JPH0381907A - Illuminating fixture for round form fluorescent lamp - Google Patents

Abstract

PURPOSE:To lessen unevenness in the lightness of a light penetrative cover and also construct it thin by arranging a photo-leading plate, which leads the incident beam of light from the external end face to the center, in a position inside of a round form fluorescent lamp, and furnishing a diffusion part for random reflection of the incident light at the oversurface of this photo-leading plate. CONSTITUTION:At the body 1 of a lighting fixture a mounting table is installed, and thereon a photo-leading plate 14 formed from clear acrylic resin in a dia. a little smaller than the inner dia. of a round form fluorescent lamp 7 is mounted in such an arrangement that the external end face of the plate 14 is mating in proximity with the inner side of the fluorescent lamp 7. This photo-leading plate 14 is formed circularly, and on its oversurface formed in a plane, a diffusion part 14a is formed by silk printing in such a concentrical striation that the spacing of stripes is narrower as approaching the center and that the width becomes wider toward the center. The beam of light emitted from the fluorescent lamp 7 and incident to the photo-leading plate 14 repeats all-reflection within the plate and is introduced to its center, during which the light is random reflected at the diffusion part 14a and major part are cast downward. As this diffusion part 14a is formed in striation, the whole surface of the photo-leading plate 14 is provided with substantially uniform brightness.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a round fluorescent lamp lighting fixture, and is particularly effective in a round fluorescent lamp lighting fixture using a round fluorescent lamp with a large tube outside. It is something.

[Conventional technology]

In general, lighting fixtures used for general indoor lighting are made with high-output lamps or with multiple lights in order to ensure sufficient illuminance in the room with just one lighting fixture. The upper part of the lamp is covered with a reflector plate so that the light emitted from the lamp can be used effectively, and the light is irradiated widely into the room where the lighting equipment is used.

However, as mentioned above, if you try to increase the illuminance of a room with a single lighting fixture by using a high-output lamp, the luminance of the lighting fixture will increase, making it feel dazzling to the eyes. Therefore, in many lighting equipment, in order to avoid this glare, the indoor side of the lamp and reflector of the lighting equipment is covered with a translucent cover or louver made of a milky white diffusion panel or the like.

When using a light-transmitting cover for a lighting fixture, if a lamp is placed too close to the light-transmitting cover, a so-called lamp image will appear on the surface of the light-transmitting cover, causing uneven brightness on the surface of the light-transmitting cover. Therefore, in a lighting fixture having a light-transmitting cover, it is necessary to provide a certain distance between the lamp and the light-transmitting cover.

On the other hand, recently, lighting fixtures are also required to have a light feel.
As lighting fixtures tend to become shallower, the distance between the lamp and the translucent cover inevitably becomes closer, so light distribution control using a reflector prevents the appearance of the lamp image and reduces the brightness of the surface of the translucent cover. I try to avoid unevenness.

[Problem to be solved by the invention]

However, especially in round fluorescent lighting fixtures that use 30W to 40W round fluorescent lamps with a relatively large tube outer diameter, the inner diameter of the round fluorescent lamp is large, so the range that can be handled by light distribution control using a reflector is limited. The area corresponding to the center of the round fluorescent lamp becomes dark and a lamp image tends to appear, making it impossible to bring the round fluorescent lamp and the light-transmitting cover very close together.

The present invention has been made in view of the above-mentioned background, and its purpose is to provide a round fluorescent lamp lamp that can prevent the appearance of a lamp image, reduce unevenness in brightness of a light-transmitting cover, and can be made thinner. The goal is to provide equipment.

[Means for Solving the Problems] A round fluorescent lamp lighting fixture according to the present invention includes a lighting fixture body equipped with a round fluorescent lamp, the round fluorescent lamp covered with a transparent cover,
A light guide plate having a disc shape with an outer diameter slightly smaller than the inner diameter of the round fluorescent lamp and guiding incident light from the outer end surface to the center by total reflection is arranged inside the round fluorescent lamp with the outer end surface facing closely. A diffusing portion is provided on the upper surface of the light guide plate to diffusely reflect the incident light.

This round fluorescent lighting fixture may also be formed in the form of concentric stripes in which the distance between the diffusion portions is narrower toward the center (and the width is wider toward the center).

Further, in this round fluorescent lamp lighting fixture, the diffusion portion may be formed by silk printing.

Further, in this round fluorescent lamp lighting fixture, a light guide plate can be provided also on the outside of the round fluorescent lamp.

〔Example〕

1 to 3 show an embodiment of the present invention, which will be explained below based on the drawings.

This embodiment is a ceiling-mounted lighting fixture that uses one round fluorescent lamp with a relatively large tube diameter of about 30W to 40W.

As shown in FIGS. 1 and 2, a lighting fixture main body 1 formed of a thin steel plate and having a substantially rectangular tray shape is painted white and also serves as a reflector. A ballast 2, a glow starter socket 4 equipped with a glow starter 3, a terminal block 5, and a round fluorescent lamp socket are arranged in the lighting equipment main body 1 and are connected to each other by wires, and are connected to each other by three lamp support springs 6. A round fluorescent lamp 7 attached to a lighting fixture body 1 can be turned on. This lighting fixture main body 1 is attached to the ceiling surface, which is the mounting surface, with two wood brackets 8, and a power wire insertion hole is provided in the center, and a power source bundling 9 is attached, and the power wire is led out from the ceiling surface. A power supply wire is inserted through the power supply bushing 9 and connected to the terminal block 5.

A translucent cover mounting device 10 is provided at the center of two opposing side edges of the lighting fixture body 1, and the translucent cover 1 is made of milky white plastic and formed into a square box shape with an open top.
1 is engaged with the light-transmitting cover attachment device 10 and attached to the lighting fixture main body 1.

A light-transmitting cover mounting device 10 and a light-transmitting cover 11 are provided at positions corresponding to the light-transmitting cover mounting device 10 of the light-transmitting cover 11.
A push button 12 is provided for releasing the engagement with the holder.

A mounting base 13 having a screw hole at the top is provided approximately at the center of the lighting fixture body l. On this mounting base 13, there is a light guide plate 14 formed of transparent acrylic resin in the shape of a disc with an outer diameter slightly smaller than the inner diameter of the round fluorescent lamp 7, and its outer end face is closely opposed to the inside of the large fluorescent lamp 7. It is attached by screwing the mounting screw 15 into the threaded hole of the mounting base 13.

The light guide plate 14 is formed of transparent acrylic resin into a disk shape, and as shown in FIG. 3, on the planar upper surface, the distance between them becomes narrower toward the center, and the width becomes wider toward the center. Concentric diffusion portions 14a are formed in white stripes by silk printing. Further, the lower surface is concave toward the center, and an outer parallel surface 14b is formed on the outside near the large fluorescent lamp 7, an inclined surface 14c toward the center, and a central parallel surface 14d at the center. ing.

The light that comes out of the large fluorescent lamp 7 and enters the light guide plate 14 undergoes repeated total reflection within the light guide plate 14 and is guided to the center of the light guide plate 14. However, during that time, the light that enters the diffuser 14a passes through the diffuser 1.
4a causes diffuse reflection, and most of the light exits from the light guide plate 14 below and irradiates the downward direction. Since the diffusion portions 14a are formed in the striped shape as described above, substantially uniform brightness can be obtained over the entire surface of the light guide plate 14.

In this round fluorescent lamp lighting fixture, a light guide plate 14 is arranged inside the large fluorescent lamp 7, and the light emitted from the large fluorescent lamp 7 is directed to the light guide plate 14.
Since the light is emitted uniformly to the inner part of the large fluorescent lamp 7, the lamp image is less likely to appear on the light-transmitting cover, and unevenness in brightness on the surface of the light-transmitting cover can be reduced. As a result, the distance between the large fluorescent lamp and the light-transmitting cover can be brought closer to make the device thinner. Furthermore, the light guide plate 14 can hide the mounting portions and electrical components of the lighting fixture main body l, thereby improving the appearance of the inside of the lighting fixture.

FIG. 4 shows another embodiment of the present invention, which is a large chain-suspended circular fluorescent lamp lighting fixture using four large fluorescent lamps.

The lighting fixture main body 20 is provided with electrical components for lighting four lights, and is equipped with four large fluorescent lamps 7. A light guide plate 14 is attached to the inside of each large fluorescent lamp 7, and is covered with a box-shaped shade 21 made of milky white plastic, which is a transparent cover.

Even in this round lighting fixture, the center of each large fluorescent light becomes dark, and the lamp image does not appear.

Note that if the light guide plate is also provided outside the large fluorescent lamp, unevenness in brightness on the surface of the light-transmitting cover can be further reduced. Further, the method of providing the diffusion portion of the light guide plate is not limited to silk printing, and the shape thereof may also be a grid-like shape, a mesh-like shape, etc. with different coarseness. Furthermore, the light guide plate 14 may be formed integrally with the inner surface of the light-transmitting cover instead of being provided independently from the light-transmitting cover.

[Effects of the Invention] Since the present invention is configured as described above, it produces the following effects.

In the round fluorescent lamp lighting fixture according to claim 1, the lamp image hardly appears on the light-transmitting cover, and unevenness in brightness on the surface of the light-transmitting cover can be reduced, and as a result, the distance between the large fluorescent lamp and the light-transmitting cover can be brought closer. It can be made thinner.

In the round fluorescent lamp lighting fixture according to the second aspect of the invention, the brightness of the light guide plate can be made uniform.

In the round fluorescent lamp lighting device according to the third aspect of the present invention, it is easy to form the diffusion portion of the light guide plate.

In the round fluorescent lamp lighting device according to the fourth aspect, unevenness in brightness on the surface of the light-transmitting cover can be further reduced.

[Brief explanation of drawings]

1 to 3 show an embodiment of the present invention, in which FIG. 1 is an exploded perspective view, FIG. 2 is a perspective view, and FIG. 3 is a sectional front view of main parts. FIG. 4 is an exploded perspective view showing another embodiment of the present invention. 1-Lighting equipment main body, 7-Large fluorescent lamp, 11--Translucent cover, 14--Light guide plate, 14a--Diffusion part, 14b
---4 side parallel surface, 14c--slanted surface, 14d... center parallel surface, 20--. lighting fixture body, 21--. shade.

Claims (4)

[Claims] (1) In a round fluorescent lighting fixture in which the lighting fixture body is equipped with a round fluorescent lamp and the round fluorescent lamp is covered with a transparent cover,
A light guide plate having a disc shape with an outer diameter slightly smaller than the inner diameter of the round fluorescent lamp and guiding incident light from the outer end surface to the center by total reflection is arranged inside the round fluorescent lamp with the outer end surface facing closely. A round fluorescent lamp lighting fixture, characterized in that a diffuser is provided on the upper surface of the light guide plate to diffusely reflect incident light. (2) The round fluorescent lamp lighting device according to claim 1, characterized in that the diffusion portions are formed in concentric striped stripes whose mutual spacing becomes narrower toward the center and wider toward the center. . (3) The round fluorescent lamp lighting fixture according to claim 1 or 2, wherein the diffusion portion is formed by silk printing. (4) The round fluorescent lamp lighting fixture according to claim 1, 2 or 3, characterized in that the light guide plate is also disposed outside the round fluorescent lamp.