JP2000243351A - Fluorescent lamp - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a fluorescent lamp capable of reducing the amount of phosphor used and reducing the price of the fluorescent lamp. SOLUTION: An ultraviolet reflecting film 4 is applied to a part of an inner wall of a glass bulb 1, and a phosphor 3 is applied to a region where the ultraviolet reflecting film 4 is not applied, so that ultraviolet light generated in a tube of the glass bulb 1 is formed. UV A reflected A by the UV reflection film 4
And the phosphor layer 3 reaches the phosphor layer 3 to generate visible light.
Thus, the amount of the fluorescent material 3 can be reduced and the price of the fluorescent lamp can be reduced, while obtaining the same light flux as the lamp in which the fluorescent material is applied to the whole tube.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorescent lamp.

[0002]

2. Description of the Related Art Fluorescent lamps have become widespread for general home lighting and office lighting because of their improved efficiency. Generally, in a fluorescent lamp, visible light is generated from the phosphor by exciting the phosphor applied to the inner wall of the tube by ultraviolet rays generated and emitted by low-pressure mercury discharge in the tube.

[0003] In this fluorescent lamp, a wavelength of 450 nm (blue) and 540 n at which the human eye feels the color well and has a strong reaction.
A three-wavelength range fluorescent lamp that achieves high color rendering without losing brightness by concentrating light near three wavelengths of m (green) and 610 nm (red) is already known. Rare earth phosphors are used in three-wavelength emission fluorescent lamps.

[0004]

However, the rare earth phosphor used in this three-wavelength band fluorescent lamp is:
Since the cost is higher than calcium halophosphate used for a general white fluorescent lamp, a fluorescent lamp using the phosphor is also more expensive than a white fluorescent lamp.

The present invention solves the above-mentioned problems, and can reduce the amount of fluorescent material used in a fluorescent lamp using an expensive fluorescent material such as a three-wavelength-band fluorescent lamp. It is an object of the present invention to provide a fluorescent lamp capable of reducing the amount of light.

[0006]

In order to solve the above-mentioned problems, a fluorescent lamp according to the present invention is provided with an ultraviolet reflecting film in a part of an inner wall of a glass bulb and a phosphor film in another part. At the same time that the phosphor film is directly illuminated by the ultraviolet light generated inside, the ultraviolet light is further guided to the phosphor film by the ultraviolet reflection film to cause the phosphor film to emit light.

According to this configuration, the amount of the phosphor used can be reduced, and the price of the fluorescent lamp can be reduced.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A fluorescent lamp according to a first aspect of the present invention is provided with an ultraviolet reflecting film in a part of an inner wall of a glass bulb and a phosphor film in another part, and is generated inside the glass bulb. At the same time that the phosphor film is directly illuminated with ultraviolet light, the ultraviolet light is guided to the phosphor film by the ultraviolet reflection film to cause the phosphor film to emit light. Ultraviolet light generated by the low-pressure mercury discharge in the tube is interreflected by an ultraviolet reflecting film applied in the tube, reaches a phosphor film applied to a part of the tube, and is absorbed to generate visible light. Therefore, only by applying the phosphor film to a part of the inside of the tube, a luminous flux similar to that of a lamp in which the phosphor is applied to the whole tube can be obtained, and the amount of the phosphor applied can be reduced.

A fluorescent lamp according to a second aspect of the present invention is the fluorescent lamp according to the first aspect, wherein the inner wall of the glass bulb and the ultraviolet reflecting film and the phosphor film, or the inner wall of the glass bulb and the phosphor film. An auxiliary ultraviolet reflecting film that reflects ultraviolet light while transmitting radiation in at least the visible wavelength range is applied. According to this configuration, the ultraviolet light transmitted through the phosphor film is also reflected by the auxiliary ultraviolet reflecting film to form a glass. Since ultraviolet rays reaching the bulb can be reduced, it is possible to prevent the glass bulb from being discolored by ultraviolet rays.

A fluorescent lamp according to a third aspect of the present invention, in the structure according to the first or second aspect, has a configuration in which the cross-section perpendicular to the glass bulb axial direction has a location which is substantially half or less of the inner wall of the glass bulb. An ultraviolet reflective film is applied and arranged so that the ultraviolet reflective films do not face each other. According to this, ultraviolet light generated by discharge is repeatedly reflected between the ultraviolet reflective films and re-absorbed by the ultraviolet radiation source. Can be reduced.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a fluorescent lamp according to an embodiment of the present invention. As shown in FIG. 1, an auxiliary ultraviolet reflecting film 2 is applied to almost the entire inner wall of a glass bulb 1 of a fluorescent lamp. The auxiliary ultraviolet reflective film 2 is coated so that the reflectance of the ultraviolet A is about 20% while transmitting at least radiation in the visible wavelength range. It prevents the glass bulb 1 from discoloring through the membrane 3 and plays a role of a protective film.

An ultraviolet reflection film 4 is further applied on a part of the ultraviolet reflection auxiliary film 2. The layer of the ultraviolet reflection film 4 is applied with a thickness that makes the reflectance of the ultraviolet light A 80% or more. The phosphor layer 3 is applied to a region of the auxiliary ultraviolet reflecting film 2 where the ultraviolet reflecting film 4 is not applied. An electrode is attached to the glass bulb 1 coated with such a phosphor layer 3 and the ultraviolet reflection film 4, and a rare gas and mercury are sealed to constitute a low-pressure mercury lamp, that is, a fluorescent lamp according to the present embodiment. ing.

Here, as the auxiliary ultraviolet reflecting film 2 and the ultraviolet reflecting film 4, for example, aluminum oxide, silicon oxide, titanium oxide, yttrium oxide, barium sulfate and the like are used. B in FIG. 1 is discharge plasma. In this configuration, the ultraviolet light A generated by the low-pressure mercury discharge in the glass bulb 1 tube is interreflected by the ultraviolet reflection film 4 applied in the tube, and is absorbed when it reaches the phosphor layer 3 to absorb visible light. appear. As shown in FIG.
In a conventional fluorescent lamp in which a phosphor layer is coated on the entire surface, if a 2/3 region in the tube cross section is an ultraviolet reflection film 4 and the remaining 1/3 region is a phosphor layer 3, Is substantially the same as the total amount of ultraviolet rays reaching the phosphor layer 3 in the fluorescent lamp in which the phosphor layer 3 is applied only to one third of the inner wall of the tube as in this embodiment. In addition, in the fluorescent lamp of the present invention, since the coating area of the phosphor layer 3 is 1/3, the luminance of the fluorescent lamp of the present invention due to the phosphor layer 3 is about three times that of the conventional fluorescent lamp, and the entire tube is covered. The amount of phosphor used can be reduced to 1/3 while obtaining a luminous flux equivalent to that of a conventional fluorescent lamp coated with a phosphor layer, so that the amount of phosphor used can be reduced and the product price can be reduced.

Further, according to this structure, since the phosphor layer 3 is provided on a part of the inner wall of the tube, the light distribution of the fluorescent lamp is specified in a cross section of the tube axis as in a conventional reflector type fluorescent lamp. Although there is a bias in the direction, this characteristic can be utilized to improve the illuminance directly below the lamp by itself without using the reflector of the lighting fixture. In the cross section of the ultraviolet reflection film 4 and the phosphor layer 3 perpendicular to the tube axis, the area to be applied to the inner wall of the glass bulb 1 is 1/3 and 2/3 in the above embodiment. However, the present invention is not limited to this. Then, as described above, the ultraviolet reflection film 4 and the phosphor layer 3
When the ratio of the area to be applied to the inner wall of the glass bulb 1 in the cross section perpendicular to the tube axis is set to ず つ, the ultraviolet reflecting films 4 do not face each other, so that the ultraviolet rays A generated by the discharge are reflected by the ultraviolet rays. The feature is that repetitive reflection between the films 4 is suppressed, and the loss of re-absorption of the ultraviolet rays A due to discharge can be reduced.

Further, as in a compact fluorescent lamp as shown in FIGS. 2A and 2B, a lamp having a bridge structure or a fluorescent lamp having a structure in which a glass bulb 1 as an arc tube 5 is bent. When the present invention is embodied, the arc tube 5
If a structure is adopted in which the UV-reflective film 4 is located at a position where self-absorption occurs due to the approach of each other and the formation of shades,
The luminous flux of the fluorescent lamp can be more effectively improved.

[0016]

As described above, according to the present invention, an ultraviolet reflecting film is provided in a part of the inner wall of the glass bulb, and a phosphor film is provided in another area, and the ultraviolet light generated inside the glass bulb is used directly. Simultaneously with the phosphor film emitting light, the ultraviolet light is guided to the phosphor film by the ultraviolet reflection film to cause the phosphor film to emit light. While the same luminous flux is obtained, the amount of phosphor used can be reduced, and the price of the fluorescent lamp can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a fluorescent lamp according to an embodiment of the present invention.

FIGS. 2 (a) and 2 (b) are a perspective view and a plan cross-sectional view showing a case where the fluorescent lamp is applied to a compact fluorescent lamp.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Glass bulb 2 Auxiliary ultraviolet reflective film 3 Phosphor layer (fluorescent film) 4 Ultraviolet reflective film A Ultraviolet

Claims (3)

[Claims] An ultraviolet reflective film is provided in a partial area of an inner wall of a glass bulb, and a phosphor film is provided in another area. The phosphor film is directly illuminated by ultraviolet rays generated inside the glass bulb. Further, the fluorescent lamp is characterized in that the ultraviolet light is guided to the phosphor film by the ultraviolet reflection film so that the phosphor film emits light. 2. The structure according to claim 1, wherein at least radiation in the visible wavelength range is transmitted between the inner wall of the glass bulb and the ultraviolet reflective film and the phosphor film, or between the inner wall of the glass bulb and the phosphor film. A fluorescent lamp characterized in that an auxiliary ultraviolet reflecting film that reflects ultraviolet light is applied while applying the light. 3. The structure according to claim 1, wherein an ultraviolet reflecting film is applied to a portion which is substantially half or less of the inner wall of the glass bulb in a cross section perpendicular to the axis of the glass bulb and reflects ultraviolet light. A fluorescent lamp, wherein the films are arranged so as not to face each other.