JPS6271143A - Formation of screen of color picture tube - Google Patents

Abstract

PURPOSE:To simplify a mechanism and enhance accuracy, by providing a concave and convex lens which is one of a plurality of corection lenses constituting a lens system, and by performing exposure to light while controlling the positional relation between a light source and the concave and convex lens for every exposed region. CONSTITUTION:After light emitted from a light source 21 is passed through a concave and convex lens 28, the light is transmitted through an optical lens 22 for performing correction to align an optical path with an electron beam path. The light is then passed through the aperture 23' of a zone shutter 23 so that a photosensitive film 26 on a faceplate 24 is selectively exposed to the light through a shadow mask 25, thus manufacturing a screen. At that time, the concave and convex lens 28 is moved in a direction X synchronously with the zone shutter 23 slid in a direction Y, to correct the discrepancy between a beam landing point and a light landing point. This results in simplifying a mechanism to simplify a light unit and enhance its accuracy to stabilize the quality of the screen.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for forming a screen for a photoreceptor color picture tube having a plurality of electron guns and a shadow mask.

[Technical Background of the Invention] Len An example of the method of exposing the screen of a color picture tube every time! Shown in Figure J2. This conventional example is
The method of exposing the fluorescent surface of a conventional color picture tube, which is shown in the third factor, is shown in FIG. 2(a).

(b) @ As shown in (c), a point light source (Ll) is placed at a position corresponding to the center of the deflection of the color picture tube, and the light from this point light source is made to match the trajectory of the electron beam of the color picture tube. A corrective lens is provided, and the corrected light is transmitted to the panel α via a shadow mask (15) attached to the panel I and then to the panel α by the correction lens (zone shutter u3 provided between Lz and panel α4). The light that can reach the inner surface of the shaft is regulated by the extended apertures (1 go) of the zone shutter a field, and these apertures (13
Move it in the direction of the arrow (Y+) in Figure 3). At this time, in synchronization with the position of this opening (13), move panel I as shown in Figure 2 (c).
) in the direction of the arrow (X+).

By this method, in the peripheral part of the screen in the Y+ and Y directions in FIG. It is possible to match with higher precision.

Figure 3 shows the phosphor driver (6a, 6G, 6B) and the electron beam ('l, 7G, 7) arriving on the screen when the ΔS correction by panel movement described above is not performed.
As is clear from Figure 11 showing the mutual positional relationship between B), the central phosphor drum (6G) and the electron beam (7G)
The centers of the dots are perfectly aligned 1, but the phosphor dots (6R, 6B) on both sides are shifted toward the center beam (7G) from the center of the electron beam (7R, 7B). .

In this state, the electron beams (7R, 7B) on both sides will protrude from the predetermined phosphor, and the danger is extremely high. Therefore, the quality of the color picture tube becomes unstable and the color purity deteriorates.

FIG. 4 shows a state in which the electron beam and the phosphor dot are perfectly aligned by performing the ΔS correction by moving the panel I.

[Problems with background technology]

However, this type of exposure apparatus requires a mechanism to move the panel α4 and the panel mounting stage in synchronization with the movement of the zone shutter (13), and the above-mentioned panel I and panel 4E mounting stage (l) are extremely heavy. It is difficult to implement this with high precision because of the large height of the panel.First of all, the mechanism is very complicated because the panel mounting is done by sliding against the main body of the sunlight device. The cost is high.Secondly, alignment of the light source I and the panel I is a complicated procedure and causes various variations.

There is a very high demand for larger screens or higher definition screens, and it goes without saying that it is essential to improve the precision of the position where the light reaches during exposure. cannot be improved.

[Purpose of the invention]

The present invention has been carried out in view of the above points, and it is an object of the present invention to provide a screen forming method and an exposure apparatus that can provide a color picture tube with simple a#I, high precision, and very stable quality. .

[Summary of the invention]

The present invention is a method for forming a screen for a color picture tube, in which a light beam emitted from a light source is trajectory-corrected by a lens system, and selectively exposes a photosensitive film formed on the inner surface of a face plate through a small beam transmission hole of a mask. The lens system is composed of a plurality of correction lenses, at least one of which is a concave-convex lens, and performs exposure while controlling the relative positional relationship between the light source and the concave-convex lens for each exposure area on the inner surface of the face plate. The present invention relates to a screen forming method for a color picture tube and an exposure device thereof, characterized in that the inner surface of the face plate is divided into sections by a sliding zone shutter, and the optimal position of the concave-convex lens in the defined exposure area is provided. Depending on the settings, it is possible to improve the accuracy of the alignment of the ray trajectory emitted from the light source and the 1 maple beam trajectory.

[Embodiments of the invention]

FIG. 1 shows a first embodiment of the present invention. (2υ is a point light source.) @ is an optical lens that corrects the trajectory of the ray emitted from light #(21). This optical lens aligns the trajectory of the light beam with the trajectory of the electron beam.In general, as the deflection angle increases, the light source appears to move forward (ΔP), and the deflection center shifts due to the increase in the deflection angle. That is, it is necessary to correct two components of the separation movement (ΔS).

The optical lens (2) of this embodiment corrects the above-mentioned ΔP and ΔS using a single lens. Naturally, ΔP and ΔS
It is also possible to correct using separate lenses, and either one can be employed in the present invention. The light beam exiting the correction lens V4 passes through the extended aperture C3 of the zone shutter (c) which slides in the direction of the arrow in FIG. 1(b) and exposes the window area of the face plate (to). A photosensitive film 4 is uniformly formed on the inner surface of the face plate, and a shadow mask (c) is supported and fixed at a predetermined distance.

The aforementioned light beam passes through the beam hole of the shadow mask □□□ and selectively exposes the photosensitive film (c) on the inner surface of the face plate □ to form a screen phosphor.

The present invention takes this. By moving the concave-convex lens (to) designed to a predetermined performance in the four-component exposure device in the direction of the arrow in Fig. 1 (C) in synchronization with the aforementioned sliding zone shutter (to), the beam is This achieves almost perfect alignment between the trajectory and the ray trajectory.

FIG. 5 is a schematic diagram showing the operating principle of the present invention. ,
! Figure 55 (a) shows the ray trajectory (57) when the off-axis distance S of the light source (51) and the off-axis distance SM of the concave-convex lens (52) are equal to the central axis (56)
) is shown. The distance between the center of the face plate and the 14th land point (55) of the light is expressed as σ.

Figure 5(b) shows the off-axis distance SM of the concave-convex lens (52).
The ray trajectory (57) is shown when changing M + ΔSM. The landing point moves to (55) and σ increases to σ + Δσ.

It is clear that similar corrections can be made at the periphery of the face plate, although the above is a schematic explanation of the central part of the face plate. FIG. 6 shows the relationship between 68M and Δσ. In the practical range of 68M, 68M and Δσ are almost proportional. For example, the specific dimensions of a concave-convex lens designed for a 21 color picture tube are as follows:
.

Lo=300m q ==9fl Δi9M=5111 Δσ = addition μm The concave-convex lens used here has an inner surface of about 3OR, an outer surface of about 40R, and a center layer of 3m.

As is clear from the above description, according to the present invention, when the concave-convex lens is moved in synchronization with the sliding zone shutter, the beam landing point and the light beam landing point (phosphor formation position) shown in FIG. It is possible to correct the discrepancy. As a result, excellent beam landing performance as indicated by m-1 in FIG. 4 is obtained.Although an in-line type dot screen is used in the explanation of the present invention, it can also be easily applied to a Δ type collar tube. In this case, the light source moves in different directions every 12σ, but the movable direction of the concave-convex lens should be the off-axis direction S of the light source, and the moving direction of the zone shutter should be a direction substantially orthogonal to this S.
Further, in the case of in-line, the screen is not limited to a dot type, but a stripe type screen can also be formed by using a long light source.

As explained in detail above, the present invention makes it possible to obtain accurate alignment between beams and light rays by making the concave-convex lens movable, while at the same time simplifying and increasing the precision of the exposure equipment, resulting in more stable performance. This makes it possible to form a screen, and its industrial value is great.

[Brief explanation of drawings]

i! Fig. 11 is a schematic diagram of an exposure apparatus according to the present invention, Fig. 2 is a configuration diagram of a conventional exposure apparatus, Fig. 3 is a diagram illustrating a state of misalignment between a phosphor dot and a beam, and Fig. 4 is a diagram illustrating a state of misalignment between a phosphor dot and a beam. FIG. 5 is a diagram illustrating the alignment state of the light body dot and the beam, FIG. 5 is a diagram illustrating the ray trajectory correction effect by the concave-convex lens of the present invention, and FIG. 6 is a diagram illustrating the relationship between 68M and Δσ. . 11.21...Light source 12.22...Correction lens 1
3.23...Zone shutter 14.24...Face plate 15.25...Shadow mask 16.26...Photosensitive film 4...Concave/convex lens Agent Patent attorney Nori Chika Ken Yudo Ogo Norio

Claims (3)

[Claims] (1) A method for forming a screen for a color picture tube, in which a light beam emitted from a light source is orbitally corrected by a lens system and selectively exposes a photosensitive film formed on the inner surface of a face plate through a small beam transmission hole of a shadow mask, At least one of the plurality of correction lenses constituting the lens system is a concave-convex lens, and exposure is performed while controlling the relative positional relationship between the light source and the concave-convex lens for each exposure area on the inner surface of the face plate. A method for forming a color picture tube screen, characterized by: (2) A patent characterized in that the light source is fixed, the concave-convex lens moves back and forth in a predetermined direction with respect to the light source, and the zone shutter that partitions the exposure area slides substantially perpendicular to the moving direction of the concave-convex lens. A method for forming a screen for a color picture tube according to claim 1. (3) Claims 1 and 2, characterized in that the moving direction of the concave-convex lens substantially coincides with the off-axis direction of the off-axis light source positioned corresponding to the non-central beam. The method for forming a screen for a color picture tube described above.