adjusting the center beam static convergence, and a magnet 10 for adjusting the side beam static convergence are arranged side by side on the outer side of each of them. Three electron beams 12 projected from an electron gun 11 (only one is shown)
Are configured to be deflected in a predetermined direction by a deflection yoke 7 and then reach the phosphor screen 4 through an opening (not shown) of the shadow mask 5. In the above configuration, the image display operation of the color picture tube shown in the present embodiment is the same as the image display operation of the known color picture tube, and such operation is already known. The description of the image display operation of the color picture tube according to the present embodiment will be omitted. Next, FIG. 2 is an enlarged view showing an example of the arrangement of the phosphor dots at a very small portion at the center and corners of the phosphor screen 4 in the embodiment of FIG. In FIG. 2, reference numeral 13 denotes a phosphor dot;
Denotes an electron beam landing area, and the same components as those shown in FIG. 1 are denoted by the same reference numerals. [0023] As shown in FIG. 2, in the central portion of the fluorescers screen 4, a b ₁ a horizontal arrangement pitch of phosphor dots 13, the oblique direction of the arrangement pitch is a
_On the other hand, in the corner portion of the phosphor screen 4, the horizontal arrangement pitch of the phosphor dots 13 is b _n larger than b ₁ and the oblique arrangement pitch is a _{1 in} the corner portion of the phosphor screen 4. A _m (in this case, b _n >
a _m ). However, the electron beam landing area 14 in each phosphor dot 13 is
Regardless of the arrangement position of the phosphor dots 13 on the phosphor screen 4, they are contained within a certain circle centered on the phosphor dots 13. FIGS. 3 to 5 show a circular picture tube in the case of the color picture tube of the embodiment of FIG. 1 in which the pitch of the circular mask openings in the shadow mask is variable in the vertical and / or horizontal directions. FIG. 3 is an explanatory diagram showing the relationship between the arrangement and the shape state of each color and the landing tolerance of other colors. FIG. 3 shows a case where the arrangement pitch of the circular openings is made variable only in the horizontal direction, and FIG. If is made variable only in the vertical direction,
FIG. 5 shows a case in which the arrangement pitch of the circular openings is made variable in the horizontal and vertical directions. The arrangement of the circular openings in the known color picture tube shown in FIGS. It corresponds to the explanatory view showing the relationship with the hitting landing margin, respectively. In FIGS. 3 to 5, reference numeral 15 denotes a round or elliptical opening of the shadow mask 5, and the same components as those shown in FIGS. 1 and 2 are denoted by the same reference numerals. I have. Also in this case,
Is the landing tolerance of the other direction in the oblique direction in the central portion of the shadow mask, is the landing tolerance of the other color in the horizontal direction in the same portion, and is the landing tolerance of the other direction in the oblique direction in the horizontal portion of the shadow mask. , Is the horizontal other color hitting landing tolerance in the same portion, is the oblique direction other color hitting landing tolerance in the peripheral portion of the vertical portion of the shadow mask, is the horizontal other color hitting landing tolerance in the same portion,
Indicates the landing tolerance of the other color in the oblique direction at the corner portion of the shadow mask, and the landing tolerance of the other color in the horizontal direction at the same portion. Here, the arrangement of the openings formed in the shadow mask 5 of this embodiment and the setting of those opening shapes will be described with reference to FIGS. [0027] First, as shown in FIG. 3, a a ₀ common arrangement pitch of the round opening in the vertical direction of the shadow mask 5, the round opening in the horizontal direction of the shadow mask arrangement pitch b ₁ , B ₂ , b ₃ , ..., b _n
However, in the case where the arrangement pitch increases from the central portion to the peripheral portion in the horizontal direction as in b ₁ > b ₂ > b ₃ >...> B _n , the shadow mask 5 is formed in a round shape. If only the openings are used, as described in the description of FIG. 6, the horizontal other-color landing landing allowance in the horizontal peripheral portion and the corner portion of the phosphor screen (screen) becomes large. Landing tolerance of other colors in the diagonal direction does not increase. Therefore, in this embodiment, the opening 15 of the shadow mask is used.
The diameter of the opening 15 in the horizontal direction is increased so as to correspond to the ratio of the spread of the arrangement pitch of the openings 15 in the horizontal direction, so that the opening 15 becomes an elliptical opening 15 having a major axis in the horizontal direction. . With such a configuration, the ratio between the other-color landing landing allowance in the oblique direction and the other-color landing landing tolerance in the horizontal direction in each portion of the phosphor screen 4 (screen) is the same. In addition, in accordance with the spread of the arrangement pitch of the openings 15 in the horizontal direction, it is possible to increase the other color hitting landing latitude in the oblique direction and the other color hitting landing latitude in the horizontal direction at substantially the same rate. it can. Next, as shown in FIG. 4, a b ₀ common arrangement pitch of the round opening in the horizontal direction of the shadow mask 5, the round opening in the vertical direction of the shadow mask arrangement pitch a _{1, a 2, a 3,} ... ..., a n
_{There, a 1> a 2> a} 3>......> as a _n, when the vertical direction from the central moieties as spread the arrangement pitch toward the periphery portion, round the shadow mask 5 If only the openings are used, as described in the description of FIG. 7, the other-color hitting landing tolerance in the oblique direction at the peripheral portion and the corner portion in the vertical direction of the phosphor screen (screen) becomes large. Landing tolerance for other color printing in the horizontal direction does not increase. Therefore, in this embodiment, the opening 15 of the shadow mask is used.
The diameter of the opening 15 in the vertical direction is increased so as to correspond to the ratio of the spread of the arrangement pitch of the openings 15 in the vertical direction, so that the opening 15 becomes an elliptical opening 15 having the major axis in the vertical direction. . With such a configuration, the ratio between the other-color landing landing allowance in the oblique direction and the other-color landing landing tolerance in the horizontal direction in each portion of the phosphor screen 4 (screen) is the same. In addition, it is possible to increase the diagonal other-color hitting landing latitude and the horizontal other-color hitting landing tolerance at substantially the same rate in accordance with the spread of the arrangement pitch of the openings 15 in the vertical direction. it can. Next, as shown in FIG. 5, the arrangement pitches b ₁ , b ₂ , b ₃ ,..., B _n of the round openings in the horizontal direction of the shadow mask are b ₁ > b ₂ > b _3.
...,> _Bn , the arrangement pitches a ₁ , a ₂ , a ₃ ,... Of the circular openings in the vertical direction of the shadow mask.
.., A _n, where a ₁ > a ₂ > a ₃ >...> A _n , the arrangement pitch increases in the horizontal and vertical directions from the central portion to the peripheral portion. When the shadow mask 5 is constituted only by the round openings, as described in the description of FIG. 8, the peripheral portions of the phosphor screen (screen) in the horizontal and vertical directions of the phosphor screen (screen) and In the corner portion, an imbalance occurs between the horizontal other-color hitting landing tolerance and the oblique-direction other-color hitting landing tolerance. For this reason, in the present embodiment, the diameters of the openings 15 in the horizontal direction and the vertical direction are made longer by making the openings 15 of the shadow mask correspond to the expansion ratio of the arrangement pitch of the openings 15 in the horizontal direction and the vertical direction. The opening 15 is configured to be an elliptical opening 15 whose major axis is the horizontal direction or the vertical direction depending on the location. With such a configuration, the ratio between the other-color landing landing allowance in the oblique direction and the other-color landing landing tolerance in the horizontal direction in each portion of the phosphor screen 4 (screen) is the same. Openings 15 in the horizontal and vertical directions.
In accordance with the spread of the arrangement pitch, the landing tolerance for other-color hitting in the oblique direction and the landing tolerance for other-color hitting in the horizontal direction can be increased at substantially the same rate. As described above, according to this embodiment, the width of the apertures 1 in the horizontal direction and / or the vertical direction corresponds to the ratio of the spread of the arrangement pitch of the apertures 15 in the shadow mask 5.
5, the horizontal and / or vertical diameters of the phosphor screen 4 (screen) are always always obliquely different color hitting landing tolerances in each part of the phosphor screen 4 (screen).
And horizontal other color landing landing tolerance ,,,
Can be made the same, and the degradation of color purity can be made uniform and small over the entire screen. As described above, according to the present invention, the horizontal direction and / or the horizontal direction of the opening of the shadow mask are made to correspond to the ratio of the spread pitch of the openings in the horizontal direction and / or the vertical direction. Alternatively, since the diameter in the vertical direction is configured to be longer, the ratio of the landing tolerance of the other-color hitting in the oblique direction to the landing tolerance in the horizontal direction of each portion of the phosphor screen (screen) is determined. It is possible to make the landing tolerances of other colors in each direction substantially the same without reducing the opening area (electron beam transmittance) of each opening, and to make the color There is an effect that deterioration of purity can be reduced uniformly and uniformly. Further, according to the present invention, the landing margin at the peripheral portion of the phosphor screen (screen) is increased, so that the shape of the phosphor dots at the peripheral portion of the screen can be increased. Also, there is an effect that the luminance of the peripheral portion of the screen can be improved and the uniformity of the luminance can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing an overall configuration of an embodiment of a color picture tube according to the present invention. FIG. 2 is an enlarged view showing an example of an arrangement of phosphor dots at a very small portion of a central portion and a corner portion of a phosphor screen 4 in the embodiment of FIG. FIG. 3 is an explanatory diagram showing the relationship between the arrangement and shape of the circular openings and the landing tolerance of other colors when the arrangement pitch of the openings of the shadow mask is made variable in the horizontal direction in the embodiment of FIG. 1; is there. FIG. 4 is an explanatory diagram showing the relationship between the arrangement and shape of the circular openings and the landing tolerance of other colors when the arrangement pitch of the openings of the shadow mask is made variable in the vertical direction in the embodiment of FIG. 1; is there. FIG. 5 shows the relationship between the arrangement and shape of the circular openings and the landing tolerance for other colors when the arrangement pitch of the openings of the shadow mask is made variable in the vertical and horizontal directions in the embodiment of FIG. FIG. FIG. 6 is an explanatory diagram showing the relationship between the arrangement state of the round openings and the landing tolerance of other colors when the arrangement pitch of the round openings of the shadow mask is changed in the horizontal direction in a known color picture tube. is there. FIG. 7 is an explanatory diagram showing a relationship between the arrangement state of the round openings and the landing tolerance of other colors when the arrangement pitch of the round openings of the shadow mask is changed in the vertical direction in a known color picture tube. is there. FIG. 8 shows the relationship between the arrangement state of the round openings and the landing tolerance of other colors when the arrangement pitch of the round openings of the shadow mask is made variable in the vertical and horizontal directions in a known color picture tube. FIG. DESCRIPTION OF SYMBOLS 1 Panel part 2 Funnel part 3 Neck part 4 Phosphor screen 5 Shadow mask 6 Mask frame 7 Deflection yoke 8 Purity adjustment magnet 9 Center beam static convergence adjustment magnet 10 Side beam static convergence adjustment magnet 11 Electronics Gun 12 Electron beam 13 Phosphor dots 14 Electron beam landing area 15 Round or elliptical aperture in shadow mask 5

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01J 29/07 H01J 9/14

Claims (1)

(57) Claims 1. At least a phosphor screen formed of a large number of phosphor dots and applied to an inner surface of a face plate, and disposed opposite to the phosphor screen; In a color picture tube provided with a shadow mask having a large number of round openings at positions corresponding to phosphor dots and an electron gun arranged in-line at a neck portion, a horizontal direction of the round openings of the shadow mask and / or Or, arrange the vertical pitch at the center of the shadow mask.
Together is sequentially increased toward the peripheral portion minutes, corresponding to an increase of the arrangement pitch, the order to increase the radial direction arrangement pitch of the round opening of the shadow mask slide into increased, the shape of the round opening In the horizontal direction and / or
Alternatively, a color picture tube having a non-circular aperture extending in the vertical direction .