JPS5922344B2 - Manufacturing method for color cathode ray tubes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a color cathode ray tube that is suitable for application to a color image projection device that uses a cathode ray tube and can obtain a color image on a large screen from the playback screen of the cathode ray tube. It pertains to the manufacturing method.

First, in order to facilitate understanding of the present invention, a color image projection apparatus will be explained.As a conventional color image projection apparatus of this kind, as shown in FIG. There is a color cathode ray tube 1 configured to project a color reproduced image 2 reproduced on its fluorescent surface onto a projection screen (not shown) by means of a reflecting mirror 3 and a projection lens system 4. .

However, a color image projection device having such a single-tube configuration has a drawback in that a sufficiently bright projected image cannot be obtained. Further, as another color image projection device, as shown in FIG. 2, three monochrome cathode ray tubes IR each reproduce only one color of red, green, and blue images 2R, 2G, and 2B, respectively;
Using IG and IB, the red, green, and blue images 2R, 2G, and 2B of each cathode ray tube IR, IG, and IB are magnified by projection lens systems 4R, 4G, and 4B, respectively, and projected (not shown). There are devices that overlap each other on a screen to obtain a color projection surface image in which images of each color are combined.

The color image projection device with such a three-tube configuration is the first
Compared to the color image projection device with a single-tube configuration explained in the figure,
In principle, it is possible to obtain a projected image that is three times brighter, but on the other hand, the disadvantage is that the device becomes significantly larger and more expensive. In order to avoid such drawbacks, the present applicant has proposed that a three-tube color image projection device can obtain a brighter projected image than a single-tube color image projection device, as described above. In comparison, we have provided a color image projection device that can be constructed at a low cost.

This two-tube type color image projection apparatus includes a first cathode ray tube for producing a reproduced image of a single primary color and a second cathode ray tube for producing a reproduced image in which the other two primary colors are combined. 5
In this color image projection device, since the first cathode ray tube obtains an image of only one primary color, it is possible to obtain a sufficiently bright image with respect to this color, but the second cathode ray tube that reproduces the two primary color image In a cathode ray tube, the light emitting area is shared between these two colors, so the brightness is reduced to at least Σ or less.

If the density of the electron beam is increased so as to increase its brightness, problems will arise in the lifetime of the cathode. The present applicant has made it possible to obtain sufficiently high brightness in such a two-primary color cathode ray tube, and has developed a special method suitable for application to the above-mentioned two-tube color cathode ray tube. Provided color cathode ray tubes.

In order to facilitate understanding of the present invention, please refer first to FIG.
Let's talk about tube-type color image projection equipment and its special color cathode ray tube.

Reference numeral 5 indicates the color image projection apparatus as a whole, and reference numeral 6 indicates its housing.

In this case, for example, among the color images to be reproduced,
For example, a red monochromatic first cathode ray tube 1R that reproduces only the red component image 2R and a second cathode ray tube that reproduces only the red component image 2R and the second cathode ray tube 1R that reproduces only the red component image 2R and the second cathode ray tube 1R that reproduces only the red component image 2R, and the second cathode ray tube that reproduces the red component image 2R only, and the second cathode ray tube that reproduces the red component image 2R only, and
A second cathode ray tube 1BG for reproducing the primary color image 2BG is provided, and a dichroic mirror 7 reflects, for example, the red reproduced image 2R obtained by the first cathode ray tube 1R. By transmitting the blue and green reproduced images 2BG obtained by the tube 1BG, both images 2R and 2
This is a case where the BG images are superimposed, and the optical images formed by these images 2R and 2BG are magnified by the projection lens system 4 and projected onto a screen (not shown). In this way, a color projection image is obtained in which both images 2R and 2BG are superimposed. In this case, the first cathode ray tube 1R has a monochromatic cathode ray tube configuration, and its fluorescent surface is made of a red phosphor, such as a rare earth phosphor such as Y2O2S:EU or YVO4:E.
The red reproduced image 2R is obtained by, for example, scanning a single beam with density modulation on the fluorescent surface. In this case, a special color cathode ray tube device is used as the second cathode ray tube 1BG.

This special color cathode ray tube is either a three-beam three-electron gun type in which three electron beams are arranged in one direction, for example, horizontally, and scanned on a fluorescent surface, or a three-beam single type as shown in Figure 4. An electrode for determining the electron beam arrival position, such as an aperture grill AG having an electron gun G and having a slit SL facing the fluorescent surface S, is arranged.

For example, the electron gun G has a cathode KG corresponding to green arranged on the tube axis, and two cathodes KBl each corresponding to blue arranged symmetrically on both sides of the cathode KG and in the same horizontal plane as the cathode KG.
and KB2 are arranged, and these cathodes KBl, KB2
and K, a common first grid G1 (control electrode), a second grid G2 (acceleration electrode), and a common third grid G3 constituting a unipotential electron lens, for example.
(first anode), a fourth grid G4 (focusing electrode), and a fifth grid G5 (second anode) are arranged in this order, and a convergence means C is arranged after the fifth grid G5.
In this way, the electron beams BBl, BB2 and BG emitted from the cathodes KBl, KB2 and KG, respectively, intersect approximately at the center of the unipotential main microwave oven constituted by the third to fifth grids. The phosphorescent surface S is then converged again by the convergence means C at a position where they intersect with each other and are further separated from each other.
made to reach the top. The convergence means C is composed of, for example, a pair of inner deflection electrode plates C and C2 and both outer deflection electrode plates C3 and C4. By applying a convergence voltage between C4 and each beam BB,,BB
2 and B. is made to deflect the convergence. Further, the aperture grille AG for use as an electrode for determining the electron beam arrival position is arranged in the vertical direction of the arrangement direction of the electron beams BB, BB2 and BG, that is, the direction substantially orthogonal to the horizontal direction, as shown in FIG. A large number of extending slits SL are arranged.

On the other hand, on the phosphor surface S, blue and green phosphor stripes B and G are alternately arranged in the slit SL of the aperture grille AG.
A green phosphor stripe G is disposed so as to face the slit SL along the extending direction of the slit SL.
Thus, three electron beams B are emitted from the electron gun G.
B,, BB2 and BG enter and communicate with the slit SL of the aperture grille AG at the required angle of incidence, and by this aperture grille AG, the central electron beam BG is connected to the slit SL of the aperture grille AG. It is arranged to land as a spot SPG on the oppositely arranged green phosphor stripes G, and the beams BBl on both sides are
and BB2 are arranged to land on the blue phosphor stripes B on both sides of this phosphor G, respectively.

According to this configuration, the landing spot SPG is irradiated onto the green phosphor G by the central beam BG, and the landing spot SPG is excited, while the two phosphors on both sides of the green phosphor G are excited. Regarding stripe B, beam BB on both sides
Since 1 and BB2 are arranged to land respectively, considering the amount of emitted light integrated over time, each blue phosphor stripe B is excited for twice as long. Therefore, even if the luminous efficiency of the phosphor stripe B is lower than that of green, a bright reproduced image can be obtained as a whole. In this case, by appropriately selecting the ratio of the widths of the blue and green phosphors B and G, it is possible to improve the brightness of both colors. For example, as shown with numerical values in Figure 5, the width of the green phosphor G on which the central beam BG lands is 62.
．． 5%, and the width of the phosphor stripe B on which the beams BBl and BB2 on both sides land, ie, the blue phosphor stripe, is 37.5%.
On the other hand, the slit SL is selected to have a width of 50% so that the beams BB on both sides and the spot SPB of BB2 land across the green phosphor G.
In this case, 50% of the beam is irradiated onto the green phosphor stripe G, roughly corresponding to the aperture ratio of the aperture grille, and the portion where the beams BB and BB2 on both sides overlap and land ( 62.5-37.5=12.
5) % x 2 = 25% will be irradiated, so for the green phosphor G, the brightness T na N = ? corresponds to 50% + 25% = 75%. 7゛ζ゜“゜ko, ?=ko:?drink, Kokushi 1
：′：． -3.7 for the brightness in a three-color tube using an aperture grill with two full aperture ratios
This means that you can get five times the brightness.

In this case, the beams BBl and B corresponding to blue on both sides
As B2 is landing astride the green fluorescent soil,
Color mixing occurs between the two, but when it comes to large screens such as color image projection devices, color fidelity is not as much of a concern as it is on the left, and brightness is a major issue. Such color mixing is not a problem, and it is extremely meaningful to improve the brightness as mentioned above. In the above example, the color cathode ray tube is a two-color tube in which blue and green phosphors are arranged, but it is also possible to use a color cathode ray tube that uses a combination of red and green, for example. .

However, in a color image projection apparatus, it is desirable to obtain red by a first cathode ray tube and configure green and blue by a second cathode ray tube, as in the example described above. This is because when it comes to blue and green, human visual acuity is not so noticeable even if the blue is slightly green, or the green is slightly blue. This is because even if BB2 is landed over a green phosphor and color mixture occurs between the two, the image quality will not be affected as much. The present invention seeks to provide a method for manufacturing a color cathode ray tube having the above-mentioned special phosphor arrangement.

An example of the present invention will be explained with reference to FIG. First of all, the 6th
As shown in FIG.
Apply 1. For this photosensitive agent layer 21, a well-known photosensitive agent such as a photosensitive resin such as KPR (trade name) can be used, but if necessary, a light absorbing material is mixed into this photosensitive agent so that it has the effect of blocking or attenuating light. do. Next, as shown in FIG. 6B, an electrode for determining the electron beam arrival position, such as an aperture grille AG, is attached to the inner surface of the panel 20 at the attachment position of the electrode for determining the electron beam arrival position in the color cathode ray tube to be finally obtained. Using this aperture grille AG as a mask, the photosensitive agent 21 is irradiated with a light beam L1 of a desired wavelength through the slit SL to harden this portion.

In this case, the light source of the light beam L1 is moved in the width direction of the slit SL, for example, by wappling, so that the irradiation of the light beam L can be performed with a width larger than the width of the slit SL of the aperture grille AG. By irradiating, a portion 21a that is hardened by exposure and has a larger width is formed in the portion facing the slit SL. Then, as shown in FIG. 2C, the photosensitive agent 21 is developed, leaving the exposed portion 21a and dissolving the other portion.

Next, as shown in FIG. D, a first phosphor slurry 22 in which a first phosphor, for example, a blue phosphor and a photosensitive binder are kneaded, is applied to the inner surface of the panel 20 having the photosensitive agent layer 21. Apply completely.

After that, as shown in FIG. 6E, from the outer surface of the panel 20,
The phosphor slurry 22 is irradiated with a light beam L2 having a wavelength capable of photosensitive coupling, using the photosensitive agent layer 21 as an exposure mask,
The portion 22a where the photosensitive agent layer 21 is not formed is selectively exposed.

Thereafter, as shown in FIG. 6F, the photosensitive agent layer 21 and the phosphor slurry thereon are removed, and the phosphor slurry 22 is selectively baked onto the panel 20 to form a blue phosphor. B
form.

Thereafter, as shown in FIG. G, a phosphor slurry 23 in which a second phosphor, that is, a green phosphor and a photosensitive binder are kneaded, is applied over the entire surface of the panel 20.

After that, for example, if the phosphor B has a relatively light-shielding property, exposure processing may be performed from the outer surface of the panel 20 using this as a mask to selectively expose and print only the portions where the phosphor B is not formed. Alternatively, although not shown, as explained with reference to FIG. 6B, an electrode for determining the electron beam arrival position, that is, an aperture grille AG, is attached to the panel 20, and using this as a mask, a light source is emitted through the slit SL. By moving the phosphor slurry 23 in the same manner as described above, the phosphor slurry 23 is exposed to light with a large width of the slit SL, and developed, and the phosphor slurry 23 is deposited on the panel 20 as shown in FIG. 6H. B and the phosphor G form a separately painted phosphor surface S. In the illustrated example, the photosensitive agent 21 is removed and the second
This is a case where the phosphor slurry 22 is applied using the aperture grille AG as a mask.
It is also possible to leave the photosensitive agent layer 21 in place when exposing the panel 3 from the inner surface of the panel 20, and to scatter and remove it during the subsequent baking process. As described above, according to the manufacturing method of the present invention, it is possible to easily obtain a phosphor surface S in which phosphors B and G having different widths are formed in a desired arrangement pattern.

In the above example, a color cathode ray tube with a combination of blue and green was explained, but it can be applied to a color cathode ray tube with a combination of other colors, and the electrode for determining the electron beam arrival position has a slit SL. Aperture grill A
Although the present invention has been described in the case of a color cathode ray tube having a phosphor pattern corresponding to the electron beam arrival position using other types of electrodes such as a shadow mask having a circular hole or a mask having a slot, etc., as the electrode for determining the electron beam arrival position, can also be applied.

[Brief explanation of the drawing]

1 and 2 are configuration diagrams of a conventional color image projection device used to explain the present invention, and FIG. 3 is an example of a color image projection device to which the color cathode ray tube obtained by the present invention can be applied. FIG. 4 is a block diagram of →u of the color cathode ray tube device obtained by the present invention, FIG. 5 is a layout diagram of its main parts, and FIG. 6 is an example of the manufacturing method of the present invention. It is a process diagram. 1R is the first cathode ray tube, 1BG is the second cathode ray tube device according to the invention, S is its phosphor surface, G and B are its green and blue phosphor stripes, BB,, BB2 are its double beams, BG is the center beam, AG is the electrode for determining the electron beam arrival position, SL is the slit, 20 is the cathode ray tube panel,
21 is a photosensitive agent layer, and 22 and 23 are first and second phosphor slurries.

Claims (1)

[Claims] 1. Coating a photosensitive agent layer on the inner surface of a cathode ray tube panel, attaching an electrode for determining the electron beam arrival position to the inner surface of the panel,
Using the electrode as a mask, the photosensitive agent layer is exposed to light through the opening of the electrode part with a width larger than the width of the opening, and a development process is performed to expose the photosensitive agent layer to the light. A phosphor slurry of a first color is coated on the inner surface of the panel, including the photosensitive agent layer, by leaving only the portion where the photosensitive agent layer has been applied, and removing the other portion. Using the photosensitive agent layer as a mask, the phosphor slurry is exposed to light from the outer surface, leaving only the exposed portion where the photosensitive agent layer is not formed. A method for manufacturing a color cathode ray tube, characterized in that a phosphor of a second color is printed on areas where the phosphor is not applied.