JPS6077344A - Fluorescent lamp - Google Patents

Abstract

PURPOSE:To move the discharge path inside a fluorescent lamp so as to achieve uniform emission over the entire lamp by switching applied voltage to multiple electrode pairs installed facing each other. CONSTITUTION:When a high frequency voltage is applied to a pair of electrodes 1 and 2 facing each other, mercuric electric discharge develops between the electrodes. The inner wall of a bulb 3 is coated with a phosphor which by being excited with ultraviolet rays produced by mercuric electric discharge emits color. The emission path is shifted by switching the electrode to which voltage is applied. A visualy uniform emission is achieved over the entire lamp by performing the switching at high speed. This fluorescent lamp can be used for general lighting, interior lighting, the light source part of a transmission-type liquid crystal display or the light source of an electric sign.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a fluorescent lamp that can emit uniform light and obtain a uniform brightness surface, and is used as a light source for general lighting, interior lighting, and transmissive liquid crystal displays. It can be used as a light source for illuminated signboards. Until now, light sources for illuminated signboards and light-emitting liquid crystal displays have been made by arranging multiple fluorescent rungs such as straight tubes or reflex type fluorescent lamps to create a surface-emitting source. However, a diffuser plate was installed at a certain distance from the light emission. However, due to the transmission loss of the diffuser plate and the distance from the light source, a decrease in the amount of light coming out to the front was unavoidable. Furthermore, the above-mentioned system has the disadvantage that the structure is complicated and the light source section is large.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a more compact and efficient light source that overcomes the above-mentioned drawbacks.

Structure of the Invention The present invention consists of a transparent sealed container whose inner surface is coated with a phosphor, a mercury discharge space formed inside the container, and a plurality of opposing electrodes for sequentially moving the discharge path. The aim is to achieve uniform light emission by moving the discharge path.

DESCRIPTION OF EMBODIMENTS As an embodiment of the present invention, a flat fluorescent lamp for a liquid crystal display will be described with reference to the drawings. A liquid crystal display creates a back surface by partially changing the transmittance of the liquid crystal surface in response to an image signal. Therefore, a light source that is flat and has a uniform luminance distribution is required. FIG. 1 shows the appearance of a flat fluorescent lamp which is an example of the present invention.

Reference numeral 1.2 denotes electrodes placed to face each other, and when a high frequency voltage is sequentially applied to this pair of electrodes, a mercury discharge occurs between the electrodes. The inner surface of the bulb 3 is coated with a phosphor, which is excited by the ultraviolet rays generated by the mercury discharge and emits light.

This light emission is moved by sequentially switching the potential to which the voltage is applied, and by performing this switching at high speed, the entire lamp emits light visually uniformly. FIG. 2 shows a cross section of the lamp. In the figure, 1 and 2 are the electrodes,
3 is the Mi bulb, and 4 is a phosphor. Further, 5 is an aluminum vapor-deposited surface for reflecting light emitted from the back surface to the front surface.

Effects of the Invention As described above, the present invention has a plurality of electrodes arranged to face each other, and by moving a discharge path inside, a uniform luminance distribution can be obtained, and it can be used as a light source for a liquid crystal display or as an electric lamp. It has the advantage of providing a thinner, smaller, and more efficient light source than a light source that has a uniform brightness distribution by arranging conventional lamps and using a diffuser plate and an optical system, such as on billboards.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a fluorescent lamp according to an embodiment of the present invention, and FIG. 2 is a sectional side view of the same lamp. 1.2... Electrode, 3... Bulb, 4 - Fluorescent material, 5- - Aluminum vapor deposited surface.

Claims (1)

[Claims] A fluorescent lamp is characterized in that a plurality of electrodes are provided facing each other, and by sequentially switching the voltage applied to the electrodes, a discharge path is moved within the lamp, and the entire lamp emits light uniformly.