JPH11162369A - Color cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress occurrence of scanning moire on a screen by making vertical pitches of respective apertures of a shadow mask on parallel lines to the vertical axis variable in the direction of preventing occurrence of the scanning moire in the case an axis passing through the plane center of a face plate part and in the direction of orthogonal to the scanning beam is set as a vertical axis. SOLUTION: This color cathode-ray tube is provided with a shadow mask 1a having a plurality of approximately circular apertures 2a arranged corresponding to color-emitting phosphor dots on a face plate part 8. Regarding vertical pitches of the apertures 2a of the shadow mask 1a on the parallel lines Y2 to the vertical axis Y, the vertical pitches P2 on the parallel lines Y2 in the peripheral part A in the horizontal axis X side are set different from the vertical pitches P3 in the parts besides the peripheral part A on the parallel lines Y2 and set to be a value as to prevent occurrence of scanning moire. Consequently, the mutual interference of the scanning beam and the vertical pitches P2 of the shadow mask 1a is weakened and occurrence of scanning moire in the peripheral part A can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color cathode ray tube used for a television receiver, an information processing device and the like.

[0002]

2. Description of the Related Art FIG. 7 shows a conventional in-line color cathode ray tube having a shadow mask having a round hole and phosphor dots to obtain good resolution and high resolution over the entire screen surface. As described above, the horizontal pitch Px of the openings 2 of the shadow mask 1 is made constant, and the shadow mask on the vertical axis Y at the center of the screen surface is set so that the horizontal arrangement line 3 of the openings of the shadow mask 1 becomes a barrel type. the shadow mask 1 on the vertical peripheral axes Y ₁ of the screen surface with respect to the longitudinal pitch P ₀ of the aperture 2 of 1
Reducing the vertical pitch P ₁ of the aperture 2 of and has a vertical pitch P ₀ and the vertical pitch P ₁ in the vertical-axis Y direction at a constant (JP 57-34640 JP).

[0003]

However, in the conventional color cathode ray tube, as shown in FIG. 8, the spot shape of the electron beam 5 at the peripheral part A on the horizontal axis X side passing through the center of the screen surface 4 is changed to the vertical axis. Collapsed to dimension h in the Y direction,
It is longer than the spot diameter D at the center of the electron beam 5. As a result, there is a problem that the scanning lines formed by the electron beam 5 and the vertical pitch of the openings 2 of the shadow mask 1 interfere with each other, and particularly, a scanning moire is generated in a peripheral portion A on the screen.

In recent years, those in which the total length of a color cathode ray tube is shortened in order to reduce the size of a computer monitor and those in which the screen aspect ratio is set to 16: 9 have a large deflection angle of an electron beam. At the peripheral portion A on the screen surface, the problem that the spot shape of the electron beam 5 is further collapsed in the vertical axis Y direction and a scanning moire with a strong contrast is generated has become apparent.

The present invention has been made to solve such a problem, and it is an object of the present invention to provide a color cathode ray tube capable of reducing the occurrence of scanning moire on a screen surface.

[0006]

A color cathode ray tube according to the present invention has a face plate portion having red, green and blue phosphor dots on its inner surface, a funnel portion connected behind the face plate portion, and a rear portion of the funnel portion. A glass bulb formed of a neck portion in which an in-line type electron gun for emitting an electron beam is disposed, and a substantially circular shape disposed corresponding to each color phosphor dot of the face plate portion. A shadow mask having a plurality of openings, an axis in a scanning line direction passing through the center of the face plate portion as a horizontal axis, and an axis passing through the center of the face plate portion and orthogonal to the scanning line. Is the vertical axis, the vertical pitch of each opening of the shadow mask on a line parallel to the vertical axis prevents the occurrence of scanning moire. They are variable in direction.

With this configuration, the interference between the scanning line and the vertical pitch of the shadow mask is reduced. Further, in the color cathode ray tube of the present invention, the horizontal arrangement line in the horizontal axis direction at the opening of the shadow mask is inclined corresponding to the inclination direction of the electron beam trio on the face plate portion surface.

[0008] With this configuration, the landing latitude of the electron beam is increased, and the hitting of other colors can be reduced.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 2, a color cathode ray tube according to an embodiment of the present invention is a tube having a reduced overall length, and includes a face plate portion 8 having red, green, and blue phosphor dots 7a on an inner surface 6; A glass bulb 13 comprising a funnel 9 connected behind the plate 8 and a neck 12 formed behind the funnel 9 and in which an in-line type electron gun 11 for emitting an electron beam 10 is disposed. And a shadow mask 1a having a plurality of substantially circular openings 2a arranged corresponding to the respective phosphor dots 7a of the face plate portion 8.

As shown in FIG. 1, the face plate 8
When the axis in the scanning line direction passing through the center of the plane is defined as the horizontal axis X, and the axis passing through the center of the face plate portion 8 in the direction orthogonal to the scanning line is defined as the vertical axis Y, a parallel line Y _{2 with} respect to the vertical axis Y
The vertical pitch of each opening 2a of the upper shadow mask 1a is variable in a direction to reduce interference with a scanning line, that is, a direction to prevent the occurrence of so-called scanning moire. For example, in order to weaken the interference of the scanning moire in the peripheral portion A of the horizontal axis X side of the face plate portion 8, the vertical pitch of the apertures 2a in the shadow mask 1a in the horizontal axis X-side of the peripheral portion parallel lines Y on the _second A P ₂ is set to a value to prevent the occurrence of different scanning moire and the longitudinal pitch P ₃ of the aperture 2a of the shadow mask 1a in a portion other than the peripheral portion a of the parallel line Y _2. Further, the horizontal arrangement line 3a in the horizontal axis X direction in the opening 2a of the shadow mask 1a shown in FIG. 1 corresponds to the electron beam trio 1 on the face plate portion 8 shown in FIG.
Inclination directions of 0R, 10G, and 10B, that is, inclination so as to have a substantially gull-wing shape expressed using a fourth-order function.

Next, the function and effect of the above color cathode ray tube will be described. Embodiments of the present invention, as shown in FIG. 1, a shadow mask on parallel lines Y ₂ with respect to the vertical axis Y 1
The longitudinal pitch of the respective apertures 2a of a, different from the vertical pitch P ₂ of the apertures 2a in the shadow mask 1a and vertical pitch P _3, since the set value to prevent the occurrence of scanning moire, scanning lines mutual interference between the vertical pitch P ₂ of the shadow mask 1a is weakened and. As a result, it is possible to reduce the occurrence of scanning moire at the peripheral portion A of the face plate portion 8 on the horizontal axis X side.

Further, as shown in FIG. 1, in the embodiment of the present invention, the horizontal arrangement line 3a of the shadow mask 1a is moved in the inclination direction of the electron beam trios 10R, 10G, 10B on the screen surface of the face plate portion 8. since inclined to correspond, from the adjacent electron beams 5 and L ₁ interval of the phosphor dots 7 is narrowed above prior art shown in FIG. 4, the electron beam 10 and the phosphor adjacent as shown in FIG. 5 distance L ₂ dots 7a is widened. As a result, the landing latitude of the electron beam is increased, and the irradiation of the predetermined phosphor dots 7a by the electron beam trios 10R, 10G, and 10B, that is, the so-called other color hitting can be reduced. The color purity can be improved over the entire surface.

[0014]

Embodiments of the present invention will be described below.

The color cathode ray tube of the present invention having the structure shown in FIGS. 1 and 2 has a reduced overall length of 19 inches-10.
Using a 0 ° tube, 1024 main scanning lines, and vertical pitches P ₂ of 0.275 mm, 0.285 mm and 0.29 mm
Three types having a size of 5 mm were used.

The above color cathode ray tubes are
The peripheral portion A on the horizontal axis X side of the face plate portion 8
(The moire wavelength is 2 mm or less.
It is difficult to see that) and the face plate 8
Examination of the color purity over the entire screen surface shows that
Was obtained. FIG. 6 shows the vertical pitch P of the present invention. _Two
Shows the relationship between the main scanning line and the moiré wavelength when
Curve A is vertical pitch P_TwoIs 0.275 mm, and curve B is vertical
Switch P_TwoIs 0.285 mm and the curve C is the vertical pitch P_TwoBut
It shows a characteristic of 0.295 mm.

[0017] In the main scanning line 1024, a color cathode ray tube of the present invention, the vertical pitch P ₂ is the moire wavelength at 0.275mm to about 3 mm, the vertical pitch P ₂ is the moire wavelength at 0.285mm to about 1. 2 mm and a vertical pitch P ₂ of 0.
A moire wavelength of about 1.0mm at 295 mm, and the color purity was good in the above respective vertical pitch P _2.

Therefore, the color cathode ray tube of the present invention
As shown in FIG. 1, the vertical pitch P ₂ on the parallel line Y ₂ at the peripheral portion A on the horizontal axis X side and on the vertical axis Y is, for example, the vertical pitch P on the parallel line Y ₂ other than the peripheral portion A.
₃ (0.275 mm), which is larger than 0.285 mm (preferably the vertical pitch P ₂ is 0.289 to 0.295 mm), can reduce the occurrence of scanning moire and improve the color purity. .

Further, as shown in FIG. 6, in the color cathode ray tube of the present invention, since the moire wavelength changes depending on the number of main scanning lines, the vertical pitch P ₂ shown in FIG. May be set in a direction that prevents the occurrence of scanning moire based on the curves A, B, and C in FIG.

In the above embodiment, in order to prevent the occurrence of scanning moire in the peripheral portion A on the horizontal axis X side,
This is a case where the vertical pitch of the apertures 2a of the shadow mask 1a is set to a value that does not cause interference with the scanning lines. However, the present invention is not limited to this, and scanning moire is generated in portions other than the peripheral portion A on the horizontal axis X side. In this case, the same effect can be obtained even if the vertical pitch of the openings 2a of the shadow mask 1a at that portion is set to a value that does not cause interference with the scanning lines. Further, the case where the horizontal arrangement line 3a of the shadow mask 1a is inclined in a substantially gull-wing shape has been described, but the present invention is not limited to this, and the electron beam trios 10R, 10G,
When the inclination direction of 10B is a barrel shape or a substantially pincushion shape, when the horizontal arrangement line 3a of the shadow mask 1a is inclined to a barrel shape or a substantially pincushion shape using a quadratic function, the same as in the above embodiment. The effect of is obtained. Further, in the above-described embodiment, the case of a color cathode ray tube having a reduced overall length has been described.
The same effect as that of the above-described embodiment can be obtained by using a color cathode ray tube having a ratio of 6: 9 and other color cathode ray tubes for computer monitors and 90 ° deflection.

[0021]

As described above, according to the present invention, since the vertical pitch of each opening of the shadow mask on a line parallel to the vertical axis is changed in a direction to prevent the occurrence of scanning moire, scanning is performed. The generation of moire can be prevented and a good image can be obtained.

Further, since the horizontal arrangement line in the horizontal axis direction at the opening of the shadow mask is inclined on the face plate surface in accordance with the inclination direction of the electron beam trio, the entire area of the screen surface of the face plate portion is provided. Color purity can be improved.

[Brief description of the drawings]

FIG. 1 is a front view of a main part of a color cathode ray tube according to an embodiment of the present invention.

FIG. 2 is a side view of the main part.

FIG. 3 is a diagram showing a tilt direction of an electron beam trio on the screen surface.

FIG. 4 is a diagram showing a relationship between a horizontal arrangement line of a shadow mask and an electron beam trio in a conventional color cathode ray tube.

FIG. 5 is a diagram showing a relationship between a horizontal arrangement line of a shadow mask and an electron beam trio in the color cathode ray tube according to the embodiment of the present invention.

FIG. 6 is a diagram showing a relationship between a main scanning line and a moire wavelength when the vertical pitch of a shadow mask in the color cathode ray tube is changed.

FIG. 7 is a front view of a main part of a shadow mask in a conventional color cathode ray tube.

FIG. 8 is a view showing a spot shape on the screen surface of the electron beam.

[Explanation of symbols]

 1a Shadow mask 2a Opening 6 Inner surface 7a Phosphor dot 8 Face plate 9 Funnel 10 Electron beam 11 In-line type electron gun 12 Neck 13 Glass bulb

Claims (4)

[Claims] 1. A face plate having red, green and blue phosphor dots on an inner surface, a funnel connected to the face plate and a funnel formed behind the funnel to emit an electron beam therein. And a shadow mask having a plurality of substantially circular openings arranged corresponding to the phosphor dots of each color of the face plate portion. When an axis in a scanning line direction passing through the center of the face plate portion is a horizontal axis and an axis in a direction perpendicular to the scanning line passing through the center of the face plate portion is a vertical axis, the axis is parallel to the vertical axis. The vertical pitch of each opening of the shadow mask on the line is variable in a direction to prevent occurrence of scanning moiré. tube. 2. The color cathode ray tube according to claim 1, wherein the vertical pitch of the apertures in the peripheral portion on the horizontal axis side of the shadow mask is variable in a direction to prevent occurrence of scanning moire. 3. The shadow array according to claim 1, wherein the horizontal arrangement line in the horizontal axis direction at the opening of the shadow mask is inclined in accordance with the inclination direction of the electron beam trio on the face plate portion. The color cathode ray tube according to claim 2. 4. The horizontal arrangement line of the openings of the shadow mask is as follows:
4. The color cathode ray tube according to claim 3, wherein the tube has a substantially gull-wing shape, a substantially barrel shape, or a substantially pincushion shape.