YANG, Dong Wook (#201, 359-91 Bunji Hwagok 1-don, Gangseo-gu Seoul 157-883, KR)
Claims
[1] A field emission flat lamp with a diffusion plate which diffuses light emitted through a panel, comprising: an external spacer between the diffusion plate and the panel, the external spacer is located at a dark region generated by an internal spacer and refracts the light emitted through the panel. [2] The field emission flat lamp as recited in claim 1, wherein the external spacer contacts the panel and covers an area broader than that of the dark region. [3] The field emission flat lamp as recited in claim 2, wherein the external spacer covers a portion of an area coated with a fluorescent substance. [4] The field emission flat lamp as recited in claim 3, wherein the external spacer is in a transparent semispherical shape. [5] The field emission flat lamp as recited in claim 3, wherein the external spacer is in a transparent semi-cylindrical shape. |
Description FIELD EMISSION FLAT LAMP
Technical Field
[1] The present invention relates to a field emission flat lamp; and, more particularly, to a field emission flat lamp with a diffusion plate, capable of improving brightness and uniformity of light using an external spacer of diffusion type for refracting light. Background Art
[2] A spacer is an element used to maintain a vacuum inside of a panel, in a vacuum packaging of a display. It is used in FEDs (Field Emission Displays) and in backlights for a display. The spacer keeps a width of a gap between an anode plate and a cathode plate constant, which ranges from several tens of microns to several millimeters. It prevents a substrate from being collapsed due to an external atmospheric pressure and blocks a cross-talk, a mutual interference among pixels during the operation process. And the spacer should not be shown visually, should have physical and chemical durability, and have a thermal expansion coefficient which coincides with the thermal expansion coefficients of upper and lower substrates in order to prevent damage by stress during heating process.
[3] Conventionally, as shown in Fig. 1, due to the effect of an internal spacer 150 inside of the panel 180, a dark region 190 occurs above the internal spacer 150, and the dark region 190 deteriorates the uniformity of brightness of light in front of the panel 180. For solving this problem, a diffusion plate such as an optical sheet has been provided in order to get a uniform brightness throughout the panel 180. As shown in Fig. 2, in order to add a diffusion plate 270, an external spacer 260 is installed at the dark region made over the panel 250 to sustain the diffusion plate 270. In this case, the thickness and number of diffusion plates 270 are required to increase to diffuse further the light passed through the panel 250, thereby lessening the dark region 280 made above the diffusion plate further than that above an internal spacer 225
[4] Accordingly, the conventional internal spacer 225 has a problem of increasing thickness and number of diffusion plates 270 for reducing the dark region 280. And also, there is a problem that the distance between the diffusion plates 270 and the panel 250 which light passes through gets longer.
[5]
Disclosure of Invention Technical Problem
[6] Therefore, the present invention has been proposed in order to overcome the above- described problems in the related art. It is an object of the present invention to obtain
the constant brightness and uniformity of light by lessening a dark region generated by an internal spacer. [7] It is another object of the present invention to reduce a thickness and the number of diffusion plates which are provided in order to lessen the dark region generated by a spacer. [8] It is still another object of the present invention to reduce a distance between a diffusion plate for lessening the dark region generated by a conventional internal spacer and a panel where light is emitted.
Technical Solution [9] In accordance with one aspect of the present invention, there is provided a field emission flat lamp with a diffusion plate which diffuses light emitted through a panel by using a field emission, comprising: an external spacer, which is located at a dark region generated by an internal spacer, between the diffusion plate and the panel, for diffusing the light emitted through the panel.
Advantageous Effects
[10] Therefore, a field emission flat lamp in accordance with the present invention is capable of obtaining a constant brightness and uniformity of light by composing an external spacer of diffusion type in a transparent semispherical or a cylindrical shape to lessen a dark region generated by an internal spacer. [11] And a field emission flat lamp in accordance with the present invention is capable of reducing thickness and number of diffusion plates provided for diffusing the light emitted from the panel. [12] And also, a field emission flat lamp in accordance with the present invention is capable of reducing distance between a diffusion plate for lessening the dark region generated by a conventional internal spacer and a panel where light is emitted.
Brief Description of the Drawings
[13] Fig. 1 is a configuration diagram showing a structure of a field emission flat lamp;
[14] Fig. 2 is a configuration diagram showing a structure of a conventional field emission flat lamp including a diffusion plate; [15] Fig. 3 is a configuration diagram illustrating an external spacer of diffusion type at a field emission flat lamp in accordance with the present invention; [16] Fig. 4 is a plan view of a flat lamp illustrating an external spacer in accordance with a first embodiment of the present invention; [17] Fig. 5 is a perspective view of a flat lamp illustrating an external spacer in accordance with the first embodiment of the present invention; [18] Fig. 6 is a plan view of a flat lamp illustrating an external spacer in accordance with a second embodiment of the present invention; and
[19] Fig. 7 is a perspective view of a flat lamp illustrating an external spacer in accordance with the second embodiment of the present invention.
[20]
[21] <Descriptions of reference numerals for major parts in the drawings>
[22] 100, 200, 300: substrate 110, 205, 310: electrode
[23] 120, 210, 330: insulating material 130, 215, 320: emitter electrode
[24] 140, 220, 340: gate 150, 225, 350: inner spacer
[25] 160, 230, 360: fluorescent substance 170, 240, 365: anode electrode
[26] 190, 280: dark region 270, 390: diffusion plate
[27] 180, 250, 370, 400, 420, 500, 520: panel
[28] 260, 380, 410, 430, 510, 530: external spacer
[29]
[30]
Mode for the Invention
[31] These and other features, aspects, and advantages of preferred embodiments of the present invention will be more fully described in the following detailed description, referring to accompanying drawings.
[32] Fig. 3 is a configuration diagram illustrating an external spacer of diffusion type at a field emission flat lamp in accordance with the present invention. The field emission flat lamp in accordance with the present invention uses a phenomenon that light which is generated when electrons emitted from an emitter electrode 320 on a substrate 300 collide with a fluorescent substance 360 passes through a panel 370 and is emitted. The emitter electrode 320, an electrode 310, an internal spacer 350, gates 340, a fluorescent substance 360 and an anode electrode 365 between the substrate 300 and the panel 370 are set in a vacuum state in order to increase a mean free path of an electron and prevent the fluorescent substance from damage by moisture, oxygen, carbon monoxide, carbon dioxide, and methane, etc. The internal spacer 350 is provided in order to sustain the vacuum state, and prevents the substrate 300 and the panel 370 at a vacuum state from collapsing due to an external atmospheric pressure.
[33] Referring to Fig. 3, light is emitted from fluorescent substance as an electron emitted from the emitter electrode 320 collides with the fluorescent substance 360. The light passes through the panel 370 and is emitted to the outside through the diffusion plate 390.
[34] The fluorescent substance 360 and the anode electrode 365 are composed under the panel 370 and the internal spacer 350 is composed at the lower part of the anode electrode 365. Light passes through an area where the fluorescent substance 360 is coated, but cannot penetrate the area where the fluorescent substance 360 is not coated,
in other words, the upper part of the internal spacer 350. However, in accordance with the present invention, the external spacer 380 is located over a portion of the area coated with the fluorescent substance 360 as well as the upper part of the internal spacer 350. The light which has penetrated through the panel 370 disposed over the fluorescent substance 360 is refracted at the external spacer. Therefore, the brightness of the light emitted through the diffusion plate 390 located over the external spacer 380 becomes uniform.
[35] Fig. 4 and Fig. 5 are respectively a plan view and a perspective view of a flat lamp illustrating an external spacer in accordance with a first embodiment of the present invention. In accordance with the first embodiment of the present invention, the external spacer 410 or 430 is located at the upper part of the panel 400 or 420 and can be made in a transparent semispherical shape.
[36] Fig. 6 and Fig. 7 are respectively a plan view and a perspective view of a flat lamp illustrating an external spacer in accordance with a second embodiment of the present invention. In accordance with the second embodiment of the present invention, the external spacer 510 or 530 is located at the upper part of the panel 500 or 520 and can be made in a transparent semi-cylindrical shape.
[37] While the present invention has been described with respect to certain preferred embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the scope of the invention as defined in the following claims.
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