JPH01261692A - Surface light source device - Google Patents

Abstract

PURPOSE:To prevent occurrence of luminance spots on the surface light source of a surface light source unit by providing an optical distributor between part adjacent to the linear light source and part adjacent to the translucent platy body of the surface light source unit. CONSTITUTION:This surface light source unit 1 is constituted of linear fluorescent lamps 2 which are arranged in one linear light source and a translucent platy body 4 composed of plural transparent thin plates 3 having different lengths piled up upon another. Since one-side edges 4a of the thin plates 3 constituting the platy body 4 are trued up on the fluorescent lamp 2 side, the other-side edges 4b form steps and radiated luminous fluxes are made incident to the trued-up edges 4a and emitted from the step-forming edges 4b. Moreover, the luminous fluxes made incident to a pair of optical distributors 9 which are abutted against each other at the position matching to the position where the two bases 2a of the two fluorescent lamps are abutted against each other are emitted from the distributors 9 after refraction. Therefore, the luminous fluxes emitted from the distributors 9 compensate the sections of the bases 2a which do not emit light, since the luminous fluxes are observed as if they are emitted from the base 2a sections. Thus the cause of a luminous spot in the surface light source can be eliminated.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement of a surface light source device that generates a surface light source using a linear light source, and particularly for use in illuminated displays, such as signboards. It is most suitable for application to a surface light source device.

[Summary of the invention]

The present invention is a surface light source device that generates a surface light source using a linear light source, and includes a plurality of surface light source units each comprising the linear light source and means for converting the linear light source into a surface light source. When a surface light source device is constructed by sequentially connecting them to each other, by providing a means for preventing brightness irregularities from occurring in the surface light source device, it is possible to easily obtain a surface light source device of a desired size, weight, and thickness. This is what I did.

[Conventional technology]

A surface light source device that uses a linear light source to obtain a surface light source of a desired size is, for example, a surface light source that uses a linear light source and a reflector with a special reflective curved surface that reflects the emitted light from the linear light source. There is one in which a plurality of surface light source units are connected to each other in sequence.

However, in the case of such a surface light source device, (1)
(2) The optical design of the reflective surface of the reflector becomes complicated in order to remove brightness spots that occur directly above the linear light source, and (2) the connection part of the linear light source where no light is emitted (the connection There were problems such as brightness unevenness inevitably occurring within the surface light source due to the metal fittings and socket parts).

Therefore, it consists of a linear light source and a light-transmitting plate-like body provided with a light reflecting layer on one plate surface and whose one end is placed near the linear light source, and the radiation of the linear light source is A surface light source unit is configured to uniformly radiate the emitted light in the thickness direction of the translucent plate by reflecting the light on the reflective layer, and a plurality of the surface light source units are sequentially connected to each other. A surface light source device configured by connecting them has been proposed.

[Problem to be solved by the invention]

However, in the case of the surface light source device configured as described above, there is a problem in that an outline of the linear light source appears within the surface light source.

In view of the above-mentioned points, the present invention provides that even if a surface light source device is configured by sequentially arranging a plurality of surface light source units each including a linear light source and a means for converting the linear light source into a surface light source, To provide a surface light source device that does not cause the outline of a linear light source to occur within the light source and does not cause brightness unevenness to occur within the surface light source.

[Means to solve the problem]

The present invention provides a plurality of surface light source units each comprising a linear light source and a translucent plate-like body disposed with one end of the linear light source close to the linear light source in order to convert the linear light source into a surface light source. are arranged in abutting order in the direction in which the linear light sources are arranged in series, and between adjacent portions of the cotton-like light sources of mutually adjacent surface light source units and adjacent portions of the transparent plate-like body. A light distributor is provided at the surface of the linear light source to prevent brightness unevenness from occurring in the surface light source due to the non-emitting portion formed in the adjacent portion of the linear light source.

In addition, a linear light source is provided, one end of which is placed close to the linear light source in order to convert the linear light source into a surface light source, and a plurality of transparent thin plates having different lengths are arranged at one end of the linear light source. A surface light source unit is constructed by stacking the translucent plate-shaped bodies in the order of the above lengths so that they are aligned on one side and in a step-like manner on the other end side, and a plurality of these surface light source units are stacked. The linear light sources are arranged in series butt against each other, and there is no light between the adjacent portions of the linear light sources of the mutually adjacent surface light source units and the adjacent portions of the translucent plate-like body. In addition to providing a distributor, a plurality of surface light source units are arranged one on top of the other in order in the direction in which the linear light sources are arranged in parallel, and the linear light source provided at one end is connected to the other. The surface light source device can also be constructed by covering the side edges so that brightness irregularities do not occur in the surface light source.

[For production]

Therefore, even if a desired number of surface light source units each consisting of a linear light source and a translucent plate are arranged in a direction in which the linear light sources are arranged in series, brightness unevenness will occur in the resulting surface light source device. There is no fear at all.

Further, the same effect can be obtained even if a desired number of the surface light source units are arranged in the direction in which the linear light sources are arranged in parallel. Thus, according to the present invention, a high-quality surface light source of any shape or size can be obtained simply and easily.

〔Example〕

Hereinafter, an embodiment in which the present invention is applied to a surface light source device used for a signboard, etc. will be described from the beginning with reference to FIGS. 1 to 10.

A surface light source unit 1 having a width W of 880 mm shown in FIGS. 1 and 2 is constructed by overlapping a linear fluorescent lamp 2, which is one linear light source, and a plurality of transparent thin plates 3 having mutually different lengths. It consists of a translucent plate-like body 4 composed of

The fluorescent lamp 2 is "Sharpline" (registered trademark) manufactured by Ohsara Houkou Kogyo, and the tube length S shown in Fig. 4 is 880 mm.
, the length ΔS of the caps 2a provided at both ends is 10 m+, and the diameter d
is 20Il1m. Further, as shown in FIG. 2, one end 4a of the light-transmitting plate-like member 4 is located along the fluorescent lamp 2 and near the fluorescent lamp 2. As shown in FIG.

Further, the fluorescent lamp 2 is covered with a case 7 which has one end attached to a translucent plate 4, except for its side parts. The other end of the case 7 supports the vicinity of the other end 4b of the translucent plate 4 so that the angle α of the translucent plate 4 with respect to the horizontal plane is maintained at 5 degrees. .

The transparent thin plate 3 is an acrylic resin plate with a thickness t=2 mm, and in the embodiment, "Acrylite" (registered trademark) #OO1 manufactured by Mitsubishi Rayon Co., Ltd. is used.

Also, the width W of the transparent thin plate 3 is 880 mm (constant), but the length! 5 varies from 5 to 350 gates, and its pitch pI is 23 mm.

Therefore, the transparent thin plate 3 constituting one translucent plate-like body 4
Further, the thickness T of the transparent plate member 4 is as follows: T=16×2=32 mm. The width W of the translucent plate 4 is 880 mm, which is the same as the width W of the transparent thin plate 3, as shown in the figure, and its length 2 is the same as the length β1816 of the largest one among the transparent thin plates 3. It becomes 350mm. Moreover, above the surface light source unit 1,
As shown in the figure, the diffuser plate 8 is horizontally arranged at a position where the height H is 63 mm. The diffusion plate 8 is an acrylic resin plate with a thickness of 2 mm, and in the embodiment, "Acrylite" (registered trademark) #432 manufactured by Mitsubishi Rayon Co., Ltd. is used.

By the way, the transparent plate 3 has a fluorescent lamp 2 as shown in FIG.
Since the one end 4a side of the translucent plate-like body 4 is aligned close to
It becomes step-like. Note that the luminous flux emitted from the fluorescent lamp 2 is incident on one side end 4a of the translucent plate-like member 4, and the other side end 4b
The four side surfaces of the transparent thin plate 3, particularly the side surfaces that serve as the incident and exit surfaces of the light flux, are sufficiently polished in advance before being assembled into the light-transmitting plate-like body 4.

Next, FIG. 3 shows a surface light source device assembled by butting together two surface light source units 1 in a direction in which the fluorescent lamps 2 of the surface light source units 1 are arranged in series.

In this surface light source device, since two surface light source units 1 are used, its size is exactly twice that of the surface light source unit 1, and the width W is 2 W%, or 1760 mm. By assembling the units 1 in the order described above, a surface light source device of a desired size can be obtained.

By the way, as shown in FIG. 4, the caps 2a are interposed in the adjacent portions of the two fluorescent lamps 2 arranged in series as described above, so that no light is emitted from this portion. For this reason, a pair of light distributors 9 are disposed in parallel with the fluorescent lamp 2 between the above-mentioned adjacent portion and the adjacent portion of the translucent plate-like body 4, as shown in FIG. This prevents this from occurring on surface light sources.

This light distributor 9 is a prism having a sawtooth-shaped protrusion on the - side, and the length P, thickness Q, and height h of the distributor 9 shown in FIG. 4 are 1001.10 mm and 30 mm, respectively. . The number of ridges in the protruding portion is 20, and the thickness q1, pitch p2, and angle θ of the inclined portion are each 4.5 mm.
, 5 mm and 48°.

Also, as shown in Figure 4, the base 23 of two wooden fluorescent lamps
The distance B between the other smooth side surface of the pair of light distributors 9 which are butted against each other and the center of the fluorescent lamp 2 is 50 mm.

Thus, in FIG. 5, the light beam that enters the light distributor 9 from the fluorescent lamp 2 as shown by the solid line is refracted and exits from the light distributor 9 as shown by the solid line. Therefore, as shown by the dashed line in the figure, this luminous flux appears to be emitted from the portion of the cap 2a, and compensates for the portion of the cap 2a that does not emit light.

Therefore, the cause of brightness unevenness within the surface light source is eliminated.

Next, the brightness of the surface light source device was measured using a Minolta NP-1/30 type brightness meter (spot diameter 10φ, close-up lens It122), and the results are shown in FIG.

In this measurement, the brightness is measured at intervals of 100 m and 171 as shown in the figure, centering on 9 positions on the X axis where the two surface light source units 1 butt each other. Further, when this result is plotted on the X axis using the Y value as a parameter, FIG. 7 is obtained, but as shown in FIG. 7, there is no particular tendency for the brightness to decrease at 9 positions on the X axis.

Next, a second embodiment will be described with reference to FIGS. 8 to 10. In this example, as shown in FIG. 8, a surface light source device was assembled by using four surface light source units.

That is, in the X-axis direction of the surface light source device, two surface light source units 1 were assembled by butting each other in exactly the same manner as in the first embodiment, and the light distributor 9 was used in the same manner as in the first embodiment.

In addition, in the direction in which the fluorescent lamps 2 of the two surface light source units are arranged in parallel, in other words, in the Y-axis direction of FIG. 8, the surface light source units 1 are superimposed to form one surface light source unit 1 indicated by the dashed-dotted line above.
The fluorescent lamp 2 provided on one side @ 4a was covered with the other end 4b of the other surface light source unit 1 shown by the solid line above.

Next, using a luminance meter similar to that used in the first embodiment, the luminance of the surface light source device was measured, and the results are shown in FIG. In the same figure, the boundary of the surface light source unit 1 in the X-axis direction is located at 9 positions on the X-coordinate axis, as in the case of the previous embodiment, and the boundary of the surface light source unit 1 in the Y-axis direction is located at 3 positions on the Y-coordinate axis. and the 4th position. By the way, as shown in FIG. 9, there is no particular tendency for the brightness at the boundary in the X-axis direction to decrease as in the case of the above embodiment. Therefore, for the purpose of examining only the luminance change at the boundary in the Y-axis direction, if we shift the results of Figure 9 along the Y-axis using the Y value as a parameter, we can obtain Figure 10 (in the same figure, the dashed line is (respective average values are shown). According to FIG. 10, as in the case of the X-axis direction, it is difficult to recognize a tendency in which the luminance particularly decreases between the 3rd and 4th positions on the Y-axis.

〔Effect of the invention〕

Since the present invention has the above-described configuration, (1) a surface light source device of a desired size can be easily divided and assembled. Therefore, designing and constructing large signboards and display devices becomes simple and easy. Furthermore, (2) the light source is skillfully used to prevent brightness irregularities within the surface light source, so even if the surface light source is enlarged, a high-quality surface light source can always be obtained, unlike conventional devices. Furthermore, (3) when increasing the size of the surface light source as described above, there is no need for any complicated optical calculations, making the construction design and construction simple and easy.

[Brief explanation of the drawing]

1 to 10 show an embodiment in which the present invention is applied to a surface light source device used for a signboard, etc. FIG. 1 is a perspective view of a surface light source unit constituting the top surface light source device, and FIG. The figure is a sectional view taken along line nn in Figure 1, Figure 3 is a perspective view of the same top light source device using two of the same top light source units in the X-axis direction, and Figure 4 is a light source used in the same top light source device. A perspective view of the arrangement of the distributor, FIG. 5 is an explanatory diagram of the operation of the same optical distributor,
Fig. 6 is a luminance measurement diagram of the same top surface light a replacement iη, Fig. 7 is a diagram of the same luminance in the X-axis direction, and Fig. 8 is a second embodiment of a surface light source device using four of the same top surface light source units. FIG. 9 is a luminance measurement diagram of the top surface optical tA device, and FIG. 10 is a diagram of the luminance in the Y-axis direction. In addition, in the symbols used in the drawings, 1---1・---1------Surface light source unit 2-
・−・−・−・−Fluorescent lamp (linear light source) 3−・・・−
−1−−−−−・−Transparent thin plate 4・−1−−−−−−−
--- Translucent plate-like body 4 a------------1~
One side end 4b・-・・−・−・・−・−・−Other side end 9−
----------1 ~ Optical distributor.

Claims (1)

[Claims] 1. A surface consisting of a linear light source and a translucent plate whose one end is placed close to the linear light source in order to convert the linear light source into a surface light source. A plurality of light source units are arranged in sequence in a direction in which the linear light sources are arranged in series, and adjacent portions of the linear light sources of mutually adjacent surface light source units and the transparent plate-shaped body are arranged. A surface light source device, wherein a light distributor is provided between adjacent portions of the linear light source to prevent brightness irregularities from occurring in the surface light source due to non-emitting portions formed in the adjacent portions of the linear light source. 2. A linear light source, one end of which is arranged close to the linear light source in order to convert the linear light source into a surface light source, and a plurality of transparent thin plates having different lengths arranged on one side of the linear light source. A surface light source unit is constituted by translucent plate-like bodies stacked in the order of the above lengths so as to be aligned on one end side and stepwise on the other end side, and a plurality of these surface light source units are arranged in sequence in the direction in which the linear light sources are arranged in series, and between the adjacent portions of the linear light sources of mutually adjacent surface light source units and the adjacent portions of the transparent plate-like body, In addition to providing a light distributor, a plurality of the surface light source units are arranged one on top of the other in order in the direction in which the linear light sources are arranged in parallel, and the linear light source provided at one end side is connected to the other side. A surface light source device that is covered with the other end to prevent brightness unevenness from occurring in the surface light source.