JPS60154432A - Manufacture of shadow-mask - Google Patents

Abstract

PURPOSE:To prevent adhesion of granular material on the coating-unnecessary part of a shadow-mask by fixing the skirt part of the shadow-mask on a shadow-mask-frame after applying the granular material on the shadow-mask through the intervention of a jig screening said skirt part. CONSTITUTION:A shadow-mask 11 formed in a fixed shape is solely set in a fixed position on a spray pedestal 16 on a spray-booth 15 with intervention of a screeinging jig 19. This screening jig 19 is extended from the skirt part 13 to the peripheral perforationless part of the principal face 12 of the shadow-mask 11 and formed in similar curvature to the corresponding part of the peripheral perforationless part. Granular material 18 is applied on the fixed part of the shadow-mask 11 so as to become a fixed thickness by being sprayed from a spray-nozzle 17 facing to the principal face 12 in the booth 15. After that, the shadow-mask 11 itself is fixed on the mask-frame after passing through a given baking furnace and thus a shadow-mask structure is accomplished.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for manufacturing a shadow mask used in a color picture tube.

[Technical background and problems of the invention]

In general, a V-Yado mask type color picture tube, as shown in Fig. 1, has an envelope typically made of insulator, consisting of a substantially rectangular panel (1), a funnel-shaped funnel (2), and a neck ( 3). The inner surface of the panel (1) is provided with, for example, a striped phosphor screen (4) emitting red, green and blue light respectively, while the net (3) is provided in a row along the horizontal axis of the panel (1). Arranged in red,
A so-called in-line type electron gun (6) that emits three electron beams 4 corresponding to green and blue is installed inside. Further, a shadow mask (5) having a curved main surface with a large number of through holes is disposed close to and opposite to the screen (4). The peripheral part of the shadow mask (5) has a skirt part (8) that is bent according to the outer shape of the panel, and this skirt part (8) is surrounded by a mask frame (7) having a cross-sectional shape. The mask frame (7) is supported and fixed, and furthermore, the mask frame (7) is locked with a bottle (not shown) embedded in the inner wall of the panel (1) via a spring (9).

In such a color picture tube, the three electron beams emitted from the electron gun (6) are deflected by a deflection device (not shown) placed outside near the funnel (2), and are substantially The colors are sorted by scanning a rectangular area corresponding to the rectangular panel (1) and through the perforations of the shadow mask (5), so that each color emitting striped phosphor is correctly matched and projected. to display a color image. Here, the effective electron beam that passes through the hole of the shadow mask (5) is less than 1/3 due to its mechanism, and the remaining electron beam impinges on the shadow mask and is converted into thermal energy ζ, sometimes up to about 8C. Heat up the shadow mask. The shadow mask (5) is generally made of so-called cold-rolled steel whose main component is iron, which has a large coefficient of thermal expansion at 0 to 100°C of 1.2 x 10-'7G, and has a thickness of 0.1 to 3V.
The mask frame (7) that supports the skirt part (8) of this shadow mask (5) is made of a thin plate of ittr, and has been subjected to a strong cross-sectional blackening process with a thickness of about lmyx. It is also made from cold rolled steel.

Therefore, since the heated shadow is in contact with the mask frame (7) which has been subjected to blackening treatment and has a large heat capacity, heat is transferred from the area around the shadow mask to the mask frame by radiation and conduction, and the temperature around the V Yadoku mask increases. lower than the center. For this reason, a temperature difference occurs between the central portion and the peripheral portion of the shadow mask (5), resulting in a so-called doming phenomenon in which the central portion is relatively thermally expanded.

This results in a shadow mask (5) and a phosphor screen (4).
), the accurate landing of the electron beam is disturbed and color purity deteriorates. This phenomenon is particularly noticeable in the early stages of operation of a color picture tube. Also, if a partially high-brightness image is displayed,
A local doming phenomenon occurs in the corresponding area.

Many proposals have been made to deal with the doming phenomenon of color picture tubes. For example, US Patent No. 28265
No. 38 proposes providing a black layer made of graphite on the curved main surface of the shadow mask in order to promote heat radiation from the shadow mask. Furthermore, a proposal to provide a glass-like layer with low thermal expansion and low thermal conductivity on the curved main surface of the shadow mask was filed in Japanese Patent Application No. 14884 by the same applicant as the present invention.
It is done in 3. In any of the above cases, coating and forming the granular material on the curved main surface of the shadow mask requires a uniform film thickness, no clogging of the through holes, and high productivity. A spray method is the simplest method for such coating formation.

Figure 2 shows an outline of such a spray-type device. First, the main surface (121 is a curved surface) has a large number of through holes, and the peripheral part of the main surface is a skirt part (a shadow mask shaped like a seagull). mask frame 0 for the skirt part Q3) of aυ
4) Support and fix by welding etc. to complete the shadow □ Umasuf structure. Next, this shadow mask structure is placed at a fixed position 191 on the spray metal side of the object in the spray booth α, and particulate matter is sprayed from the spray nozzle (17) in the booth 9 to form particulate matter on the main surface (12i). Layer (2) is applied and formed.Then, the film is passed through a firing furnace and incorporated into a color picture tube.In some cases, a blackening treatment may be performed.

However, with this application method, the spray wraps around areas other than the required areas, such as the skirt area (1
Particulate matter is irregularly formed on the mask frame 0 and 3, and peeling is likely to occur due to multiple attachment and detachment operations of the shadow mask structure during the subsequent step of forming the fluorescent surface exposure, and after the shadow mask structure is installed in the pipe. This can cause clogging of through holes and a decrease in insulation resistance. In addition, if the calibration after the coating process is found to be defective, at least the mask frame is mechanically stronger than the shadow mask and should be recovered and reused.In this case, particles attached to the mask frame should be recovered. A separate process is required to remove.

[Purpose of the invention]

The present invention has been made in view of the above points, and an object of the present invention is to provide a manufacturing method that prevents particulate matter from adhering to unnecessary parts and that is easy to collect when forming particulate matter on a shadow mask. .

[Summary of the invention]

The present invention provides a method for manufacturing a shadow mask, in which, before fixing the skirt part of the shadow mask and the mask frame, a particulate material is applied and formed through a jig that shields at least the skirt part to fix the rear skirt part and the mask frame. It is.

[Embodiments of the invention]

Examples of the present invention will be described below. Incidentally, since the shadow mask and color picture tube itself applied to the present invention are the same as those shown in FIG. 1, the explanation of the overall structure (=) will be omitted.

FIG. 3 shows an example of a coating device applied to an embodiment of the present invention. First, the shadow mask Uυ formed into a predetermined shape is individually passed through a shielding jig ttS to a spray booth (15
The spray stand on 1 (placed at a predetermined position on the IQ. This shielding jig holder is formed in a similar shape to the peripheral edge of the shadow mask aυ, and the V-yado mask is inserted into this shielding jig. Just that is enough.

In this example, the shielding jig is a shadow mask (1
m) extends from the skirt portion u3 to the peripheral imperforate member of the main surface 1'IJ, and the corresponding portion of the peripheral impermeable portion (to) is formed into a similar curved surface shape. Next, particulate matter (l) is applied to a predetermined part of the shadow mask αυ from the spray nozzle η facing the main surface of the booth (1 powder) to a predetermined film thickness. Then, the shadow mask (11)
After passing through a predetermined firing furnace, the single body is fixed to a mask frame to complete a V-yado mask structure.

Such a manufacturing method has the following advantages.

First, the shielding jig position can be arbitrarily set according to the part where the particulate matter is applied, and since the particulate matter does not adhere to unnecessary parts, the risk of clogging of the through holes and insulation resistance due to peeling is reduced. Furthermore, since it has nothing to do with the mask frame, recovery of the mask frame in the event of an inspection failure as in the conventional method becomes irrelevant. Furthermore, the skirt portion of the shadow mask is fixed to the inside or outside of the mask frame. [Effect of the Invention] As described above, according to the present invention, the necessary parts of the shadow mask are It is possible to apply and form the granular material only on the portions, reduce the risk of clogging of the through holes and decrease in insulation resistance, and provide a method for manufacturing a shadow mask that is highly suitable for mass production.

[Brief Description of the Drawings] Figure 1 is a schematic sectional view showing the configuration of a shadow mask type color picture tube, Figure 2 is a schematic configuration diagram of a conventional granule coating device, and Figure 3 is a schematic configuration diagram of the present invention. It is a schematic configuration diagram showing a coating device applied to an embodiment of the present invention.
... Skirt River 5a4) ... Mask frame (15)
...Booth (161...spray joint shaft)...spray nozzle (181-...granular storage...shielding jig agent patent attorney Noriyuki Chika (one idiot) No. 1
Figure 2

Claims (1)

[Scope of Claims] 1) A V-Yadoku mask consisting of a curved main surface with a large number of through holes and a skirt section extending around the periphery of the main surface, and a mask frame that supports and fixes the skirt section. The granular material is coated on at least the curved main surface of the shadow mask structure, and the granular material is coated on at least the curved main surface of the shadow mask structure, and the granular material is applied to at least the curved main surface of the shadow mask structure by using a jig that shields at least the skirt portion before fixing the skirt portion and the mask frame. 1. A method of manufacturing a shadow mask, comprising: coating and forming a substance; and then fixing the skirt portion and the mask frame. 2) A jig extending from the skirt portion to the peripheral edge of the main surface, and having a portion corresponding to the peripheral edge of the main surface has substantially the same curvature as the curved surface of the peripheral edge. 2. The method of manufacturing a shadow mask according to claim 1, wherein the granular material is formed by coating on a surface.