JPH11260314A - Electric discharge device and lighting system using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent uneven application of a fluorescent material or uneven discharge from appearing to be uneven light emission as it is, so as to improve luminance uniformity with a simple structure by forming either an outer surface or an inner surface of a front face plate or both of them into a diffusion face (s) by frost machining or the like. SOLUTION: A translucent front face plate 10 made of soda glass or the like and a box-shaped insulated base board 20 made of soda glass or ceramic are sealed integrally airtightly by low melting point glass, and a flat-shaped sealed container 1 is constructed. A fluorescent material 60 is applied to the inside faces of the front face plate 10 and the insulated board 20, and an electric discharge space 70 inside the sealed container 1 is filled with an electric discharge gas such as mercury gas or rare gas. The outside face of the front face plate 10 is formed into a diffusion layer 11 by frost machining and the like. In this way, unevenness of light emission, which is due to the unevenness in the application of the fluorescent material 60 or in electric discharge, and generation of a dark part or the shade due to influence of a rib or a supporting column 80 can be reduced, so that a display with good uniformity can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge device such as a flat discharge device which emits light in a plane, for example, a display device which requires a backlight such as a liquid crystal panel, for example, a television,
The present invention relates to a discharge device in an information video device such as a game machine or a car navigation system, an OA device such as a word processor, or a display system incorporating a light source, and a lighting device using the same.

[0002]

2. Description of the Related Art Liquid crystal panels are widely used as various types of information video displays such as personal computers and televisions because of their thinness, lightness and low power consumption. A backlight that supplies light from the back of the liquid crystal panel is required. The backlight generally used is mainly a combination of a small-diameter fluorescent lamp and an acrylic resin light guide, but a flat discharge lamp is also used.

FIG. 5 is a cross-sectional view of a conventional flat discharge device described in, for example, JP-A-9-115483. As shown in the figure, a translucent front plate 1 made of soda glass or the like.
0 and an insulating substrate 2 made of soda glass, ceramic, or the like
The flat plate 1 and the side plate 30 are hermetically sealed integrally with, for example, low-melting glass (not shown) to form a flat closed container 1.

A pair of parallel discharge electrodes 40 and 41 are provided on the inner surface of the front plate 10 serving as a light emitting surface, and the surfaces of the discharge electrodes 40 and 41 are covered with a dielectric layer 52. Further, a phosphor 60 is applied to the inner surface of the insulating substrate 21, and a mixed gas such as mercury and a starting gas such as argon or neon-argon, or xenon, krypton, A discharge gas made of a rare gas such as argon, helium, or neon is sealed.

In the flat discharge device of the present invention, a discharge is generated in the discharge space 70 by applying a high frequency voltage between the discharge electrodes 40 and 41, and the phosphor 60 is excited by ultraviolet rays generated by the discharge to emit light. Then, light is radiated outside through the front plate 10.

[0006]

As described above, the conventional flat-plate type discharge device excites and emits the phosphor with the ultraviolet rays generated by the discharge, and displays the display. And the brightness uniformity is deteriorated.

Further, there is an increasing demand for a backlight of a liquid crystal display device to be thinner and lighter. In order to make a discharge device thinner and lighter for a backlight, a glass plate constituting a container must be made thinner and lighter. It is necessary to reduce the thickness. However, when the glass plate is thinned, the closed container is usually in a reduced pressure state and may not be able to withstand the atmospheric pressure and may be damaged. For this reason, ribs and columns are reinforced by putting them inside the sealed container.However, the ribs and columns do not emit light, which results in dark shadows, resulting in poor uniformity of the display surface and difficulty in displaying the display. there were.

In order to improve the uniformity of the display surface, a diffusion sheet is used in a conventional liquid crystal display device or the like, but there is a problem that the cost is increased.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a discharge device having a simple structure and good luminance uniformity.

[0010]

In order to achieve the above object, according to the present invention, a flat airtight container is formed by combining a light-transmitting front plate and an insulating substrate, and an inner surface of the front plate is formed on the inner surface of the front plate. Is provided with a pair of discharge electrodes parallel to each other, the surface of the discharge electrodes is covered with a dielectric layer, and the inner surface of the front plate or the insulating substrate is coated with a phosphor, and the inside of the sealed container is discharged. In the discharge device filled with gas, one or both of the outer surface and the inner surface of the front plate are made to be diffusion surfaces by frost processing or the like.

Further, a white diffusion film is formed on one or both of the outer surface and the inner surface of the front plate.

In these cases, columns, spheres, ribs and the like are provided between the front plate and the insulating substrate.

[0013] Further, the lighting device is configured to illuminate using the above-described discharge device.

In the liquid crystal display device, the above-described discharge device is used as a backlight.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a sectional perspective view showing one embodiment of a flat discharge device according to the present invention. As shown in the figure, a light-transmitting front plate 10 made of, for example, soda glass or the like and a box-shaped insulating substrate 20 made of soda glass, ceramic, or the like are integrally hermetically sealed with, for example, low-melting glass (not shown). And
A flat closed container 1 is configured. A pair of parallel discharge electrodes 40 and 41 are provided on the inner surface of the front plate 10, and the surfaces of the discharge electrodes 40 and 41 are covered with dielectric layers 50 and 51 provided by a thick film printing method or the like. .

The outer surface of the front plate 10 has a diffusion surface 11 by, for example, frosting. A phosphor 60 is applied to the inner surfaces of the front plate 10 and the insulating substrate 20, and a discharge space 70 in the sealed container 1 is filled with a discharge gas of mercury or a rare gas. Further, between the front plate 10 and the insulating substrate 20, there are provided columnar columns 80 at appropriate intervals so that the sealed container 1 is not broken at atmospheric pressure, and the phosphor 60 is applied to the surface thereof. Have been.

As shown in FIG. 2, the driving method of the flat discharge device according to the present embodiment is, for example, as shown in FIG.
(A) A rectangular wave voltage V having a voltage of -Vh indicated by 45 in FIG.
2 and 46 are applied to the electrode 41, the rectangular wave voltage V2 having a phase shift of half a period from 45 as shown in FIG.
By using such a driving method, a discharge is generated in the discharge space 70, and the phosphor 60 is excited by the ultraviolet rays generated by the discharge to emit light, and the light is emitted to the outside through the front plate 10.

In the discharge device according to this embodiment, since the surface of the front plate 10 is formed as the diffusion surface 11, even if there is a partial non-uniform light emission on the light emitting surface, the light is diffused on the diffusion surface of the front plate and becomes uniform. It emits light and the luminance uniformity can be greatly improved. This eliminates the need for two diffusion sheets, such as a conventional light guide type backlight.

The diffusion surface 11 can be easily formed on the frost surface by, for example, sandblasting or chemical treatment. Further, the front plate 10 has a diffusion surface not only on the outer surface but also on the inner surface, so that the diffusion effect is further increased, and the luminance uniformity can be improved.

FIG. 3 is a sectional view showing another embodiment of the discharge device according to the present invention. In the discharge device according to the present embodiment, a white diffusion film, for example, a white low-melting glass film 90 is formed on the surface of the front plate 10 by a thick film printing method, a spraying method, a thin film method, or the like. A similar diffusion film 91 is formed between the layers 50 and 51, and the effect is the same as described above. The diffusion film 91 may cover the surfaces of the dielectric layers 50 and 51.

The diffusion film is made of Al ₂ O ₃ or SiO ₂ other than glass.
The powder may be formed by spraying with a spray or the like, or may be formed by a method such as printing or flowing coating. Also,
The diffusion layer 90 on the outer surface of the front plate may be formed by applying after the closed container 1 is assembled.

FIG. 4 is a cross-sectional view showing another embodiment of the discharge device according to the present invention, which is an example of a structure in which there is no support inside the discharge space 70. The structure of the discharge device according to the present embodiment is such that the outer surface of the front plate 10 is a diffusion surface 11 of frost processing, and the dielectric layer 52 covering the inner surfaces of the discharge electrodes 40 and 41 is made of white glass paste. It consists of printed and fired ones. This dielectric layer 52 also functions as a diffusion layer. The phosphor 60 is thinly applied on the surface of the dielectric layer 52.

The discharge device according to the present embodiment also has the same effect as described above, and can realize a backlight having excellent luminance uniformity.

As described in detail above, the discharge device according to the present invention can greatly improve the uniformity of light emission by forming the inner and outer surfaces of the front plate as a diffusion surface or forming a diffusion layer, and the luminance uniformity is good. Display becomes possible.

[0025]

According to the discharge device of the present invention, with a simple structure in which the surface of the front plate is made to be a diffusion surface, non-uniform light emission due to uneven coating of the phosphor at the time of manufacture of the discharge device or uneven discharge at the time of lighting. In addition, it is possible to reduce dark portions and shadows generated by the influence of the ribs and columns provided inside the closed container, and to provide an effect of displaying images with good uniformity. As a result, a backlight having excellent brightness uniformity can be obtained. Further, there is no need to attach a diffusion sheet or the like to the light emitting surface unlike the light guide type, so that there is also an effect that costs required for parts and assembly can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional perspective view of a discharge device according to an embodiment of the present invention.

FIG. 2 is a waveform diagram of a driving voltage of the discharge device of the present invention.

FIG. 3 is a sectional view showing another embodiment of the discharge device according to the present invention.

FIG. 4 is a sectional view showing another embodiment of the discharge device according to the present invention.

FIG. 5 is a sectional view showing a conventional discharge device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Closed container, 10 ... Front plate, 11 ... Diffusion layer, 20, 2
DESCRIPTION OF SYMBOLS 1 ... Insulating substrate, 30 ... Side plate, 40, 41 ... Discharge electrode, 4
5, 46: drive voltage waveform, 50, 51, 52: dielectric layer, 60: phosphor, 70: discharge space, 80: support, 9
0, 91: diffusion film.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Hiroharu Kiname 2-chome, Shinmachi 6-chome, Ome-shi, Tokyo 2 (72) Inventor Yasushi Ikuta 6-16, Shinmachi, Ome-shi, Tokyo Address 2 Ome Sangyo Co., Ltd.

Claims (5)

[Claims] A flat closed container is formed by combining a light-transmitting front plate and an insulating substrate, and at least one pair of discharge electrodes is provided on an inner surface of the front plate, and the surface of the discharge electrodes is covered. In a discharge device in which a dielectric layer was provided, a phosphor was applied to the inner surface of the sealed container, and a discharge gas was sealed therein, either one of the outer surface or inner surface of the front plate, or both surfaces were made diffusion surfaces. Discharge device characterized by the above-mentioned. 2. A discharge device wherein a white diffusion film is formed on one or both of an outer surface and an inner surface of the front plate. 3. The discharge device according to claim 1, wherein a reinforcing member made of a support, a rib, a sphere, or the like is provided between the front plate and the insulating substrate. 4. An illuminating device configured to illuminate using the discharge device according to claim 1. 5. A liquid crystal display device using the discharge device according to claim 1 as a backlight.