JPS62296184A - Fluorescent lamp apparatus - Google Patents

Abstract

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

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention relates to a fluorescent lamp device suitable for backlighting, for example, a liquid crystal display from the back side. , g! is a fluorescent lamp device with an improved method for improving illuminance distribution. I do it.

(Prior Art) This type of fluorescent lamp device, which the present inventors have conventionally developed, is a so-called backlight that illuminates an illuminated object such as a liquid crystal display from the back side.
As shown in the figure, a small straight fluorescent lamp 2 is installed on the bottom of the reflector 1 which has been curved into a flat U-shape.
Through a direct light attenuation filter 3 placed over a U-shaped opening, almost the entire surface to be illuminated, such as the back surface of a liquid crystal display (not shown), is illuminated almost uniformly.

The direct light attenuation filter 3 is formed by, for example, dot-shaped attenuating wires 3a that attenuate direct light and aluminum vapor-deposited in the form of dots on a transparent film 3b, so that the amount of direct light from the fluorescent lamp 2 is small. Using the low-illuminance part of the illuminated surface as a reference, direct light from a place where more direct light is irradiated than this low-illuminance part, for example, a place close to and facing the fluorescent lamp 2, is reduced to the reference, and the illuminance distribution of the illuminated surface is determined. However, in other words, an improvement is made so that the brightness distribution on the filter 3 of the light transmitted through the filter 3 and radiated to the outside is uniform.

Therefore, in the central part of the direct light attenuation filter 3 where the amount of direct light attenuation is large, the attenuation cord 3a is larger than the peripheral part.
are arranged more densely.

FIG. 6 shows another conventional example, in which two small straight fluorescent lamps 2 2A and 2B are arranged side by side on a reflector 1 at a required interval in the radial direction. Yes, the fluorescent lamps 2A and 2B are illuminated by the direct light attenuation filter 3 as in the conventional example above.
By attenuating the direct light from the direct light attenuation filter 3, an illuminated surface (not shown) parallel to the direct light attenuating filter 3 is almost uniformly illuminated.

(Problems to be solved by the invention) However, in such a conventional fluorescent lamp device,
Fluorescent lamps 2.2A, 2B by direct light neutral density filter 3
There is a problem in that the brightness of the fluorescent lamp device as a whole is reduced because the direct light from the fluorescent lamp device is attenuated.

Further, since the direct light attenuation filter 3 requires a predetermined size, it impedes miniaturization of the fluorescent lamp device, and this is particularly a problem in liquid crystal displays for automobiles, liquid crystal televisions, and the like.

Furthermore, the direct light attenuation filter 3 has a problem in that it is expensive because the attenuation element 3a is deposited with aluminum on the transparent film 3b.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an inexpensive fluorescent lamp device that can make the illuminance distribution on a surface to be illuminated substantially uniform.

[Structure of the invention]

(Means for Solving the Problems) The present invention aims to equalize the illuminance distribution on the illuminated surface by irradiating light from the aperture of a fluorescent lamp onto a low-illuminance part of the illuminated surface. It is configured as follows.

That is, it has a fluorescent lamp with a phosphor film coated on the inner wall of the bulb, and a reflector that reflects the direct light from the fluorescent lamp. In a fluorescent lamp device that irradiates an illuminated surface, the fluorescent lamp is a fluorescent lamp in which a portion of the phosphor film is removed and seven apertures for light extraction are opened, and the apertures are arranged in a direction that does not closely face the illuminated surface. It is characterized by its orientation.

(Function) When the fluorescent lamp is turned on, the light from the fluorescent lamp is directly irradiated onto the surface to be illuminated, and is also reflected and diffused by the reflector plate, so that almost the entire surface of the surface to be illuminated is irradiated.

At this time, the light emitted from the aperture of the fluorescent lamp is irradiated directly or reflected by a reflector to the low-illuminance part of the illuminated surface that is not closely facing the fluorescent lamp, and the illuminated surface that is closely opposed to the fluorescent lamp is irradiated with light derived from the aperture of the fluorescent lamp. Direct light from the fluorescent lamp is reduced in the high-illuminance area by providing an averte in a different direction, and the overall illuminance distribution on the illuminated surface is made approximately equal.

Therefore, according to the present invention, it is possible to equalize the illuminance distribution on the illuminated surface without attenuating the direct light from the fluorescent lamp using the conventional expensive direct light neutralization filter. can increase the illumination intensity.

(Example) Examples of the present invention will be described below with reference to FIGS. 1 to 4.

FIG. 1 shows the appearance of the main parts of an embodiment of the present invention.
For example, a small fluorescent lamp 1 bent into a substantially U-shape is mounted on the bottom portion 11a of the reflecting plate 11 which is bent into a flat U-shape.
2 is listed.

The reflecting plate 11 is bent into a flat U-shape as shown in FIGS.
A curved side wall 11 that curves to form a concave surface concave inward.
b and 11c are integrally connected, and an illuminated surface 13 is arranged above the U-shaped opening of the reflection plate 11.

The illuminated surface 13 indicates, for example, the back surface of an object to be illuminated such as a liquid crystal display (not shown), and is arranged close to and above the fluorescent lamp 12.

The fluorescent lamp 12 includes, for example, a straight glass bulb 12a having a diameter of approximately 8all, which is bent into a substantially U-shape.
One end of each of the straight parts 12b and 12c of the book is connected to a U-shaped bent end 1.
A phosphor film 12 made of phosphor is coated over almost the entire length of the inner wall of the glass bulb 12a, and a small amount of mercury and a rare gas such as argon is injected into the inside of the phosphor film 12. A pair of electrodes (not shown) are sealed at both ends of the glass bulb 12a by sealing at a predetermined pressure.

These electrodes are connected to a lighting circuit (not shown).

The fluorescent lamp 12 has each straight portion 12b, 12C connected to a reflector 11.
The U-shaped bent end portion 12d and both end portions on the electrode side are fixed on a support stand (not shown).

Then, as shown in FIGS. 1 and 2, a fluorescent lamp 1
Apertures 14a and 14b for guiding light are opened outward over almost the entire length on the outer surfaces of the two straight portions 12t) and 12C, respectively.

Each aperture 14a, 14b is formed by cutting out the phosphor film 12 (3) in the axial direction with a required width, exposing the inner wall of the glass bulb 12a, and forming the curved side wall 11b, 11C of the reflection plate 11.
The concave surfaces thereof are open to each other over almost the entire length thereof.

The light intensity derived from each aperture 14a, 14b is, for example, about 1°3 to 1.4, assuming that the amount of light outputted from locations other than the apertures 14a, 14b is “1”, and the light intensity is somewhat low. It is done between places.

Next, the operation of this embodiment will be described.

When a pair of electrodes of the fluorescent lamp 12 are energized by a lighting circuit (not shown), discharge occurs between the electrodes, and a positive column is generated within the glass bulb 12a.

This pillar of sunlight is phosphor 1! ! The fluorescent lamp 12 is excited to emit light, and light is emitted radially from the entire circumference of the fluorescent lamp 12 over its entire length.

A part of these emitted lights is directly irradiated onto the illuminated surface 13 adjacent to the upper side of the fluorescent lamp 12 as direct light.
The light is reflected by the concave surfaces of the bottom portion 11a and the curved side walls 1ib and 1ic of 1 and diffused, and is irradiated onto almost the entire surface of the illuminated surface 13.

At this time, the illuminance distribution of the illuminated surface 13, in other words, the luminance distribution of the light transmitted through this illuminated surface is distributed as shown in the characteristic curve A in FIG.
Relative Ti at a location near the illuminated surface 13 near the top surface of 2c
It shows a bimodal property in which each peak of the brightness is shown, and the relative brightness decreases at locations other than these peaks. That is, low illuminance portions are distributed in the light to the illuminated surface 13.

In this embodiment, the light emitted from the apertures 14a and 14b of the fluorescent lamp 12 is directly irradiated onto the low-illuminance portion of the illuminated surface 13, or is irradiated by being reflected by the reflection plate 11. As the illuminance of the area increases, the illuminance of the area close to the fluorescent lamp 12 decreases due to the reduction of light radiation in this direction, and the relative brightness of the light transmitted through the illuminated surface 13 as a whole is as shown in FIG. As shown in characteristic curve B, the curve becomes substantially flat and equalized in the radial direction of the fluorescent lamp 12.

The graph in FIG. 3 is based on experimental data conducted on this example having the following dimensions.

Width of reflector 11: 60m + Height = 11 shoe length: 180M Dimensions and diameter of fluorescent lamp 12: 8M Center distance between each straight #12b and 13c: 0mrs Distance between the top surface of fluorescent lamp 12 and illuminated surface 14 :3M Also, in the above actual IM@, a case was described in which a U-shaped bent fluorescent lamp 12 was incorporated, but the present invention is not limited to this, and for example, a straight fluorescent lamp may be incorporated. Two or more, or three or more straight portions of bent fluorescent lamps bent into a desired shape may be placed on the reflecting plate 11, or roughly one as shown in FIG. The required width of the phosphor film 20a on both the right and left sides of the straight fluorescent lamp 20 may be omitted, and the apertures 21a and 21b may be opened over almost the entire length along the axial direction of the fluorescent lamp 20, respectively.

According to this embodiment, a portion of the illuminated surface 22 close to the top surface of the fluorescent lamp 20 has high illuminance, and the other portions have a low illuminance portion.
The illuminance of the high-illuminance area is reduced by providing the aperture in a different direction, and the illuminance of the illuminated area is reduced by providing the aperture in a different direction. Equalized.

In this embodiment, since the illuminated surface 22 is irradiated with one fluorescent lamp 20, it is possible to reduce the size of -m.

Although this embodiment describes the case where one straight fluorescent lamp 20 is incorporated, two or more fluorescent lamps 20 may be incorporated, or a bent type fluorescent lamp bent into a desired shape may be incorporated. It can also be applied to

Further, although a light diffusing plate is not used in the above embodiment, a light diffusing plate may be placed between the illuminated surface and the fluorescent lamp. The illuminance distribution on the illuminated surface can be made uniform.

〔Effect of the invention〕

As explained above, the present invention reduces the light to the high-illuminance part of the illuminated surface by orienting the aperture in a different direction, and also irradiates the low-illuminance part of the illuminated surface with light from the aperture of the fluorescent lamp to increase the illuminance. Since the illuminance distribution as a whole of the illuminated surface is equalized, it is possible to equalize the illuminance and increase the illuminance of the illuminated surface at low cost.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a main part of an embodiment of a fluorescent lamp device according to the present invention, FIG. 2 is an end view taken along line II-II in FIG. 1, and FIG. 3 is a view similar to that shown in FIG. The light distribution characteristic of the example shown in is the actual f! Graphs shown in correspondence with example schematic diagrams,
FIG. 4 is a cross-sectional view of a main part of another example of the present invention, and FIGS. 5 and 6 are perspective views of the conventional example. 11.23...Reflector, 11a...Bottom, 11b. 11C...Curved side wall, 12.20...Fluorescent lamp,
12a...Glass bulb (bulb), 12b, 12c
... Straight portion, 13 ... Illuminated surface, 14a, 14b,
21a, 21b...Aperture. Applicant's agent Hisa Cha Hatano! Zuna 2 Figure 3 Ward Sheep 4 Prisoner μ Article 6 Figure

Claims (1)

[Claims] It has a fluorescent lamp with a phosphor film coated on the inner wall of the bulb and a reflector that reflects the direct light from the fluorescent lamp, and directs the direct light from the fluorescent lamp and the reflected light from the reflector to the illuminated surface. In the fluorescent lamp device for irradiation, the fluorescent lamp is a fluorescent lamp in which a part of the phosphor film is removed and an aperture for guiding light is opened, and the aperture is oriented in a direction that does not closely face the surface to be illuminated. A fluorescent lamp device characterized by: