JP2628636B2 - Planar light source - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planar light source, and more particularly, to efficiently apply light emitted from a light source to a transmission plate by a lens function of a ring transmission light and apply the light to the transmission plate. The present invention relates to a planar light source that efficiently diffuses and reflects forward by a diffused fringe.

[Conventional technology]

As a conventional planar light source, for example, a plurality of fluorescent lamps or incandescent light bulbs are arranged in a box having an open top surface having reflecting mirrors arranged on the bottom and side surfaces, and further, light emitted from an opening of the box is provided. Some are provided with a scattering plate (mat glass) in the mouth.

In the above configuration, when a fluorescent lamp or an incandescent lamp is turned on, light is transmitted through the scattering plate and irradiated forward,
It is visually recognized as if it were emitting light in a planar manner.

[Problems to be solved by the invention]

However, according to the conventional planar light source, since a plurality of fluorescent lamps or incandescent lamps are used, the luminance distribution is not uniform, and the illuminance of each fluorescent lamp or incandescent lamp changes with the passage of time. There is a fear that illuminance unevenness may occur in the entire light source. Also, it was difficult to provide various illuminance distributions, and the light distribution characteristics were poor.

Furthermore, since a plurality of fluorescent lamps or incandescent lamps are arranged in the box, the heat generated from them is transmitted through the scattering plate and released, so when used as a light source for photochemical reactions and lighting for production, heat is removed. It was necessary to provide a filter to perform this. In addition, it is necessary to provide a vent in the box to release the heat trapped in the box,
Therefore, when used as an advertising light, an indicator light, or the like to be installed outdoors, it is required to provide protection to prevent rainwater and dust, and the configuration for that purpose has been complicated.

Furthermore, since a plurality of fluorescent lamps and incandescent light bulbs are incorporated in the box, the depth becomes relatively large with respect to the exit light aperture surface where the scattering plate is located. Electrical noise on the surface illuminated by the bulb has been a problem.

[Means and actions for solving the problems]

The present invention has been made in view of the above, to improve the light distribution characteristics by making the luminance distribution uniform, and preventing the occurrence of illuminance unevenness due to aging, and also having various illuminance distributions. Further, in order to prevent heat emission and electric noise from being generated on the irradiation surface and to be able to be installed at an arbitrary place, a transmission plate coated with diffusion stripes on one surface and an outer peripheral end of the transmission plate are provided. Along with surrounding and covering the ring transmission light and the ring transmission light coated with diffusion fringes on the outer peripheral side opposite to the side where the outer peripheral end is located, at a position facing the diffusion stripes of the ring transmission light, An object of the present invention is to provide a planar light source having a cylindrical reflecting mirror having an opening for inserting an outer peripheral end of a transmission plate, and a light source for emitting light to the ring transmission light.

The light emitted from the light source is efficiently taken into the transmission plate from the periphery of the transmission plate by the lens action of the ring transmission light having diffusion stripes, and is efficiently diffusely reflected forward by the diffusion stripes on the surface of the transmission plate. You. At this time, the luminance distribution of the planar light source and the illuminance distribution of the illuminated surface can be appropriately adjusted by the application density of the diffusion fringes.

〔Example〕

Hereinafter, a planar light source according to the present invention will be described in detail with reference to the drawings.

FIGS. 1 and 2 show an embodiment according to the present invention, in which a light source 2 such as an incandescent lamp for condensing light on an end face 1a of a light transmission rod 1 is joined to a joint 1b of the light transmission rod 1. A predetermined curvature (preferably, a diffusion fringe 3 coated on the outer peripheral surface).
110R-150R), a cylindrical reflecting mirror 6 for covering the light transmission rod 1 and the ring transmission light 4 with a spacer 5 interposed therebetween, and a ring transmission light 4 which is inserted into the ring transmission light 4 and diffused on the back surface. A transmission plate 8 coated with stripes 7, a protective glass (mat glass) 9 disposed on the surface of the transmission plate 8,
It consists of a reflector 10 arranged on the back of the transmission plate 8.

The light transmission rod 1 and the ring transmission light 4 are solid and have a rod shape having a circular cross section. The material is preferably as transparent and light-resistant as possible. For example, a quartz glass rod, an optical glass rod, Acrylic resin rods, polycarbonate rods and the like can be used.

On the outer peripheral surface of the ring transmission light 4 having a predetermined curvature, a diffusive reflector in which fine powder having a high refractive index is dispersed in a light-resistant transparent binder such as silicone resin is adhered in the form of linear fine stripes in the axial direction. Diffusion fringes 3 formed in this way.

The joint between the light transmission rod 1 and the ring transmission light 4 is as follows.
These end faces can be appropriately selected, for example, by welding, bonding with a light-resistant transparent binder (eg, silicone resin), or bonding with a light-resistant transparent binder (eg, silicone resin) via a reflecting mirror.

The cylindrical reflecting mirror 6 covers the light transmission rod 1 and the ring transmission light 4 via the spacer 5, and efficiently transmits the light emitted from the ring transmission light 4 to the transmission plate 8. The connection between the ring transmission light 4 and the transmission plate 8 is maintained by the flange 6a of the mirror 6.

The transmission plate 8 has a circular shape inserted into the ring transmission light 4, and the front surface, the back surface, and the outer peripheral end surface are finished to a smooth surface by optical polishing or the like. Like the ring transmission light 4, the material is preferably a material having high transparency and good light resistance. For example, quartz glass, optical glass, acrylic resin, polycarbonate and the like are used. On the back surface of the transmission plate 8, a diffusive reflector in which fine powder having a high refractive index is dispersed in a light-resistant transparent binder such as a silicone resin is applied to form diffusion fringes 7.

In the above configuration, the light incident on the light transmission rod 1 from the light source 2 passes through the inside of the light transmission rod and is incident on the ring transmission light 5. The light incident on the ring transmission light 4 is diffusely reflected by the diffusion stripes 3 formed on the outer peripheral surface of the ring transmission light 4 as shown in FIG. Because of the shape
The light is efficiently incident on the outer peripheral end surface of the transmission plate 8 by the lens function of the rod. At this time, the light leaked from the ring transmission light 4 to the outside of the transmission plate 8 is also reflected by the cylindrical reflecting mirror 6 and re-enters the diffusion fringe 3 to increase the amount of reflected light, or the reflected light is It is incident on the end face. Light that has entered the transmission plate 8 from the outer peripheral end face is radiated forward by the diffusion action of the diffusion stripes 7 applied to the back surface of the transmission plate. Since the reflection mirror 10 is provided on the surface on which the diffusion fringes 7 are formed, light can be emitted more efficiently forward, and a protective glass is provided on the surface side of the transmission plate 8 as the emission surface. Since the (mat glass) 9 is provided, the emitted light is appropriately scattered and a uniform planar light source can be obtained.

In order to make the luminance and the illuminance distribution of the light emitted from the transmission plate 8 uniform, the coating shapes of the diffusion stripes 3 formed on the ring transmission light and the diffusion stripes 7 formed on the surface of the transmission plate 8 are appropriately determined. Adjust it. That is, the light incident from the light source 2 is
Diffusion stripe 3 of ring transmission light 4 passing through optical transmission rod 1
The light is radiated toward the center portion of the transmission plate 8 and is radiated toward the center of the transmission plate 8. However, in a portion near the incident side, the rod itself of the ring transmission light 4 has a predetermined curvature, so that the amount of emitted light increases. . For this reason, for example, near the incident side, the diffusion fringes 3 are attached in the form of dots, and the diffusion fringes 3 are continuously formed while gradually narrowing the intervals between the dots according to the path of light, and are attached in the form of fine stripes or incident. Near the side, the width of the diffused fringes 3 is reduced and gradually increased to a predetermined width, for example, so that the luminance of the emitted light with respect to the center of the transmission plate 8 over the entire circumference of the ring transmission light 4 is determined. Alternatively, the illuminance distribution can be made uniform. By making the light emitted from the ring transmission light 4 uniform, the light emitted from the transmission plate 8 can be made uniform.

As a result of an experiment conducted by the applicant, the measurement was performed at the measurement points in FIG. 7A, and as shown in FIG. 7B, an extremely uniform illuminance distribution was obtained. However, 1. the light transmission rod 1 and the ring transmission light 4 The light transmission rod 1 (linear portion) and the ring transmission light 4 (curvature portion) are integrally formed.

1) Rod material: quartz glass 2) Rod diameter: 10mmφ 3) Optical transmission rod 1 (linear part): 220mm 4) Ring transmission light 4 (curvature part): inner diameter 290mmφ 2. In ring transmission light 4 1) Diffusion fringe Material: Binder (silicone resin) High refractive index material (titanium fine powder) 2) Diffusion fringe width: As shown in FIG.
First about 1 mm width for about 380 mm, 1.5 mm width for about 510 mm Remaining about 75
The mm part was applied with a width of 3 m.

Diffusion fringe thickness is 0.5mm t 3.Transmission plate 8 1) Material: quartz glass Dimension: Diameter 284mmφ Thickness 5.0mm t 2) Diffusion fringe, Material: Binder (silicon resin) 0.5mm t 4. Protective glass (mat glass) 9 Material: Pyrex glass Dimensions: 276mmφ in diameter, 3mm thickness on both sides 250 # grain 5. Cylindrical mirror 6 Material: Aluminum Inner mirror finish 6. Reflector 10 Material: Aluminum (bright aluminum plate) Dimensions: diameter 262mmφ, thickness 1.0mm t 7. Light source 2 Halogen lamp 12v35W.

In the transmission plate 8, the diffusion fringes 7 formed on the back surface are formed.
Is applied not only uniformly on the entire back surface, but also at a predetermined interval in a concentric manner, or by adhering in a dot form, thereby providing a uniform illuminance distribution or a surface having an arbitrary illuminance distribution. A shaped light source can be obtained.

Since the light source 2 is provided separately, the ring transmission light 4
Further, since the thickness of the transmission plate 8 can be reduced, the transmission plate 8 can be installed even in a narrow place, and sealing against rainwater, dust, and the like becomes easy. In the light source 2, only visible light that does not include a heat ray can be obtained as planar emission light by performing appropriate thermal cutoff, and no electrical noise is emitted from the transmission plate 8.

In this embodiment, the cylindrical reflecting mirror 6 and the reflecting mirror
Although the light was emitted more efficiently using 10, the planar emission light can be obtained without disposing the light. Although the protective glass (mat glass) 9 is provided on the emission surface in order to scatter the light and change the texture of the light, it is needless to say that this need not be provided.

In the present embodiment, the ring transmission light 4 and the transmission plate 8 are circular in shape.
As shown in FIGS. 1 (a) and 1 (b), it is needless to say that the shape may be substantially various shapes such as an ellipse, a square having a predetermined curvature, a pentagon, or the like, and the shape may be appropriately selected.

Further, in the present embodiment, the light source for incident light is provided at one point, and the light is incident on the ring transmission light via the optical transmission rod. However, the invention is not limited to this, and FIG. As shown in FIGS. 6 (a) and 6 (b), it is also possible to provide a plurality of incident light sources, and the light may directly enter the ring transmission light without passing through the light transmission rod.

Further, the ring transmission light and the transmission plate can be manufactured integrally with the above-described quartz glass, acrylic resin, or the like, and the optical transmission rod can also be manufactured integrally therewith.

〔The invention's effect〕

As described above, according to the surface light source of the present invention, the transmission plate coated with diffusion fringes on one surface and the outer peripheral surface surrounding the outer peripheral surface of the transmission plate and opposite to the side where the outer peripheral end is located. And a cylindrical reflector having an opening for covering the outer peripheral end of the transmission plate at a position facing the diffusion stripe of the ring transmission light while covering the ring transmission light. And, so as to have a light source for incident light to the ring transmission light,
Uniform brightness distribution, prevents uneven illuminance due to aging, improves light distribution characteristics by providing various illuminance distributions, and prevents heat emission and electrical noise from being emitted to the illuminated surface And can be installed in any location.

Further, according to the present invention, since the ring transmission light having a solid circular cross section is used, the light diffusely reflected by the diffusion fringes is efficiently incident on the outer peripheral end face of the transmission plate by the lens function.

Furthermore, since a solid light transmission rod is provided between the light source and the ring transmission light, a cool planar light source that blocks heat from a light source such as an incandescent lamp can be obtained.

[Brief description of the drawings]

FIG. 1 is a structural explanatory view showing one embodiment of the present invention, FIG. 2 is a sectional view taken along the line II-II of FIG. 1, FIG. 3 is an explanatory view showing a light emitting state, and FIG. (B) to FIG. 6 (a)
(B) is an explanatory view showing the configuration of another embodiment, FIG. 7 (a) is an explanatory view showing measurement points of the illuminance distribution of the planar light source, and FIG. 7 (b) is an illustration in FIG. 7 (a). A diagram showing an illuminance distribution,
FIGS. 8 (a) and 8 (b) are diagrams showing the state of attachment of the diffusion fringes 7 attached to the ring transmission light 4. FIG. DESCRIPTION OF SYMBOLS 1 ... light transmission rod 2 ... light source 3 ... diffusion fringe 4 ... ring transmission light 5 ... spacer 6 ... cylindrical mirror 7 ... diffusion fringe 8 ... transmission plate 9 ... … Protective glass (mat glass) 10 …… Reflection mirror

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Toru Omiyama 4-6-56, Suimeidai, Kawanishi-shi (72) Inventor Taku Fukunishi 2634-15 Tana, Sagamihara-shi (72) Inventor Masafumi Shigeoka, Mutsutagawa, Minami-ku, Yokohama-shi Town 3 76-3 Yokohama Park Town J-908 (72) Inventor Hiroshi Sudo 1-4-15-1 Yamane, Zushi City Examiner Masao Kashiwazaki (56) References JP-A-60-118806 (JP, A) JP-A-59-143202 (JP, A) JP-A-59-189334 (JP, A) JP-A-54-40086 (JP, U) JP-A-57-167503 (JP, U)

Claims (2)

(57) [Claims] A light source; a light transmission rod having a solid circular cross section for transmitting light generated by the light source; and an outer peripheral portion of a ring having a solid circular cross section, transmitted from the light transmission rod. It has a diffusion fringe applied in the form of a dot whose interval is continuously narrowed from the vicinity of the light incident end according to the path of light, and makes the light transmitted by the light transmission rod uniform in the inner circumferential direction of the ring. A ring transmission light that irradiates the ring transmission light, a transparent transmission plate that is surrounded by the ring transmission light, receives irradiation light from the ring transmission light, and emits surface light with diffusion stripes applied to one surface, and covers the ring transmission light. An opening for sandwiching the outer peripheral end of the transparent transmission plate at a position facing the diffusion stripes of the ring transmission light, and light leaking out of the transparent transmission plate from the ring transmission light. And a cylindrical reflector for reflecting the light again into the ring transmission light, re-entering the diffusion fringes of the ring transmission light, and causing the diffusely reflected light to enter the outer peripheral end surface of the transparent transmission plate. 2. The ring transmission light has a width gradually changed from the vicinity of the light incident end of the light from the light transmission rod in accordance with the light path, instead of the diffusion fringes applied in a dot shape on the outer periphery thereof. 2. The planar light source according to claim 1, wherein the planar light source has diffusion stripes applied in a spread linear shape.