JPH01209636A - Color picture tube - Google Patents

Abstract

PURPOSE:To make it possible to correct the PD(Purity Drift) for a long time by placing a metal member with the thermal expansion coefficient different from a shadow mask and a mask frame, between the shadow mask and the mask frame, and fixing either the shadow mask or the mask frame close to one end of the metal member in the tube axial direction while the other member close to the other end thereof. CONSTITUTION:Between a shadow mask 7 and a mask frame 8, a metal member 10 with the thermal expansion coefficient different from both the shadow mask 7 and the mask frame 8 is placed. While the shadow mask 7 is welded locally to the metal member 10 at the position A closer to the main surface side of a panel 11 in the tube axial direction, the mask frame 8 is welded locally to the metal member 10 at the position B closer to the electron gun side. As a result, when the correction of PD is carried out for a long time, it can be carried out without depending only on the regulation of the mask holder angle which gives the influence to the drop-away property or the other characteristics. Consequently, the correction of PD can be carried out without reducing the drop-away property and the like for a long period of time.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a shadow mask type color picture tube.

(Prior Art) In general, a shadow mask type color picture tube, as shown in FIG. It has an envelope consisting of a shaped funnel 2 and a small-diameter cylindrical neck 3 connected to the other end of the funnel 2. On the inside of the main surface of the panel 1, red, green, and blue colors are arranged. A phosphor layer 4 of three primary color phosphor elements that emit light in each of the three primary colors is provided.

Further, an in-line electron gun 6 is disposed inside the neck 3 and emits three electron beams 5 corresponding to the three primary colors toward the phosphor layer 4.

Further, inside the panel 1, a shadow mask 7 having a large number of holes is disposed facing the phosphor layer 4 at a predetermined distance. The shadow mask 7 has a rectangular main surface part 7a and a skirt part 7b formed by bending the main surface part 7a around the main surface part 7a along the inner peripheral surface of the panel 1. The skirt part 7b of the shadow mask 7 is made of metal. It is fixed to the mask frame 8 by welding.

The mask frame 8 is secured to panel stud pins (not shown) embedded in the four corners of the inner wall surface of the panel 1 via the mask holder 9.

(Problem to be Solved by the Invention) By the way, in a color picture tube having such a structure, the proportion of the electron beam 5 from the electron gun 6 passing through the aperture of the shadow mask 7 is 20% of the total, and 80% is It hits the shadow mask 7 and mask frame 8 and is absorbed. Since the electron beam 5 that has struck is emitted as thermal energy, the shadow mask 7 and the mask frame 8 do not undergo thermal expansion.

If this heat makes it impossible to maintain a predetermined distance between the shadow mask 7 and the phosphor layer 4 inside the panel 1, so-called doming phenomenon will occur and the color purity of the screen will deteriorate.

Therefore, as shown by broken lines in FIG. 4, in general, when the shadow mask 7 and the mask frame 8 undergo thermal expansion, their displacement in the X and Y axis directions perpendicular to the tube axis is caused by the movement of the mask holder 9. It is converted into a displacement in the Z-axis (tube axis) direction, and correction is performed as a result.

Generally, in a color picture tube, if the size or the material of the tube internal components such as the mask frame 8 change, the correction 1 for long-time PD (Purity Drift) must also be changed. This correction amount is shadow mask 7
This is done by moving the main surface of the panel closer to or away from panel 1.
Conventionally, adjustments were made by changing the shape or angle of the mask holder 9.

However, since the angle of the mask holder 9 is closely related to the falling characteristics, loading characteristics, etc., it is not possible to determine the angle by considering only the amount of displacement during long-term operation, and adjustment is difficult. was there.

The present invention has been made to solve such problems, and an object of the present invention is to provide a color picture tube that allows long-term PD correction without changing the shape or angle of the mask holder.

[Structure of the Invention] (Means for Solving the Problems) The color picture tube of the present invention has a mask frame fixed to the outer peripheral edge of a shadow mask, and this mask frame is attached to panel stud pins protruding from the inner wall of the panel. In a color picture tube supported via a mask holder, a metal member having a coefficient of thermal expansion different from the shadow mask and the mask frame is interposed between the shadow mask and the mask frame, and either the shadow mask or the mask frame It is characterized in that one side is fixed to the -@ side of the tube axis direction of the metal member, and the other side is fixed to the side near the sacral end.

The manner in which the shadow mask and mask frame are fixed to the metal member can be selected from the following two methods depending on their materials and the direction of correction.

(1) As shown in FIG. 1, a metal member 10 having a different coefficient of thermal expansion is interposed between the shadow mask 7 and the mask frame 8, and the shadow mask 7 is inserted in the tube axis direction of the metal member 10. The mask frame 8 is locally welded to a position near the main surface of the panel 1 (point A), and the mask frame 8 is locally welded to a position of the metal member 10 near the electron gun in the tube axis direction (point B).

■ As shown in FIG. 2, a metal member 10 having a different coefficient of thermal expansion is interposed between the shadow mask 7 and the mask frame 8, and the mask frame 8 is inserted in the tube axis direction of the metal member 10. The shadow mask 7 is locally welded to a position near the main surface of the panel 1 (point A), and the shadow mask 7 is locally welded to a position of the metal member 10 near the electron gun in the tube axis direction (point B).

In each of the above methods, the material of the metal part U10 needs to have a different coefficient of thermal expansion from both the shadow mask 7 and the mask frame 8, but if the coefficient of thermal expansion is larger than that of the material of the shadow mask 7 and the mask frame 8, It can also be used if it is small.

Further, the present invention can be applied even when the materials of the shadow mask 7 and the mask frame 8 have different coefficients of thermal expansion.

(Function) In the configuration shown in FIG. 1, if the coefficient of thermal expansion of the metal member 1o is larger than that of the mask frame 8, the correction moves so that the shadow mask 7 approaches the inner surface of the panel as the temperature rises, and conversely, When the coefficient of thermal expansion of the metal member 10 is smaller than that of the mask frame 8, correction works to move the shadow mask 7 away from the inner surface of the panel as the temperature rises.

The amount of correction in this case can be adjusted by adjusting the distance between A and 8.

Furthermore, in the configuration shown in FIG. 2, if the coefficient of thermal expansion of the metal member 10 is larger than that of the shadow mask 7, a correction will be made to move the shadow mask 7 closer to the inner surface of the panel as the temperature rises, and conversely, If the coefficient of thermal expansion of the metal member 10 is smaller than that of the shadow mask 7, a correction will be made to move the shadow mask 7 away from the inner surface of the panel as the temperature increases.

The amount of correction in this case can also be adjusted by adjusting the distance between A and 8.

(Example) Examples of the present invention will be described below.

Example 1 A color picture tube having the structure shown in FIG. 1 was manufactured by constructing the shadow mask 7 and the mask frame 8 from Fe material, and using the metal member 10 from /l material, which has a larger thermal expansion than l"e. At this time, the distance between the welding point A between the metal member 10 and the shadow mask 7 and the welding point 8 between the metal member 10 and the mask frame 8 was set to 40 m5+.

In a color picture tube with such a structure, the thermal expansion coefficients of Fe and A℃ are each 11.7X10-6/'C.
and 23.5x 10-'/'C, so if the temperature rise in the long-term PD is 30°C, the apparent thermal light [ffi] of the metal member 10 is 2862 μm, and the shadow mask 7 is further extended by this length. You can approach the inside of the panel.

Example 2 The shadow mask 7 and the mask frame 8 are made of Fe material, and the metal member 10 is made of A, which has a larger thermal expansion than Fe.
A color picture tube having the structure shown in Fig. 2 was manufactured using λ material. At this time, the distance between the welding point A between the metal member 10 and the mask frame 8 and the welding point 8 between the metal member 10 and the shadow mask 7 was set to 40 mm. A color picture tube with such a structure has the same size as in Example 1 (28.2 μm).
The correction amount m) moves in the direction of moving the shadow mask 7 away from the panel.

Example 3 The shadow mask 7 and the mask frame 8 are made of Fe material, and the intervening metal has a thermal expansion smaller than that of Fe.
．． 69x 10-'/'C) A color picture tube having the same configuration as Example 1 was manufactured except that an amber material was used.

In the color picture tube having this structure, the thermal expansion ω of the amber material due to the temperature rise during long-term PD is about 2 μm, and the mask frame (Fe material) 14 is heated when the intervening metal member 10 is not provided. Since the 8-ball amount is 14 μm, by using the metal member 10 made of amber, correction is applied in a direction that substantially moves the shadow mask 7 away from the inner surface of the panel by 12 μm.

Example 4 The shadow mask 7 and the mask frame 8 are made of Fe material, and the intervening metal is made of Fe material (1,
69x 10= /'C) A color picture tube having the same configuration as Example 2 was manufactured except that an amber material was used.

In the color picture tube of this embodiment, the same amount of correction as in the third embodiment is applied in the direction of moving the shadow mask 7 closer to the inner surface of the panel due to the temperature rise in the PD for a long time.

[Effects of the Invention] As explained above, in the color picture tube of the present invention, when correcting PD for a long time, it is possible to correct the PD without relying only on adjusting the angle of the mask holder, which affects other characteristics such as drop characteristics. As a result, long-term PD correction can be performed without deteriorating the drop characteristics or the like.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the main parts of an example of a color picture tube of the present invention, FIG. 2 is a cross-sectional view showing the main parts of another embodiment, and FIG. FIG. 4 is a cross-sectional view of a main part for explaining correction of long-time PD using a mask holder. 1... Panel 4... Phosphor element layer 6... Electron gun 7... Shadow mask 8... Mask frame 10... ...Metal parts

Claims (1)

[Claims] (1) A color picture tube in which a mask frame is fixed to the outer periphery of the shadow mask, and the mask frame is supported via a mask holder by panel stud pins protruding from the inner wall of the panel. A metal member having a different coefficient of thermal expansion is interposed between the shadow mask and the mask frame, and one of the shadow mask and the mask frame is fixed to one end of the metal member in the tube axis direction, and the other is fixed to the other end. A color picture tube characterized by being fixed near the end.