JP2002164005A - Cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cathode-ray tube capable of easily realizing overlapping display with a multi-neck type cathode-ray tube without setting the deflection magnetic field of a deflection device asymmetrical with respect to the centers of divided regions or setting a signal applied to the deflection device asymmetrical. SOLUTION: This cathode-ray tube has a panel 1 and a funnel 3 having two funnel-like cone parts 2a and 2b. An image is divided into two regions in the direction of a long axis X, and the regions mutually overlap in a width H by centering a boundary 11. The funnel-like cone parts and necks are off-centered inward along the long axis X with respect to the centers of the corresponding divided regions 10a and 10b, and when it is assumed that the distance between the center axes of the funnel-like cone parts and the distance between the centers of the divided regions 10a and 10b are La and Lb, respectively, the ratio La/Lb of the distance La between the center axes of the funnel-like cone parts to the distance Lb between the centers of the divided regions is set to 0.85-0.98 when the panel inside surface is flat and to 0.88-1.02 when the panel inside surface has a predetermined radius of curvature along the long axis.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of a cathode ray tube, and more particularly to a multi-neck system in which a plurality of electron gun assemblies are divided and a region where each electron gun assembly faces is divided and scanned. It relates to the structure of a cathode ray tube.

[0002]

2. Description of the Related Art In recent years, various studies have been made to meet demands for high-definition picture tubes for high-definition broadcasting or accompanying large screens. In order to achieve higher resolution of the picture tube, the electron beam spot diameter on the screen surface must be reduced.

On the other hand, the electrode structure of an electron gun, which is an electron beam generating source, has been conventionally improved, or the diameter and length of the electron gun itself have been increased. However, sufficient results have been obtained. Absent. This is mainly because the distance from the electron gun to the phosphor screen becomes longer as the tube becomes larger, and the magnification of the electron lens becomes too large. Therefore, it is important to shorten the distance from the electron gun to the phosphor screen in order to realize high resolution. In this case, wide-angle deflection increases the magnification difference between the center and the periphery of the screen. For this reason, wide-angle deflection is not advantageous for achieving high resolution.

For this reason, a method of arranging a plurality of independent small picture tubes to provide a large screen with a high resolution has been disclosed in Japanese Patent Laid-Open No. 48-9 / 1981.
No. 0428, JP-A-49-21019, and JP-A-53-117130. This type of method is effective for displaying a huge screen with a large number of divisions arranged outdoors or the like. However, when displaying a medium-sized large screen with a screen size of about 40 inches, the joining of the screens between the areas is performed. The part stands out and reproduces an unsightly image. Therefore, when used as a home television receiver or as a terminal for graphic display in computer-aided design (CAD), the connection portion of the screen becomes a fatal defect.

On the other hand, US Pat. No. 3,071,7.
No. 06, JP-B-39-25641, JP-B-42-4928, JP-A-50-17167, U.S. Pat. No. 4,777,407, and the like, disclose a plurality of independent image receiving devices. A structure in which a fluorescent screen of a tube is integrated is disclosed. These cathode ray tubes deflect an electron beam emitted from an electron gun arranged in a plurality of necks by a magnetic field generated by a corresponding deflecting device, and form a phosphor screen integrally formed on the inner surface of the panel. Is divided into a plurality of corresponding areas and scanned. As an example, Japanese Patent Application Laid-Open No. 7-45215 discloses a cathode ray tube including a panel 21, an intermediate glass 22, and a plurality of funnels 23a and 23b, as shown in FIG.
In such a cathode ray tube, it is necessary to provide the electron beam passage holes 24a and 24b in the intermediate glass 22 by a water jet method or the like, which is costly.

On the other hand, in a multi-neck type cathode ray tube, a so-called overlap display is used in which a predetermined width centering on the boundary of a divided area is displayed so as to overlap each other in order to smoothly connect images drawn on a phosphor screen. The method is effective. In this overlapping area, for example, a sine function luminance modulation is applied, and the luminance of the overlapping area is smoothly connected to other parts. By such divided scanning, even if there is a manufacturing error in the electron gun or the deflection device, the image quality error amount can be diffused, so that a single image in which a break or overlap is hardly recognized on the entire phosphor screen is reproduced. be able to.

[0007]

The conventional multi-neck type cathode ray tube has a structure in which the central axis of the funnel-shaped cone passes through the center of the divided area, and a plurality of necks are arranged in parallel with the tube axis. In the case of the structure, the center of the neck is located at the center of the divided area.

In the case of performing the above-described overlap display with such a cathode ray tube, the deflection scanning range must be partially enlarged to a portion where the overlap is to be made. For that purpose, it is necessary to form the deflection magnetic field by the deflection device asymmetrically with respect to the center of the divided area, or to form the deflection device state asymmetrically to overlap the deflection scanning range. When such a deflecting device is used, the adjustment work at the time of manufacturing and mounting the deflecting device becomes complicated, and ultimately causes a cost increase.

In view of such problems, an object of the present invention is to provide a multi-neck type cathode ray tube capable of easily realizing an overlap display.

[0010]

According to a first aspect of the present invention, there is provided a panel having a phosphor screen formed on an inner surface thereof and a funnel having a plurality of funnel-shaped cone portions and connected to the panel. A vacuum envelope having a neck connected to each funnel-shaped cone, and an electron gun disposed in the neck, wherein the phosphor screen is divided into a plurality of divided regions by an electron beam emitted from the electron gun. In the cathode ray tube which scans the cathode ray tube, the center axis of the funnel-shaped cone portion is eccentric with respect to the center of the divided area.

In the first invention, the inner surface of the panel is substantially flat in the major axis direction, and the plurality of necks are parallel to each other. Further, when the distance between the center axes of the first adjacent funnel-shaped cones is La and the distance between the centers of the adjacent divided regions is Lb, 0.85 <La / Lb <0.98. .

[0012] In a second aspect of the present invention, a panel having a phosphor screen formed on an inner surface thereof, a funnel having a plurality of funnel-shaped cones and connected to the panel, and a neck connected to each funnel-shaped cone are provided. A cathode ray tube that includes a vacuum envelope having an electron gun disposed in a neck and scans a phosphor screen by dividing the phosphor screen into a plurality of divided regions by an electron beam emitted from the electron gun. It has a curvature in the axial direction, and a plurality of necks are parallel to each other, and the distance between the center axes of adjacent funnel-shaped cone portions is La,
The cathode ray tube is characterized in that 0.88 <La / Lb <1.02, where Lb is the distance between centers of adjacent divided regions.

Further, in the first or second invention, the funnel is characterized in that it is integrally formed from a single glass. Further, the outer surface of the funnel between the plurality of funnel-shaped cone portions has a flat portion.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show an embodiment of a cathode ray tube according to the present invention. 1 is a cross-sectional view in the long axis direction, FIG. 2 is a cross-sectional view in the short axis direction, and FIG. 3 is a front view of the panel. This cathode ray tube has a vacuum comprising a panel 1, a funnel 3 connected to the panel and having two funnel-shaped cone portions 2a and 2b, and necks 4a and 4b connected to the funnel-shaped cone portions 2a and 2b. It has an envelope 5. Panel 1
The inner surface is substantially flat along the major axis X direction, has a shape having a constant curvature along the minor axis Y direction, and has the phosphor screen 6 formed thereon. Each neck 4a,
4b are parallel to each other, and electron guns 7a and 7b are disposed inside. The electron beams 8a, 8b emitted from the electron guns 4a, 4b are deflected and scanned by a deflection magnetic field generated by deflection devices 9a, 9b provided on the funnel-shaped cone portions 2a, 2b. In the present embodiment, the image is divided into two divided regions 10 a and 10 b in the major axis X direction, and overlaps on the phosphor screen 6 with a width H around the boundary 11 between the divided regions.

Funnel-shaped cone portions 2a, 2b and neck 4
a and 4b are provided eccentrically inward along the major axis X with respect to the centers of the corresponding divided regions 10a and 10b. That is, when the distance between the center axes of the funnel-shaped cone portions is La and the distance between the centers of the divided regions 10a and 10b is Lb, La
<Lb. The amount of eccentricity is set so that the deflection angles of the electron beams 8a and 8b are symmetric when viewed on an axis along the long axis X. When the inner surface shape of the panel 1 is substantially flat along the major axis X, the amount of eccentricity δ is as follows: δ = (Lb−La) / 2 = H / 4. By setting the amount of eccentricity δ as described above, it is possible to form the deflecting devices 9a and 9b so as to be asymmetric or to perform the overlap display without making the signals applied to the deflecting devices 9a and 9b asymmetric. Therefore, it is possible to suppress an increase in cost required for manufacturing, mounting, and adjusting the deflection devices 9a and 9b.

When an image is displayed by adding luminance modulation in the overlap area, the error amount of the image quality can be diffused, but the effect of the error diffusion differs depending on the overlap width. As a result of simulations, experiments, and the like, the inventors have found that setting the overlap width H to be larger than 2% of the phosphor screen diameter in the major axis X direction is effective for error diffusion. Note that increasing the overlap width H increases the deflection scanning area, which leads to an increase in deflection power. On the other hand, it is also known that an appropriate shape of the funnel-shaped cone portion leads to a reduction in deflection power (U.S. Pat. No. 5,763,995). In consideration of the combined use, it has been found that there is generally no problem if the overlap width H is smaller than 15% of the phosphor screen diameter in the major axis X direction.

In general, the inner surface of the panel is represented by various curved surfaces according to the type of the cathode ray tube, but it can be considered that the inner surface is an arc having a radius R along the long axis. At this time,
The amount of eccentricity when the deflection angle of the electron beam is symmetrical with respect to a vertical line passing through the midpoint of the long axis can be approximately expressed by a linear expression of the overlap width H. Since the overlap width is preferably 2% to 15% of the screen diameter in the major axis direction, considering this condition, the ratio La / of the center axis distance La of the funnel-shaped cone portion and the center distance Lb of the divided region is expressed as La / When the preferable range of Lb is calculated, when the inner surface of the panel is flat, the range of 0.
85 to 0.98, and 0.88 to 1.02 when the panel inner surface has a predetermined radius of curvature along the long axis.

The two funnel-shaped cone portions 2a, 2
The funnel 3 having b is integrally formed from a single glass as shown in FIG. 4, similarly to a conventional cathode ray tube having one funnel-shaped cone. As a means for producing a funnel, a method described in JP-A-11-283535 can be used.

Also, such a multi-neck type cathode ray tube has a sealing step of joining a panel and a funnel, a sealing step of sealing an electron gun in a neck, and an exhausting step, like a color picture tube having a single neck. Manufactured through such as. In such a process, the cathode ray tube is loaded while maintaining a predetermined posture. In the cathode ray tube of the present embodiment, the horizontal positioning is performed by using the funnel-shaped cone portions 2a and 2b, and the adjacent cone portions 2a and 2b of the funnel 3 are arranged.
The outer surface between them is a flat portion 12 perpendicular to the tube axis Z to enhance the positioning in the vertical direction and the accuracy of the verticality.

(Example 1) A 36-inch cathode ray tube having a phosphor screen having a diagonal diameter of 86 cm will be described as an example. Since the overall configuration is as described above, the description will focus on the dimensional relationship. Aspect ratio of the phosphor screen: 16 to 9 Diameter of the phosphor screen in the major axis direction: 749.6 mm Distance from the center of the phosphor screen to the reference line: 240 mm Overlap width: 60 mm Radius of major axis in the major axis direction of panel inner surface: approx. 100,000 mm (almost infinity) Radius of curvature in the short axis direction on the inner surface of the panel: 1,900 mm (approximate value) The distance between the central axes of the funnel-shaped cone portion is La: 344.8 mm The distance between the centers of the divided areas Lb: 374.8 mm La / Lb: 0.92

The funnel 3 of the cathode ray tube is integrally formed by the same method as in the prior art. When the deflection devices 9a and 9b are provided on the cone portions 2a and 2b of the cathode ray tube and the cathode ray tube device is operated, a sine-function luminance modulation is applied to the overlap region H, so that the overlapped region is reduced. The luminance was smoothly connected to the luminance of the other portions, and one image in which no cut or overlap was visually recognized on the entire surface of the phosphor screen 6 could be reproduced.

(Embodiment 2) A 36-inch cathode ray tube having a phosphor screen having a diagonal diameter of 86 cm, as in Embodiment 1, will be described as an example. The overall configuration is the same as that of the first embodiment. In this embodiment, the shape of the panel inner surface is different from that of the first embodiment. Aspect ratio of the phosphor screen: 16 to 9 Phosphor screen diameter in the major axis direction: 749.6 mm Distance from the center of the phosphor screen to the reference line: 240 mm Overlap width: 60 mm Radius of major axis in the major axis direction of panel inner surface: 7 , 030 mm (approximate value) Radius of curvature in the minor axis direction of the inner surface of the panel: 1,900 mm (approximate value) The distance between the center axes of the funnel-shaped cone portion is La: 347.5 mm The distance between the centers of the divided areas Lb: 374.8 mm La / Lb: 0.93

The cathode ray tube of this embodiment is similar to the first embodiment,
By applying a sine function luminance modulation to the overlap area H, the luminance of the overlapped area is smoothly connected to the luminance of the other parts, and one image in which no cut or overlap is visible on the entire surface of the phosphor screen is reproduced. I was able to.

Although the above embodiment has been described with reference to a cathode ray tube using a funnel 3 having two funnel-shaped cone portions 2a and 2b, the present invention is not limited to this, and has three or more funnel-shaped cone portions. The present invention is also applicable to a cathode ray tube using a funnel. FIG. 5 shows La and Lb in a cathode ray tube using a funnel having three funnel-shaped cone portions.

Further, the sectional shape of the cone may be either a conical shape or a pyramid shape. Further, the present invention can be applied not only to a monochrome cathode ray tube but also to a shadow mask type color cathode ray tube and a beam index type color cathode ray tube.

[0026]

As described above, according to the present invention, the multi-necked cathode ray line can be formed without forming the deflection magnetic field by the deflection device asymmetrically with respect to the center of the divided area or by making the signal applied to the deflection device asymmetrical. It is possible to provide a cathode ray tube capable of easily realizing overlap display with the tube.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a configuration of a cathode ray tube according to an embodiment of the present invention.

FIG. 2 is a short-axis sectional view showing a configuration of a cathode ray tube according to an embodiment of the present invention.

FIG. 3 is a front view showing a configuration of a cathode ray tube according to the embodiment of the present invention.

FIG. 4 is a cross-sectional view illustrating a structure of a funnel of the cathode ray tube.

FIG. 5 is a longitudinal sectional view showing a structure of a cathode ray tube according to another embodiment.

FIG. 6 is a sectional view showing a conventional multi-neck type cathode ray tube.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Panel 2a, 2b ... Cone part 3 ... Funnel 4a, 4b ... Neck 5 ... Vacuum envelope 6 ... Phosphor screen 7a, 7b ... Electron gun 8a, 8b ... Electron beam 9a, 9b ... Deflection device 10a. 10b: divided region 11: boundary of divided region H: overlap width La: distance between center axes of funnel-shaped cone portion Lb: distance between centers of divided region

Claims (6)

[Claims] 1. A vacuum envelope having a panel having a phosphor screen formed on an inner surface thereof, a funnel having a plurality of funnel-shaped cone portions and connected to the panel, and a neck connected to each funnel-shaped cone portion. An electron gun disposed in the neck, wherein the cathode ray tube scans the phosphor screen by dividing the phosphor screen into a plurality of divided regions by an electron beam emitted from the electron gun. A cathode ray tube, wherein an axis is eccentric with respect to the center of the divided area. 2. The cathode ray tube according to claim 1, wherein the inner surface of the panel is substantially flat in a longitudinal direction, and the plurality of necks are in a parallel relationship with each other. 3. When the distance between the center axes of adjacent funnel-shaped cone portions is La and the distance between the centers of adjacent divided regions is Lb, 0.85 <La / Lb <0.98. The cathode ray tube according to claim 2, wherein 4. A vacuum envelope having a panel having a phosphor screen formed on an inner surface thereof, a funnel having a plurality of funnel-shaped cone portions connected to the panel, and a neck connected to each funnel-shaped cone portion. An electron gun disposed in the neck, the cathode ray tube scanning the phosphor screen by dividing the phosphor screen into a plurality of divided regions by an electron beam emitted from the electron gun, wherein the panel inner surface has a major axis direction. 0.88, where the plurality of necks are in parallel with each other, and the distance between the center axes of adjacent funnel-shaped cone portions is La, and the distance between the centers of adjacent divided regions is Lb. <La / Lb <1.02. A cathode ray tube characterized in that: 5. The cathode ray tube according to claim 1, wherein said funnel is integrally formed from a single glass. 6. The cathode ray tube according to claim 5, wherein an outer surface of the funnel between the plurality of funnel-shaped cone portions has a flat portion.