JP3029663B2 - Color picture tube and method of manufacturing the same - Google Patents

Description

The present invention relates to a color picture tube, and more particularly to a color picture tube provided with a shadow mask for preventing color purity from deteriorating and a method of manufacturing the same. Things.

(Prior Art) Generally, as shown in FIG. 5, a shadow mask type color picture tube has a fluorescent screen 2 having a light emitting area of each color formed on an inner surface of a panel 1 of the picture tube, and a large number of through holes 3 formed therein. A shadow mask 4 having a curved effective surface and a mask frame 5 for holding the shadow mask 4 around the shadow mask 4
And an electron gun 7 for emitting a plurality of electron beams 6,
The shadow mask 4 is supported on the inner surface of the panel 1 by being engaged with a stud pin 9 embedded in the inner wall of the upright end of the panel 1 via a holder 8 provided on the mask frame 5. The color picture tube displays a color image by passing the electron beam 6 through the through-hole 3 on the effective surface of the shadow mask 4 and projecting the electron beam 6 on a predetermined fluorescent area of the fluorescent screen 2. Is what you do. In such a color picture tube, more than one third of the electron beam 6 collides with a region other than the through hole 3 of the shadow mask 4 due to its structure, and a so-called doming phenomenon occurs in which the shadow mask 4 thermally expands. In some cases, the landing position of the electron beam 6 on the light-emitting area is shifted to cause color purity degradation.

In order to suppress the mislanding due to the doming phenomenon, conventionally, a proposal has been made to form a ceramic layer or an electron absorption layer on a shadow mask. For example, Japanese Patent Application Laid-Open No. 60-54139 discloses that a ceramic layer is formed on the main surface of the shadow mask on the electron gun side to suppress residual doping of the shadow mask by incorporating residual tensile stress in the shadow mask. In addition, Japanese Patent Publication No. 57-18824 discloses a low-conductivity electron corresponding to a non-light-emitting region on the surface of a fluorescent screen on which an electron beam impinges. It describes that an absorption layer is formed and the electron absorption layer is negatively charged to electrostatically correct the trajectory of the electron beam.

However, simply forming a ceramic layer on the main surface of the shadow mask on the electron gun side is still insufficient to suppress mislanding. On the other hand, in the case where the electron absorbing layer is formed in the non-light emitting region of the fluorescent screen, firstly, a deceleration electric field due to negative charging starts to act after landing due to the doming phenomenon, so that a time delay occurs, and secondly, the negative effect of the electron absorbing layer. The charged part is only the part where mislanding occurred, and the small area is insufficient for the deceleration electric field.
Third, there is a problem that it is not effective against mislanding due to doming at the beginning of the operation, and fourth, the formation method is not suitable for mass production both in terms of work and accuracy.

By simply forming a ceramic layer or an electron absorbing layer on the electron gun side main surface of the shadow mask or on the non-light emitting area of the fluorescent screen, it is possible to immediately correct mislanding due to the doming phenomenon and correct color purity deterioration. There is a problem in that mislanding cannot be sufficiently corrected because the correction cannot be performed or a portion that exerts a correction action is too small.

Therefore, Japanese Patent Application Laid-Open No. Sho 62-188135 proposes a shadow mask 4 in which an electron absorbing layer is also formed on the wall surface of the through hole 3 as shown in FIG. That is, assuming that the intersection point between the shadow mask 4 and the tube axis is the center of the shadow mask, the center of the through-hole 3 of the shadow mask 4 on the shadow mask center side (hereinafter, referred to as the center side wall surface 10a) or the center side wall surface 10a. An electron absorption layer 11 is formed which is charged according to the electron flow density of the electron beam with the peripheral side wall surface 10b facing the central side wall surface 10a and electrostatically deflects the electron beam.

 This electron absorption layer is formed as follows.

That is, the coefficient of thermal expansion is 1.2 × 10 ⁻⁵ / ° C. A thickness of 0.1 mm to 0.3 made of a so-called cold-rolled steel having iron as a main component.
A large number of through-holes are formed in a thin plate of mm by ordinary etching means, and molded into a predetermined shape by pressing. Before the panel and the funnel are sealed, a crystalline lead borate glass melted with a butyl acetate solution in which several percent of nitrocellulose is melted is applied to the main surface of the shadow mask on the electron gun side and the center of the through hole. The shadow mask coated with the crystalline lead borate glass by spray coating on the side wall surface is mounted in the panel. Thereafter, the panel and the funnel are placed on a predetermined frame, and passed through a furnace having a maximum temperature of about 400 ° C. and a holding time of 35 minutes or more to crystallize the lead borate glass, thereby obtaining a conductivity of 10 ^−. A lead borate glass layer having a low conductivity of ¹ Ω ⁻¹ .m ⁻¹ is formed as an electron absorbing layer on the main surface of the shadow mask on the electron gun side and the central side wall of the through hole.

When the electron absorbing layer is sprayed on the electron gun side main surface of the shadow mask and the wall surface of the through hole as described above, the electron is sprayed by the spray device 12a located on the electron gun side of the shadow mask 4, as shown in FIG. The electron absorbing layer 11 on the gun-side main surface 10c is formed, and the electron absorbing layer is applied to the central side wall surface 10a of the through hole 3 by tilting the spray device 12b on the fluorescent screen side from the peripheral side of the shadow mask 4 to the central side. Was.

However, even when a color picture tube as disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 62-188135 is operated, the landing shifts with the lapse of time of the doming phenomenon. Hereinafter, changes in the trajectory of the electron beam due to doming of the shadow mask will be described with reference to FIGS. In FIG. 8, the electron beam is configured to land at a predetermined position on the fluorescent screen 2 when the shadow mask 4 does not cause the doming phenomenon. Here, if the electron current density of the electron beam incident on the shadow mask 2 increases and the shadow mask is heated and causes a doming phenomenon and moves to the position shown by the broken line in FIG. The electron beams A and B to be landed at the time of landing move to the beams DA1 and DB1 due to the doming phenomenon, and mislanding at a point on the center side of the shadow mask. If the amount of mislanding exceeds the limit of the landing margin due to the arrangement of each color light emitting phosphor group, the color purity will be degraded. The doming phenomenon shown in FIG. 8 mainly occurs at an early stage of the operation. In the initial stage of the operation, the moving direction of the beam due to doming is the same in both the central part and the peripheral part of the screen, and this is corrected by the function of the electron absorbing layer 11 formed on the central side wall surface 10a of the through hole 3. That is,
Since the electron absorbing layer 11 is charged in accordance with the electron flow density, the electron beam moved by doming bends its trajectory away from the tube axis by the action of the negative charge on the surface of the central side wall 10a of the through hole 3. Can be

Thereafter, as the operating time elapses, the heat of the shadow mask is transmitted to the mask frame, and the mask frame 5 undergoes thermal expansion as shown in FIG. The state at this time is represented by a broken line in FIG. The peripheral portion of the shadow mask 4 is pulled in the peripheral direction by the expansion of the mask frame 5. As a result, the beam A at the center of the screen moves in the same beam DA2 direction as the doming at the beginning of the operation, and the beam B at the periphery of the screen moves in the beam DB2 direction. As shown in FIG. 10, this movement of the beam causes both the beam DA2 in the central portion and the beam DB2 in the peripheral portion to move in the same direction, that is, in the A2 and B2 directions by the action of the electron absorbing layer. However, the movement direction of the beam due to doming in the peripheral portion of the screen is in the opposite direction between the initial operation and after the elapse of time, so that the function of the electron absorbing layer promotes mislanding after the elapse of time. . In fact, since the duration of the doming phenomenon at the beginning of the operation is short, the above-described mislanding around the screen is a major problem.

(Problems to be Solved by the Invention) As described above, simply forming an electron absorbing layer on the central side wall surface or the central side wall surface of the through hole of the shadow mask and the peripheral side wall surface facing the central side wall is required to correct the landing deviation. Is insufficient, and there is a problem that the correction action in the peripheral portion of the screen is different between the initial operation and the subsequent state.

Therefore, there is a method of improving the quality by using a bimetal for the holder. However, 1.The correction operation is delayed due to heat conduction. 2.The thicker frame is required to maintain the mask rigidity. 3. The heat capacity of the frame is increased, which promotes 1). 3. In addition to the temperature change of the panel, the frame, and the mask system, there is a problem that an unnecessary correction, that is, an erroneous operation is caused because of a change in the environmental temperature.

Further, when the electron absorbing layer is applied and formed, since the spray is performed from both sides across the mask, there is a problem that the turbulence on the mask surface is too large, and the turbulence is formed in a region other than a predetermined region or is not formed uniformly. . In addition, since the constituent material of the electron absorption layer contains expensive heavy metals, spraying from both sides increases the amount of extra spray flow, which is problematic in terms of cost and environment.

In addition, when a fluorescent screen is formed on the inner surface of the panel, exposure printing is performed using a correction lens. However, it is difficult to predict the electron beam trajectory because the mislanding direction due to doming is different between the center and the periphery of the shadow mask. This makes it difficult to design a desired lens shape.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a color picture tube in which the correction operation at the peripheral portion and the central portion of the screen are both directed to correct the mislanding of the beam due to doming, and the color purity is less deteriorated. . Still another object of the present invention is to provide a method for easily manufacturing the color picture tube.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention relates to a fluorescent screen formed on the inner surface of a panel, and a plurality of transparent screens arranged in close proximity to the fluorescent screen. At least a shadow mask having holes formed therein, and an electron gun for emitting an electron beam through which the phosphor of the fluorescent screen selectively emits light through the shadow mask, wherein at least a wall of each through-hole of the shadow mask has an electron. In a color picture tube having an electron absorbing layer that charges according to the flow density and deflects the electron beam, the thickness of the electron absorbing layer formed on the wall surface of the through hole is
At the shadow mask central portion, the layer thickness of the shadow mask central side wall surface is larger than the layer thickness of the opposing peripheral side wall surface, and at the shadow mask peripheral portion, the layer thickness of the peripheral side wall surface is larger than the layer thickness of the opposing central side wall surface. It is characterized by having.

Also, a fluorescent screen formed on the inner surface of the panel, a shadow mask arranged in close proximity to the fluorescent screen and having a large number of through holes, and a phosphor of the fluorescent screen is selectively illuminated through the shadow mask. A color picture tube having at least an electron gun for injecting an electron beam, and having an electron absorbing layer that deflects the electron beam according to the electron flow density on at least the wall surface of each through hole of the shadow mask, Spraying a solution containing the constituent material of the electron absorption layer from the electron gun side of the shadow mask and from the shadow mask peripheral side, so that the inclination angle of the spray flow by the spray and the inclination angle of the wall surface of the through-hole are substantially matched. The electron absorption layer is formed by the following.

(Operation) The doming phenomenon in the early stage of the operation of the color picture tube is thermal expansion of the shadow mask toward the fluorescent screen side. As a result, the beam mislandes toward the center of the shadow mask in both the central portion and the peripheral portion of the screen. The doming phenomenon in the normal operating state after a certain period of time involves thermal expansion of the mask frame, so that the peripheral portion of the shadow mask is pulled in the peripheral direction, so that the mislanding direction is reversed between the peripheral portion of the shadow mask and the central portion. Becomes

In the present invention, in the peripheral portion of the shadow mask where the mislanding direction is reversed as described above, the thickness of the electron absorption layer on the peripheral side wall surface of the through hole of the shadow mask is made larger than the central side wall surface, so A difference in the amount of charge is generated between the electron absorbing layers on the wall surface, and the beam is electrostatically deflected by the potential difference. In the central portion, mislanding is corrected by making the thickness of the layer on the central side wall relatively thicker than the layer on the peripheral side wall to increase the action of the electron absorbing layer on the central side wall.

Further, in the present invention, the spray device for applying and forming the electron absorbing layer is located on the electron gun side of the shadow mask,
The shadow mask is sprayed from the periphery to the center. The split flow of the spray passing through the through-hole flows along the wall surface of the through-hole. In other words, the inclination of the spray flow by the spray device is set such that the side wall where the branch flows flows on the side of the central side wall surface on the side with the spray device that generates the spray flow from the center of the shadow mask, and the peripheral side wall surface on the side without the spray device. decide. Further, the thickness distribution of the electron absorbing layer between the opposing wall surfaces at the central portion and the peripheral portion of the shadow mask is also controlled by controlling the flow rate of the spray flow and the spray area.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

The overall structure of the color picture tube according to the present invention is the same as that shown in FIG. 5, and comprises a panel 1 having a substantially rectangular front surface and a vacuum envelope comprising a funnel-shaped funnel and a neck. Have been. On the inner surface of the panel 1, a phosphor screen 2 made of a striped phosphor layer that emits red, green and blue light, respectively, is formed, and the neck is arranged in a line along the horizontal axis of the panel 1. A so-called in-line type electron gun 7 for emitting three electron beams 6 corresponding to red, green, and blue is provided. Also, at a position facing and opposing the fluorescent screen 2,
A large number of slit-shaped through holes 3 are arranged in the vertical direction, and a curved shadow mask 4 in which the vertical arrangement is arranged in a large number in the horizontal direction is supported and fixed by a mask frame 5. Further, the mask frame 5 is supported by the stud pin 9 embedded in the inner wall of the upright end of the panel 1 via the holder 8 so as to be supported in the panel. The three in-line arranged electron beams 6 are deflected by a deflecting device (not shown) outside the funnel, scan a rectangular area corresponding to the rectangular panel 1, and pass through holes of the shadow mask 4. 4 and land on the stripe-shaped phosphor layer to reproduce a color image.

The shadow mask, which is disposed in close proximity to the fluorescent screen, has a coefficient of thermal expansion of 1.2 × 10 ^-5 / ° C. And the main surface on the electron gun side as shown in FIG.
10c, at least the central side wall surface 10a of the shadow mask 4 of each through hole 3 and the peripheral side wall surface 10b facing the central side wall surface 10a are made of low conductive crystalline lead containing, for example, about 70% by weight of lead oxide (PbO). Electron absorption layer 11 made of borate glass is sealed and joined by high-temperature heat treatment.

The thickness distribution of the electron absorbing layer 11 on the wall surface of the through hole 3 is as shown in FIG. That is, in the central portion of the shadow mask, the layer of the central side wall surface 10a is relatively thicker than the layer of the peripheral side wall surface 10b, and in the peripheral portion of the shadow mask, the layer of the peripheral side wall surface 10b is also relatively thicker than the layer of the central side wall surface 10a. ing. Here, the central part and the peripheral part of the shadow mask
The central portion is a region where the moving direction of the electron beam due to the doming in the normal operation state is the same as the movement direction due to the doming at the beginning of the operation, and the peripheral portion is a region where the moving direction is the opposite direction. Also, in the case of a slit through hole, the central side wall surface and the peripheral side wall surface of the wall surface of the through hole are slit-type holes, and the wall closer to the short axis of the effective surface of the shadow mask is defined as the center side, and the far side is defined as the peripheral side. In the case of a hole, the wall closer to the center point of the effective surface is called the center side, and the one farther away is called the peripheral side.

The change in the trajectory of the electron beam due to the doming of the shadow mask when such a color picture tube is operated and the correcting action thereof will be described with reference to FIGS. 9, 1 and 2. FIG. In FIG. 9, the electron beams A and B are configured to land at a predetermined position on the fluorescent screen 2 when the shadow mask 4 does not cause the doming phenomenon. Here, in a substantial operation state of the color picture tube, when the electron flow density incident on the shadow mask 4 increases and the shadow mask 4 is heated to cause a doming phenomenon, only the thermal expansion of the shadow mask 4 due to the electron beam is performed. However, thermal expansion of the mask frame 5 also occurs, and the shadow mask 4 is in the state shown by the broken line in FIG. As a result, the electron beams A and B move to DA2 and DB2, and mislanding occurs in the opposite direction between the central portion and the peripheral portion of the shadow mask 4. If the amount of mislanding exceeds the limit of the landing margin due to the arrangement of each color light emitting phosphor group, the color purity will be degraded.

Here, in the case of the present invention, as shown in FIG. 1, an electron absorbing layer 11 is formed on the wall surfaces 10a, 10b of the through holes 3 of the shadow mask 4, and a part of the electron absorbing layer 11 is irradiated with the electron beam of the shadow mask 4. Since the electron beam is located on the gun-side main surface 10c, when the electron beam is deflected and scanned, the electron beam is negatively charged according to the electron flow density. This means that the electron absorbing layer 11 has a thickness of about the average depth at which electrons penetrate or more, about 10 μm in this embodiment.
m and the primary electron energy, usually 10 keV
It means that it has a secondary electron emission coefficient for up to 30 keV. As shown in FIG. 2, the central side wall surface 10a is formed to be thicker at the central portion of the shadow mask than at the peripheral side wall surface 10b.
More negative charges. This negative charge, especially the negative charge on the surface of the central side wall surface 10a of the through-hole, is the first charge.
The trajectory of the electron beam moved by doming indicated by the dashed line in the drawing is bent in a direction away from the center of the shadow mask and deflected as indicated by the solid line A0. Therefore, the landing point of the electron beam, which tends to move from the predetermined landing point toward the center of the shadow mask due to the doming phenomenon, acts so as to cancel each other back to the original landing point. Can be suppressed and reduced. Further, in the peripheral portion of the shadow mask, the peripheral side wall surface 10b is formed thicker than the central side wall surface 10a. Therefore, in the peripheral portion of the shadow mask, more negative charges are charged on the peripheral side wall surface 10b. Therefore, the beam moved by doming by the same action is bent toward the center of the shadow mask and deflected as shown by the solid line B0. The direction of this deflection is opposite to the direction of movement of the beam due to doming shown in FIG. 10, and mislanding can be suppressed and reduced.

As described above, the electron absorption layer is formed on the wall surface of the through hole of the shadow mask, and the relative thickness of the layer is changed between the opposing wall surfaces in the central portion and the peripheral portion of the shadow mask. In the case of color purity deterioration at the periphery of the screen due to thermal expansion of the frame at the time, it is negatively charged according to the electron flow density, and in cooperation with the doping suppression effect of the electron absorption layer using low thermal conductivity. Works effectively.

Further, since the electron absorbing layer is always irradiated with an electron beam and secondary electrons from a screen surface or the like as long as the picture tube is operated, a conventional example is disclosed in Japanese Patent Publication No. 57-18824. The working area is much larger than that of an electron absorbing layer formed in the non-light emitting area of such a screen,
Also, there is almost no time delay at which the suppression effect occurs.

As described above, by controlling the thickness of the electron absorbing layer formed on the wall surface of the through hole of the shadow mask, it is possible to control the change in the trajectory of the electron beam due to negative charging. Therefore, the design of the exposure lens can be facilitated.

The above-mentioned electron absorption layer is formed as follows.
Before the panel and the funnel are sealed, a crystalline lead borate glass melted with a butyl alcohol solution containing several percent of nitrocellulose is applied to the central side wall of the shadow mask. A glass-coated shadow mask is mounted in the panel. After that, place the panel and funnel on the designated frame,
By passing through a furnace with a holding time of 35 minutes or more at ℃ to crystallize the lead borate glass, the conductivity is 10 ^-1 Ω
A lead borate glass layer having a low conductivity of ⁻¹ · m ⁻¹ is formed on the central side wall surface and the peripheral side wall surface of the through hole of the shadow mask.

As a method of applying the electron absorbing layer, for example, a large number of through holes are formed by a usual etching means, press-molded, and then spray-coated.

Hereinafter, the spraying method will be described in detail with reference to FIG. 3 and FIG. As shown in FIG. 3, spray devices 30a and 30 for spraying a solution containing the constituent material of the electron absorption layer.
b is located on the electron gun side of the shadow mask 4 and sprays from the peripheral side of the shadow mask 4 toward the center side. Spray flow 3 by this spray device 30a
1 is divided into a shunt 32 that collides with the electron gun side main surface 10c of the shadow mask 4 and a shunt 33 that flows along the wall surfaces 10a and 10b of the through hole 3. The wall surface where the branch flow 33 flows differs between a half area near the spray device 30a and a half area far from the center of the shadow mask. In the half region near the spray device 30a, the diverted flow 33 flows along the central side wall surface 10a, and in the half region far from the spray device 30a, flows along the peripheral side wall surface 10b. In other words, the spray flow by the spray device 30a is performed such that the wall surface of the branch flow 33 at the center of the shadow mask becomes the central side wall surface 10a and the peripheral side wall surface 10b.
What is necessary is just to determine the inclination of 31. Further, the layer thickness distribution of the electron absorbing layer can be controlled by changing the nozzle shape of the spray device 30a to adjust the spray flows 31, 32, and 33, or to partially limit the spray area with a shielding plate or the like. The third
Although the drawing does not show the spray flow by the spray device 30b, it is the same as the spray device 30a.

In the present embodiment, 30a, 30b and 2
FIG. 4 (a) is provided by providing two spray devices and performing the above-described control for each spray device.
And (b), the thickness of the layer between the opposing wall surfaces is changed between the central portion and the peripheral portion of the mask. 4 (a) and 4 (b), the solid line indicates the layer thickness distribution of the electron absorbing layer formed by the spray device 30a, and the broken line indicates the layer thickness distribution of the electron absorbing layer formed by the spray device 30b. Represents.

As described above, according to the present invention, the electron absorption layer can be formed only by spraying from the electron gun side, so that the turbulence of the spray flow can be reduced and the quality can be improved. In addition, since the spray flow is used efficiently, cost and environmental improvements can be achieved without wasting expensive materials.

In this embodiment, when the electron absorbing layer is formed by coating, the thickness of the layer between the opposing wall surfaces is controlled by adjusting the spray flow by the spray device. It is also possible to form the electron absorption layer only on the wall surface.

In addition, the electron absorption layer is not limited to this embodiment, and can be applied to the formation of a ceramic layer.

Furthermore, although the present embodiment describes a slit-shaped through-hole, it goes without saying that the present invention can also be applied to a dot-shaped through-hole.

[Effect of the Invention] According to the present invention, the electron absorption layer is formed on the wall surface of the through hole of the shadow mask, and the layer thickness between the opposing wall surfaces at the central portion and the peripheral portion of the shadow mask is changed. As a result, the beam deflecting action due to the negative charging of the electron absorbing layer works effectively, and the deterioration of color purity can be suppressed. Further, according to the present invention, since the electron absorbing layer can be formed only by spraying from the electron gun side, the turbulence of the spray flow can be reduced and the quality can be improved. In addition, since the spray flow is used efficiently, cost and environmental improvements can be achieved without wasting expensive materials.

[Brief description of the drawings]

FIG. 1 is an enlarged simplified view showing an embodiment of a shadow mask of a color picture tube according to the present invention, FIG. 2 is a view showing a layer thickness distribution of an electron absorbing layer on a wall surface of a through hole in FIG. FIG. 4 is a schematic view showing a method for forming an electron absorbing layer according to the present invention, and FIG.
FIG. 3 is a diagram showing the relationship between the spray device and the layer thickness of the electron absorption layer in FIG. 3, FIG. 5 is a schematic cross-sectional view showing the overall structure of a color picture tube, and FIG. FIG. 7 is a schematic view showing a method of forming the electron absorbing layer shown in FIG. 6, FIG. 8 is a schematic view for explaining beam movement by doming at the beginning of operation, and FIG. 9 is a normal view. FIG. 10 is a schematic diagram for explaining movement of a beam due to doming in an operating state, and FIG. 10 is a schematic diagram for explaining the operation of the shadow mask shown in FIG. 3 ... Through-hole 4 ... Shadow mask 10a ... Central side wall surface 10b ... Peripheral side wall surface 10c ... Electron gun side main surface 11 ... Electron absorption layer 30a, 30b ... Spray device 31, 32, 33 ... Spray flow

──────────────────────────────────────────────────続 き Continuing on the front page (72) Akira Masada, Inventor 1-9-9, Harara-cho, Fukaya-shi, Saitama Pref. Inside the Toshiba Fukaya Braun Tube Factory (72) Inventor Hiroshi Sugawara 1-9-9, Harara-cho, Fukaya-shi, Saitama No. 2 Toshiba Fukaya CRT factory (72) Inventor Kimiyoshi Nishizawa No. 1-9-9 Harara-cho, Fukaya-shi, Saitama Prefecture No. 2 Toshiba Fukaya CRT factory (58) Field surveyed (Int. Cl. ⁷ , DB name) ) H01J 29/07 H01J 9/14

Claims (2)

(57) [Claims] 1. A fluorescent screen formed on an inner surface of a panel, a shadow mask disposed in close proximity to the fluorescent screen and having a large number of through holes, and a phosphor of the fluorescent screen via the shadow mask. At least an electron gun that emits an electron beam that selectively emits light.
In a color picture tube having an electron absorbing layer that is charged according to the electron flow density and deflects an electron beam on at least the wall surface of each through hole of the shadow mask, the thickness of the electron absorbing layer formed on the wall surface of the through hole is In the central part of the shadow mask, the layer thickness of the central side wall of the shadow mask is larger than the layer thickness of the opposing peripheral side wall, and in the peripheral part of the shadow mask, the layer thickness of the peripheral side wall is larger than the layer thickness of the opposing central side wall. A color picture tube, characterized in that: 2. A fluorescent screen formed on an inner surface of a panel, a shadow mask disposed in close proximity to the fluorescent screen and having a large number of through holes, and a phosphor of the fluorescent screen via the shadow mask. At least an electron gun that emits an electron beam that selectively emits light.
In a method for manufacturing a color picture tube having an electron absorption layer that is charged according to an electron flow density and deflects an electron beam on at least a wall surface of each through-hole of the shadow mask, a spray of a solution containing a constituent material of the electron absorption layer is applied. The electron absorbing layer is formed by making the inclination angle of the spray flow by the spray substantially equal to the tendency of the wall surface of the through hole, which is performed from the electron gun side of the shadow mask and from the shadow mask peripheral side. A method for manufacturing a color picture tube.