JP2002298748A - Shadow mask with pattern corrected - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shadow mask subjected to a pattern correction capable of making the boundary of an image area appearing on a panel straight or in a curved line near the straight. SOLUTION: The shadow mask 1 is furnished with electron beam apertures A and B in a slot form and subjected to a pattern correction capable of forming the desired image area on the panel of a cathode-ray tube owing to the apertures A and B, wherein the apertures A are formed in columns at a certain pitch while the apertures B are subjected to a pattern correction in a vertical length (M+N) to allow formation of the desired image area on the panel at the top and bottom of each column. Therein the arrangement is such that the vertical length (M+N) of each aperture B may be designed to be longer gradually as going toward the left and right ends.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a pattern-corrected shadow mask capable of forming a desired image area.

[0002]

2. Description of the Related Art A shadow mask for a cathode ray tube having a slot-shaped electron beam passage hole is constituted by a hole having an electron beam passage hole formed therein and a skirt provided on the periphery of the hole. I have. The shadow mask is press-formed or stretched so as to have the same curved surface as the inner surface of the cathode ray tube, and is mounted on the cathode ray tube.

The shadow mask 1 mounted on the cathode ray tube 11 forms a desired image area 13 on a panel 12 in front of the cathode ray tube 11, as shown in FIG. In the image area 13, the boundary 17 between the perforated portion of the shadow mask 1 mounted on the cathode ray tube 11 and the skirt provided on the periphery of the perforated portion appears on the panel 12 as the boundary of the image area 13.

Therefore, the shape of the image area 13 formed on the panel 12 is specified by the contour shape of the perforated portion in which the electron beam passage hole is formed, and the shadow mask 1 after being press-formed or stretched. Is also affected by the shape of

Since the shape of the image area 13 can be visually recognized by the user, it is considered that the boundary 17 of the image area 13 is preferably a straight line or a curve close to a straight line. I have.

[0006]

SUMMARY OF THE INVENTION The present invention provides a pattern-corrected shadow mask which enables the boundary of an image area appearing on a panel to be a straight line or a curve close to a straight line.

[0007]

According to a first aspect of the present invention, there is provided a slot-shaped electron beam passage hole, which is subjected to pattern correction by which a desired image area can be formed on a panel of a cathode ray tube. An electron beam passage hole A formed in a row at a constant pitch, and an electron pattern corrected to a vertical length at both upper and lower ends of the row to form a desired image area on a CRT panel. It is characterized by having a row composed of the beam passing holes B.

According to the present invention, in order to form a desired image area on the panel of the cathode ray tube, a desired image is formed on the panel of the cathode ray tube at upper and lower ends of a row in which electron beam passage holes A are formed at a constant pitch. Since the electron beam passing holes B having the pattern corrected to the vertical length to form the area are formed, the boundary of the image area appearing on the panel is formed by attaching a shadow mask having such a row to the cathode ray tube. Can be

According to a second aspect of the invention, in the pattern-corrected shadow mask of the first aspect, the vertical length of the electron beam passage hole B gradually increases from the center of the shadow mask to the left and right ends. It is characterized by being longer.

According to the present invention, in order to form a desired image area on the panel of the cathode ray tube, the vertical length of the electron beam passage hole B gradually increases toward the left and right ends, so that the shadow having such rows is provided. By attaching the mask to the cathode ray tube, the boundary of the image area appearing on the panel can be made a straight line or a curve close to a straight line.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A pattern-corrected shadow mask 1 of the present invention has slot-shaped electron beam passage holes (A, B) as shown in FIGS. (A, B) is a pattern-corrected shadow mask 1 that can form a desired image area 13 on the panel 12 of the CRT 11.

A feature of the present invention is that electron beam passing holes A formed in a row at a constant pitch P, and a desired image area 13 on a panel 12 of a cathode ray tube 11 at both upper and lower ends of the row. An electron beam passing hole B whose pattern is corrected to have a vertical length (M + N). By attaching the shadow mask 1 of the present invention having such rows to the cathode ray tube 11, the boundary 17 of the image area 13 appearing on the panel 12 can be made a straight line or a curve close to a straight line, which is visually preferable on the panel 12. An image area 13 can be formed.

Hereinafter, the configuration of the present invention will be described in detail.

The shadow mask 1 according to the present invention comprises a perforated portion having a slot-shaped electron beam passage hole and a skirt provided on the periphery of the perforated portion. It is press-formed or stretched so as to have the same curved surface or a similar curved surface, and is mounted on the cathode ray tube 11.

An electron beam passage hole formed in the shadow mask 1 is designed and formed so that an electron beam can be landed at a predetermined position on the fluorescent screen 16 on the inner surface of the cathode ray tube 11 in a desired shape and size. ing. The perforated portion is a region in which such electron beam passage holes are formed, and the size and shape are arbitrarily designed and formed according to the size and shape of the image area 13 formed on the panel 12 of the cathode ray tube 11. Is done.

FIG. 1 is a partially enlarged view showing an example of a pattern-corrected shadow mask according to an embodiment of the present invention.

In the shadow mask 1 of the present invention, the length M of the electron beam passage holes B at the upper and lower ends on the boundary S is further outside the boundary S between the perforated portion and the skirt of the conventional shadow mask. Have a row that is formed longer and is pattern-corrected to an arbitrary length (M + N).

The length N that has been elongated (hereinafter referred to as the protruding length N)
That. ) Is arbitrarily set depending on each position of the shadow mask 1. The setting at this time is adjusted so that the boundary 17 of the image area 13 appearing on the panel 12 of the cathode ray tube 11 can be a straight line or a curve close to a straight line.

It is preferable that the protruding length N is gradually increased from the center (center line C) of the shadow mask 1 to both right and left ends. Such a change in the protruding length N is caused by the length M of the electron beam passing holes B at the upper and lower ends on the boundary S in the conventional shadow mask.
Is formed gradually longer from the center line C of the shadow mask toward the left and right ends. as a result,
When the shadow mask is press-formed or stretched to have the same shape or a shape similar to the curved surface of the inner surface of the cathode ray tube, the boundary 17 of the image area 13 appearing on the panel 12 can be made a straight line or a curve close to a straight line. .

The protruding length N differs depending on the shape of the curved surface of the inner surface of the cathode ray tube and the degree of processing of the shadow mask, but is preferably in the range of 50 to 150 μm.

The electron beam passage holes A other than the electron beam passage hole B described above are not different from the electron beam passage holes generally formed in the conventional shadow mask. That is, the electron beam passage hole A is formed by regularly changing the slot shape and size (length, width) according to the coordinate position formed on the shadow mask. Then, in the row, they are formed at a constant pitch P.

In the shadow mask of the present invention, the electron beam passage holes (A, B) formed for each column are provided.
Is formed without changing the number of holes and without changing the pitch P of the electron beam passage holes A in the row. Therefore, in the shadow mask 1 of the present invention, the length M of the electron beam passage holes B at the upper and lower ends.
Is changed to an arbitrary length (M + N), thereby making the boundary 17 of the image area 13 appearing on the panel 12 a straight line or a curve close to a straight line.

The above-mentioned electron beam passage holes (A,
B) is a front opening provided on the side from which the electron beam exits, and a back opening provided on the side on which the electron beam enters, as in the case of the shadow mask in which the usual slot-shaped electron beam passage holes are formed. The hole is a slot-like hole formed from the portion, and may be a shape approximating a rectangular shape or a shape approximating an elliptical shape, and is not particularly limited.
In addition, around the perforated portion of the shadow mask, the front opening corresponds to the distance from the center of the shadow mask to the back opening so as not to obstruct the passage of the electron beam incident from the back opening. It is formed so as to be shifted toward the outer periphery of the shadow mask by a shift amount.

Next, a method of manufacturing a shadow mask will be described.

The shadow mask 1 of the present invention can be manufactured by a conventionally known method. Usually, a photo-etching process is used, and the device is manufactured by a continuous in-line device. For example, a water-soluble colloidal photoresist or the like is applied to both sides of a thin metal plate and dried. Thereafter, a photomask on which a front-side opening pattern that has been subjected to pattern correction to form a desired electron beam passage hole B is adhered to the front surface, and the desired electron beam passage hole B is also formed on the back surface. For this purpose, a photomask on which a backside opening pattern having been subjected to pattern correction is formed is brought into close contact, exposed to ultraviolet light such as high pressure mercury, and developed with water. The positional relationship between the photomask on which the front opening pattern is formed and the photomask on which the back opening pattern is formed and the shape thereof are determined in consideration of the shape of the electron beam passage holes (A, B) to be formed. Designed and deployed. The exposed portion of the metal whose periphery is covered by the resist film image is formed in each of the shapes described above based on the difference in the etching progress rate of each portion. The etching process is performed by spraying a ferric chloride solution from both sides after heat treatment or the like. Thereafter, a shadow mask is manufactured by continuously performing post-processes such as washing with water and peeling.

Next, the shadow mask thus obtained is pressed into the same or similar curved surface as the inner surface of the cathode ray tube, and is mounted on the cathode ray tube. The shadow mask 1 of the present invention can make the boundary of the image area appearing on the panel a straight line or a curve close to a straight line.

[0027]

The present invention will be described more specifically below with reference to examples and comparative examples.

Example 1 A shadow mask 1 for a 29 inch cathode ray tube having a thickness of 0.250 mm was manufactured by the above-described method. This shadow mask 1 has a constant pitch P
And an electron beam passage hole A formed in a row and electron beam passage holes B which are vertically corrected to form a desired image area on a CRT panel at both upper and lower ends of the row. Have columns.

The vertical length (L) of the electron beam passage hole A and the vertical length (M + N) of the electron beam passage hole B in each part of the shadow mask were formed in the dimensions shown in Table 1.

[0030]

[Table 1]

The shadow mask thus obtained was pressed so as to have the same curved surface as the inner surface of the cathode ray tube, and was mounted on the cathode ray tube. As a result, as shown in FIG. 2 or 3, the boundary of the image area appearing on the panel of the cathode ray tube could be a straight line or a curve close to a straight line.

(Comparative Example 1) A conventional shadow mask having an electron beam passage hole B having no protruding length (N) was manufactured. Other conditions were the same as in Example 1.

The shadow mask thus obtained was pressed so as to have the same curved surface as the inner surface of the cathode ray tube, and was mounted on the cathode ray tube. As a result, as shown in FIG. 5, the boundary of the image area appearing on the panel of the cathode ray tube became a remarkable curved surface convex outward.

[0034]

As described above, according to the pattern-corrected shadow mask of the present invention, electron beam passage holes A are formed at a constant pitch in order to form a desired image area on a CRT panel. At the upper and lower ends of the row, the electron beam passing holes B, which were pattern-corrected in the vertical direction to form a desired image area on the panel of the CRT, were formed. The boundary of the image area appearing on the panel can be a straight line or a curve close to a straight line.

The pattern-corrected shadow mask of the present invention can be preferably applied to shadow masks of various sizes regardless of its inch size and plate thickness. It is preferably applied to a shadow mask for a cathode ray tube.

[Brief description of the drawings]

FIG. 1 is a partial enlarged view showing an example of a pattern-corrected shadow mask according to an embodiment of the present invention.

FIG. 2 is a front view showing an example of the shape of an image area formed on a panel of a cathode ray tube equipped with a shadow mask whose pattern has been corrected according to the present invention.

FIG. 3 is a front view showing another example of the shape of an image area formed on a panel of a cathode ray tube equipped with a shadow mask whose pattern has been corrected according to the present invention.

FIG. 4 is a schematic diagram illustrating the structure of a cathode ray tube.

FIG. 5 is a front view showing an example of a shape of an image area formed on a panel of a conventional cathode ray tube equipped with a shadow mask.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shadow mask 11 CRT 12 Panel 13 Image area 14 Electron gun 15 Electron beam 16 Phosphor screen 17 Boundary A Electron beam passage hole with fixed pitch B Corrected electron beam passage hole L Vertical length of electron beam passage hole A M Electron beam passage Vertical length of hole B N Length of protrusion of electron beam passing hole B P Constant pitch within row of electron beam passing hole A S Boundary line C Center line of shadow mask

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5C031 EE02 EF06 EG04 EH08

Claims (2)

[Claims] An electron beam passage hole having a slot shape;
A pattern-corrected shadow mask capable of forming a desired image area on a panel of a cathode ray tube by the electron beam passage holes, the electron beam passage holes A formed in a row at a constant pitch;
A pattern-corrected shadow mask comprising, at both upper and lower ends of the row, a row composed of a vertically elongated electron beam passage hole B for forming a desired image area on a CRT panel. . 2. The pattern-corrected shadow mask according to claim 1, wherein the vertical length of the electron beam passage hole B gradually increases from the center of the shadow mask to the left and right ends.