JP3622572B2 - Flat light source - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a flat-type light source that emits light in a planar shape, and more specifically uses a display element that requires a backlight such as a liquid crystal panel, for example, information video equipment such as a television, a game machine, a car navigation system, a word processor, etc. The present invention relates to a flat type light source suitable for use in a OA device or a display system incorporating a light source.
[0002]
[Prior art]
Liquid crystal panels are widely used as various information video displays such as personal computers and televisions because they are thin and light and consume low power. However, the liquid crystal itself is not a light emitting element, and a backlight for supplying light from the back surface of the liquid crystal panel is necessary for display. The backlight that is usually used is mainly a combination of a small fluorescent lamp and an acrylic light guide, but a flat discharge lamp is also used.
[0003]
FIG. 7 is a cross-sectional view of a conventional flat light source described in, for example, Japanese Patent Laid-Open No. 9-115483. As shown in the figure, a translucent front plate 2 made of soda glass, etc., an insulating substrate 14 made of soda glass or ceramic, and a side plate 15 are integrally hermetically sealed with, for example, low-melting glass (not shown). A flat airtight container 1 is constructed. A pair of discharge electrodes 4, 5 parallel to each other are provided on the inner surface of the front plate 2 serving as the light emitting surface, and the surfaces of the discharge electrodes 4, 5 are covered with a dielectric layer 7.
[0004]
A phosphor 8 is applied to the inner surface of the insulating substrate 14, and mercury and a mixed gas such as argon, neon, and argon as a starting gas, or xenon, krypton, and helium in the discharge space 9 in the hermetic vessel 1. A discharge gas composed of a rare gas such as neon is enclosed.
[0005]
The flat light source according to the present configuration generates a discharge in the discharge space 9 by applying a high-frequency voltage between the discharge electrodes 4 and 5, and excites the phosphor 8 by the ultraviolet rays generated by the discharge to emit light. Light emitted from the phosphor is radiated to the outside through the front plate 2. Reference numeral 16 denotes the direction of light emission.
[0006]
[Problems to be solved by the invention]
Devices that use a flat light source as a backlight in liquid crystal display devices are used in a wide range of fields such as digital still cameras and car navigation systems. When these devices are not in use, they are often covered with a case or the like for a long period of time and stored in a dark state, or used in a wide temperature range from a low temperature to a high temperature. For this reason, there have been problems such as a delay in lighting during use and poor startability at low temperatures.
[0007]
An object of the present invention is to solve the above-described problems, and is to provide a flat light source having a simple structure and improved lighting delay after being left in the dark and improved startability at low temperatures.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, in the present invention, a flat airtight container is formed by combining a translucent front plate serving as a light emitting surface and a back plate comprising a shallow dish container, and the inner surface of the front plate. A pair of parallel discharge electrodes that are discharge main electrodes to each other, and an auxiliary electrode is provided near one of the discharge electrodes, and the surface of the discharge electrode and the auxiliary electrode is covered with a dielectric layer, and the back plate frame portion An auxiliary electrode is formed between the front plate and the front plate.
[0009]
In addition, a discharge space is provided inside the back plate frame portion of the auxiliary electrode portion, and a protective film is formed on the surface of the dielectric layer covering the surfaces of the discharge main electrode and the auxiliary electrode . Before SL applying a different phosphor thicknesses on the back plate and the front plate, and plate type light source enclosing a discharge gas inside said airtight container.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are views showing an embodiment of a flat light source according to the present invention. FIG. 1 is a partial cross-sectional perspective view, and FIG. 2 is a cross-sectional view taken along line AA ′ of FIG.
[0011]
As shown in the figure, a translucent front plate 2 made of, for example, soda glass and a shallow dish-shaped back plate 3 made of soda glass, ceramics, or the like are integrally hermetically sealed with, for example, low-melting glass (not shown). A flat airtight container 1 is formed. A pair of substantially parallel discharge electrodes 4, 5 are provided inside the front plate 2, an auxiliary electrode 6 is provided in the vicinity of the discharge electrode 5, and the surfaces of the discharge electrodes 4, 5 and the auxiliary electrode 6 are thick. It is covered with a dielectric layer 7 provided by a film printing method or the like. A part of the auxiliary electrode 6 is exposed to the discharge space 9 via the dielectric layer 7.
[0012]
Phosphors 8 having different film thicknesses are applied to the inner surface of the front plate 2 and the inner surface of the rear plate 3, and the discharge space 9 in the hermetic vessel 1 is mixed with a rare gas such as argon or xenon or a mixture containing xenon. Gas is sealed.
[0013]
FIG. 3 is a sectional view of a structure in which the auxiliary electrode 6 is embedded in the frame portions of the front plate 2 and the back plate 3. FIG. 4 is a sectional view of a flat light source having a structure in which a discharge space 10 is provided in the vicinity of the auxiliary electrode 6 provided in the frame portion of the back plate 3. FIG. 5 shows an embodiment in which the surfaces of the discharge electrodes 4, 5 and the auxiliary electrode 6 are covered with a dielectric layer 7 and a protective film 11 such as magnesium oxide or aluminum oxide is formed on the surface of the dielectric layer 7.
[0014]
As shown in FIG. 6A, for example, the electrode 4 has a rectangular wave voltage V ₁ having a voltage of −V _h indicated by 12 as shown in FIG. As shown in FIG. 6B, 13 rectangular wave voltages V ₂ having a half-cycle phase shift from the voltage 12 are applied. By using such a driving method, a discharge is generated in the discharge space 9, the phosphor 8 is excited by the ultraviolet rays generated by the discharge and emits light, and the light is emitted outside through the front plate 2.
[0015]
Further, the auxiliary electrode 6 is connected to the discharge electrode 4 through a high resistance or capacitor (not shown) so as to be kept at the same potential, and the discharge electrode 5 is initially applied when a rectangular wave voltage is applied to the discharge electrodes 4 and 5. And the auxiliary electrode 6 generate a slight discharge. When normal discharge was performed between the discharge electrodes 4 and 5, the slight discharge between the discharge electrode 5 and the auxiliary electrode 6 was stopped.
[0016]
If various display elements that require a backlight, such as a liquid crystal panel, are configured using the flat light source of the above-described embodiment, for example, information video equipment such as televisions, game machines, car navigation systems, and display equipment such as word processors and personal computers. Can be used widely.
[0017]
【The invention's effect】
According to the flat plate type light source of the present invention, as described above, the auxiliary electrode is provided in the vicinity of one of the pair of parallel discharge electrodes provided on the front plate of the present invention and the discharge electrode , and the other electrode in which the auxiliary electrode is not adjacent. By making the discharge electrode and the auxiliary electrode have the same potential through a high resistance, a slight discharge is generated between the auxiliary electrode close to the electrode and the discharge electrode close to the electrode at the initial stage of voltage application. With the above configuration, it is possible to easily discharge even in a state where it is difficult to discharge such as in the dark. In addition, a dielectric layer is provided to cover the surfaces of the discharge electrode and the auxiliary electrode, and a protective film such as magnesium oxide or aluminum oxide is formed on the surface of the dielectric layer, thereby increasing the amount of initial electrons and improving the lighting performance. from that, there is also the starting voltage low Kude kill effect.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional perspective view of a flat light source according to an embodiment of the present invention.
2 is a cross-sectional view of the flat light source of FIG.
FIG. 3 is a cross-sectional view of a flat light source showing another embodiment of the present invention.
FIG. 4 is a sectional view of a flat light source showing another embodiment of the present invention.
FIG. 5 is a cross-sectional view of a flat light source showing another embodiment of the present invention.
FIG. 6 is a waveform diagram of a driving voltage of a flat light source in one embodiment of the present invention.
FIG. 7 is a cross-sectional view of a conventional flat light source.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Airtight container, 2 ... Front plate, 3 ... Back plate, 4, 5 ... Discharge electrode, 6 ... Auxiliary electrode, 7 ... Dielectric layer, 8 ... Phosphor, 9 ... Discharge space, 10 ... Discharge of auxiliary electrode part Space, 11 ... protective film, 14 ... insulating substrate, 15 ... side plate, 16 ... radiation direction of light.

Claims (2)

A light-transmitting front plate and a rear plate are positioned substantially parallel to form an airtight container having a flat discharge space, and a phosphor is applied to the inner surface of the front plate and the inner surface of the rear plate, A pair of discharge main electrodes are provided on the inner surface of the front plate and spaced apart from each other over a predetermined length, and an auxiliary electrode is provided on the inner surface of the front plate in proximity to one of the discharge main electrodes, and the pair of discharge main electrodes and It said covering the surface of the auxiliary electrode to the provision of the dielectric layer, and the flat plate type light source you characterized in that the formation of the auxiliary electrode between the frame portion and the front plate of the back plate. 2. The flat light source according to claim 1 , wherein a discharge space is provided in the back plate frame portion in the vicinity of the auxiliary electrode.

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