JPH02197096A - Electrodeless multiple lamp light source apparatus - Google Patents

Abstract

PURPOSE:To uniformize the emission of lamplight by parallel-dividing the output of a high-frequency generator circuit via a distributor for supplying each of the divided outputs to the induction coil of each lamp and also providing a matching circuit near the coil. CONSTITUTION:An electrodeless discharge lamp 1 is divided into plural lamps such as 1a, 1b and 1c, with each of induction coils 3 arranged along the periphery of each of discharge vessels 2. The output of a high-frequency generator circuit 4 is parallel-divided into plural outputs by a distributor 5 for being supplied to the coils 3 respectively. Each of matching circuits 6 arranged near each of the coils 3 between the distributor 5 and the coils 3 adjusts difference in impedance between the high-frequency generator circuit 4 and the lamp 1. Since the discharge lamp is thus divided into plural pieces, each of the discharging spaces thereof becomes smaller, thereby permitting to uniformize the emission of lamplight. Moreover, electric power supplied to each of the lamps can be stabilized by each of the matching circuits. And the use of the electrodeless discharge lamp also enables a high output to be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrodeless multi-lamp light source device used, for example, as a backlight for a liquid crystal display device or the like, or for general illumination.

BACKGROUND OF THE INVENTION In recent years, there has been an increasing demand for a light source device that emits light uniformly in a plane for use as a backlight light source for liquid crystal displays or as a base light for general lighting.

Conventionally, this type of light source device has been constructed by arranging a large number of straight tube fluorescent lamps, or by arranging the fluorescent lamps on the end face of a light-transmitting diffuser plate and using the flat surface of the diffuser plate as the light emitting surface. things are well known. However, since conventional fluorescent lamps have a pair of filament electrodes at both ends of the tube, the light emission uniformity in the longitudinal direction of the lamp is poor, and the emitter material applied to the filament during continuous lighting is absorbed into the tube near both ends of the lamp. It has the disadvantage that it easily adheres to walls and causes blackening, and because it has a filament, the input current is limited and the amount of light is insufficient.

[Problems to be Solved by the Invention] The present invention has been made in view of the above-mentioned drawbacks, and its purpose is to provide an electrodeless multi-lamp light source device that has high light emission uniformity and can provide a sufficient amount of light. It is in.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides an electrodeless multi-lamp light source device including a plurality of electrodeless discharge lamps in which induction coils are arranged along the outer periphery of a discharge vessel; a high-frequency generating circuit that generates a high-frequency current; a distributor that divides the output of the high-frequency generating circuit in parallel into a plurality of parts and supplies the high-frequency current to the induction coil; The lamp is characterized by comprising a matching circuit disposed near the high frequency generating circuit and the lamp to adjust an impedance difference occurring between the lamp.

[Example 1] Figure 1 shows an example of the present invention, and in the figure,
Reference numeral 1 denotes an electrodeless discharge lamp composed of a discharge vessel 2 and an induction coil 3. The discharge vessel 2 is airtightly formed of a translucent material, and a discharge body is sealed inside it. The inner surface is coated with phosphor. The induction coil 3 is arranged along the outer periphery of the discharge vessel 1. 4 is a high frequency generating circuit that generates a high frequency current; 5 is a distributor that divides the output of the high frequency generating circuit 4 into a plurality of parallel parts and supplies the high frequency current to the induction coil 3; 6 is a circuit between the high frequency generating circuit 4 and the lamp 1; This is a matching circuit that adjusts the impedance difference that occurs, and is composed of a variable capacitor or variable inductor.
and the induction coil 3 and near the induction coil 3. In addition, between the high frequency generation circuit 4 and the distributor 5, and between the distributor 5 and the matching port Ia! r6 are connected to each other by high frequency transmission lines 7.

In the electrodeless multiple light source device configured in this way,
Since the electrodeless discharge lamp l is divided into a plurality of parts, the discharge space for one lamp can be small. Therefore, there is no problem that the plasma in the discharge vessel 2 becomes irregular and does not emit uniform light, and since the matching circuit 6 is provided in the vicinity of each lamp 1, for example, the adjacent lamps 1a in FIG. The distance from the high-frequency generation circuit 4 and the lamp 1b are different, and the distance of the transmission line through which the high-frequency current flows is also limited, and the difference in impedance caused by the difference in inductance and resistance of the transmission line is Can be adjusted with a variable capacitor or variable inductor,
The electric power supplied to each of the lamps 1alb and lc is also stabilized and there is no variation, and a light source device with high luminous uniformity can be obtained. Moreover, since it is an electrodeless discharge lamp 1, naturally a high light output can be obtained.

FIG. 2 shows a different embodiment of the present invention, which differs from the previous embodiment in that a light-transmitting diffuser plate 8 is provided between each of the plurality of lamps la, 1b, and lc. The other configurations are the same as those of the previous embodiment except that the flat plate surface is used as an indirect light emitting surface.

With this configuration, mutual interference of high-frequency electromagnetic fields between the lamps will not occur even when the lamp spacing becomes narrow due to equipment design or when high-frequency current is applied to increase the amount of light.
A flat plate light source with stable electrical characteristics can be obtained.

FIG. 3 shows still another embodiment of the present invention, in which the discharge vessel 2 constituting the lamp 1 has two straight tube sections parallel to each other, and both tube sections communicate near their respective ends. , so that a circulating discharge path is formed.

Further, the induction coil 3 is arranged along the circular discharge path of the discharge vessel 2. Note that the other configurations are the same as those of the first embodiment, so the description will be omitted by assigning the same reference numerals to the equivalent configurations.

According to this embodiment, compared to light source devices using conventional straight tube fluorescent lamps, the use of an electrodeless discharge lamp has features such as high output and long life, as well as uniformity from one end to the other in the longitudinal direction. It has the feature of shining brightly. Furthermore, lamp 1
By configuring the shape of the discharge path so that it circulates around the discharge path, the uniformity is also improved due to the stabilization of the plasma.

In addition, according to the above-mentioned embodiment, the aim is to emit light uniformly over the entire surface, but in contrast, when it is used in such a manner that only the vicinity of both ends is bright and the central part is dark, the variable capacitor etc. of the above-mentioned matching circuit 6 may be adjusted. It also has the advantage of being able to control light distribution.

Further, the lamp shape in the third embodiment may be in the shape of two discharge vessels as in the first embodiment, or may be configured such that a plurality of coils are arranged in one elongated discharge vessel. .

Furthermore, the lamp 1 of each of the above embodiments may be a so-called aperture type fluorescent lamp in which a portion of the inner surface of the discharge vessel 2 is not coated with a fluorescent material.

[Effects of the Invention] As described above, the present invention divides the output of one high frequency generation circuit into a plurality of parts in parallel via a distributor, and supplies the divided parts to at least two or more induction coils of electrodeless discharge lamps.
By installing a matching circuit near the induction coil to adjust the impedance difference that occurs between the high-frequency generator circuit and the lamp, the electrical characteristics and light output of each lamp are made uniform, making this an electrodeless multi-lamp light source device that emits light uniformly as a whole. can be provided.

[Brief explanation of the drawing]

FIG. 1 is a simplified diagram showing a first embodiment of the invention, FIG. 2 is a simplified sectional view showing a second embodiment of the invention, and FIG. 3 is a simplified diagram showing a third embodiment of the invention. It is a diagram. 1... Electrodeless discharge lamp, 2... Discharge vessel, 3...
- Induction coil, 4... High frequency generation circuit, 5... Distributor, 6... Matching circuit. Figure 111

Claims (1)

[Claims] (1) A plurality of electrodeless discharge lamps each having an induction coil arranged along the outer periphery of a discharge vessel, a high frequency generation circuit that generates a high frequency current, and an output of the high frequency generation circuit that is divided in parallel into a plurality of parts. a distributor that supplies high-frequency current to an induction coil; and a matching circuit that is arranged between the distributor and the induction coil and near the induction coil and adjusts an impedance difference that occurs between the high-frequency generation circuit and the lamp. An electrodeless multi-lamp light source device consisting of.