JPS6220658B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shadow mask type color picture tube that reduces the number of steps required to form a fluorescent surface.

In the conventional shadow mask type color picture tube, as shown in FIGS. 1 and 2, the support frame 3 is
The shadow mask 4, whose periphery is supported, is fixed to the support frame 3 by welding or the like, and is removably attached to the panel 5 via a spring 2 that fits into a panel pin 1 embedded in the inner peripheral side of the panel 5 and projected. It was getting worse. The reason for this structure is that extremely high precision is required for the relative position between the holes in the shadow mask and the dots or stripes of the phosphor that forms the phosphor surface on the panel. Because it was not possible to mass-produce phosphor panels and shadow masks uniformly with sufficiently accurate shapes and dimensions, we used a type of alignment process called the exposure method to create dots or stripes of phosphor for each specific combination of panel and shadow mask. This is because they are forced to form. In the process of forming a fluorescent surface using the exposure method, each conventional picture tube
The shadow mask 3 must be attached to and removed from the panel 5 several times. At present, this attachment/detachment work mainly relies on manual labor, but in mass production the number of man-hours involved is considerably large, and if this process were to be carried out by automatic machines, a large amount of capital investment would be required.

An object of the present invention is to provide a color picture tube that can reduce the man-hours and equipment investment required to combine a shadow mask with a panel when forming a fluorescent surface, compared to the above-mentioned conventional color picture tube. .

In order to achieve the above object, in the present invention,
Three or more reference surfaces are provided on a portion of the inner surface of the face panel that forms a fluorescent surface that does not become a screen, and portions that protrude by a predetermined length are provided at locations corresponding to each of the reference surfaces of the support frame of the shadow mask, and the The tips of the protruding portions were fixed to each reference surface to set the relative position between the inner surface of the panel and the shadow mask.

In the conventional case, one specific relative position for a specific pair of shadow mask and panel combination is determined before the fluorescent surface forming operation.
In the case of the present invention, the shadow mask of any product is regulated to always exist uniformly within a parallel plane separated by a predetermined length from one plane determined by three or more reference planes on the inner surface of the panel. However, before the tip of the projection of the shadow mask support frame is fixed to a specific location within the reference plane provided on the inner surface of the panel, the shadow mask has a degree of freedom that allows it to move somewhat within the parallel plane. In other words, in the present invention, the relative position of the shadow mask with respect to the panel is limited to a specific plane so that it can be easily handled by machines and instruments until the fluorescent surface forming work is completed, and the machines and instruments are not allowed to operate within this plane. After the fluorescent surface forming work is completed, the specific relative position determined by the machine and equipment within the specific plane is set so that the tip of the protruding portion of the shadow mask support frame is aligned with the reference plane on the inner surface of the panel. By fixing it, it is kept as it is. Note that the reference plane on the inner surface of the panel can be formed, for example, by using a polishing method or the like to provide a portion of a parallel plane that is separated by a predetermined length from the joint surface of the panel with the funnel as a reference, and then the predetermined length can be obtained. can be ensured uniformly and with sufficient accuracy for each product.

Examples will be explained in detail below.

Example 1 A first example of the present invention is shown in FIGS. 3 to 5. To simplify the explanation, a case is shown in which a flat panel and a flat shadow mask are used. FIG. 3a shows the formation of phosphor dots or stripes by an exposure method. In the figure, 51 is a panel, 41 is a shadow mask, 7 is a light source, and 9 is a correction lens. Reference pin 6 provided in the exposure device
1 and 62, respectively, by supporting the reference points of the panel 51 and the mask 41.
1. The masks 41 are each positioned at the correct position. The predetermined length q between the mask 41 and the inner surface of the panel 51 is determined by the mechanical precision of the exposure apparatus. Each color phosphor exposure device has sufficient accuracy, and the reference points of the panel 51 and the mask 41 are set with sufficient accuracy, so the panel 5
1. The mask 41 is always held at a predetermined relative position in each color phosphor exposure device, and has the predetermined length q.
are also held at the same value. FIG. 3b shows panel 51,
FIG. 4 is a diagram showing the positioning state of the mask 41 viewed from the light source side. After exposure, as shown in FIG. 4, protruding parts 71 having L-shaped tips are attached to the four corners of the mask 41 so that the tips protrude by a predetermined length q. Next, the mask 41 with the protruding part 71 attached thereto is arranged so that the L-shaped bent end of the protruding part 71 rests on the reference plane provided on the inner surface of the panel 51, and the relative positions of the mask 41 and the panel 51 are determined as follows. As in the case of the exposure apparatus, each reference point is determined by defining it with reference pins 62 and 61. At this time, the predetermined length q is set by the protruding part 71. In this state, both the panel 51 and the mask 41 are heated to 250 to 400°C, and as shown in FIG.
A voltage of 900V is applied to electrostatically fix the two (electrostatic sealing).

Embodiment 2 FIG. 6 shows a second embodiment of the present invention. In this embodiment, the entire inner surface of the panel 51 is finished as a parallel plane separated by a predetermined distance with respect to the surface to be joined to the funnel, and stripes of phosphor are formed on this surface by a mask 41 that is combined with this panel 51. For example, it is formed by a printing method without using a . This panel 51 on which a fluorescent surface has been formed is combined with a mask 41 whose tip protrudes by a predetermined length q and protruding parts 71 are attached to the four corners, and the detector 8
0, for the fluorescent surface of the inner surface of the panel 51,
The slots of the shadow mask 41 are aligned. At this time, since the predetermined length q is secured by the protruding parts 71 at the four corners, the panel 51 and the mask 4
1 and can only be displaced in planes parallel to each other. When the alignment is completed, the protruding part 71 is moved at that position.
Electrostatically fixing the tip to the inner surface of the panel 51,
The correct relative position of the mask 41 with respect to the panel 51 is maintained. In this embodiment, since the entire inner surface of the panel is finished in one plane with sufficiently high precision, a uniform pattern of the luminescent surface can be formed on each product by printing or the like. Although the inner surface of the panel must be finished with high precision, other processes are extremely easy to automate.

Note that in order to fix the tip of the protruding part of the shadow mask to the inner surface of the panel, you can use not only electrostatic sealing but also inorganic adhesive such as cement or solder glass. ) Metal may be embedded, a reference surface provided there, and the tip of the protruding portion of the shadow mask welded. In the case of the first embodiment, it is clear that the shapes of the panel and mask need not be limited to flat plates.

As explained above, according to the present invention, the handling of the shadow mask in the step of forming a fluorescent surface of a shadow mask type color picture tube is extremely simple, and the assembly and fixation of the panel and mask is facilitated.

[Brief explanation of the drawing]

FIG. 1 is a diagram of the engagement between the panel and the mask of a conventional shadow mask type color picture tube, FIG. 2 is a sectional view taken along the line A-A in FIG. 1, and FIG. FIG. 4 is a perspective view showing the assembly of a shadow mask according to the present invention, FIG. 5 is a diagram showing how the panel and mask according to the present invention are assembled and fixed by electrostatic sealing, and FIG. 6 is a positioning diagram according to the second embodiment of the present invention. It is a figure which shows the assembly fixation of the panel and mask using a detector. 41...Shadow mask, 51...Panel, 6
1,62...Reference pin, 71...Protruding part, 80
……Detector.

Claims (1)

[Claims] 1. In a shadow mask type color picture tube, a support frame having three or more reference surfaces provided on the inner surface of the face panel that forms the fluorescent surface and portions protruding by a predetermined length at the locations corresponding to these reference surfaces. and a supported shadow mask,
A color picture tube characterized in that the relative positions of the inner surface of the panel and the shadow mask are set by directly electrostatically fixing the tips of the protruding portions to each of the reference surfaces without using any other member.