JPH087776A - Spring for frame support of cathode-ray tube - Google Patents

Abstract

PURPOSE: To provide a spring for supporting the frame of a cathode-ray tube which is mostly optimize the compensation amount for the thermal change of a shadow mask and shadow mask frame. CONSTITUTION: This spring includes a first metal part 10 and a second metal part 11a, having a thermal expansion coefficient different with the first metal part 10, connected to one side of the first metal part, and a third metal part 11b, having the same thermal expansion coefficient as the second metal part, 11a, connected to the other side of the first metal part 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frame supporting spring for a shadow mask of a cathode ray tube.
The present invention relates to a frame supporting spring for a cathode ray tube that optimizes a compensation amount of a shadow mask and a shadow mask frame against thermal changes.

[0002]

2. Description of the Related Art In a shadow mask type color cathode ray tube, an electron beam emitted from an electron gun selectively passes through an electron beam passing portion of a shadow mask and collides with R, G and B pixels of a fluorescent layer. .

A part of the electron beam passes through the electron beam passage portion (hole or the like) of the shadow mask and reaches these pixels, while the rest collides with the inner surface of the shadow mask and heats the shadow mask. As a result, the shadow mask and the shadow mask frame are thermally expanded, and the positional relationship between the electron beam passage portion and the pixel is changed to cause a doming phenomenon in which color purity is lowered. Therefore, this change must be compensated.

As a general method for solving the doming phenomenon of the shadow mask, a support member called a heat compensation (compensation) spring is used. The heat compensation spring is locked to the cathode ray tube by a stud pin attached to a predetermined position of the panel portion of the cathode ray tube, and supports a shadow mask having an electron beam passage portion (hole or the like). The shadow mask frame is supported and the position change of the electron beam passage portion due to the doming phenomenon is corrected. For example, Korean Patent Application Publication No. 94-29
No. 05 discloses a frame supporting spring for such a cathode ray tube.

FIG. 5 is a plan view showing the spring of the above application. Referring to FIG. 5, the spring 1 has a substantially plate shape, two metals having different thermal expansion coefficients, a first metal part 10 made of SUS (stainless steel) and a second metal part made of INVAR (amber; low thermal expansion). It is a bimetal type in which the metal portion 11a is joined. The first metal portion 10 has a recess on the side surface on the open side (the other side surface opposite to the joining surface with the second metal portion 11a), and a stud is formed in the vicinity of one end of the first metal portion 10 from the flat surface toward the lower surface. The pin coupling portion 12 is formed. The other end surface of the spring 1 opposite to the stud pin coupling portion 12 is a shadow mask frame weld portion 13 to which the shadow mask frame is welded.

[0006]

However, the above-mentioned conventional bimetal type spring 1 appropriately compensates for a temperature change up to a certain value, but the thermal expansion coefficient of the two metals is increased when the temperature change exceeds a certain value. There is a problem that excessive compensation is performed because the difference in the expansion amount due to the difference occurs in excessively.

FIG. 4 is a graph showing this, where the horizontal axis T is the time axis and the vertical axis μ is the error amount of the electron beam passing through the shadow mask according to time (that is, the electron beam is the target). The line a represents an amount of error (+ direction) caused by a thermal change of the shadow mask. , Line b
Is the error amount (-direction) generated by the thermal change of the shadow mask frame, line c is the sum of the two error amounts a and b, line d is the compensation amount by the spring 1 (+ direction), and line e is the two. Total error amount a, b c
And the compensation amount d (that is, the final error amount) are shown. The width A between the line e and the line c indicates the compensation amount of the spring 1.

As shown in FIG. 4, the conventional spring is
If the temperature gradually rises after a certain time t, the spring will perform excessive compensation, and the final error amount e will not be balanced and will increase.

[0009]

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a frame supporting spring for a cathode ray tube that optimizes the amount of compensation for thermal changes in the shadow mask and shadow mask frame. .

[0010]

In order to achieve the above object, a frame supporting spring for a cathode ray tube according to the present invention comprises:
A first metal part and a thermal expansion coefficient different from that of the first metal part,
A second metal part formed on one side surface of the first metal part, and a third metal part having a thermal expansion coefficient different from that of the first metal part and formed on the other side surface of the first metal part. It is characterized by

The frame supporting spring of the cathode ray tube according to the present invention is preferably characterized in that the first metal portion is made of a material having a thermal expansion coefficient larger than those of the second and third metal portions.

The frame supporting spring of the cathode ray tube according to the present invention is preferably characterized in that the first metal portion is made of a material having a thermal expansion coefficient smaller than that of the second and third metal portions.

The frame supporting spring of the cathode ray tube according to the present invention is preferably characterized in that the second metal portion and the third metal portion are made of materials having different thermal expansion coefficients.

In the frame supporting spring of the cathode ray tube according to the present invention, preferably, the first metal portion is substantially plate-shaped and has a recessed portion at the center of one side surface of the first metal portion, and the first metal portion faces each other. A second metal portion and a third metal portion are formed on the side portions, respectively, and two of the first metal portion, the second metal portion, and the third metal portion are formed.
The two joint surfaces are inclined with respect to the side surface of the first metal portion, and a stud pin fitting portion for fitting a stud pin for locking the frame supporting spring to the cathode ray tube near one end surface of the first metal portion. Is provided, and the other end surface of the first metal portion is used as a shadow mask frame welded portion for fixing the frame of the shadow mask.

[0015]

According to the frame supporting spring of the cathode ray tube of the present invention, the combination of the thermal expansion coefficients of the first, second and third metal parts can be appropriately selected. As an example, the first metal part and the second metal part can be selected. When the displacement direction due to the thermal expansion of the metal part is positive (+), the displacement direction due to the thermal expansion of the first metal part and the third metal part can be set to the opposite (-), and the total displacement of the spring is the above two displacements. This total displacement is the spring compensation amount (heat compensation amount). Therefore, in the heat correction (heat compensation) spring for a cathode ray tube according to the present invention, the two displacements (forces to displace) increase in opposite directions even if the temperature increases and the displacements increase. These displacements (forces to be displaced) can be canceled out to prevent excessive compensation. Therefore, regardless of the thermal expansion of the shadow mask or shadow mask frame due to the collision of the electron beam with the shadow mask or the rise in the temperature inside the cathode ray tube, the electron beam has a high probability of landing on a predetermined phosphor, and thus provides a good image quality. To be done.

[0016]

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

FIG. 1 is a plan view schematically showing a frame supporting spring 1 for a cathode ray tube according to a first embodiment of the present invention.

Referring to FIG. 1, a spring 1 is a two-part split type having two joining lines, whereas a conventional bimetal type frame supporting spring is one split type having one joining line. There is.

That is, in the spring 1, after the first metal portion 10 having a predetermined thermal expansion coefficient is arranged in the middle,
The first part is formed on both side surfaces of the first metal part 10 with the metal part 10 as the center.
The second metal portion 11a and the third metal portion 11b, which have a thermal expansion coefficient different from the thermal expansion coefficient of the metal portion 10, are joined and formed.

Then, the first metal portion 10 and the second metal portion 11
When the displacement direction due to thermal expansion with respect to a is viewed in the positive direction (+), the displacement direction due to thermal expansion of the first metal part 10 and the third metal part 11b is opposite (-). The second metal portion 11a is joined to one side surface of the first metal portion 10
The third metal portion 11b is joined to the other side surface.

The third metal portion 11b has a recess on the open surface (the front surface, the surface opposite to the surface where the first metal portion 10 is joined), and one end of the first metal portion 10 has a stud from a flat surface to a lower surface. The pin coupling portion 12 is formed. Stud pin joint 1
2 The other end surface of the spring 1 on the opposite side has a shadow mask frame welded portion 13 where the shadow mask frame is welded.
Is.

The compensation of the positional displacement of the shadow mask or the like due to thermal expansion by the spring 1 will be described. Spring 1
Is pressed in the direction of the stud pin coupling portion 12 from the shadow mask frame welded portion 13 by the thermally expanded shadow mask or shadow mask, and in the direction in which the recess is formed (from one side surface (second metal portion 11a) side to the other side surface ( Third metal part 1
1b) side, that is, from the upper side to the lower side in FIG. 1) and the like to absorb the thermal expansion of the shadow mask or the shadow mask frame. The operation of the spring 1 is the same as the operation of the conventional bimetal type frame support spring shown in FIG.

However, as described above, the spring 1
Is the second and third metal parts 11 which are high expansion parts having a coefficient of thermal expansion larger than the coefficient of thermal expansion of the first metal part 10 on both sides of the first metal part 10 which is a low expansion part.
Since the springs 1 and 11b are provided, the overall compensation of the spring 1 is displacement (+) due to the difference in expansion amount between the first metal portion 10 and the second metal portion 11a, and the first metal portion 10 and the third metal portion 11a.
It is the total of the displacement (-) due to the difference in expansion amount from b.

Therefore, as the temperature rises,
First metal part 10, second metal part 11a, and first metal part 1
The difference in the amount of expansion between 0 and the third metal portion 11b increases sharply, but due to the displacement direction of the first metal portion 10 and the second metal portion 11a and the displacement direction of the first metal portion 10 and the third metal portion 11b. Since the displacement directions are opposite to each other, the total displacement does not change rapidly. Therefore, large deformation or unexpected deformation of the spring 1 itself due to thermal expansion is prevented, and thus displacement of the shadow mask or shadow mask frame due to thermal expansion is preferably compensated.

The displacement by the first metal portion 10 and the second metal portion 11a and the displacement by the first metal portion 10 and the third metal portion 11b so that the spring 1 performs the desired compensation are the first and the second. Further, it can be further optimized by adjusting the size or shape of the width and the like of the third metal parts 10, 11a, 11b.

The heat compensation characteristics of the spring 1 are as follows:
And the coefficient of thermal expansion of the third metal parts 10, 11a, 11b,
It varies depending on the area ratio between them and their geometric shape. Therefore, in order to obtain a more preferable heat compensation function, the value of the coefficient of thermal expansion, the area ratio, the shape, etc. of each metal portion should be properly designed.

Preferably, the first metal portion 10 is INVAR.
It is a low expansion part made of (amber) material, and the second and third metal parts 11a and 11b are high expansion parts made of SUS (stainless steel) material. On the contrary, the first metal part 10 may be a high expansion part made of SUS (stainless steel) and the second and third metal parts 11a and 11b may be low expansion parts made of INVAR (amber) material. The spring 1 can be processed by using rolled clad steel or the like, or the second metal part 11a and the third metal part 11b can be used as the first metal part 10.
It can be provided by a known forming method such as vapor deposition, plating and welding.

FIG. 2 shows a frame supporting spring 1 for a cathode ray tube according to a second embodiment of the present invention. In order to make the production of the spring 1 advantageous (convenient), both side surfaces of the first metal part are shown. The shadow mask frame welded portion 13 side of the spring 1 is provided on each of the opposing side portions of the spring 1 so as to sandwich the front surface and the rear surface (in this embodiment, the substantially diagonal side areas of the first metal portion 10). The second metal portion 11a is formed on the side portion, and the third metal portion 11b is formed on the side portion near the stud pin coupling portion 12 of the spring 1. Further, the two joining lines are inclined with respect to the length direction (side surface) of the spring 1. According to such a configuration, the second and third metal parts 11
The proportion occupied by a and 11b is reduced, and the concave portion can be provided in the first metal portion 10. The rest of the configuration, the manufacturing method, etc. are the same as those of the first embodiment of the present invention, and therefore will be omitted.

FIG. 3 is a graph showing the characteristics of the spring 1 for supporting the frame of the cathode ray tube according to the first and second embodiments of the present invention, and the reference numeral of this graph is the same as that of FIG. The explanation is given below.

Referring to FIG. 3, the horizontal axis T is the time axis and the vertical axis μ
Indicates the error amount of the electron beam passing through the shadow mask over time (that is, the degree to which the electron beam deviates from the target phosphor in the positive and negative (±) directions), and the line a is generated by the thermal change of the shadow mask. Error amount (+ direction), line b indicates error amount (-direction) caused by thermal change of shadow mask frame, line c
Is the sum of the two error amounts a and b, the line d is the compensation amount (+ direction) by the spring 1, and the line e is the sum of the two error amounts a and b and the compensation amount d (that is, the final error amount). ) Are shown respectively. The width A between the line e and the line c indicates the amount of compensation by the spring.

Substantially, the lines a and b showing the amount of error generated by the shadow mask and the shadow mask frame of FIG. 3 are the same as those of the prior art shown in FIG. The line d showing the amount of compensation by is different. It can be seen that the line d shown in FIG. 4 described above rapidly increases after a certain time t, and the final error amount e rapidly increases. However, according to the spring 1 of this embodiment, the line d shown in FIG.
It can be understood that the final error amount e shown in FIG. 3 does not increase sharply as in the conventional case shown in FIG. Therefore, the electron beam has a higher probability of passing through the shadow mask and reaching the target phosphor, and the image quality is improved.

[0032]

As described above, according to the frame supporting spring of the cathode ray tube of the present invention, the combination of the thermal expansion coefficients of the first, second and third metal parts can be appropriately selected and the temperature can be increased. It is possible to suppress a rapid change in the compensation amount of the positional displacement due to the thermal expansion of the shadow mask or the shadow mask frame as it rises, for example, a rapid bending of the spring in one direction. Therefore, the electron beam has a high probability of landing on the target phosphor regardless of the thermal expansion of the shadow mask or the shadow mask frame due to the collision of the electron beam with the shadow mask or the rise in the temperature in the cathode ray tube. It is possible (Claim 1).

Further, the coefficient of thermal expansion of the first metal part is set to be larger or smaller than that of the second and third metal parts, or the coefficient of thermal expansion of the second metal part and the third metal part is different. By doing so, abrupt changes in the compensation amount of positional displacement due to thermal expansion of the shadow mask or shadow mask frame as the temperature rises, for example, abrupt bending of the spring in one direction is preferably suppressed, and good Image quality is provided (claims 2-4).

Further, the plate-shaped first metal portion has a concave portion on the front surface, and the second metal portion and the third metal portion are provided on opposite sides of the first metal portion, respectively.
The metal portion is formed, and the two joining lines of the first metal portion, the second metal portion, and the third metal portion are inclined with respect to the front length direction (side surface) of the first metal portion. In addition to the effect of item 1, it is advantageous in manufacturing the spring (claim 5).

[Brief description of drawings]

FIG. 1 is a plan view schematically showing a frame supporting spring of a cathode ray tube according to a first embodiment of the present invention.

FIG. 2 is a plan view schematically showing a frame supporting spring of a cathode ray tube according to a second embodiment of the present invention.

FIG. 3 is a graph showing the characteristics of the frame supporting spring of the cathode ray tube according to the first and second embodiments of the present invention.

FIG. 4 is a graph showing characteristics of a conventional frame supporting spring for a cathode ray tube.

FIG. 5 is a plan view schematically showing a conventional frame supporting spring of a cathode ray tube.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Spring 10 ... 1st metal part 11a ... 2nd metal part 11b ... 3rd metal part 12 ... Stud pin coupling part 13 ... Shadow mask frame welded part

Claims (5)

[Claims] 1. A substantially plate-shaped spring for supporting a frame of a shadow mask having an electron beam passage portion in a cathode ray tube, the first metal portion having a thermal expansion coefficient different from that of the first metal portion. A second metal part formed on one side surface of the first metal part; having a coefficient of thermal expansion different from that of the first metal part;
And a third metal portion formed on the other side surface of the metal portion; 2. The frame supporting spring for a cathode ray tube according to claim 1, wherein the first metal part is made of a material having a coefficient of thermal expansion larger than that of the second and third metal parts. 3. The frame supporting spring for a cathode ray tube according to claim 1, wherein the first metal portion is made of a material having a thermal expansion coefficient smaller than that of the second and third metal portions. 4. The frame supporting frame for a cathode ray tube according to claim 1, wherein the second metal portion and the third metal portion are made of materials having different thermal expansion coefficients. spring. 5. The first metal portion is substantially plate-shaped, and has a recessed portion at the center of one side surface of the first metal portion, and the second metal portions are respectively provided on opposite sides of the first metal portion. The third metal portion is formed, and two joining surfaces of the first metal portion, the second metal portion, and the third metal portion are inclined with respect to the side surface of the first metal portion, A stud pin fitting portion for fitting a stud pin for locking the frame supporting spring to the cathode ray tube is provided near one end surface of the first metal portion, and the other end surface of the first metal portion is provided at the other end surface of the first metal portion. The shadow mask frame welded portion for fixing the frame of the shadow mask, wherein the frame supporting spring for a cathode ray tube according to any one of claims 1 to 4.