JPH01132024A - Manufacturing device for shadow mask structure - Google Patents

Abstract

PURPOSE:To improve material utilization efficiency and reduce cost by arranging a rectangular or square shaped frame on the periphery of a mask frame and giving tension to the shadow mask. CONSTITUTION:A rectangular frame 25 is arranged on a support plate 24. The inner dimension of the frame 25 is set to be larger than a mask frame 14 while its outer dimension is set to be smaller than the inner dimensions of rectangular openings 22, 23 of depression plates 15, 16. When a vertical feed device 30 is operated, the support plate 24 moves to come near to the depression plates 15, 16 and a tension is applied to a shadow mask member 131 while being bent by the rectangular frame 25 according to the relationship between the rectangular frame 25 and the depression plates 15, 16. An unnecessary part of the shadow mask member 131 is then cut off. In this case, the area of the unnecessary part of the shadow mask is 25% compared with the case in which conventional circular frame is used. This increases the utilization efficiency of the material and reduces the production cost.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a shadow mask structure manufacturing apparatus, and in particular, to improve the color purity reproduction characteristics of a shadow mask type color picture tube. The present invention relates to an apparatus for manufacturing a shadow mask structure configured such that a flat shadow mask is stretched over a mask frame under tension.

(Prior art) Generally, in a shadow mask type color picture tube, red,
Three electron beams corresponding to green and blue pass through one electron beam passage hole of the shadow mask, and are then formed on the inner surface of the panel facing the shadow mask. The phosphor impinges on the layers, causing each phosphor layer to emit light.

Therefore, in order to achieve good color reproduction, the relative positional relationship between the many electron beam passing holes of the shadow mask and the corresponding three color phosphor layers must be in a predetermined matching relationship, and the electron beam passing holes must be aligned. It is necessary for the passed electron beam to accurately land on a predetermined phosphor layer.

However, the shadow mask transmittance of the electron beam is usually 15
20%, and most of the other electron beams collide with the shadow mask, causing it to heat and expand.

This heating and expansion becomes particularly large when the anode voltage and beam current of the color picture tube are increased in order to obtain a bright screen, and as a result, the beam landing position changes significantly and the color purity deteriorates. Become.

Next, an example of a normal shadow mask type color picture tube will be explained with reference to FIGS. 6 and 7.

That is, a panel 1 has a phosphor screen 2 formed of phosphor dots that emit red, green, and blue light adhered to its inner surface; a shadow mask 3 disposed at a predetermined distance from the phosphor screen 2;
A shadow mask structure 5 consisting of a mask frame 4 to which this shadow mask 3 is fixed, a bottle 6 that supports and fixes the mask frame 4 to the panel 1, a funnel 7 joined to the panel 1, and a funnel 7 joined to the funnel 7. It consists of a neck 8 and an electron gun 9 provided inside the neck 8.

In such a color picture tube, the shadow mask 3 is made by press-molding a thin iron plate of 0.1 to 0.2 mm into a dome shape, which is provided with a large number of electron beam passage holes by etching or the like. The shadow mask structure 5 is fixedly welded to a mask frame 4 having a thickness of ~1.5 mm at multiple points.
It consists of

As mentioned above, the electron beam 10 emitted from the electron gun 9
A part of the electron beam passes through the electron beam passage hole of the shadow mask 3 and hits the phosphor screen 2, causing a predetermined phosphor dot to emit light, but most of the remaining part collides with the shadow mask 3 and hits the phosphor screen 2. Heat 3. Due to this heating, the temperature of the shadow mask 3 rises and expands.Furthermore, this heat is transmitted from the mask frame 4 and pins 6 to the panel 1, causing temperature differences in each part and deforming the parts. , a so-called landing error occurs in which the position where the electron beam 10 lands on the phosphor screen 2 through the electron beam passage hole deviates from a predetermined position.

This landing error changes over time, and the shadow mask 3 expands rapidly immediately after an operation or when a locally bright part occurs on the screen. However, since the temperature of the mask frame 4 having a relatively large heat capacity does not rise immediately, the shadow mask 3 bulges toward the position 3', that is, toward the phosphor screen 2.

As a result, the electron beam 11 passing through the same electron beam passage hole shifts to 11', and the landing position also shifts from 12 to 12', causing a landing error. Furthermore,
If the color picture tube continues to operate, the mask frame 4 will also thermally expand after a sufficiently long period of time has elapsed, so that the beam landing position will change in the opposite direction to that immediately after the above-mentioned operation.

The amount of displacement of this landing position is several tens of μm to 100 μm.
It is on the order of μm and causes deterioration of color purity. Furthermore, as the anode voltage of the color picture tube increases and the beam current increases in an attempt to obtain a bright screen, the energy colliding with the shadow mask 3 also increases, which increases the landing error and significantly degrades color purity. Become.

On the other hand, in order to realize a high-definition image, the distance between the electron beam passage holes of the shadow mask 3 should be reduced.
It is necessary to increase the number of picture elements.

This reduces the spacing between the three color phosphor dots deposited on the phosphor screen 2 and the landing margin of each phosphor dot. Therefore, high-definition color picture tubes require more accurate beam landing.

To reduce the beam landing error mentioned above,
Various proposals have been made in the past. For example, the shadow mask may be blackened or coated with a black coating to improve heat dissipation and reduce temperature rise, or the thickness and length of the side wall of the shadow mask may be adjusted, or holes or notches may be provided to increase heat capacity. There are structures that aim to equalize heat by making the size smaller, and structures that use low thermal expansion materials such as invar.

However, these measures were insufficient for applications that require high brightness and are used under bright external light, such as in aircraft.

As a structure to solve this problem, “All-B” by R. C. Robinder
rightnessShadow-Mask Co1
or CRT f'or Cockpit Dlspl
ays.

Digest of' Paper of' 1983
Symposia+ of 5ocietyf'o
r Information Display 9.5
”, a color picture tube equipped with an improved shadow mask structure was announced.

This color picture tube consists of a flat shadow mask 3 fixed to a mask frame 4 under tension as shown in FIG.
Thermal expansion of the shadow mask structure 5 is absorbed by tension relaxation, and a shadow mask structure 5 that does not deform even under high brightness is realized. It is reported that this color picture tube has a significantly improved landing error compared to a conventional color picture tube equipped with a dome-shaped shadow mask.

Next, this type of shadow mask structure manufacturing apparatus will be briefly described based on Japanese Patent Application Laid-Open No. 167936/1983.

That is, in FIGS. 9 and 10, the shadow mask 3
After the shadow mask 3 is placed, the L-shaped extension ring 41 is tightened to create tension in the shadow mask 3. Further, the side surfaces of the mask frame 4 are compressed by compression arms 42 in the direction indicated by an arrow 43. In this state, shadow mask 3 is created by spot welding.
is fixed to the mask frame 4. At this time, in order to prevent distortion occurring around the fixed portion of the shadow mask 3, each side of the mask frame 4 is skipped and alternately welded and fixed. Thereafter, the shadow mask assembly is removed and the excess shadow mask is cut off to complete the shadow mask structure.

(Advantages to be Solved by the Invention) In a conventional shadow mask structure manufacturing apparatus that applies a predetermined tension to a shadow mask, a circular L-shaped extension ring 41 is used to generate tension in the shadow mask. Therefore, when forming the shadow mask structure 5, the area of the extra shadow mask is large, resulting in poor material utilization and high cost.

This invention was made to solve the above-mentioned conventional problems, and provides a shadow mask structure that can be manufactured at a low cost to which a tension is applied for a high-brightness color picture tube without deteriorating color purity. The object of the present invention is to provide a manufacturing device for a mask structure.

[Structure of the Invention] (Means for Solving the Problems) The present invention includes a pair of presser slopes having an opening in the center, and a pair of presser plates disposed below the presser plate so as to be movable in the axial direction. a frame larger than the mask frame and having an outer diameter smaller than the opening, a shadow mask material is clamped and fixed by the pair of presser plates, a mask frame is arranged inside the frame, and the frame and the mask are provided. An apparatus for manufacturing a shadow mask structure, characterized in that the frame and the shadow mask material are moved relatively, the frame body applies tension to the shadow mask material, and the shadow mask material is fixed to the mask frame in this state. , and both the opening and the frame have a rectangular or square shape.

(Function) According to the present invention, a substantially rectangular or square frame is arranged around the outer periphery of the mask frame, and this frame applies tension to the shadow mask. Compared to conventional devices that apply a predetermined tension to the mask frame, unnecessary parts of the shadow mask outside the mask frame can be significantly reduced, resulting in higher material utilization and manufacturing that is inexpensive and easy to mass produce. A device is obtained.

Conventionally, this type of shadow mask structure manufacturing apparatus used a circular frame to apply tension to the shadow mask material, but the present invention uses a rectangular frame.
This is because applying tension using a rectangular frame can reduce the difference in tension depending on the direction of the shadow mask structure when it is assembled into a color picture tube.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

The shadow mask structure manufacturing apparatus according to the present invention includes a first
It is constructed as shown in FIGS. 3 to 3.

That is, the entire manufacturing apparatus is shown in FIG. 2, in which a plurality of support rods 29 are installed on a base 31, a pair of presser plates 15 and 16 are fixed to the support rods 29, and ,
A support plate 24 having a rectangular frame 25 is disposed so as to be freely movable in the axial direction.

First, the pair of presser plates 15.16 will be described. The pair of presser plates 15.16 are constructed as shown in FIG. It has a rectangular opening 22,23. Although details will be described later, when in use, this pair of presser plates 15
．． 16, the peripheral portion of the shadow mask material 131, in which a large number of electron beam passage holes are regularly provided over the entire surface, is clamped and fixed. The rubber plates 17 and 18 are provided to prevent the shadow mask material 131 from moving when tension is applied to the shadow mask material 131.

On the other hand, as shown in FIG. 1(b), a rectangular frame 25 is provided on the support plate 24.
The inner diameter of the mask frame is set to be larger than the mask frame 14, and the outer diameter is set to be smaller than the inner diameter of the rectangular opening 22.23 of the holding plate 15.16. Therefore, when the support plate 24 is moved in the axial direction, the rectangular frame 25 enters the rectangular opening 22.23 with a predetermined gap.

The height of the rectangular frame 25 is equal to the welded portion 1 of the mask frame 14 fixed to the rectangular frame 25 with a presser pin 28.
The height is set to be the same as that of 41, or slightly lower.

Further, as shown in FIG. 2, between the base 31 and the support plate 24, hydraulic pressure or air pressure is used to move the support plate 24 up and down, and to bring the press plate 15.16 and the support plate 24 closer to each other and away from them. A vertical feed device 30 is provided.

In addition, as shown in FIGS. 1(a) and (b), the presser plate 15.
16. At each of the four corners of the shadow mask material 131 and the support plate 24, through holes 19 are bored into which support rods 29 can be inserted.

Next, the process of manufacturing a shadow mask structure using this shadow mask structure manufacturing apparatus will be described using the same drawing.

First, as shown in FIG. 2, the shadow mask material 13 is clamped and fixed between the press plates 15 and 16 via the support rods 29. The shadow mask material 131 used was a 0.13 mm thick material made of 36Ni--Fe alloy, which is a low thermal expansion material, and in which a large number of electron beam passage holes were formed over the entire surface by etching. When the shadow mask material 131 is clamped and fixed between the presser plates 15 and 16, the support plate 24 is attached to the rectangular frame 25 and the welded portion 1 of the mask frame 14.
41 and the shadow mask material 131 are lowered to such an extent that they are in contact with each other or are slightly separated from each other.

Next, as shown in FIG. 3, when the vertical feed device 30 is operated, the support plate 24 comes close to the presser plates 15 and 16. The shadow mask material 131 has a presser plate 15.1.
6 and the rectangular frame 25, tension is applied while being bent by the rectangular frame 25.

Next, when a predetermined tension is applied to the shadow mask material 13 in the rectangular frame 25, the ribbon-shaped frame 26 corresponding to the welded portion 141 of the mask frame 14 is inserted into the shadow mask material 13 from above, and the welded portion is 141, then weld tightly from above the ribbon frame 26 at the welding point 27 to clamp and fix it, and then cut off the unnecessary portion of the shadow mask material 131 to complete the shadow mask structure shown in FIG. 4. do.

In the above case, the mask frame 14 has a thickness of 1 to 2 m.
A 42Ni-Fe alloy, which is a low thermal expansion material of 1.5 mm, is used, and the ribbon-shaped frame 26 is made of the same material as the mask frame 14, with a thickness of 0.1 mm, and welding is performed using an intermittent pulsed laser beam. I did it.

Now, the state of the tension in the shadow mask when the manufacturing apparatus of the present invention is used will be explained with reference to FIGS. 5(a) to 5(e).

Figures (a) and (d) show the tension applied to the shadow mask material in a rectangular frame and a circular frame, respectively. A case will be explained in which the maximum value of the tension applied to the shadow mask material is equal between a rectangular frame body and a circular frame body.

In a rectangular frame, the maximum tension T1 is applied in the short axis direction where the distance from the center to the frame is the shortest, and the minimum tension T2 is applied in the diagonal direction where the distance from the center to the frame is the longest. However, in the case of a circular frame, since the distance from the center to the frame is constant in any direction, a --like tension T1 is applied.

Next, FIG. 5(b) shows the state of the mask frame deformed to a state that balances the tension of the shadow mask material. The deformation in the diagonal direction is small, and the deformation in the short axis direction of the long side is the largest. Figures 5(c) and 5(c) show the tension of the shadow mask structure manufactured using a rectangular frame and a circular frame.
Shown in e).

When a rectangular frame is used, the tension t1 applied in the short axis direction and the tension t2 applied in the diagonal direction are 1·T1 at t, - (1) T2 - It is expressed as 2 ・T2 (2). Here, the proportionality coefficient represents the relaxation of tension due to deformation of the mask frame, and is -1 when the mask frame is a rigid body and does not deform, and K<1 when the mask frame is deformed.

Similarly, when a circular frame is used, the tension t3 applied in the minor axis direction and the tension t4 applied in the diagonal direction are t3 - K 1 ・T1 ...... (
3) At t4-, 2・T2...becomes a river (4). From the above explanation, since T1>T2 and K1, especially 2, 11 times t3<i2<t4, and when a rectangular frame is used, the difference in tension depending on the direction becomes small.

The inventor used a 7 // x 7 // square frame to manufacture a 6 x 6 shadow mask structure, which made the shadow smaller than when using a conventional circular frame. We were able to reduce the area of unnecessary parts of the mask to 25%. This shadow mask structure was incorporated into a color picture tube and operated repeatedly at high input for a long period of time, but it was possible to obtain extremely stable operation without deterioration of color purity.

(Modification) In the above embodiment, the rectangular frame 25 was used to apply tension to the shadow mask material 131, or the rectangular frame 25 was not used in the shadow mask structure manufacturing apparatus of the present invention. Alternatively, the mask frame 14 can also be used to further simplify the process.

Further, the above-described embodiments are not intended to limit the configuration of the present invention, but are merely examples in which the inventors have obtained favorable results. Therefore, for example, the ribbon-shaped frame 26 may not be used, and
Welding also does not need to be done with pulsed laser light.

Further, in the above embodiment, the openings 22.23 of the pair of presser plates 15, 16 and the frame 25 are both rectangular, but they may be square.

[Effects of the Invention] As described above, according to the present invention, since tension is applied in advance to prevent landing errors due to thermal expansion of the shadow mask, a shadow mask structure of good quality can be manufactured at low cost. It is possible to provide an apparatus for manufacturing a shadow mask structure, which has extremely high industrial value.

[Brief explanation of the drawing]

FIGS. 1(a), 1(b) to 3 are diagrams showing an embodiment of a shadow mask structure manufacturing apparatus of the present invention, and FIG.
Figures (a) and (b) are perspective views of the main parts, Figure 2 is a cross-sectional view of the entire structure before applying tension to the shadow mask material, and Figure 3 is a mask after applying tension to the shadow mask material. 4 is a cross-sectional view showing the state fixed to the frame, FIG. 4 is a perspective view showing the completed shadow mask structure, and FIGS. 5(a) to (e)
6 is an explanatory diagram showing the tension state of the shadow mask, and FIG. 6 is a sectional view showing a conventional shadow mask type color picture tube.
FIG. 7 is a sectional view showing the main parts of the color picture tube shown in FIG. 6 during operation, FIG. 8 is a sectional view showing the main parts of another example of the conventional shadow mask color picture tube, and FIG. 9 is a sectional view showing the main parts of the color picture tube shown in FIG. FIG. 10 is a plan view showing a conventional shadow mask structure manufacturing apparatus, and is a sectional view taken along line A-A' in FIG. 9 and viewed in the direction of the arrow. 13...Shadow mask, 131...Shadow mask material, 14...Mask frame, 15.16...Press plate, 17.18...Rubber plate, 24...Support plate, 2
5... Rectangular frame body, 26... Ribbon-shaped frame, 27...
・Welding point, 28... Holding pin, 29... Support rod, 3
0... Vertical feed device, 31... Base. Applicant's representative Patent attorney Takehiko Suzue (a) Figure 1 Figure 2 @ Figure 3 Figure 4 (d) (b) Yu 5 Pile 6 Figure 7 Figure 9 Figure 10

Claims (3)

[Claims] (1) A pair of holding plates having an opening in the center, and a frame body disposed below the pair of holding plates so as to be freely movable in the axial direction and having an inner diameter larger than the mask frame and an outer diameter smaller than the opening. A shadow mask material is clamped and fixed between the pair of presser plates, a mask frame is placed inside the frame body, and the frame body and the mask frame are moved relatively to the shadow mask material to form a frame. A shadow mask structure manufacturing apparatus characterized by applying tension to the shadow mask material by a body and fixing the shadow mask material to a mask frame in this state. (2) The apparatus for manufacturing a shadow mask structure according to claim 1, wherein both the opening and the frame have a rectangular or square shape. (3) The apparatus for manufacturing a shadow mask structure according to claim 1 or 2, wherein the frame is the mask frame.