Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
  • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
  • G02B6/0081—Mechanical or electrical aspects of the light guide and light source in the lighting device peculiar to the adaptation to planar light guides, e.g. concerning packaging
  • G02B6/0086—Positioning aspects
  • G02B6/0091—Positioning aspects of the light source relative to the light guide
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
  • F21V17/00—Fastening of component parts of lighting devices, e.g. shades, globes, refractors, reflectors, filters, screens, grids or protective cages
  • F21V17/10—Fastening of component parts of lighting devices, e.g. shades, globes, refractors, reflectors, filters, screens, grids or protective cages characterised by specific fastening means or way of fastening
  • F21V17/104—Fastening of component parts of lighting devices, e.g. shades, globes, refractors, reflectors, filters, screens, grids or protective cages characterised by specific fastening means or way of fastening using feather joints, e.g. tongues and grooves, with or without friction
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
  • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
  • G02B6/0013—Means for improving the coupling-in of light from the light source into the light guide
  • G02B6/0023—Means for improving the coupling-in of light from the light source into the light guide provided by one optical element, or plurality thereof, placed between the light guide and the light source, or around the light source
  • G02B6/0031—Reflecting element, sheet or layer

Definitions

• the present invention relates to a surface light source device used as, for example, a backlight of a liquid crystal display device, and particularly to a surface light source device using a light guide.
• FIG. 1 is a cross-sectional view showing an example of a conventional surface light source device using a light guide.
• 1 is a plate-shaped light guide having a square planar shape and an appropriate thickness and size
• 2 is, for example, a double-sided adhesive tape 3 on one end of the light guide 1 on the exit surface 1 a of the light guide 1.
• the light diffusion sheet 4 having substantially the same size as the light guide 1 placed in a state where the light guide 1 is fixed, for example, faces the emission surface 1 a of the light guide 1 with a double-sided adhesive tape 5.
• the reflection sheet has substantially the same size as the light guide 1 placed with the one end fixed on the surface 1b.
• Reference numeral 6 designates the light guide 1, the light diffusion sheet 2 and the reflection sheet 4 sandwiching the other ends of the light guide 1, the light diffusion sheet 2 and the reflection sheet 4 by the flanges 6a and 6b.
• the holders 1 and 7 having a substantially annular cross section and extending along the incident end face 1c of the light guide 1 so as to cover the other end of the port 4 are placed in the holder 6.
• An elongated light source such as a cold-cathode tube, which is fixed by an appropriate method and extends along the side surface 1 of the light guide 1.
• 8 is a flange 6 a, a light diffusion sheet 2, a light guide 1, a reflection sheet 4 and Bolt penetrated through a hole coaxially drilled in the flange 6b
• Reference numeral 9 denotes a nut screwed to an end of a bolt 8 projecting from the lower surface of the flange 6b.
• the light source configured as described above, the light source
• the light emitted from the light source 7 is reflected by the reflection surface formed on the inner surface of the holder 16 or directly from the light source 7 to the incident end face 1 c of the light guide 1. Opposite, light guide from incident end face 1 c
• the light enters the light guide 1 and propagates through the light guide 1. During this time, the incident light is reflected by the reflection sheet 4 or is reflected by the inner surface of the light guide 1, exits from the exit surface lb, and spreads out.
• the surface of the light diffusion sheet 2 becomes a surface light source because the light is diffused by passing through the light 2.
• a surface light source device may be used in a high-temperature and high-humidity environment.
• the linear expansion coefficients of the light guide 1, the light diffusion sheet 2 and the reflection sheet 4 are different from each other, the expansion of the light guide 1, the light diffusion sheet 2 and the reflection sheet 4 may be reduced.
• the shrinkage caused a difference in the amount of shrinkage, and as a result, the light diffusion sheet and / or the reflection sheet sometimes became slack. If the light diffusion sheet 2 and Z or the reflection sheet 4 becomes loose, the light emitted from the light exit surface 1a of the light guide 1 is affected, and the brightness of the surface light source device is reduced. It was one of their causes.
• an object of the present invention is to provide a surface light source device in which dust and the like do not enter between them.
• Another object of the present invention is to provide a surface light source device which has a smaller number of parts than a conventional device and is easy to assemble.
• the distance between the flange of the holder and the light emitting surface of the light guide and / or the distance between the flange of the holder and the light guide surface on the side opposite to the light emitting surface is determined.
• the flanges of the holder are attached so that a gap slightly larger than the thickness of the light diffusion sheet and the reflection sheet is formed between them.
• One end of the light diffusion sheet and the reflection sheet are arranged in the gap so as to be freely movable within a predetermined range, and the other end is fixed to the light guide by fixing means. .
• the light diffusion sheet, the light guide, and the reflection sheet are mutually affected by changes in temperature and humidity. Regardless of the amount of expansion or contraction, the one end of the light diffusion sheet and the reflection sheet can move freely with respect to the light guide, and the light diffusion sheet. There is no slack in the reflection sheet.
• the tip of a bolt for fixing the collar portion of the holder to the light guide is directly screwed to one of the collar portions. This eliminates the need for nuts and simplifies assembly.
• FIG. 1 is a cross-sectional view showing an example of a conventional surface light source device using a light guide
• FIG. 2 is an exploded perspective view of an essential part of an embodiment of the surface light source device according to the present invention
• FIG. FIG. 4 is a sectional view of a principal part showing an assembled state of the surface light source device shown in FIG. 2
• FIG. 4 is a sectional view of a principal part showing another embodiment of the surface light source device according to the present invention
• FIG. FIG. 6 is a sectional view of a principal part of still another embodiment of the surface light source device according to the present invention
• FIG. 6 is a sectional view of a principal part of still another embodiment of the surface light source device according to the present invention.
• a washer-shaped projection 6 a ′ is provided on the inner surface of the flange 6 a of the holder 16.
• -It is physically formed and has a flange 6a
• the projection 6a ' is formed with a see through 6a ⁇ .
• a washer-like projection 6b ' is formed on the inner surface of the flange 6b of the hoselder 6, and the flange 6b and the projection 6b' Screw holes 6 b ⁇ are formed.
• the through-hole 6 a ⁇ and the screw hole 6 b ⁇ are aligned vertically, and the pair of the projection 6 a ′ with the hole and the projection 6 b ′ with the screw hole is formed by a flange 6 a ⁇ . , 6b are provided at predetermined intervals along the longitudinal direction.
• a semicircular notch 2 a for example, having a semicircular notch 2 a that can be loosely fitted to the projections 6 a ′ and 6 b ′ of the holder 6. It is formed corresponding to the pair.
• a similar cutout 4a is also formed in the reflection sheet 4. As can be seen in FIG.
• the heights of the projections 6a 'and 6b' are slightly larger than the thickness of the light diffusion sheet 2 and the reflection sheet 4.
• 10 (Fig. 3) is a clip for integrally fixing the ends of the light guide 1, the light diffusion sheet 2 and the reflection sheet 4 on the side opposite to the holder 6. You.
• the light diffusion sheet 2 and the reflection sheet 4 are placed on the opposing surface of the light guide 1, and one end thereof is integrally fixed using the clip 10. .
• the other ends of the light diffusion sheet 2 and the reflection sheet 4 are temporarily fixed by heat welding or double-sided adhesive tape 11 as schematically shown in FIG.
• the light diffusion sheet 2 and the reflection sheet 4 are fitted between the flanges 6a and 6b so as to sandwich the light diffusion sheet 2 and the reflection sheet 4 from above and below, so that the projection 6a 'and the notch 2a are fixed to the projection 6b.
• the notch portions 4a are adjusted so that the through holes 6a ⁇ and the through holes 1d and the screw holes 6b ⁇ formed in the light guide 1 are aligned with each other.
• the bolt 8 is inserted into the through holes 6a ⁇ and 1d from above, and the tip is screwed into the screw hole 6b ⁇ , and the holder 16 is fixed to the light guide 1.
• You Temporary fixing by heat welding or double-sided adhesive tape 11 is a method in which the light diffusion sheet 2 and the reflection sheet 4 are separated from the surface of the light guide 1 during the above assembling work. This is done to prevent dust etc. from entering the body 1 and to prevent fingerprints from sticking to the diffusion sheet 2, and to reduce the temperature and humidity after assembly.
• the light body 1 is easily separated from the light guide 1. It is done with a very small area to get it.
• the light guide 1 is made of a metal resin
• the light diffusion sheet 2 is made of a polycarbonate, etc.
• the reflection sheet 4 is made of a polyethylene film. It is made of base foam.
• Methacrylic resin has an extremely high degree of expansion and contraction with respect to changes in humidity as compared to polycarbonate, polyethylene, latex, etc.
• the light guide 1, the light diffusion sheet 2 and the reflection sheet change due to changes in temperature and humidity. Even if 4 shrinks by different amounts, light diffusion sheet 2 and reflection sheet 4 are free to light guide 1 in the direction of arrows A and / or B in FIG. I can move. Accordingly, since the light diffusion sheet 2 and the reflection sheet 4 generally have a certain degree of rigidity, the light diffusion sheet 2 and the reflection sheet 4 may be loosened. There is nothing.
• the light diffusion sheet 2 is covered by the flange 6a, and the reflection sheet 4 is covered by the flange 6b with a slight gap. However, it does not come out of the flange. Therefore, even if there is a change in temperature or humidity, it does not cause uneven brightness as a surface light source.
• FIG. 4 shows a second embodiment of the surface light source device according to the present invention.
• the projections 6 a ′ and 6 b ′ are configured as washers 12, 13 different from the flanges 6 a, 6 b, and the tip of the bolt 8 is
• the light guide 1, the light diffusion sheet 2, and the reflection sheet 4 are integrally fixed by the plastic rivet 14. This is different from the first embodiment in that Since the operation and effect of this embodiment are the same as those of the first embodiment, description thereof will be omitted.
• FIG. 5 shows a third embodiment of the surface light source device according to the present invention.
• the edge of the light diffusion sheet 2 and the reflection sheet 4 on the holder 6 side is located at a position simply separated from the washers 12 and 13 by a predetermined distance.
• the second embodiment is different from the second embodiment in that it is mounted on the light guide 1 in advance. Also in this case, the operation and effect are the same as those in the above-described 'Example, and therefore the description is omitted.
• FIG. 6 shows a fourth embodiment of the surface light source device according to the present invention. ing.
• the openings of the light diffusion sheet 2 and the reflection sheet 4 on the holder 6 side are larger than the washers 12 and 13 by a predetermined size and a larger diameter. It differs from the second and third embodiments in that 2c and 4c are provided respectively. Since the operation and effect of this embodiment are the same as those of the above-described embodiment, description thereof will be omitted.
• the double-sided adhesive tapes 3 and 5 may be used.
• Other appropriate mechanical methods such as heat welding and screws can be used.
• a through hole is formed on the flange 6a side and a screw hole is formed on the flange 6b side, so that the bolt 8 is inserted from above.
• a screw hole may be formed on the part 6a side, and a through hole may be formed on the flange part 6b side, so that the bolt 8 is inserted from below.
• the light guide 1, the light diffusion sheet 2, and the reflection sheet 4 are movable relative to each other by the flanges 6a, 6b of the holder 16 of the reflection sheet 4.
• the arrangement of the ends may be a combination of the embodiments described above.
• the surface light source device according to the present invention is extremely useful as a backlight for various liquid crystal display devices.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Planar Illumination Modules (AREA)
• Optical Elements Other Than Lenses (AREA)

Priority Applications (4)

Applications Claiming Priority (1)

Publications (1)

Family

ID=14098334

Family Applications (1)

Country Status (4)

Families Citing this family (33)

Citations (2)

Family Cites Families (8)

• 1994
  • 1994-04-22 DE DE69426978T patent/DE69426978T2/de not_active Expired - Fee Related
  • 1994-04-22 US US08/244,673 patent/US5497293A/en not_active Expired - Fee Related
  • 1994-04-22 WO PCT/JP1994/000675 patent/WO1995029364A1/ja active IP Right Grant
  • 1994-04-22 EP EP94913805A patent/EP0706073B1/en not_active Expired - Lifetime

Patent Citations (2)

Non-Patent Citations (1)

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