JPH0950783A - Flat-panel fluorescent tube and lighting method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lower the power consumption by dividing a discharge tube to plural parallel long and narrow discharge areas, and connecting one of electrodes provided in this area to an input power source, and grounding the other electrode through an electron switch, and forming an earth electrode opposite to the other electrode through a window near the other electrode. SOLUTION: A discharge space 10 is divided to plural parallel long and narrow spaces by partitioning plates 15, and electrodes 21, 22 are provided in both ends of these space, and the electrode 21 is connected to an input power source, and the electrode 22 is grounded through an electron switch 30, and the electrodes 22 are scanned in order so that the divided spaces adjacent to each other discharge phosphor in order. This discharge is easily performed by an earth electrode opposite to the electrode 21 through a window near the electrode 21. With this structure for supplying the power of the power source to the only one divided space in order, a flat surface type fluorescent tube, which can evenly emit the light with a small power consumption, can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat fluorescent tube suitable for use as a backlight of a liquid crystal display device or the like, and more particularly to a flat fluorescent tube having a plurality of parallel discharge paths. is there.

[0002]

2. Description of the Related Art Among liquid crystal display devices used for personal computers, liquid crystal televisions, viewfinders of video cameras, and the like, a transmissive liquid crystal display device requires a backlight to illuminate from the back surface of a liquid crystal panel.

This backlight needs to illuminate the entire surface of the liquid crystal panel, and is required to have a uniform brightness as a whole. In a general backlight, the irradiation light is guided to the back surface by a light guide plate from a thin fluorescent tube placed on the end face of the liquid crystal panel, and is reflected to the liquid crystal panel side by a reflection plate.

On the other hand, a flat-emission type backlight that emits light over the entire back surface of the liquid crystal panel has been considered. This is a technique in which a phosphor is applied to the inner surfaces of two glass plates, a rare gas is sealed therein, and discharge is caused by an electrode arranged in the space to emit light. Also, as one of the structures, there is a structure in which the discharge space is divided into U-shape and W-shape to form a long and narrow discharge path, and electrodes are arranged at both ends to discharge and emit light.

[0005]

In the light guide plate method, conversion efficiency is low due to loss and reflection at the introduction portion, and it is difficult to obtain uniform light emission. With a flat tube, the luminous efficiency is low and sufficient brightness cannot be obtained. In addition, the meandering structure has a large loss in the bent portion and consumes more power than a straight pipe.

The present invention provides a flat fluorescent tube and a method of lighting the same, which enables substantial surface emission with low power consumption.

[0007]

According to the present invention, in a flat type fluorescent tube having a structure in which straight tube type fluorescent tubes are arranged in parallel, each straight tube type fluorescent tube is switched by a switch and sequentially discharged and lit. This is to solve the above problems.

That is, in a flat fluorescent tube in which a rare gas is enclosed in a space composed of a transparent front plate having a phosphor coated on its inner surface, a back plate and a frame holding a space between them, and electrodes are arranged, The space is divided into a plurality of parallel elongated space parts by partition plates, electrodes are arranged at both ends of these parts, one end is connected to an input power source, the other end is connected to an electronic switch means, and a back plate It is characterized in that an electrode connected to the ground potential is provided at a position facing the electrode connected to the input power source on the surface.

Further, a method for lighting a flat fluorescent tube in which a rare gas is enclosed in a space composed of a transparent front plate having a phosphor coated on its inner surface, a back plate and a frame holding a space therebetween and electrodes are arranged. In the above, the space is divided into a plurality of parallel elongated space portions by partition plates, electrodes are arranged at both ends of these portions, one end is connected to an input power source, and the other end is connected to an electronic switch means. It is characterized in that an electrode connected to the ground potential is formed at a position facing the electrode connected to the input power source on the surface of the back plate, and the electronic switch means sequentially turns on the elongated space.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A plurality of parallel spaces each form a discharge space, and when a switch is closed, a discharge is generated, which causes a phosphor to emit light. If the switch of the circuit configuration using a transistor is switched at 100Hz or more and sequentially energized to emit light, the flicker disappears to the human eye, and the state is equivalent to that the entire surface emits light uniformly.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an explanatory view showing an embodiment of the present invention.
(A) is a plan view and (b) is a front view. The fluorescent tube 10 is
Glass or ceramic frame 11, 12 and surface plate
A discharge space is formed by the back plate 14 and the back plate 14. In the flat fluorescent tube according to the present invention, a partition plate 15 is arranged in parallel inside and the discharge space is divided into a plurality of elongated spaces.

Electrodes 21 are provided at both ends of each elongated space.
22 is arranged, the electrode 21 is connected to the input power source, that is, the high voltage side, and the electrode 22 is connected to the low voltage, that is, the ground side. An electronic switch 30 is connected between the electrode 22 and ground. The electronic switch 30 can be formed by a normal switch circuit that sequentially switches a plurality of transistors.

Frames 11 and 12, partition plate 15 and surface plate 13,
A phosphor is applied to the inner wall surface of the back plate 14 in advance.
Further, a rare gas such as argon is sealed in the discharge space. Although not shown, a mercury getter may be placed in the discharge space together with the electrodes.

A window 16 is formed on the electrode 21 side of the partition plate 15, that is, on the high-voltage electrode side, and is connected to an adjacent discharge space. By providing this window, when the switch is changed, the discharge in the adjacent discharge space is affected and the discharge easily occurs. Also, the electrode 21 connected to the input power source
An electrode 23 connected to the ground potential is formed on the surface of the back plate 14 at a position facing to. Discharge is generated between the electrode 21 connected to the input power source and the ground electrode 23, and the impedance of the discharge path between the electrode 21 and the electrode 22 is smaller than the impedance between the electrodes via the rear plate plate 14. When this happens, a discharge occurs in the discharge path, causing the phosphor to emit light.

By turning on / off the electronic switch 30, a discharge is generated in the connected discharge space, and the phosphor emits light. If the adjacent discharge spaces are made to emit light sequentially by the switching scan of the switch, the state is almost the same as the case where the whole is emitting light uniformly. To do this, switch the switch at a frequency of 100Hz or higher. The upper limit is limited by the rising characteristics of the discharge part, but 500
It is possible up to about Hz.

[0017]

According to the present invention, since the straight fluorescent tubes are sequentially turned on, the power consumption for one straight tube can be completed, and the flat fluorescent tube can be reduced in power consumption.

It is easy to obtain uniformity of light emission, and since the switch is connected to the low voltage side, the circuit configuration of the switch circuit can be simplified.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of the present invention, in which (a) is a plan view and (b) is a front view.

[Explanation of symbols]

 11, 12: Frame 13: Front plate 14: Back plate 21, 22: Electrode 23: (Earth) electrode 30: Electronic switch

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsuyoshi Takano 828 Hinohara, Tamagawa, Hamahara, Hiki-gun, Saitama Prefecture Toko Co., Ltd. Tamagawa factory

Claims (5)

[Claims] 1. A flat fluorescent tube in which a rare gas is sealed in a space formed of a transparent front plate having a fluorescent material coated on its inner surface, a rear plate and a frame holding a space therebetween, and electrodes are arranged, The space is divided into a plurality of parallel elongated space portions by partition plates, electrodes are arranged at both ends of these portions, one end is connected to an input power source, the other end is connected to an electronic switch means, and a back plate A flat-type fluorescent tube having an electrode connected to a ground potential at a position facing an electrode connected to an input power source on the surface. 2. A method of lighting a flat fluorescent tube in which a rare gas is enclosed and an electrode is arranged in a space composed of a transparent front plate having a phosphor coated on its inner surface, a back plate and a frame holding a space between them. In the above, the space is divided into a plurality of parallel elongated space portions by partition plates, electrodes are arranged at both ends of these portions, one end is connected to an input power source, and the other end is connected to an electronic switch means. Lighting a flat fluorescent tube characterized in that an electrode connected to the ground potential is formed at a position facing the electrode connected to the input power source on the surface of the back plate, and the elongated space is sequentially turned on by the electronic switch means. Method. 3. A flat fluorescent tube in which a rare gas is enclosed and an electrode is arranged in a space composed of a transparent front plate having a phosphor coated on its inner surface, a back plate and a frame holding a space between them. The space is divided into a plurality of parallel elongated space parts by partition plates, electrodes are arranged at both ends of these parts, one end is connected to an input power source, the other end is connected to an electronic switch means, and the back plate surface A flat fluorescent tube characterized in that it has an electrode connected to the ground potential at a position facing the electrode connected to the input power source, and a window connecting the space to the partition plate between the electrodes on the input power source side. 4. A method of lighting a flat fluorescent tube in which a rare gas is enclosed in a space formed by a transparent front plate having a phosphor coated on its inner surface, a back plate and a frame holding a space between them, and electrodes are arranged. In the above, the space is divided into a plurality of parallel elongated space parts by partition plates, electrodes are arranged at both ends of these parts, one end is connected to an input power source, the other end is connected to an electronic switch means, and An electrode connected to the ground potential is formed at a position facing the electrode connected to the input power source on the plate surface, a window for connecting a space is formed in the partition plate between the electrodes on the input power source side, and electronic switching means are sequentially arranged. A method for lighting a flat fluorescent tube, characterized in that the elongated spaces are sequentially discharged to light when closed. 5. The flat fluorescent tube according to claim 1, wherein the mercury getter is housed in the elongated space together with the electrode.