Electric lamp and discharge devices – Cathode ray tube – Shadow mask – support or shield
Reexamination Certificate
2001-08-29
2003-04-08
Patel, Vip (Department: 2879)
Electric lamp and discharge devices
Cathode ray tube
Shadow mask, support or shield
C313S407000
Reexamination Certificate
active
06545401
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of Korean Application No. 2000-83082, filed Dec. 27, 2000, in the Korean Patent Office, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a cathode ray tube, and more particularly, to a color selection apparatus for a cathode ray tube in which a color image is displayed in the cathode ray tube.
2. Description of the Related Art
A cathode ray tube that is a main image display device is being developed in various types as a result of changing times. Recently, to display a natural and clear image on the whole screen, a flat panel cathode ray tube, in which an entire surface of a panel provided with a screen is formed in a flat panel, is receiving much attention.
Furthermore, because of the preferences of consumers who desire to view an image displayed in a cathode ray tube such as a color television and a monitor for a computer on a larger screen, it is a general tendency that the screen of the cathode ray tube, i.e., the panel provided with the screen, has a large size.
In view of a flat panel with a large size in a cathode ray tube, it is a given that a shadow mask adapted to display colors also has a large size. However, there are limitations, such as intensity and other factors, in forming a large sized shadow mask with a curved shape. In this respect, new shadow masks for a cathode ray tube have been developed.
One of them is disclosed in the Japanese Patent Publication No. 62-249339. In this Japanese Patent Publication, a shadow mask having a plurality of electron beam through holes is not curved but is formed in a flat panel, so that it is maintained at a predetermined tension. The shadow mask is based on an aperture grill-type in which an electrode frame having a plurality of grid members arranged at a predetermined pitch is formed by applying a tension thereon. In the shadow mask, it is noted that the distribution of the tension applied to the electrode frame along a longitudinal side of the electrode frame gradually increases from the center of the electrode frame to both end portions.
Another shadow mask for a cathode ray tube is disclosed in the U.S. Pat. No. 5,801,479. This shadow mask is also based on an aperture grill-type. The distribution of tension applied to the aperture grill gradually increases from the center of the aperture grill to both end portions along a longitudinal side of the aperture grill. The aperture grill-type shadow mask, as is known, has advantages in that it can improve doming or discoloration characteristics as compared with a typically formed mask with a curved shape. However, the shadow mask has a problem in that is likely to generate howling due to external sound or impact.
To solve the above problem, a shadow mask for a cathode ray tube has been suggested in which damper wires are mounted across an outer surface of the aperture grill to prevent howling from being generated, as disclosed in the U.S. Pat. No. 5,382,871. However, the shadow mask provided with the damper wires has a problem in that unnecessary lines occur on the screen of the cathode ray tube due to the damper wires, thereby deteriorating picture quality. This problem seriously arises when the cathode ray tube is adapted for a monitor for a computer.
Furthermore, in another related art, a color cathode ray tube is disclosed in the Japanese Patent Publication No. 11-250824. In this related art, the color cathode ray tube has a shadow mask of Invar material (36% Ni—Fe alloy) applied with a tension of 5~90% against a tension generated when electron beams do not move at all. Since the color cathode ray tube can effectively suppress howling generated in the shadow mask without damper wires, it is possible to prevent a visual problem resulting from the damper wires. However, since the shadow mask is formed of expensive Invar material, a problem arises in that the manufacturing cost is high.
As described above, the related art shadow masks for a flat panel cathode ray tube are configured to form one assembly body by differentiating the distribution of the tension applied to the shadow mask (or aperture grill). However, they do not give the best satisfaction to consumers or manufacturers for a flat panel cathode ray tube due to the aforementioned problems.
SUMMARY OF THE INVENTION
Accordingly, the present invention is directed to a color selection apparatus for a cathode ray tube that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a color selection apparatus for a cathode ray tube that can optimize satisfaction for use in view of visual, performance, and cost aspects.
Another object of the present invention is to provide a cathode ray tube having a color selection apparatus that can optimize satisfaction for use in view of visual, performance, and cost aspects.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, a color selection apparatus for a cathode ray tube according to the present invention includes: an iron mask having a longitudinal axis and a short axis; and a frame coupled with the mask and tensing the mask in one direction of the longitudinal and short axes, the mask comprising a plurality of strips spaced apart from one another at predetermined intervals, and a plurality of electron beam through holes formed by a plurality of real bridges arranged between the respective strips at predetermined pitches, wherein a center point of the mask along the longitudinal axis is A, both end points of the mask along the longitudinal axis are B, a length of a longitudinal side of the mask is 2L, point greater than L/4 from the point A in each direction are C, a tension applied to the strip of the point A is smaller than a tension applied to the strips of the points B and a distribution curve of a tension applied to the strips of the mask along the longitudinal direction satisfies the following equation;
|S
A-C
|<|S
C-B
|
wherein S
A-C
represents a slope of a straight line that links the point A to one of the points C on the tension distribution curve, and S
C-B
represents a slope of a straight line that links the one point C to the corresponding point B on the tension distribution curve.
To further achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, a cathode ray tube according to the present invention includes: a panel provided with a fluorescent screen inside thereof; a funnel connected with the panel and provided with a deflection unit on a circumference thereof, the deflection unit deflecting electron beams; a neck portion connected with the funnel and provided with an electron gun to scan the electron beams to the fluorescent screen; and a color selection apparatus fixed inside the panel, selecting the electron beams to land on corresponding phosphors of the fluorescent screen, the color selection apparatus comprising an iron mask having a longitudinal axis and a short axis; and a frame coupled with the mask and tensing the mask in one direction of the longitudinal and short axes, the mask comprising a plurality strips spaced apart from one another at predetermined intervals; a plurality of electron beam through holes formed by a plurality of real bridges arranged between the respective strips at predetermined pitches, and at least one dummy bridge extended from the strips in one direction of the electron beam
Choe Duk-Hyun
Ha Kuen-Dong
Kim Gui-Bae
Kim Hoo-Deuk
Lee Kwang-Sik
Patel Vip
Samsung SDI & Co., Ltd.
Staas & Halsey , LLP
LandOfFree
Color selection apparatus for cathode ray tube does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Color selection apparatus for cathode ray tube, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Color selection apparatus for cathode ray tube will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3093014