JPH09245646A - Funnel for cathode ray tube and cathode ray tube sealing method using this funnel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease wearing amount of a support fixture and shorten a time for polishing so as to attain improving of productivity, by forming a relation between 10-point mean roughness and a mean waviness period of a reference surface of a pad for positioning, in a specific range. SOLUTION: A wearing amount of a support fixture 5 depends upon roughness and irregular density in reverse proportion to a space period of waviness of a reference surface 3 of a pad 2 of a funnel 1. By setting 10-point mean roughness R2 and a mean waviness period Sm of the reference surface 3 in a range displayed by 0.7%<=R2 /Sm<=3%, a relatively short treating time and a relatively small wearing amount of the support fixture are discovered to be compatible. In the case of R2 /Sm less than 0.7%, a time required for polishing is rapidly increased, and in the case of exceeding 3.0%, a wearing amount of the support fixture 5 is largely increased, so as to make undesirable. Preferably, R2 is set to 10μm or less. Further, preferably, a carbon material or the like, which is a material of 2 or more by Morse hardness lower than glass of the funnel 1, is used so as to prevent the pad 2 from flawing, in the support fixture 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a funnel for a cathode ray tube that constitutes a cathode ray tube of a television or the like and a method for sealing a cathode ray tube using the funnel.

[0002]

2. Description of the Related Art A glass bulb for a cathode ray tube, which is usually used for receiving television broadcasts, includes a front glass (hereinafter referred to as a panel) as an image display area and a yoke coil for deflection which is behind the front glass and is sealed to the panel glass. It is composed of a funnel for attaching the and the three glass members of the neck connected to the funnel for accommodating the electron gun.

Since such a panel usually has a rectangular image display area, the sealing surface of the funnel is a rectangle similar to the display area, and the sealing portion of the funnel with the panel is a large rectangular opening end. ing. On the other hand, since the neck that houses the electron gun is cylindrical, the small open end with the neck is circular. Therefore, a predetermined positioning accuracy is required when sealing the funnel and the panel. In order to ensure a certain positioning accuracy, the outer surface near the large opening end of the funnel is provided with pads with reference points for positioning at three points on the short side and the long side, which are relatively diagonal with high dimensional accuracy. ing.

FIG. 1 is a side view of a funnel for a cathode ray tube, and FIG. 2 is a perspective view schematically showing the pad periphery. In the figure, 1 is a funnel, 2 is a pad for alignment, and 3 is a reference surface of the pad. It should be noted that in these drawings and other device drawings described later, the pad portion is exaggerated for clarity.

FIG. 3 is a side view of the process of sealing the panel and the funnel in the process of assembling the cathode ray tube, and FIG. 4 is a plan view thereof. As shown in FIGS. 3 and 4, the pad 2 of the funnel 1 of the cathode ray tube to be sealed,
2A, 2B, and 2C are supported at predetermined positions by supporting tools 5, 5A, 5B, and 5C, the relative position with the panel 4 is adjusted, and both are sealed with low melting point powder glass applied on the sealing surface. To do.

At the time of assembly and sealing, the funnel 1 is shown in FIG.
As indicated by the arrow A in FIG. 3, the pad 2A is slightly inclined toward the corner where the two pads 2A and 2C are formed (the inclination is not shown). As a result, these three pads 2A, 2B,
2C is brought into contact with supporters 5A, 5B, 5C made of carbon provided on the assembly jig side to support the funnel 1 and the panel 4 thereon.

Support tools 5A, 5B, 5C on the assembly jig side
Is formed in advance at a predetermined position with a predetermined protruding length, and the end faces of the pads 2A, 2B, 2C on the funnel 1 side are brought into contact with the end faces of the support tools 5A, 5B, 5C, thereby 1 is held in place and alignment with the panel 4 is achieved.

The cathode ray tube in which the panel 4 and the funnel 1 are aligned as described above is fired at a high temperature of about 440 ° C. while being held by this assembly jig, and placed between the panel 4 and the funnel 1. The low melting point powdered glass melted to form a frit seal.

[0009]

The dimensional accuracy of the reference surface of the positioning pad is ensured by grinding with a diamond grinding tool or the like. However, such a reference surface has a large roughness, and there is a problem that a support made of a carbon material having heat resistance is worn in a short time and the positioning accuracy deteriorates.

It is generally known that the wear amount of a support made of a carbon material can be reduced by reducing the 10-point average roughness R _z of the reference surface of the pad. Therefore, in order to prevent the support made of the carbon material from being worn in a short time, the surface of the reference surface has been finished with a finishing tool such as urethane resin containing alundum. However, in order to reduce R _z by such a finishing treatment method, an extremely long finishing time is required and there is a problem that productivity is lowered. For this reason, it has been desired to reduce the amount of wear of the support and increase the productivity.

[0011]

The present invention has been made to solve the above problems, and has a substantially rectangular large open end and a substantially circular small open end, and is sealed to a CRT front glass. In a funnel for a cathode ray tube having a plurality of pads forming a reference surface for positioning, which is provided on the outer surface near the large opening end, the 10-point average roughness R _z of the reference surface of the pad and the average waviness period S _m
And 0.7% ≦ R _z / S _m ≦ 3%, and the above funnel for CRT, wherein R _z is R _z ≦ 10 μm. .

Further, the reference surfaces of the pads of the funnels for cathode ray tubes are brought into contact with a positioning support made of a material having a hardness lower than the Mohs hardness of the funnel by 2 or more to perform the positioning, and the funnel and the panel. The present invention provides a cathode ray tube sealing method, which comprises sealing glass with a low melting point powder glass.

[0013]

According to the present invention, the wear amount of the support tool is relatively reduced by setting the relationship between the 10-point average roughness R _z of the reference surface of the pad and the average waviness period S _m within a specific range. Very low, the time required for polishing is short, and productivity is good.

The amount of wear of the support made of a relatively soft carbon material is not only determined by the roughness R _z of the funnel pad reference surface, but also depends on the density of the irregularities. Since the unevenness density is proportional to the reciprocal of the undulation spatial period S _m , the amount of wear of the support is related to R _z and S _m . The present invention seeks to solve the above problems by finding an appropriate range of the ratio R _z / S _m of R _z and S _m , and achieving both a relatively short processing time and a relatively small amount of wear of the support. Is.

The appearance of the funnel of the present invention is the same as that of FIGS. 1 and 2 described above. However, the 10-point average roughness R _z of the reference surface 3 of the pad 2 and the average waviness period S _m are 0.7
% ≦ R _z / S _m ≦ 3% is satisfied. In a normal funnel, as shown in FIG. 4, there are two pads at one end on one long side and one at one end on one short side.
A total of three are provided. The position and the number of the pads may be changed.

The reason why R _z / S _m is 0.7% or more is that
If it is less than this range, the time required for polishing sharply increases. On the other hand, if R _z / S _m exceeds 3.0%, the amount of wear of the support also greatly increases, which is not preferable. In particular, it is preferable that 1.0% ≦ R _z / S _m ≦ 2.5%.
Even if the above relationship is satisfied, R _z itself is preferably not too large, and is preferably 10 μm or less.

As a finishing treatment method for finishing R _z / S _m of the reference surface of the pad within the above range in a relatively short time, there are the following methods, but these are merely examples and the present invention is not limited thereto. For example, there is a method in which a polishing tool made of urethane resin impregnated with cerium oxide is attached to a rotary shaft of a spindle motor and rotated at high speed. There is also a method of polishing the reference surface of the positioning pad while supplying a polishing slurry containing water or cerium oxide. It is preferable to use such a finishing treatment method, because the grinding removability of the urethane resin and the undulation period expanding effect of cerium oxide can be combined to easily form the reference surface of the pad having the surface in the above range.

The process of sealing the panel and the funnel in the process of assembling the cathode ray tube described above can be performed in the same manner as the conventional process. Specifically, as shown in FIGS. 3 and 4, the funnel 1 of the cathode ray tube to be sealed.
The pads 2, 2A, 2B, 2C of the support members 5, 5A, 5
B and 5C may be supported at predetermined positions, the relative position with the panel 4 may be adjusted, and both may be sealed with the low melting point powder glass applied on the sealing surface.

At the time of this assembly and sealing, the funnel 1 is pressed toward the corner where the two pads 2A and 2C are formed, as shown by the arrow A in FIG. For this purpose, the stand itself may be tilted and pressed by its own weight, or may be pressed from the opposite side by some mechanical force, for example, an air cylinder or a spring. In this way, by pressing from the direction of arrow A, these three pads 2A, 2B, 2C
Is brought into contact with the support tools 5A, 5B, 5C provided on the assembly jig side to support the funnel 1 and the panel 4 thereon.

That is, the support jig 5A on the assembly jig side,
5B and 5C are formed in advance at predetermined positions with predetermined protrusion lengths, and the end surfaces of the pads 2A, 2B and 2C on the funnel 1 side are brought into contact with the end surfaces of the support tools 5A, 5B and 5C. As a result, the funnel 1 is held in a predetermined position, and the alignment with the panel 4 is achieved.

Supports 5, 5A, 5 for this alignment
B and 5C must be materials that do not damage the funnel pad, and it is preferable to use a material having a Mohs hardness of 2 or more lower than that of the funnel glass. Then, a material that withstands the firing temperature of the low melting point powder glass is used.

For this reason, it is preferable that these supports are specifically made of a carbon material.
Carbon-based materials are most suitable in terms of heat resistance, softness that does not damage glass, and slip characteristics (small friction) when pressed.

In this way, the panel 4 and the funnel 1 are
The cathode ray tube whose position has been adjusted is fired at a high temperature of about 440 ° C. while being held by this assembly jig, and the low melting point powder glass arranged between the panel 4 and the funnel 1 is melted to frit seal. Is formed.

Finally, although there are cases where the steps are performed before and after, a shadow mask, an aperture grill, phosphor coating, an electron gun, and a neck tube are arranged to form a cathode ray tube.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIGS. 1, 2 and 4, positioning pads 2, 2A, 2B and 2C are integrally formed by projecting at three locations on the outer peripheral edge. The reference surface 3 of the positioning pad of this embodiment is subjected to finishing treatment, and R _z /
_Sm is set to 0.7% ≦ R _z / S _m ≦ 3%. As a comparative example, a material outside this range was also prepared.

The values of R _z / S _{m in} these examples are as follows: Example 1 (R _z / S _m = 0.5), Example 2 (R _z / S _m = 0.7), Example 3 (R _z / S _m = 1.5), Example 4 (R _z / S _m) = 2.0), Example 5 ( _Rz / _Sm = 3.0), Example 6 ( _Rz / _Sm = 5.0), Example 7 ( _Rz / _Sm = 7.0), Example 8 ( _Rz / _Sm = 10). In Example 8, R _z was 13 μm, but in other examples, R _z was 10 μm or less.

Polishing of the reference surface 3 of these positioning pads 2 was carried out by attaching a polishing tool made of urethane resin impregnated with cerium oxide to a rotary shaft of a spindle motor and rotating it at a high speed.

FIG. 5 is a Haydon 14D for measuring the dynamic friction resistance of the reference surface when the polishing treatment is performed in this way.
It is a graph which shows the relationship of the amount of relative wear of a carbon support tool in the same frequency | count of friction when a carbon support tool is repeatedly rubbed by a test machine at a load of 1 kg, a speed of 4.6 mm / sec, and a distance of 9 mm.

As a result, within the range of R _z / S _m ≤3%, the relative polishing amount is almost proportional to R _z / S _m , and if it exceeds this, the relative polishing amount increases greatly. Furthermore, R _z / S _m
As a result, it was found that the relative polishing amount gradually increased again as the value increased.

FIG. 6 is a graph showing the relationship between R _z / S _m of this reference plane and the relative polishing processing time. As a result, R
It was found that polishing time was remarkably required if _z / _Sm <0.7% was attempted.

Next, the funnels of Examples 2 to 7 and the panel were sealed. Originally, the phosphor was applied in the panel, the shadow mask was placed, and then the panel was sealed. However, in the following test, neither the phosphor nor the shadow mask was used.

First, low melting point powder glass was printed on the end face of the funnel 1 having a substantially rectangular large open end (the side to be sealed with the panel). Next, as shown in FIG. 3 and FIG. 4, the pads 2, 2A, 2 of the funnel 1 of the cathode ray tube to be sealed are attached.
B and 2C were supported at predetermined positions by carbon supporters 5, 5A, 5B and 5C. At this time, the table on which the support tool is placed is tilted so that the funnel 1 is supported by its own weight.
It can be pressed against B and 5C.

After that, the panel 4 is placed on it and the relative position thereof is adjusted, and it is fired at about 450 ° C. while being held on this table, and the low melting point powder disposed between the panel 4 and the funnel 1. The glass was melted to form a frit seal.

[0034]

As described above, according to the present invention, R _z / R of the reference surface of the positioning pad used when the panel and the funnel are sealed with the frit seal in assembling the cathode ray tube.
S _{m is set} to 0.7% ≦ R _z / S _m ≦ 3%. Therefore, the position change of the reference surface due to wear of the support is prevented,
Positioning and sealing can always be performed at a fixed reference position. As a result, the reliability of the CRT image receiver is improved, a high-quality image can be realized, and the yield is improved.

Further, in the frit sealing process, it is possible to create a reference surface in which abrasion is suppressed when the pad reference surface is brought into contact with the support tool on the assembly jig side in a relatively short time. Therefore, the time required for polishing the reference surface is short, and the productivity is less likely to decrease. The present invention can be applied to various applications within a range that does not impair the effects of the present invention.

[Brief description of drawings]

FIG. 1 is a side view of a funnel for a cathode ray tube.

FIG. 2 is a schematic partial perspective view of a funnel for a cathode ray tube.

FIG. 3 is a side view showing the configuration of a jig for frit seal of a cathode ray tube.

FIG. 4 is a plan view showing the configuration of a frit seal jig for a cathode ray tube.

FIG. 5 is a graph showing the relationship between the relative amounts of wear of carbon supports.

FIG. 6 is a graph showing the relationship between relative polishing processing times for the reference surface of the pad.

[Explanation of symbols]

 1: Funnel 2: Pad 3: Reference surface 4: Panel 5: Support

Claims (3)

[Claims] 1. A reference plane for positioning, which has a large opening end having a substantially rectangular shape and a small opening end having a substantially circular shape, is provided on an outer surface near the large opening end for sealing with a CRT front glass. In a cathode ray tube funnel having a plurality of formed pads, 0.7% ≦ R between the 10-point average roughness R _z of the pad reference surface and the average undulation period S _m.
A funnel for a cathode ray tube having a relationship of _z / S _m ≦ 3%. 2. The funnel for a cathode ray tube according to claim 1, wherein R _z is R _z ≦ 10 μm. 3. The reference surface of the pad of the funnel for CRT according to claim 1 or 2 is 2 more than the Mohs hardness of the funnel.
A cathode ray tube sealing method characterized in that the above-mentioned lower hardness material is brought into contact with a positioning tool to perform positioning, and the funnel and the panel are sealed with a low melting point powder glass.