JPS63108605A - Electrode-free discharge lamp apparatus - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Technical Field] The present invention applies a high-frequency electromagnetic field to a translucent bulb filled with metal vapor and inert gas, thereby discharging the gas inside the bulb and This invention relates to a so-called electrodeless discharge lamp device that converts emitted light or generated ultraviolet light into visible light using a phosphor coated on the inner wall of the bulb.

[Background Art] Generally widely used incandescent light bulbs have drawbacks such as low efficiency and short lifespan. An electrodeless discharge lamp is one of the lamps that eliminates such drawbacks and can replace the incandescent light bulb, which is a small light source.

Electrodeless discharge lamps do not require a filament, have a long life, and have the same efficiency as regular fluorescent lamps, so they are currently being researched and developed in various places. An example of such a conventional electrodeless discharge lamp is shown in FIG. In the figure, 1 is a so-called electrodeless fluorescent lamp, which is filled with metal vapor such as mercury vapor and inert gas such as argon, and whose inner wall surface is coated with a fluorescent material. . 2 is a high frequency oscillation circuit, 3 is an oscillation coil, and 4 is a power supply. The high frequency oscillation circuit 2 is generally a lamp circuit as shown in FIG.

In the electrodeless discharge lamp configured in this way, the metal vapor in the pump 1 is excited by applying a high frequency voltage output from the high frequency oscillation circuit 2 to the lamp 1 via the oscillation coil 3. The emitted ultraviolet rays are converted into visible light by the fluorescent material on the inner wall of the lamp 1 and emitted. Since such an electrodeless discharge lamp does not have an electrode inside the lamp 1, it has the advantage that there is no life expectancy due to filament breakage or blackening of the tube end, and the lamp life is very long.

However, in such an electrodeless discharge lamp, light is emitted over the entire length of the lamp in the lamp longitudinal direction (A-B line direction in FIG. 6), so the light emission length is long, but the illuminance at the end of the tube is as shown in FIG. As is clear from the longitudinal illuminance distribution shown, the illuminance is significantly lower than at the center of the lamp. Therefore, for example, when an electrodeless discharge lamp is applied to a light source that requires uniform light emission in the longitudinal direction, such as a copying machine exposure light source, the actual effective luminous length of the lamp is The length of the lamp is short compared to the total length, and it has been difficult to realize the requirement of increasing the effective light emitting length, in other words, the requirement of a lamp that emits light uniformly over the entire length of the lamp.

[Object of the Invention] The present invention has been made in view of the above problems, and its purpose is to provide an electrodeless discharge lamp device that emits light uniformly over the entire length of the lamp by improving the illuminance distribution in the longitudinal direction of the lamp. is to provide.

[Disclosure of the Invention] The present invention will be described below based on examples. FIG. 1 shows an embodiment of the present invention, in which an oscillation coil 3 disposed in an electrodeless discharge lamp 1 includes a main oscillation coil 3a wound around the entire length of the lamp, and a main oscillation coil 3a wound around the entire length of the lamp. Auxiliary oscillation coils 3b are wound around each end. Note that 2 is a high frequency oscillation circuit similar to the above-mentioned high frequency oscillation circuit, and 4
is the power source.

In this way, the main oscillation coil 3a that causes the entire length of the lamp to emit light
In addition, an auxiliary oscillation coil 3b is installed to compensate for the decrease in illuminance near both ends.
By arranging these near both ends of the lamp 10, the illuminance distribution in the longitudinal direction of the lamp becomes as shown in Figure 2, the light emission uniformity can be greatly improved, and the effective light emission length with respect to the lamp length becomes longer. It has a particularly great effect when used as a light source for exposure. In addition, in Fig. 2, characteristic A
Characteristic B shows the case where only the main oscillation coil 3a is used, characteristic C shows the case where only the auxiliary oscillation coil 3b is used, and characteristic C shows the case where the main oscillation coil 3a and the auxiliary oscillation coil 3b are used.

In this embodiment, three oscillation coils 3a, 3b, 3b are connected in parallel from one oscillation circuit 2, but the invention is not limited to this, and as shown in FIG.
If the three oscillation circuits 2a, 2b, 2b are connected in parallel to the oscillation coils 3a, 3b, 3b in series, it is easier to control the dimming, light distribution, etc. for each one circuit. There are also some advantages.

Next, FIG. 4 shows a different embodiment of the present invention, in which the main oscillation coil 3a is not wound over the entire lamp area as in the previous embodiment, but wound in the longitudinal direction near the center of the lamp 1. At the same time, the main oscillation coil 3a and the auxiliary oscillation coil 3b
, 3b are in a positional relationship such that they face each other through an aperture portion 5 having a certain opening angle, and the auxiliary oscillation coils 3b, 3b are located near both ends of the main oscillation coil 3a, respectively.
The lamps are arranged so as to overlap with each other via the lamp 1, and light is emitted from the aperture section 5. In addition,
The cross section of the lamp 1 is as shown in FIG. 5, where 6 is a glass bulb, 7 is a reflective film, 8 is a phosphor, 3a is the main oscillation coil, and 3b is an auxiliary oscillation coil.

By configuring in this way, each oscillation coil 3a can achieve the same effect as the embodiment described above.

3b, 3b can be made smaller, and each oscillation circuit 2a,
The outputs of 2b and 2b can also be made smaller, which is advantageous in terms of circuit design, component breakdown voltage, cost, etc. Furthermore, since the light is emitted from the aperture portion 5, there is no vignetting of the light caused by the oscillation coil 3, and uniform, high-intensity light emission can be obtained.

[Effects of the Invention] As described above, the present invention provides an electrodeless discharge lamp in which a high-frequency voltage is applied to an oscillation coil wound around the outside of the lamp bulb to discharge the discharge gas sealed inside the bulb and cause it to emit light. In the device, the oscillation coil is divided into a main oscillation coil and an auxiliary oscillation coil, and the main oscillation coil is arranged so that it overlaps with the auxiliary oscillation coil in a part of the pulp, so that light emission in the longitudinal direction of the lamp is achieved. An electrodeless discharge lamp device with good uniformity could be provided. Therefore, when the electrodeless discharge lamp according to the present invention is used, for example, as a light source for document reading or exposure in a copying machine, etc., the required lamp length is shortened, and the equipment housing the lamp can be downsized. Also,
By individually controlling each oscillation coil, it is possible to intensify the light emission at the center of the lamp, or conversely, to intensify the light emission at the ends of the lamp.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing one embodiment of the present invention, Fig. 2 is an illuminance distribution diagram according to the present invention, Fig. 3 is a block diagram showing a different embodiment of the present invention, and Fig. 4 is a block diagram showing a further embodiment of the present invention. A configuration diagram showing a different embodiment, FIG. 5 is a sectional view of the main part of the embodiment shown in FIG. 4,
FIG. 6 is a configuration diagram of a conventional example, FIG. 7 is a circuit diagram showing an example of a high frequency oscillation circuit, and FIG. 8 is an illuminance distribution diagram according to the conventional example.

Claims (1)

[Claims] (1) In an electrodeless discharge lamp device that discharges discharge gas sealed in the bulb and causes it to emit light by applying a high frequency voltage to an oscillation coil wound around the outside of the lamp bulb, the oscillation coil is used as the main oscillation coil. 1. An electrodeless discharge lamp device comprising a main oscillation coil and an auxiliary oscillation coil, the main oscillation coil being arranged so as to overlap the auxiliary oscillation coil in a part of the bulb.