WO2022009525A1 - Planar illumination device - Google Patents

Planar illumination device Download PDF

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Publication number
WO2022009525A1
WO2022009525A1 PCT/JP2021/018548 JP2021018548W WO2022009525A1 WO 2022009525 A1 WO2022009525 A1 WO 2022009525A1 JP 2021018548 W JP2021018548 W JP 2021018548W WO 2022009525 A1 WO2022009525 A1 WO 2022009525A1
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WO
WIPO (PCT)
Prior art keywords
guide plate
light guide
light
lighting device
planar lighting
Prior art date
Application number
PCT/JP2021/018548
Other languages
French (fr)
Japanese (ja)
Inventor
和正 安達
良太 倉田
Original Assignee
ミネベアミツミ株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by ミネベアミツミ株式会社 filed Critical ミネベアミツミ株式会社
Priority to CN202180032911.0A priority Critical patent/CN115552324A/en
Priority to JP2021553362A priority patent/JP7340028B2/en
Publication of WO2022009525A1 publication Critical patent/WO2022009525A1/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S2/00—Systems of lighting devices, not provided for in main groups F21S4/00 - F21S10/00 or F21S19/00, e.g. of modular construction
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336—Illuminating devices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
    • F21Y2105/00—Planar light sources
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
    • F21Y2115/00—Light-generating elements of semiconductor light sources
    • F21Y2115/10—Light-emitting diodes [LED]

Definitions

  • the present invention relates to a planar lighting device.
  • a planar lighting device used as a backlight of a liquid crystal display device is known (see Patent Documents 1, 2, etc.).
  • a top frame (housing frame) provided with an opening for light emission is often used as a part of the housing, and the portion of the top frame forming the opening for light emission is It is called a picture frame.
  • a picture frame the portion of the top frame forming the opening for light emission is It is called a picture frame.
  • edge light type planar lighting device in which light is incident from the incoming light side surface of the light guide plate and is emitted from one main surface of the light guide plate, and the exit surface has a horizontally long shape and is guided.
  • the exit surface has a horizontally long shape and is guided.
  • elastic members such as rubber, which are arranged on the terminal side (opposite to the light entrance side) of the light guide plate and on the left and right sides and press the light guide plate to the light entrance side, are eliminated, and the light entrance side of the light guide plate has high adhesive strength.
  • the frame is narrowed on three sides.
  • the size of the liquid crystal display device increases, the size of the planar lighting device increases, and when the long side on the incoming light side becomes, for example, about 700 to 800 mm, it is fixed by a thermocompression bonding tape or the like at a place where the amount of elongation of the light guide plate is large.
  • the light guide plate could not be sufficiently fixed due to the structural failure (aggregation failure) of the portion.
  • the longest possible range on the side of the incoming light should be fixed, but it was difficult to predict the expansion and contraction of the light guide plate, and it was difficult to maximize the fixed range. ..
  • the structurally broken portion affects the optical characteristics of the light guide plate, it should be fixed within a range where the structural failure does not occur. Further, since the amount of expansion and contraction of the horizontally long light guide plate to the left and right is not determined, it is difficult to design the frame on the left and right sides.
  • the present invention has been made in view of the above, and it is possible to stably fix the light guide plate and facilitate the frame design, and it is possible to narrow the frame even for a large light guide plate. It is an object of the present invention to provide a shape lighting device.
  • the planar lighting device includes a bottom frame, a recess, a center pin, and a fixing portion.
  • the bottom frame has a floor portion and a side wall erected on the peripheral edge of the floor portion, and accommodates a light guide plate.
  • the recess is provided substantially in the center of the side of the light guide plate on the light receiving side.
  • the center pin is erected on the floor and fits into the recess.
  • the fixing portion fixes the light guide plate to the bottom frame within a predetermined distance from the center pin on the side of the light guide plate on the light entrance side.
  • the planar lighting device can stably fix the light guide plate and facilitate the frame design, and can narrow the frame even for a large light guide plate.
  • FIG. 1 is a plan view of a planar lighting device according to an embodiment.
  • FIG. 2 is a perspective view of a flat type planar lighting device.
  • FIG. 3 is an exploded perspective view of a main part of a flat type planar lighting device.
  • FIG. 4 is a perspective view of a curved type planar lighting device.
  • FIG. 5 is an exploded perspective view of a main part of a curved type planar lighting device.
  • FIG. 6 is a plan view near the center of the long side of the incoming light side of the planar lighting device.
  • FIG. 7 is a plan view of the planar lighting device in a state where the top frame, the optical sheet, and the like near the center of the long side on the incoming light side are removed.
  • FIG. 1 is a plan view of a planar lighting device according to an embodiment.
  • FIG. 2 is a perspective view of a flat type planar lighting device.
  • FIG. 3 is an exploded perspective view of a main part of a flat
  • FIG. 8 is a plan view in a state where the top frame, the optical sheet, the light guide plate, the reflection sheet, and the like near the center of the long side on the incoming light side of the planar lighting device are removed.
  • FIG. 9 is a cross-sectional view of X1-X1 in FIG. 6 of the planar lighting device.
  • FIG. 10 is a diagram showing an example of the relationship between the elongation amount of the thermocompression bonding tape and the stress in an environment of 85 ° C.
  • FIG. 11 is a diagram showing an example of a model for verifying a range in which cohesive failure of the thermocompression bonding tape does not occur.
  • FIG. 12 is a diagram showing an example of the length of the fixing portion by the thermocompression bonding tape when the planar lighting device is diagonally 32 inches.
  • FIG. 13 is a diagram showing an example of the length of the fixing portion by the thermocompression bonding tape when the planar lighting device has a diagonal of 12.3 inches.
  • FIG. 14 is a plan view showing an example of an optical sheet.
  • FIG. 15 is an enlarged view of the portion A1 shown by the broken line in FIG.
  • FIG. 16 is a cross-sectional view of X2-X2 in FIG. 6 of the planar lighting device.
  • FIG. 1 is a plan view of the planar lighting device 1 according to the embodiment.
  • the plan view of FIG. 1 is also used as the plan view of the curved type planar lighting device 1 described later.
  • FIG. 2 is a perspective view of the flat type planar lighting device 1.
  • FIG. 3 is an exploded perspective view of a main part of the flat type planar lighting device 1. Further, for convenience, the long side direction of the planar lighting device 1 is the X-axis direction, the short side direction is the Y-axis direction, and the thickness direction is the Z-axis direction.
  • the planar lighting device 1 has a shape in which a reflective sheet 4, a light guide plate 7, and an optical sheet 9 are sequentially laminated on a bottom frame 3 and covered with a top frame 10. .
  • the bottom frame 3 and the top frame 10 have a flat main surface.
  • a plurality of light sources that emit light to the light entrance side surface (the side surface of the long side on the front side in the figure) of the light guide plate 7 and a substrate on which these light sources are mounted are omitted.
  • the connecting portion 2 is a member having one end connected to an internal substrate and used for electrical connection with the outside.
  • the bottom frame 3 is made of metal, for example, and is formed of die casting, sheet metal, or the like.
  • the reflective sheet 4 is for reflecting the light leaked from the light guide plate 7 to the bottom frame 3 side and returning it to the light guide plate 7 side. If the floor surface of the bottom frame 3 is painted white and has good reflection characteristics, the reflection sheet 4 may be omitted.
  • the light guide plate 7 is made of a transparent resin such as polycarbonate or acrylic, and guides the light incident from the incoming light side surface on the long side to the entire surface and emits light from one main surface (upper main surface in the figure). do.
  • the optical sheet 9 is one or a plurality of sheets that exert an optical action, such as a diffusion sheet, a prism sheet, a brightness increasing film (DBEF: Dual Brightness Enhancement Film), and the like.
  • One end of the long side of the optical sheet 9 (the front side in the figure) is fixed to, for example, one piece of the sheet fixing frame 8 in which an elongated plate is bent into a substantially L-shaped cross section, and the sheet fixing frame 8 is fixed.
  • the other piece is sandwiched and fixed between the side wall of the bottom frame 3 and the side wall of the top frame 10.
  • the optical sheet 9 may be fixed by passing the center pin 11 through the hole provided in the optical sheet 9.
  • the top frame 10 is made of, for example, a resin or the like.
  • FIG. 4 is a perspective view of the curved type planar lighting device 1
  • FIG. 5 is an exploded perspective view of the main part of the curved type planar lighting device 1.
  • the plan view is the same as that in FIG. 4 and 5, the bottom frame 3, the reflective sheet 4, the light guide plate 7, the optical sheets 9A to 9C (corresponding to the optical sheet 9), and the top frame 10 are shown except that the main surface is curved. 2 and FIG. 3 are similar.
  • the bottom frame 3 and the top frame 10 are formed in a curved state from the beginning, the reflective sheet 4, the light guide plate 7, and the optical sheets 9A to 9C are not curved before assembly, and are on the bottom frame 3. It is curved when placed and fixed in a state of being pressed by the top frame 10.
  • FIG. 6 is a plan view of the planar lighting device 1 near the center of the long side on the incoming light side.
  • a center pin 11 is erected in the Z-axis direction near the center of the long side on the incoming light side of the planar lighting device 1, and the center pin 11 is erected from the hole portion 10h of the frame portion 10a of the top frame 10. You can see the tip of.
  • the hole 10h may not be provided.
  • the convex portion 3c provided on the side wall of the bottom frame 3 is fitted into the hole portion 10c provided in the frame portion 10a of the top frame 10, and the side wall of the top frame 10 is on the outside (in the figure). It is prevented from bending in a bow shape (lower side, in the Y-axis direction).
  • FIG. 7 is a plan view in a state where the top frame 10 and the optical sheets 9 (9A to 9C) near the center of the long side on the incoming light side of the planar lighting device 1 are removed.
  • an arcuate notch 7b (corresponding to the “recess” of the present invention) is provided near the center of the long side of the light guide plate 7 on the light entrance side, and this notch 7b is the center pin 11. It is designed to come into contact with the outer peripheral surface of the.
  • the center pin 11 positions the central portion of the light guide plate 7, and it is desirable that the center pin 11 and the notch portion 7b are loosely fitted so as not to give unnecessary stress to the light guide plate 7 and deteriorate the optical characteristics. ..
  • the emission surface of the light source 6 such as a plurality of LEDs (Light Emitting Diodes) provided on the substrate 5 is arranged so as to face the light entrance side surface 7a of the light guide plate 7.
  • the side wall 3b of the bottom frame 3 is provided with a claw-shaped convex portion 3d protruding outward (lower side in the figure), and by fitting with a hole provided in the side wall of the top frame 10, the side wall 3b is fitted with a hole portion.
  • the bottom frame 3 and the top frame 10 are fixed in the Z-axis direction.
  • FIG. 8 is a plan view in a state where the top frame 10, the optical sheets 9 (9A to 9C), the light guide plate 7, the reflective sheet 4, and the like near the center of the long side on the incoming light side of the planar lighting device 1 are removed. ..
  • a strip-shaped white double-sided tape 13 is attached to the outer peripheral portion of the inner surface of the floor portion 3a of the bottom frame 3 on the light receiving side so as to extend in the X-axis direction while avoiding the center pin 11.
  • a base film 14 made of a band-shaped transparent polycarbonate or the like is attached to the outer peripheral portion of the double-sided tape 13 on the light receiving side.
  • thermocompression bonding tapes 16 arranged between the light sources 6 so as not to affect the incident light on the light guide plate 7 are provided in a flying island shape. ing. Further, on the left and right and above, which are a part of the peripheral edge of each thermocompression bonding tape 16, spacers 15 made of white resin divided in the longitudinal direction so as to surround them at a predetermined distance are formed by double-sided tape or the like. It is pasted.
  • thermocompression bonding tape 16 is melted by heating and adheres between the base film 14 and the light guide plate 7 with high strength. Since the base film 14 is strongly fixed to the floor portion 3a of the bottom frame 3 by the double-sided tape 13 having a large area, the light guide plate 7 is strongly fixed to the bottom frame 3.
  • the spacer 15 functions as a flow stop when the thermocompression bonding tape 16 melts, and secures an adhesive force by securing a predetermined adhesive area and thickness. The reason why the spacer 15 is divided in the longitudinal direction is to absorb the difference in linear expansion coefficient from the base film 14 or the like to be attached.
  • a fixing member of an adhesive type that can be applied with a syringe or the like and that does not require a heat source and is cured by moisture in the atmosphere can also be used.
  • FIG. 9 is a cross-sectional view of X1-X1 in FIG. 6 of the planar lighting device 1.
  • the center pin 11 is screwed and fixed to the floor portion 3a of the bottom frame 3 from the outside (lower side in the figure) via the nut 12, and the head portion 11b of the center pin 11 is fixed to the bottom frame 3. It's on the outside.
  • the center pin 11 may be fixed to the bottom frame 3 by press fitting instead of screwing.
  • the shaft portion 11a of the center pin 11 penetrates the reflective sheet 4, the light guide plate 7, and the optical sheets 9 (9A to 9C) and extends to the inside of the hole portion 10h of the frame portion 10a of the top frame 10. As described above, the shaft portion 11a of the center pin 11 is in contact with the notch portion 7b at the center of the long side of the light guide plate 7 on the incoming light side.
  • a substrate 5 in which a plurality of light sources 6 are arranged in the long side direction is fixed by double-sided tape or the like, and the emission surface of the light source 6 is on the entrance side surface 7a of the light guide plate 7. Facing each other.
  • the light source 6 a top-view type LED or the like that emits light on the top surface side is shown as an example, but a side-view type LED or the like that emits light on the side surface side can also be used.
  • the substrate 5 is arranged parallel to the floor portion 3a of the bottom frame 3.
  • FIG. 10 is a diagram showing an example of the relationship between the elongation amount of the thermocompression bonding tape 16 and the stress in an environment of 85 ° C.
  • the amount of elongation is a reversible change up to 0.7 mm
  • the stress increases with the amount of elongation
  • the stress decreases as the amount of elongation decreases.
  • the amount of elongation exceeds 0.7 mm
  • an irreversible change occurs, the stress decreases with the amount of elongation, and even if the amount of elongation is reduced, it cannot be restored.
  • there is only one inflection point, and the elongation limit and the fracture are the same point.
  • FIG. 11 is a diagram showing an example of a model for verifying a range in which cohesive failure of the thermocompression bonding tape 16 does not occur.
  • GLASS D263 is the base part, and on top of that, "BST” corresponding to double-sided tape 13, "Base Film PC” corresponding to base film 14, and Tobishima-shaped "” corresponding to thermocompression bonding tape 16.
  • "HBT” and "LGP” corresponding to the light guide plate 7 are arranged.
  • the inside of the wall on the left side of “GLASS D263” is the reference position for expansion and contraction, and linear expansion occurs to the right.
  • the reason why glass is used instead of metal for the base corresponding to the bottom frame is that the difference in the amount of thermal expansion from the light guide plate is ⁇ X due to the use of a member having a smaller coefficient of thermal expansion than metal. This is to realize.
  • the central portion of the long side of the light guide plate 7 on the incoming light side is positioned by the center pin 11, and the central portion serves as a reference position for linear expansion.
  • the fixing range can be maximized.
  • the amount of expansion and contraction on the left and right is the same, it is easy to design the frame on the left and right sides.
  • FIG. 12 is a diagram showing an example of the length of the fixed portion by the thermocompression bonding tape when the planar lighting device 1 is diagonally 32 inches, and has a flying island shape in a range of 400 mm centered on the central portion of the long side. It is within the range of fixing with the thermocompression bonding tape 16.
  • FIG. 13 is a diagram showing an example of the length of the fixed portion by the thermocompression bonding tape when the planar lighting device 1 has a diagonal of 12.3 inches, and has a flying island shape of 300 mm, which is the entire range of the long side. The range of fixing with the thermocompression bonding tape 16 is set.
  • the strength as a device will be considered.
  • a light guide plate is fixed with ordinary double-sided tape, and a light guide plate with a weight of 18.6 g is used for comparison.
  • the shear strength is 4 N / mm 2
  • the adhesive area per 1 g is 4 mm 2 / g
  • the adhesive strength of the backlight is 298 N
  • [adhesive area per 1 g] ⁇ [adhesive strength of the backlight] ⁇ . 10 2 is 12.
  • the light guide plate weight 272 g, shear strength is 25 N / mm 2, the adhesion area adhesive area per 143.9mm 2, 1g 0. 5 mm 2 / g, the adhesive strength of the backlight is 3598 N, and [adhesive area per 1 g] ⁇ [adhesive strength of the backlight] ⁇ 10 2 is 19.
  • the light guide plate weight 93 g, shear strength is 25 N / mm 2, the adhesive area bonded area 107.93Mm 2, per 1 g 1.
  • the adhesive strength of the backlight is 2698 N
  • [adhesive strength of the backlight] ⁇ 10 2 is 31.
  • the surface illumination device 1 of FIG. 12 or 13 is higher strength than the standard model.
  • the drop impact resistance, the thermal impact resistance, and the brightness drop rate are all good including the standard model.
  • FIG. 14 is a plan view showing an example of the optical sheet 9 (9A, 9B, 9C).
  • FIG. 15 is an enlarged view of the portion A1 shown by the broken line in FIG.
  • the center of the optical sheet 9 (9A, 9B, 9C) is located at a predetermined distance from the end in the lateral direction at the substantially center of the side on the incoming light side (lower side in the figure).
  • a hole 9a into which the pin 11 (FIGS. 6 to 9) is fitted is provided.
  • the outer diameter of the center pin 11 and the hole diameter of the hole portion 9a of the optical sheet 9 are designed so that there is no play, but the optical sheet 9 is slightly deformed even if it is designed with tight tolerances. No problem.
  • notches 9c extending in the longitudinal direction are provided at both ends of the portion of the optical sheet 9 (9A, 9B, 9C) where the hole portion 9a is provided, and the portion where the hole portion 9a is provided is the selvage portion 9b. ..
  • the cutout portion 9c is for avoiding interference with the rib 10i of the top frame 10 described later.
  • the optical sheet 9 (9A, 9B, 9C) rotates around the center pin 11 (hole portion 9a) at both ends of the side of the optical sheet 9 (9A, 9B, 9C) on the incoming light side.
  • a claw portion 9d is provided to prevent the generation of rattle noise.
  • the claw portion 9d abuts on the side wall 3b of the bottom frame 3 or the substrate 5.
  • the optical sheet was mainly fixed to the light guide plate with double-sided tape on the left and right sides of a horizontally long rectangle.
  • the weight of the optical sheet also increases, and it has become difficult to stably hold the optical sheet by fixing it with double-sided tape.
  • fixing on the left and right sides has been abolished, and fixing on the incoming side has been started.
  • the light guide plate is the only place where the optical sheet can be fixed on the light entrance side, and if the optical sheet is fixed directly to the light guide plate, there is a problem that the brightness is lowered and the reliability is lowered due to the generation of wrinkles.
  • the optical sheet 9 in fixing the optical sheet 9 by the center pins 11 (FIGS. 6 to 9) of FIGS. 14 and 15, the optical sheet 9 has a simple structure in which the holes 9a of the optical sheet 9 are simply inserted into the center pins 11. Can be stably supported. Further, since the optical sheet 9 is not directly fixed to the light guide plate 7, it does not affect the optical characteristics and reliability. Furthermore, since it is fixed without using double-sided tape, it is easy to obtain position accuracy and clearance can be reduced, which can further contribute to narrowing the frame. Further, since the optical sheet 9 is supported at one place by the center pin 11, wrinkles do not occur as in the case of fixing with double-sided tape.
  • FIG. 16 is a cross-sectional view of X2-X2 in FIG. 6 of the planar lighting device 1.
  • a rib 10i projecting toward the light guide plate 7 and extending in the longitudinal direction is provided.
  • the ribs 10i are arranged on both sides of the selvage portion 9b of the optical sheet 9 so as not to come into contact with the optical sheet 9.
  • the rib 10i presses the main surface of the light guide plate 7 on the incoming light side toward the floor portion 3a of the bottom frame 3 via the cushion material 17.
  • the surface of the cushion material 17 facing the light guide plate 7 is subjected to a reflection treatment such as white.
  • a reflection treatment such as white.
  • the fixing of the light guide plate 7 to the bottom frame 3 by the double-sided tape 13, the base film 14, and the thermocompression bonding tape 16 described above can be strengthened, and the light guide plate 7 can be prevented from rising or shifting.
  • the reflection treatment of the cushion material 17 by white or the like can reduce the leakage of light to the cushion material 17 side and suppress the influence on the optical characteristics of the light guide plate 7.
  • the planar lighting device has a floor portion and a side wall erected on the peripheral edge of the floor portion, and has a bottom frame for accommodating the light guide plate and a light receiving side of the light guide plate.
  • the light guide plate is bottomed within a predetermined distance from the concave portion provided in the substantially center of the side, the center pin erected on the floor and fitted with the concave portion, and the center pin on the side of the light receiving side of the light guide plate. It has a fixing part to be fixed to the frame. As a result, the light guide plate can be stably fixed and the frame design can be facilitated, and the frame can be narrowed even for a large light guide plate.
  • the predetermined distance is a distance at which the fixed portion does not collapse due to expansion and contraction within the operating temperature range of the light guide plate. As a result, it is possible to prevent an adverse effect on the optical characteristics of the light guide plate due to the structural failure of the fixed portion.
  • the fixing portion has a base film attached to the bottom frame via double-sided tape, a thermocompression bonding tape for fixing the base film and the light guide plate, or a fixing member that can be replaced with the thermocompression bonding tape. This makes it possible to firmly fix the light guide plate to the bottom frame.
  • thermocompression bonding tape or the fixing member is arranged between the light sources in a flying island shape discrete in the extending direction of the side of the light guide plate on the incoming light side. This makes it possible to prevent the thermocompression bonding tape or the fixing member from adversely affecting the incident light from the light source to the light guide plate.
  • thermocompression bonding tape or a spacer that surrounds at least a part of the peripheral edge of the fixing member, which is attached to the base film via double-sided tape.
  • a top frame that fits on the opening side of the bottom frame and has a rib that presses the light guide plate via a cushion material is provided on the back side of the frame portion. As a result, it is possible to strengthen the fixing of the light guide plate to the bottom frame and prevent the light guide plate from rising or shifting.
  • the optical sheet has holes that fit into the center pin at a predetermined distance from the substantially central end of the side that enters the light, and can be used as the side wall of the bottom frame or the substrate of the light source at both ends of the side that enters the light. It has one or more optical sheets that have claws that come into contact with each other and are laminated on the emission side of the light guide plate. As a result, the optical sheet can be easily fixed and rotation of the optical sheet can be prevented.
  • a predetermined distance from the top frame which is fitted to the opening side of the bottom frame and has ribs on the back side of the frame portion to press the light guide plate via the cushioning material, and the substantially central end portion of the side on the light entering side. It has a hole that fits into the center pin at the position, a notch that avoids ribs on the side of the incoming light, and a claw that contacts the side wall of the bottom frame or the substrate of the light source at both ends of the side on the incoming light side. It has a portion and includes one or more optical sheets laminated on the emission side of the light guide plate. This makes it possible to prevent the configuration for pressing the light guide plate by the ribs and cushioning material of the top frame from interfering with the configuration for fixing the optical sheet.
  • the surface of the cushion material facing the light guide plate is subjected to reflection treatment. As a result, it is possible to prevent light from leaking from the light guide plate to the cushion material side and prevent deterioration of optical characteristics.
  • the present invention is not limited to the above embodiments.
  • the present invention also includes a configuration in which the above-mentioned components are appropriately combined. Further, further effects and modifications can be easily derived by those skilled in the art. Therefore, the broader aspect of the present invention is not limited to the above-described embodiment, and various modifications can be made.
  • 1 planar lighting device 2 connection part, 3 bottom frame, 3a floor part, 3b side wall, 4 reflective sheet, 5 board, 6 light source, 7 light guide plate, 7b notch part, 8 sheet fixing frame, 9 optical sheet, 9 , 9A-9C optical sheet, 9a hole, 9c notch, 9d claw, 10 top frame, 10a frame, 10b side wall, 10i rib, 11 center pin, 11a shaft, 11b head, 12 nut, 13 double-sided Tape, 14 base film, 15 spacer, 16 thermocompression bonding tape, 17 cushion material

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  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • Mathematical Physics (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Planar Illumination Modules (AREA)

Abstract

A planar illumination device (1) of one embodiment comprises: a bottom frame (3); a recess (7b); a center pin (11); and a fixing part. The bottom frame (3): has a floor section (3a) and a side wall (3b) which is erected on a peripheral edge of the floor section (3a); and accommodates a light guide plate (7). The recess (7b) is provided in approximately the center of the light incidence side of the light guide plate (7). The center pin (11) is erected on the floor section (3a), and is fit with the recess (7b). The fixing part fixes the light guide plate (7) to the bottom frame (3) within the range of a predetermined distance from the center pin (11) on the light incidence side of the light guide plate (7).

Description

面状照明装置Planar lighting device
　本発明は、面状照明装置に関する。 The present invention relates to a planar lighting device.
　液晶表示装置のバックライト等として用いられる面状照明装置が知られている（特許文献１、２等を参照）。 A planar lighting device used as a backlight of a liquid crystal display device is known (see Patent Documents 1, 2, etc.).
　一般的な面状照明装置では、光出射用の開口が設けられたトップフレーム（ハウジングフレーム）が筐体の一部として用いられることが多く、トップフレームにおける光出射用の開口を形成する部分は額縁と呼ばれる。昨今では主にデザイン上の観点から、額縁の幅を狭くする狭額縁化が要請されている。 In a general planar lighting device, a top frame (housing frame) provided with an opening for light emission is often used as a part of the housing, and the portion of the top frame forming the opening for light emission is It is called a picture frame. Nowadays, there is a demand for narrowing the width of the frame, mainly from the viewpoint of design.
　ここで、導光板の入光側面から光を入射し、導光板の一方の主面から光を出射する、いわゆるエッジライト型の面状照明装置であって、出射面が横長の形状で、導光板の長辺の一方（説明上、下側の長辺）が入光側となる場合を考える。この場合、上側の長辺および左右の短辺における３辺の狭額縁化は、筐体内で導光板がどのように支持されるかによって影響を受けるため、導光板の支持構造について種々のものが提案されてきた。例えば、導光板の終端側（入光側と反対側）および左右に配置され、導光板を入光側に押圧するゴム等の弾性部材をなくして、導光板の入光側を接着力の高い熱圧着テープ等により固定することで、３辺の狭額縁化が図られている。 Here, it is a so-called edge light type planar lighting device in which light is incident from the incoming light side surface of the light guide plate and is emitted from one main surface of the light guide plate, and the exit surface has a horizontally long shape and is guided. Consider the case where one of the long sides of the light plate (for the sake of explanation, the lower long side) is the entrance side. In this case, the narrowing of the three sides of the upper long side and the left and right short sides is affected by how the light guide plate is supported in the housing, so various support structures for the light guide plate are used. It has been proposed. For example, elastic members such as rubber, which are arranged on the terminal side (opposite to the light entrance side) of the light guide plate and on the left and right sides and press the light guide plate to the light entrance side, are eliminated, and the light entrance side of the light guide plate has high adhesive strength. By fixing with a thermocompression bonding tape or the like, the frame is narrowed on three sides.
特開２０１１－２２２３３１号公報Japanese Unexamined Patent Publication No. 2011-22231 特開２０１８－１８８９５５号公報Japanese Unexamined Patent Publication No. 2018-188955
　しかしながら、液晶表示装置等の大型化に伴って面状照明装置が大型化し、入光側の長辺が例えば７００～８００ｍｍ程度になると、導光板の伸び量の大きい箇所で熱圧着テープ等による固定部が構造破綻（凝集破壊）してしまい、導光板の充分な固定が行えなくなるという問題があった。導光板の安定的な固定のためには入光側の辺のできるだけ長い範囲を固定すべきであるが、導光板の伸縮が予測しづらく、固定する範囲を最大化するのが困難であった。なお、構造破綻した部分は導光板の光学特性に影響を与えてしまうため、構造破綻しない範囲で固定すべきである。また、横長の導光板の左右への伸縮量が定まらないため、左右の辺の額縁設計が困難であった。 However, as the size of the liquid crystal display device increases, the size of the planar lighting device increases, and when the long side on the incoming light side becomes, for example, about 700 to 800 mm, it is fixed by a thermocompression bonding tape or the like at a place where the amount of elongation of the light guide plate is large. There was a problem that the light guide plate could not be sufficiently fixed due to the structural failure (aggregation failure) of the portion. For stable fixing of the light guide plate, the longest possible range on the side of the incoming light should be fixed, but it was difficult to predict the expansion and contraction of the light guide plate, and it was difficult to maximize the fixed range. .. Since the structurally broken portion affects the optical characteristics of the light guide plate, it should be fixed within a range where the structural failure does not occur. Further, since the amount of expansion and contraction of the horizontally long light guide plate to the left and right is not determined, it is difficult to design the frame on the left and right sides.
　本発明は、上記に鑑みてなされたものであって、導光板の安定した固定と額縁設計の容易化を図ることができ、大型の導光板に対しても狭額縁化を図ることができる面状照明装置を提供することを目的とする。 The present invention has been made in view of the above, and it is possible to stably fix the light guide plate and facilitate the frame design, and it is possible to narrow the frame even for a large light guide plate. It is an object of the present invention to provide a shape lighting device.
　上述した課題を解決し、目的を達成するために、本発明の一態様に係る面状照明装置は、ボトムフレームと、凹部と、センターピンと、固定部とを備える。前記ボトムフレームは、床部と、該床部の周縁に立設された側壁とを有し、導光板を収容する。前記凹部は、前記導光板の入光側の辺の略中央に設けられる。前記センターピンは、前記床部に立設され、前記凹部と嵌合する。前記固定部は、前記導光板の入光側の辺の前記センターピンから所定の距離の範囲内において、前記導光板を前記ボトムフレームに固定する。 In order to solve the above-mentioned problems and achieve the object, the planar lighting device according to one aspect of the present invention includes a bottom frame, a recess, a center pin, and a fixing portion. The bottom frame has a floor portion and a side wall erected on the peripheral edge of the floor portion, and accommodates a light guide plate. The recess is provided substantially in the center of the side of the light guide plate on the light receiving side. The center pin is erected on the floor and fits into the recess. The fixing portion fixes the light guide plate to the bottom frame within a predetermined distance from the center pin on the side of the light guide plate on the light entrance side.
　本発明の一態様に係る面状照明装置は、導光板の安定した固定と額縁設計の容易化を図ることができ、大型の導光板に対しても狭額縁化を図ることができる。 The planar lighting device according to one aspect of the present invention can stably fix the light guide plate and facilitate the frame design, and can narrow the frame even for a large light guide plate.
図１は、一実施形態にかかる面状照明装置の平面図である。FIG. 1 is a plan view of a planar lighting device according to an embodiment. 図２は、フラットタイプの面状照明装置の斜視図である。FIG. 2 is a perspective view of a flat type planar lighting device. 図３は、フラットタイプの面状照明装置の主要部の分解斜視図である。FIG. 3 is an exploded perspective view of a main part of a flat type planar lighting device. 図４は、湾曲タイプの面状照明装置の斜視図である。FIG. 4 is a perspective view of a curved type planar lighting device. 図５は、湾曲タイプの面状照明装置の主要部の分解斜視図である。FIG. 5 is an exploded perspective view of a main part of a curved type planar lighting device. 図６は、面状照明装置の入光側の長辺の中央付近の平面図である。FIG. 6 is a plan view near the center of the long side of the incoming light side of the planar lighting device. 図７は、面状照明装置の入光側の長辺の中央付近のトップフレームおよび光学シート等を外した状態における平面図である。FIG. 7 is a plan view of the planar lighting device in a state where the top frame, the optical sheet, and the like near the center of the long side on the incoming light side are removed. 図８は、面状照明装置の入光側の長辺の中央付近のトップフレーム、光学シート、導光板および反射シート等を外した状態における平面図である。FIG. 8 is a plan view in a state where the top frame, the optical sheet, the light guide plate, the reflection sheet, and the like near the center of the long side on the incoming light side of the planar lighting device are removed. 図９は、面状照明装置の図６におけるＸ１－Ｘ１断面図である。FIG. 9 is a cross-sectional view of X1-X1 in FIG. 6 of the planar lighting device. 図１０は、８５°Ｃの環境下での熱圧着テープの伸び量と応力との関係の例を示す図である。FIG. 10 is a diagram showing an example of the relationship between the elongation amount of the thermocompression bonding tape and the stress in an environment of 85 ° C. 図１１は、熱圧着テープの凝集破壊が生じない範囲を検証するためのモデルの例を示す図である。FIG. 11 is a diagram showing an example of a model for verifying a range in which cohesive failure of the thermocompression bonding tape does not occur. 図１２は、面状照明装置が対角３２インチである場合の熱圧着テープによる固定部の長さの例を示す図である。FIG. 12 is a diagram showing an example of the length of the fixing portion by the thermocompression bonding tape when the planar lighting device is diagonally 32 inches. 図１３は、面状照明装置が対角１２．３インチである場合の熱圧着テープによる固定部の長さの例を示す図である。FIG. 13 is a diagram showing an example of the length of the fixing portion by the thermocompression bonding tape when the planar lighting device has a diagonal of 12.3 inches. 図１４は、光学シートの例を示す平面図である。FIG. 14 is a plan view showing an example of an optical sheet. 図１５は、図１４において破線で示される部分Ａ１の拡大図である。FIG. 15 is an enlarged view of the portion A1 shown by the broken line in FIG. 図１６は、面状照明装置の図６におけるＸ２－Ｘ２断面図である。FIG. 16 is a cross-sectional view of X2-X2 in FIG. 6 of the planar lighting device.
　以下、実施形態に係る面状照明装置について図面を参照して説明する。なお、この実施形態によりこの発明が限定されるものではない。また、図面における各要素の寸法の関係、各要素の比率などは、現実と異なる場合がある。図面の相互間においても、互いの寸法の関係や比率が異なる部分が含まれている場合がある。また、１つの実施形態や変形例に記載された内容は、原則として他の実施形態や変形例にも同様に適用される。 Hereinafter, the planar lighting device according to the embodiment will be described with reference to the drawings. The present invention is not limited to this embodiment. In addition, the relationship between the dimensions of each element in the drawing, the ratio of each element, etc. may differ from the reality. Even between the drawings, there may be parts where the relationship and ratio of the dimensions are different from each other. Further, in principle, the contents described in one embodiment or modification are similarly applied to other embodiments or modifications.
　図１は、一実施形態にかかる面状照明装置１の平面図である。なお、図１の平面図は、後述する湾曲タイプの面状照明装置１の平面図と兼用している。図２は、フラットタイプの面状照明装置１の斜視図である。図３は、フラットタイプの面状照明装置１の主要部の分解斜視図である。また、便宜上、面状照明装置１の長辺方向をＸ軸方向、短辺方向をＹ軸方向、厚み方向をＺ軸方向としている。 FIG. 1 is a plan view of the planar lighting device 1 according to the embodiment. The plan view of FIG. 1 is also used as the plan view of the curved type planar lighting device 1 described later. FIG. 2 is a perspective view of the flat type planar lighting device 1. FIG. 3 is an exploded perspective view of a main part of the flat type planar lighting device 1. Further, for convenience, the long side direction of the planar lighting device 1 is the X-axis direction, the short side direction is the Y-axis direction, and the thickness direction is the Z-axis direction.
　図１～図３において、面状照明装置１は、ボトムフレーム３の上に反射シート４、導光板７、光学シート９が順次に積層され、トップフレーム１０により蓋をされる形となっている。図２および図３において、ボトムフレーム３およびトップフレーム１０は、主面がフラットな形状となっている。なお、図３では、導光板７の入光側面（図における手前側の長辺の側面）に光を出射する複数の光源と、これらの光源が搭載される基板とが省略されているが、その配置については後述の図面にて示されている。図２および図３において、接続部２は、内部の基板に一端が接続されており、外部と電気的な接続のために使用される部材である。 In FIGS. 1 to 3, the planar lighting device 1 has a shape in which a reflective sheet 4, a light guide plate 7, and an optical sheet 9 are sequentially laminated on a bottom frame 3 and covered with a top frame 10. .. In FIGS. 2 and 3, the bottom frame 3 and the top frame 10 have a flat main surface. In FIG. 3, a plurality of light sources that emit light to the light entrance side surface (the side surface of the long side on the front side in the figure) of the light guide plate 7 and a substrate on which these light sources are mounted are omitted. The arrangement is shown in the drawings below. In FIGS. 2 and 3, the connecting portion 2 is a member having one end connected to an internal substrate and used for electrical connection with the outside.
　ボトムフレーム３は、例えば、金属製であり、ダイカストや板金等により形成されている。反射シート４は、導光板７からボトムフレーム３側に漏れた光を反射して、導光板７側に戻すためのものである。ボトムフレーム３の床面に白色の塗装等が施されて反射特性が良好な場合は、反射シート４が省略される場合もある。導光板７は、ポリカーボネート、アクリル等の透明な樹脂により形成されており、長辺側の入光側面から入射された光を全面に導き、一の主面（図における上側の主面）から出射する。 The bottom frame 3 is made of metal, for example, and is formed of die casting, sheet metal, or the like. The reflective sheet 4 is for reflecting the light leaked from the light guide plate 7 to the bottom frame 3 side and returning it to the light guide plate 7 side. If the floor surface of the bottom frame 3 is painted white and has good reflection characteristics, the reflection sheet 4 may be omitted. The light guide plate 7 is made of a transparent resin such as polycarbonate or acrylic, and guides the light incident from the incoming light side surface on the long side to the entire surface and emits light from one main surface (upper main surface in the figure). do.
　光学シート９は、１枚ないしは複数枚の光学的な作用を及ぼすシートであり、拡散シート、プリズムシート、輝度上昇フィルム（ＤＢＥＦ：Dual　Brightness　Enhancement　Film）等である。光学シート９の長辺側の一端（図における手前側）は、例えば、細長い板が断面略Ｌ字型に折り曲げられたシート固定用フレーム８の一方の片に固定され、シート固定用フレーム８の他方の片はボトムフレーム３の側壁とトップフレーム１０の側壁との間に挟み込まれて固定される。また、シート固定用フレーム８による光学シート９の固定に代え、光学シート９に設けられた孔にセンターピン１１が通されることにより、光学シート９の固定が行われるようにしてもよい。トップフレーム１０は、例えば、樹脂等により形成されている。 The optical sheet 9 is one or a plurality of sheets that exert an optical action, such as a diffusion sheet, a prism sheet, a brightness increasing film (DBEF: Dual Brightness Enhancement Film), and the like. One end of the long side of the optical sheet 9 (the front side in the figure) is fixed to, for example, one piece of the sheet fixing frame 8 in which an elongated plate is bent into a substantially L-shaped cross section, and the sheet fixing frame 8 is fixed. The other piece is sandwiched and fixed between the side wall of the bottom frame 3 and the side wall of the top frame 10. Further, instead of fixing the optical sheet 9 with the sheet fixing frame 8, the optical sheet 9 may be fixed by passing the center pin 11 through the hole provided in the optical sheet 9. The top frame 10 is made of, for example, a resin or the like.
　図４は、湾曲タイプの面状照明装置１の斜視図であり、図５は、湾曲タイプの面状照明装置１の主要部の分解斜視図である。平面図は、図１と同様である。図４および図５において、ボトムフレーム３、反射シート４、導光板７、光学シート９Ａ～９Ｃ（光学シート９に対応）、トップフレーム１０は、主面が湾曲した形状となっている以外は図２および図３と同様である。なお、ボトムフレーム３およびトップフレーム１０は当初から湾曲した状態に形成されているが、反射シート４、導光板７、光学シート９Ａ～９Ｃは組立前は湾曲しておらず、ボトムフレーム３上に配置される際に湾曲され、トップフレーム１０によって押さえ付けられた状態で固定される。 FIG. 4 is a perspective view of the curved type planar lighting device 1, and FIG. 5 is an exploded perspective view of the main part of the curved type planar lighting device 1. The plan view is the same as that in FIG. 4 and 5, the bottom frame 3, the reflective sheet 4, the light guide plate 7, the optical sheets 9A to 9C (corresponding to the optical sheet 9), and the top frame 10 are shown except that the main surface is curved. 2 and FIG. 3 are similar. Although the bottom frame 3 and the top frame 10 are formed in a curved state from the beginning, the reflective sheet 4, the light guide plate 7, and the optical sheets 9A to 9C are not curved before assembly, and are on the bottom frame 3. It is curved when placed and fixed in a state of being pressed by the top frame 10.
　以下、上述のフラットタイプおよび湾曲タイプの両者の面状照明装置１に共通する細部について説明する。 Hereinafter, details common to both the flat type and curved type planar lighting devices 1 described above will be described.
　図６は、面状照明装置１の入光側の長辺の中央付近の平面図である。図６において、面状照明装置１の入光側の長辺の中央付近にはＺ軸方向にセンターピン１１が立設されており、トップフレーム１０の額縁部１０ａの孔部１０ｈからセンターピン１１の先端が見えている。なお、孔部１０ｈは設けられていなくてもよい。また、トップフレーム１０の額縁部１０ａに設けられた孔部１０ｃに、ボトムフレーム３の側壁に設けられた凸部３ｃが嵌合するようになっており、トップフレーム１０の側壁が外側（図の下側、Ｙ軸方向）に弓状に湾曲するのが防止されている。 FIG. 6 is a plan view of the planar lighting device 1 near the center of the long side on the incoming light side. In FIG. 6, a center pin 11 is erected in the Z-axis direction near the center of the long side on the incoming light side of the planar lighting device 1, and the center pin 11 is erected from the hole portion 10h of the frame portion 10a of the top frame 10. You can see the tip of. The hole 10h may not be provided. Further, the convex portion 3c provided on the side wall of the bottom frame 3 is fitted into the hole portion 10c provided in the frame portion 10a of the top frame 10, and the side wall of the top frame 10 is on the outside (in the figure). It is prevented from bending in a bow shape (lower side, in the Y-axis direction).
　図７は、面状照明装置１の入光側の長辺の中央付近のトップフレーム１０および光学シート９（９Ａ～９Ｃ）等を外した状態における平面図である。図７において、導光板７の入光側の長辺の中央付近には、円弧状の切り込み部７ｂ（本発明の「凹部」に相当）が設けられており、この切り込み部７ｂがセンターピン１１の外周面に当接するようになっている。なお、センターピン１１は導光板７の中央部を位置決めするものであり、導光板７に無用なストレスを与えて光学特性を悪化させないよう、センターピン１１と切り込み部７ｂは緩く嵌り合うことが望ましい。また、基板５上に複数設けられたＬＥＤ（Light　Emitting　Diode）等の光源６の出射面は、導光板７の入光側面７ａと対向して配置されている。なお、ボトムフレーム３の側壁３ｂには外側（図の下側）に突き出た爪状の凸部３ｄが設けられており、トップフレーム１０の側壁に設けられた孔部と嵌合することで、ボトムフレーム３とトップフレーム１０とがＺ軸方向に固定されるようになっている。 FIG. 7 is a plan view in a state where the top frame 10 and the optical sheets 9 (9A to 9C) near the center of the long side on the incoming light side of the planar lighting device 1 are removed. In FIG. 7, an arcuate notch 7b (corresponding to the “recess” of the present invention) is provided near the center of the long side of the light guide plate 7 on the light entrance side, and this notch 7b is the center pin 11. It is designed to come into contact with the outer peripheral surface of the. The center pin 11 positions the central portion of the light guide plate 7, and it is desirable that the center pin 11 and the notch portion 7b are loosely fitted so as not to give unnecessary stress to the light guide plate 7 and deteriorate the optical characteristics. .. Further, the emission surface of the light source 6 such as a plurality of LEDs (Light Emitting Diodes) provided on the substrate 5 is arranged so as to face the light entrance side surface 7a of the light guide plate 7. The side wall 3b of the bottom frame 3 is provided with a claw-shaped convex portion 3d protruding outward (lower side in the figure), and by fitting with a hole provided in the side wall of the top frame 10, the side wall 3b is fitted with a hole portion. The bottom frame 3 and the top frame 10 are fixed in the Z-axis direction.
　図８は、面状照明装置１の入光側の長辺の中央付近のトップフレーム１０、光学シート９（９Ａ～９Ｃ）、導光板７および反射シート４等を外した状態における平面図である。図８において、ボトムフレーム３の床部３ａの内面の入光側の外周部には、センターピン１１を避けて、Ｘ軸方向に延在して、帯状の白色の両面テープ１３が貼り付けられ、両面テープ１３の入光側の外周部には帯状の透明なポリカーボネート等によるベースフィルム１４が貼り付けられている。更に、ベースフィルム１４の入光側の端部には、導光板７への入射光に影響しないよう光源６の間に配置された、矩形状の複数の熱圧着テープ１６が飛島状に設けられている。また、各熱圧着テープ１６の周縁の一部である、図における左右と上には、所定の距離を隔てて囲むように、長手方向に分割された白色の樹脂によるスペーサ１５が両面テープ等により貼り付けられている。 FIG. 8 is a plan view in a state where the top frame 10, the optical sheets 9 (9A to 9C), the light guide plate 7, the reflective sheet 4, and the like near the center of the long side on the incoming light side of the planar lighting device 1 are removed. .. In FIG. 8, a strip-shaped white double-sided tape 13 is attached to the outer peripheral portion of the inner surface of the floor portion 3a of the bottom frame 3 on the light receiving side so as to extend in the X-axis direction while avoiding the center pin 11. A base film 14 made of a band-shaped transparent polycarbonate or the like is attached to the outer peripheral portion of the double-sided tape 13 on the light receiving side. Further, at the end of the base film 14 on the incoming light side, a plurality of rectangular thermocompression bonding tapes 16 arranged between the light sources 6 so as not to affect the incident light on the light guide plate 7 are provided in a flying island shape. ing. Further, on the left and right and above, which are a part of the peripheral edge of each thermocompression bonding tape 16, spacers 15 made of white resin divided in the longitudinal direction so as to surround them at a predetermined distance are formed by double-sided tape or the like. It is pasted.
　熱圧着テープ１６は、加熱により溶融し、ベースフィルム１４と導光板７との間を高い強度で接着するものである。ベースフィルム１４は広い面積の両面テープ１３によりボトムフレーム３の床部３ａに強力に固定されているため、ボトムフレーム３に対して導光板７が強力に固定される。スペーサ１５は、熱圧着テープ１６が溶融する際の流れ止めとして機能し、所定の接着面積と厚みとを確保することで接着力を確保する。スペーサ１５が長手方向に分割されているのは、貼り付けられるベースフィルム１４等との線膨張係数の違いを吸収するためである。なお、熱圧着テープ１６に代えて、シリンジ等により塗布可能な接着剤タイプであって、熱源が不要で大気中の湿気等により硬化するタイプの固定部材を用いることもできる。 The thermocompression bonding tape 16 is melted by heating and adheres between the base film 14 and the light guide plate 7 with high strength. Since the base film 14 is strongly fixed to the floor portion 3a of the bottom frame 3 by the double-sided tape 13 having a large area, the light guide plate 7 is strongly fixed to the bottom frame 3. The spacer 15 functions as a flow stop when the thermocompression bonding tape 16 melts, and secures an adhesive force by securing a predetermined adhesive area and thickness. The reason why the spacer 15 is divided in the longitudinal direction is to absorb the difference in linear expansion coefficient from the base film 14 or the like to be attached. Instead of the thermocompression bonding tape 16, a fixing member of an adhesive type that can be applied with a syringe or the like and that does not require a heat source and is cured by moisture in the atmosphere can also be used.
　図９は、面状照明装置１の図６におけるＸ１－Ｘ１断面図である。図９において、ボトムフレーム３の床部３ａには外側（図の下側）よりナット１２を介してセンターピン１１がねじ込まれて固定されており、センターピン１１の頭部１１ｂはボトムフレーム３の外側にある。なお、ボトムフレーム３へのセンターピン１１の固定は、ねじ込みに代えて、圧入による固定としてもよい。また、センターピン１１の軸部１１ａは、反射シート４、導光板７および光学シート９（９Ａ～９Ｃ）を貫通してトップフレーム１０の額縁部１０ａの孔部１０ｈの内部まで延びている。センターピン１１の軸部１１ａは、前述のように、導光板７の入光側の長辺の中央部の切り込み部７ｂに当接するようになっている。 FIG. 9 is a cross-sectional view of X1-X1 in FIG. 6 of the planar lighting device 1. In FIG. 9, the center pin 11 is screwed and fixed to the floor portion 3a of the bottom frame 3 from the outside (lower side in the figure) via the nut 12, and the head portion 11b of the center pin 11 is fixed to the bottom frame 3. It's on the outside. The center pin 11 may be fixed to the bottom frame 3 by press fitting instead of screwing. Further, the shaft portion 11a of the center pin 11 penetrates the reflective sheet 4, the light guide plate 7, and the optical sheets 9 (9A to 9C) and extends to the inside of the hole portion 10h of the frame portion 10a of the top frame 10. As described above, the shaft portion 11a of the center pin 11 is in contact with the notch portion 7b at the center of the long side of the light guide plate 7 on the incoming light side.
　また、ボトムフレーム３の側壁３ｂの内面には、複数の光源６が長辺方向に配置された基板５が両面テープ等により固定され、光源６の出射面は導光板７の入光側面７ａに対向している。なお、光源６として、天面側が発光するトップビュー型のＬＥＤ等を例に図示しているが、側面側が発光するサイドビュー型のＬＥＤ等を用いることもできる。この場合、基板５はボトムフレーム３の床部３ａに平行に配置されることになる。 Further, on the inner surface of the side wall 3b of the bottom frame 3, a substrate 5 in which a plurality of light sources 6 are arranged in the long side direction is fixed by double-sided tape or the like, and the emission surface of the light source 6 is on the entrance side surface 7a of the light guide plate 7. Facing each other. As the light source 6, a top-view type LED or the like that emits light on the top surface side is shown as an example, but a side-view type LED or the like that emits light on the side surface side can also be used. In this case, the substrate 5 is arranged parallel to the floor portion 3a of the bottom frame 3.
　図１０は、８５°Ｃの環境下での熱圧着テープ１６の伸び量と応力との関係の例を示す図である。図１０において、伸び量が０．７ｍｍまでは可逆変化であり、伸び量とともに応力が増加し、伸び量を減らせば応力も減る。しかし、伸び量が０．７ｍｍを超えると不可逆変化となり、伸び量とともに応力が低下し、伸び量を減らしても元には戻らない。なお、変曲点は１箇所であり、伸び限界と破断とが同一点となる。 FIG. 10 is a diagram showing an example of the relationship between the elongation amount of the thermocompression bonding tape 16 and the stress in an environment of 85 ° C. In FIG. 10, the amount of elongation is a reversible change up to 0.7 mm, the stress increases with the amount of elongation, and the stress decreases as the amount of elongation decreases. However, when the amount of elongation exceeds 0.7 mm, an irreversible change occurs, the stress decreases with the amount of elongation, and even if the amount of elongation is reduced, it cannot be restored. It should be noted that there is only one inflection point, and the elongation limit and the fracture are the same point.
　図１１は、熱圧着テープ１６の凝集破壊が生じない範囲を検証するためのモデルの例を示す図である。「GLASS　D263」は基台となる部分であり、その上に、両面テープ１３に対応する「BST」、ベースフィルム１４に対応する「Base　Film　PC」、熱圧着テープ１６に対応する飛島状の「HBT」、導光板７に対応する「LGP」が配置されている。「GLASS　D263」の左側の壁の内側が伸縮の基準位置となっており、右方向に線膨張が起きる。なお、ボトムフレームに相当する基台に金属ではなくガラスを用いたのは、金属よりも熱膨張係数が小さい部材を用いることにより、長さの短い基台で導光板との熱膨張量差ΔＸを実現するためである。 FIG. 11 is a diagram showing an example of a model for verifying a range in which cohesive failure of the thermocompression bonding tape 16 does not occur. "GLASS D263" is the base part, and on top of that, "BST" corresponding to double-sided tape 13, "Base Film PC" corresponding to base film 14, and Tobishima-shaped "" corresponding to thermocompression bonding tape 16. "HBT" and "LGP" corresponding to the light guide plate 7 are arranged. The inside of the wall on the left side of "GLASS D263" is the reference position for expansion and contraction, and linear expansion occurs to the right. The reason why glass is used instead of metal for the base corresponding to the bottom frame is that the difference in the amount of thermal expansion from the light guide plate is ΔX due to the use of a member having a smaller coefficient of thermal expansion than metal. This is to realize.
　線膨張方向の「GLASS　D263」および「LGP」の長さを３００ｍｍとすることにより、実機において８００ｍｍの長さで生じる線膨張量差ΔＸ１．３ｍｍを与えることができる。冷熱衝撃試験の結果、２００Ｈ（時間）経過において約２２０ｍｍまでは問題なく、それを越えた部分で凝集破壊が生じることが確認された。この実測値は、図１０から求められる計算値ともほぼ一致している。これより、線膨張の基準位置より約２００ｍｍは熱圧着テープ１６の凝集破壊が生じない範囲と考えることができる。 By setting the lengths of "GLASS D263" and "LGP" in the linear expansion direction to 300 mm, it is possible to give a linear expansion amount difference ΔX1.3 mm that occurs in a length of 800 mm in an actual machine. As a result of the thermal shock test, it was confirmed that there was no problem up to about 220 mm in the lapse of 200 H (hours), and that cohesive fracture occurred in the portion beyond that. This actually measured value is almost the same as the calculated value obtained from FIG. From this, it can be considered that about 200 mm from the reference position of linear expansion is a range in which cohesive failure of the thermocompression bonding tape 16 does not occur.
　図６～図９に示された実施形態では、導光板７の入光側の長辺の中央部がセンターピン１１により位置決めされ、その中央部が線膨張の基準位置となるため、その中央部から左右に２００ｍｍ（左右で合計４００ｍｍ）の範囲を熱圧着テープ１６により固定する範囲とすることで、固定する範囲を最大化することができる。また、左右の伸縮量が同じになるため、左右の辺の額縁設計が容易となる。 In the embodiment shown in FIGS. 6 to 9, the central portion of the long side of the light guide plate 7 on the incoming light side is positioned by the center pin 11, and the central portion serves as a reference position for linear expansion. By setting the range of 200 mm to the left and right (400 mm in total on the left and right) as the range to be fixed by the thermocompression bonding tape 16, the fixing range can be maximized. In addition, since the amount of expansion and contraction on the left and right is the same, it is easy to design the frame on the left and right sides.
　一方、図２および図３に示された実機としてのフラットタイプの面状照明装置１では、所定時間経過において長辺の中央部を中心とする約４５０ｍｍの範囲で形状が安定していることが確認されている。また、図４および図５に示された湾曲タイプの面状照明装置１では、湾曲の半径Ｒ＝１５００ｍｍの場合、所定時間経過において４０２ｍｍの範囲で形状が安定していることが確認されている。すなわち、フラットタイプに比して湾曲タイプは端部において熱圧着テープ１６が剥がれやすく、固定範囲を中央部寄りに短くすべきであるが、湾曲タイプにおいても長辺の中央部を中心とする約４００ｍｍの範囲であれば、安定して固定することが可能である。 On the other hand, in the flat type planar lighting device 1 as an actual machine shown in FIGS. 2 and 3, the shape is stable within a range of about 450 mm centered on the central portion of the long side over a predetermined time. It has been confirmed. Further, in the curved type planar lighting device 1 shown in FIGS. 4 and 5, it has been confirmed that when the radius of curvature R = 1500 mm, the shape is stable within a range of 402 mm over a predetermined time. .. That is, the thermocompression bonding tape 16 is more likely to peel off at the end of the curved type than the flat type, and the fixing range should be shortened toward the center. If it is within the range of 400 mm, it can be stably fixed.
　図１２は、面状照明装置１が対角３２インチである場合の熱圧着テープによる固定部の長さの例を示す図であり、長辺の中央部を中心とする４００ｍｍの範囲を飛島状の熱圧着テープ１６による固定の範囲としている。図１３は、面状照明装置１が対角１２．３インチである場合の熱圧着テープによる固定部の長さの例を示す図であり、長辺の全ての範囲である３００ｍｍを飛島状の熱圧着テープ１６による固定の範囲としている。 FIG. 12 is a diagram showing an example of the length of the fixed portion by the thermocompression bonding tape when the planar lighting device 1 is diagonally 32 inches, and has a flying island shape in a range of 400 mm centered on the central portion of the long side. It is within the range of fixing with the thermocompression bonding tape 16. FIG. 13 is a diagram showing an example of the length of the fixed portion by the thermocompression bonding tape when the planar lighting device 1 has a diagonal of 12.3 inches, and has a flying island shape of 300 mm, which is the entire range of the long side. The range of fixing with the thermocompression bonding tape 16 is set.
　次に、装置としての強度について考察する。標準的なモデルとして、導光板が通常の両面テープで固定され、導光板重量が１８．６ｇのものを比較対象とする。この標準的なモデルでは、せん断強度が４Ｎ／ｍｍ２、１ｇ当たりの接着面積が４ｍｍ２／ｇ、バックライトの接着強度が２９８Ｎ、［１ｇ当たりの接着面積］×［バックライトの接着強度］×１０２が１２である。 Next, the strength as a device will be considered. As a standard model, a light guide plate is fixed with ordinary double-sided tape, and a light guide plate with a weight of 18.6 g is used for comparison. In this standard model, the shear strength is 4 N / mm 2 , the adhesive area per 1 g is 4 mm 2 / g, the adhesive strength of the backlight is 298 N, [adhesive area per 1 g] × [adhesive strength of the backlight] ×. 10 2 is 12.
　これに対し、図１２に示された３２インチの面状照明装置１では、導光板重量が２７２ｇ、せん断強度が２５Ｎ／ｍｍ２、接着面積が１４３．９ｍｍ２、１ｇ当たりの接着面積が０．５ｍｍ２／ｇ、バックライトの接着強度が３５９８Ｎ、［１ｇ当たりの接着面積］×［バックライトの接着強度］×１０２が１９である。また、図１３に示された１２．３インチの面状照明装置１では、導光板重量が９３ｇ、せん断強度が２５Ｎ／ｍｍ２、接着面積が１０７．９３ｍｍ２、１ｇ当たりの接着面積が１．２ｍｍ２／ｇ、バックライトの接着強度が２６９８Ｎ、［１ｇ当たりの接着面積］×［バックライトの接着強度］×１０２が３１である。［１ｇ当たりの接着面積］×［バックライトの接着強度］×１０２から明らかであるが、図１２または図１３の面状照明装置１は標準的なモデルよりも強度が高い。また、落下衝撃耐性、冷熱衝撃耐性および輝度落ち率は、標準的なモデルを含めていずれも良好である。 In contrast, in the spread illuminating apparatus 1 of the 32-inch shown in FIG. 12, the light guide plate weight 272 g, shear strength is 25 N / mm 2, the adhesion area adhesive area per 143.9mm 2, 1g 0. 5 mm 2 / g, the adhesive strength of the backlight is 3598 N, and [adhesive area per 1 g] × [adhesive strength of the backlight] × 10 2 is 19. Further, in the spread illuminating apparatus 1 12.3 inch shown in FIG. 13, the light guide plate weight 93 g, shear strength is 25 N / mm 2, the adhesive area bonded area 107.93Mm 2, per 1 g 1. 2 mm 2 / g, the adhesive strength of the backlight is 2698 N, and [adhesive area per 1 g] × [adhesive strength of the backlight] × 10 2 is 31. As will be apparent from the adhesive strength of the back light] × 10 2 [adhesive area per 1 g] ×, the surface illumination device 1 of FIG. 12 or 13 is higher strength than the standard model. In addition, the drop impact resistance, the thermal impact resistance, and the brightness drop rate are all good including the standard model.
　次に、光学シート９（９Ａ、９Ｂ、９Ｃ）のセンターピン１１（図６～図９）による固定の例と、導光板７の固定を強化する例について説明する。 Next, an example of fixing the optical sheet 9 (9A, 9B, 9C) with the center pin 11 (FIGS. 6 to 9) and an example of strengthening the fixing of the light guide plate 7 will be described.
　図１４は、光学シート９（９Ａ、９Ｂ、９Ｃ）の例を示す平面図である。図１５は、図１４において破線で示される部分Ａ１の拡大図である。図１４および図１５において、光学シート９（９Ａ、９Ｂ、９Ｃ）の入光側の辺（図における下側の辺）の略中央の短手方向の端部から所定の距離の位置に、センターピン１１（図６～図９）が嵌る孔部９ａが設けられている。センターピン１１の外径と、光学シート９の孔部９ａの孔径とは、ガタが無いように設計されるが、きつめの公差での設計であっても光学シート９は多少変形が起こるため問題はない。 FIG. 14 is a plan view showing an example of the optical sheet 9 (9A, 9B, 9C). FIG. 15 is an enlarged view of the portion A1 shown by the broken line in FIG. In FIGS. 14 and 15, the center of the optical sheet 9 (9A, 9B, 9C) is located at a predetermined distance from the end in the lateral direction at the substantially center of the side on the incoming light side (lower side in the figure). A hole 9a into which the pin 11 (FIGS. 6 to 9) is fitted is provided. The outer diameter of the center pin 11 and the hole diameter of the hole portion 9a of the optical sheet 9 are designed so that there is no play, but the optical sheet 9 is slightly deformed even if it is designed with tight tolerances. No problem.
　また、光学シート９（９Ａ、９Ｂ、９Ｃ）の孔部９ａが設けられる部分の両端には長手方向に延びる切欠部９ｃが設けられ、孔部９ａが設けられる部分は耳部９ｂとなっている。切欠部９ｃは、後述するトップフレーム１０のリブ１０ｉとの干渉を避けるためのものである。 Further, notches 9c extending in the longitudinal direction are provided at both ends of the portion of the optical sheet 9 (9A, 9B, 9C) where the hole portion 9a is provided, and the portion where the hole portion 9a is provided is the selvage portion 9b. .. The cutout portion 9c is for avoiding interference with the rib 10i of the top frame 10 described later.
　また、光学シート９（９Ａ、９Ｂ、９Ｃ）の入光側の辺の両端には、光学シート９（９Ａ、９Ｂ、９Ｃ）がセンターピン１１（孔部９ａ）を中心に回転するのを防止し、ラトルノイズの発生を防止するための爪部９ｄが設けられている。爪部９ｄはボトムフレーム３の側壁３ｂまたは基板５に当接する。 Further, it is prevented that the optical sheet 9 (9A, 9B, 9C) rotates around the center pin 11 (hole portion 9a) at both ends of the side of the optical sheet 9 (9A, 9B, 9C) on the incoming light side. However, a claw portion 9d is provided to prevent the generation of rattle noise. The claw portion 9d abuts on the side wall 3b of the bottom frame 3 or the substrate 5.
　一般に、光学シートの固定は、横長の矩形の左右辺において導光板に両面テープでの固定が主流であった。しかし、面状照明装置の大型化により、光学シートの重量も大きくなるため、両面テープによる固定では安定に保持することが難しくなってきた。また、狭額縁化の要求もあり、左右辺での固定が廃止され、入光辺での固定に移行してきた。しかし、入光辺で光学シートを固定できる場所は導光板しかなく、導光板に直接に光学シートを固定してしまうと、輝度低下や皺の発生による信頼性低下の問題がある。 Generally, the optical sheet was mainly fixed to the light guide plate with double-sided tape on the left and right sides of a horizontally long rectangle. However, due to the increase in size of the planar lighting device, the weight of the optical sheet also increases, and it has become difficult to stably hold the optical sheet by fixing it with double-sided tape. In addition, due to the demand for narrower frames, fixing on the left and right sides has been abolished, and fixing on the incoming side has been started. However, the light guide plate is the only place where the optical sheet can be fixed on the light entrance side, and if the optical sheet is fixed directly to the light guide plate, there is a problem that the brightness is lowered and the reliability is lowered due to the generation of wrinkles.
　その点、図１４および図１５のセンターピン１１（図６～図９）による光学シート９の固定では、センターピン１１に光学シート９の孔部９ａを差し込むだけの単純な構造により、光学シート９を安定に支持することができる。また、導光板７に光学シート９が直接に固定されるものではないため、光学特性や信頼性に影響を与えることはない。更に、両面テープを使用しない固定であるため、位置精度が出しやすく、クリアランスを減少できるため、狭額縁化にいっそう貢献することができる。また、光学シート９はセンターピン１１により１箇所で支持されるため、両面テープによる固定のように皺が発生することもない。 In that respect, in fixing the optical sheet 9 by the center pins 11 (FIGS. 6 to 9) of FIGS. 14 and 15, the optical sheet 9 has a simple structure in which the holes 9a of the optical sheet 9 are simply inserted into the center pins 11. Can be stably supported. Further, since the optical sheet 9 is not directly fixed to the light guide plate 7, it does not affect the optical characteristics and reliability. Furthermore, since it is fixed without using double-sided tape, it is easy to obtain position accuracy and clearance can be reduced, which can further contribute to narrowing the frame. Further, since the optical sheet 9 is supported at one place by the center pin 11, wrinkles do not occur as in the case of fixing with double-sided tape.
　図１６は、面状照明装置１の図６におけるＸ２－Ｘ２断面図である。図１６において、トップフレーム１０の額縁部１０ａの裏側には、導光板７側に突出し、長手方向に延びるリブ１０ｉが設けられている。リブ１０ｉは、図１５の平面図に示されるように、光学シート９の耳部９ｂの両側に、光学シート９に接触しないように配置される。 FIG. 16 is a cross-sectional view of X2-X2 in FIG. 6 of the planar lighting device 1. In FIG. 16, on the back side of the frame portion 10a of the top frame 10, a rib 10i projecting toward the light guide plate 7 and extending in the longitudinal direction is provided. As shown in the plan view of FIG. 15, the ribs 10i are arranged on both sides of the selvage portion 9b of the optical sheet 9 so as not to come into contact with the optical sheet 9.
　リブ１０ｉは、クッション材１７を介して、導光板７の入光側の主面をボトムフレーム３の床部３ａ側に押圧するようになっている。なお、クッション材１７の導光板７に対向する面には、白色等による反射処理が施されている。これにより、前述した両面テープ１３、ベースフィルム１４および熱圧着テープ１６による、導光板７のボトムフレーム３への固定を強化し、導光板７の浮き上がりやズレ等を防止することができる。また、クッション材１７の白色等による反射処理により、クッション材１７側への光の漏れを少なくし、導光板７の光学特性への影響を抑えることができる。 The rib 10i presses the main surface of the light guide plate 7 on the incoming light side toward the floor portion 3a of the bottom frame 3 via the cushion material 17. The surface of the cushion material 17 facing the light guide plate 7 is subjected to a reflection treatment such as white. As a result, the fixing of the light guide plate 7 to the bottom frame 3 by the double-sided tape 13, the base film 14, and the thermocompression bonding tape 16 described above can be strengthened, and the light guide plate 7 can be prevented from rising or shifting. Further, the reflection treatment of the cushion material 17 by white or the like can reduce the leakage of light to the cushion material 17 side and suppress the influence on the optical characteristics of the light guide plate 7.
　以上、本発明の実施形態について説明したが、本発明は上記実施形態に限定されるものではなく、その趣旨を逸脱しない限りにおいて種々の変更が可能である。 Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made as long as the gist of the present invention is not deviated.
　以上のように、実施形態に係る面状照明装置は、床部と、床部の周縁に立設された側壁とを有し、導光板を収容するボトムフレームと、導光板の入光側の辺の略中央に設けられた凹部と、床部に立設され、凹部と嵌合するセンターピンと、導光板の入光側の辺のセンターピンから所定の距離の範囲内において、導光板をボトムフレームに固定する固定部とを備える。これにより、導光板の安定した固定と額縁設計の容易化を図ることができ、大型の導光板に対しても狭額縁化を図ることができる。 As described above, the planar lighting device according to the embodiment has a floor portion and a side wall erected on the peripheral edge of the floor portion, and has a bottom frame for accommodating the light guide plate and a light receiving side of the light guide plate. The light guide plate is bottomed within a predetermined distance from the concave portion provided in the substantially center of the side, the center pin erected on the floor and fitted with the concave portion, and the center pin on the side of the light receiving side of the light guide plate. It has a fixing part to be fixed to the frame. As a result, the light guide plate can be stably fixed and the frame design can be facilitated, and the frame can be narrowed even for a large light guide plate.
　また、所定の距離は、導光板の使用温度範囲内における伸縮により固定部が構造破綻しない距離である。これにより、固定部の構造破綻により導光板の光学特性への悪影響を防止することができる。 Further, the predetermined distance is a distance at which the fixed portion does not collapse due to expansion and contraction within the operating temperature range of the light guide plate. As a result, it is possible to prevent an adverse effect on the optical characteristics of the light guide plate due to the structural failure of the fixed portion.
　また、固定部は、ボトムフレームに両面テープを介して貼り付けられたベースフィルムと、ベースフィルムと導光板とを固定する熱圧着テープまたはこの熱圧着テープに代替可能な固定部材とを有する。これにより、導光板をボトムフレームに強力に固定することができる。 Further, the fixing portion has a base film attached to the bottom frame via double-sided tape, a thermocompression bonding tape for fixing the base film and the light guide plate, or a fixing member that can be replaced with the thermocompression bonding tape. This makes it possible to firmly fix the light guide plate to the bottom frame.
　また、熱圧着テープまたは固定部材は、導光板の入光側の辺の延在方向に離散した飛島状で、光源の間に配置される。これにより、光源から導光板への入射光に熱圧着テープまたは固定部材が悪影響を与えることを防止することができる。 Further, the thermocompression bonding tape or the fixing member is arranged between the light sources in a flying island shape discrete in the extending direction of the side of the light guide plate on the incoming light side. This makes it possible to prevent the thermocompression bonding tape or the fixing member from adversely affecting the incident light from the light source to the light guide plate.
　また、ベースフィルムに両面テープを介して貼り付けられ、熱圧着テープまたは固定部材の周縁の少なくとも一部を囲むスペーサ、を備える。これにより、熱圧着テープ等が溶融する際の流れ止めとして機能し、所定の接着面積と厚みとを確保することで接着力を確保することができる。 It is also provided with a thermocompression bonding tape or a spacer that surrounds at least a part of the peripheral edge of the fixing member, which is attached to the base film via double-sided tape. As a result, it functions as a flow stop when the thermocompression bonding tape or the like melts, and it is possible to secure the adhesive force by securing a predetermined adhesive area and thickness.
　また、ボトムフレームの開口側に嵌合し、額縁部の裏側にクッション材を介して導光板を押圧するリブを有するトップフレームを備える。これにより、導光板のボトムフレームへの固定を強化し、導光板の浮き上がりやズレ等を防止することができる。 Further, a top frame that fits on the opening side of the bottom frame and has a rib that presses the light guide plate via a cushion material is provided on the back side of the frame portion. As a result, it is possible to strengthen the fixing of the light guide plate to the bottom frame and prevent the light guide plate from rising or shifting.
　また、入光側の辺の略中央の端部から所定の距離の位置にセンターピンに嵌合する孔部を有し、入光側の辺の両端部にボトムフレームの側壁または光源の基板に当接する爪部を有し、導光板の出射側に積層される１以上の光学シートを備える。これにより、光学シートを簡易に固定することができ、光学シートの回転も防止することができる。 In addition, it has holes that fit into the center pin at a predetermined distance from the substantially central end of the side that enters the light, and can be used as the side wall of the bottom frame or the substrate of the light source at both ends of the side that enters the light. It has one or more optical sheets that have claws that come into contact with each other and are laminated on the emission side of the light guide plate. As a result, the optical sheet can be easily fixed and rotation of the optical sheet can be prevented.
　また、ボトムフレームの開口側に嵌合し、額縁部の裏側にクッション材を介して導光板を押圧するリブを有するトップフレームと、入光側の辺の略中央の端部から所定の距離の位置にセンターピンに嵌合する孔部を有し、入光側の辺にリブを避ける切欠部を有し、入光側の辺の両端部にボトムフレームの側壁または光源の基板に当接する爪部を有し、導光板の出射側に積層される１以上の光学シートとを備える。これにより、トップフレームのリブおよびクッション材による導光板の押圧のための構成が、光学シートを固定するための構成に干渉することを防止することができる。 Further, a predetermined distance from the top frame, which is fitted to the opening side of the bottom frame and has ribs on the back side of the frame portion to press the light guide plate via the cushioning material, and the substantially central end portion of the side on the light entering side. It has a hole that fits into the center pin at the position, a notch that avoids ribs on the side of the incoming light, and a claw that contacts the side wall of the bottom frame or the substrate of the light source at both ends of the side on the incoming light side. It has a portion and includes one or more optical sheets laminated on the emission side of the light guide plate. This makes it possible to prevent the configuration for pressing the light guide plate by the ribs and cushioning material of the top frame from interfering with the configuration for fixing the optical sheet.
　また、クッション材の導光板に対向する面は、反射処理が施されている。これにより、導光板からクッション材側に光が漏れるのを防止し、光学特性の劣化を防止することができる。 In addition, the surface of the cushion material facing the light guide plate is subjected to reflection treatment. As a result, it is possible to prevent light from leaking from the light guide plate to the cushion material side and prevent deterioration of optical characteristics.
　また、上記実施の形態により本発明が限定されるものではない。上述した各構成要素を適宜組み合わせて構成したものも本発明に含まれる。また、さらなる効果や変形例は、当業者によって容易に導き出すことができる。よって、本発明のより広範な態様は、上記の実施の形態に限定されるものではなく、様々な変更が可能である。 Further, the present invention is not limited to the above embodiments. The present invention also includes a configuration in which the above-mentioned components are appropriately combined. Further, further effects and modifications can be easily derived by those skilled in the art. Therefore, the broader aspect of the present invention is not limited to the above-described embodiment, and various modifications can be made.
　１　面状照明装置，２　接続部，３　ボトムフレーム，３ａ　床部，３ｂ　側壁，４　反射シート，５　基板，６　光源，７　導光板，７ｂ　切り込み部，８　シート固定用フレーム，９　光学シート，９、９Ａ～９Ｃ　光学シート，９ａ　孔部，９ｃ　切欠部，９ｄ　爪部，１０　トップフレーム，１０ａ　額縁部，１０ｂ　側壁，１０ｉ　リブ，１１　センターピン，１１ａ　軸部，１１ｂ　頭部，１２　ナット，１３　両面テープ，１４　ベースフィルム，１５　スペーサ，１６　熱圧着テープ，１７　クッション材 1 planar lighting device, 2 connection part, 3 bottom frame, 3a floor part, 3b side wall, 4 reflective sheet, 5 board, 6 light source, 7 light guide plate, 7b notch part, 8 sheet fixing frame, 9 optical sheet, 9 , 9A-9C optical sheet, 9a hole, 9c notch, 9d claw, 10 top frame, 10a frame, 10b side wall, 10i rib, 11 center pin, 11a shaft, 11b head, 12 nut, 13 double-sided Tape, 14 base film, 15 spacer, 16 thermocompression bonding tape, 17 cushion material

Claims (9)

  1. 　床部と、該床部の周縁に立設された側壁とを有し、導光板を収容するボトムフレームと、
    　前記導光板の入光側の辺の略中央に設けられた凹部と、
    　前記床部に立設され、前記凹部と嵌合するセンターピンと、
    　前記導光板の入光側の辺の前記センターピンから所定の距離の範囲内において、前記導光板を前記ボトムフレームに固定する固定部と、
    を備える面状照明装置。     A bottom frame having a floor portion and a side wall erected on the peripheral edge of the floor portion and accommodating a light guide plate, and
    A recess provided in the substantially center of the side of the light guide plate on the incoming light side, and
    A center pin that stands on the floor and fits into the recess,
    A fixing portion for fixing the light guide plate to the bottom frame within a predetermined distance from the center pin on the light receiving side side of the light guide plate, and
    A planar lighting device equipped with.
  2. 　前記所定の距離は、前記導光板の使用温度範囲内における伸縮により前記固定部が構造破綻しない距離である、
    請求項１に記載の面状照明装置。     The predetermined distance is a distance at which the fixed portion does not collapse due to expansion and contraction within the operating temperature range of the light guide plate.
    The planar lighting device according to claim 1.
  3. 　前記固定部は、前記ボトムフレームに両面テープを介して貼り付けられたベースフィルムと、該ベースフィルムと前記導光板とを固定する熱圧着テープまたは該熱圧着テープに代替可能な固定部材とを有する、
    請求項１または２に記載の面状照明装置。     The fixing portion has a base film attached to the bottom frame via double-sided tape, and a thermocompression bonding tape for fixing the base film and the light guide plate, or a fixing member that can be replaced with the thermocompression bonding tape. ,
    The planar lighting device according to claim 1 or 2.
  4. 　前記熱圧着テープまたは前記固定部材は、前記導光板の入光側の辺の延在方向に離散した飛島状で、光源の間に配置される、
    請求項３に記載の面状照明装置。     The thermocompression bonding tape or the fixing member is arranged between the light sources in a flying island shape discrete in the extending direction of the side of the light guide plate on the incoming light side.
    The planar lighting device according to claim 3.
  5. 　前記ベースフィルムに両面テープを介して貼り付けられ、前記熱圧着テープまたは前記固定部材の周縁の少なくとも一部を囲むスペーサ、を備える、
    請求項４に記載の面状照明装置。     A spacer attached to the base film via a double-sided tape and surrounding at least a part of the peripheral edge of the thermocompression bonding tape or the fixing member.
    The planar lighting device according to claim 4.
  6. 　前記ボトムフレームの開口側に嵌合し、額縁部の裏側にクッション材を介して前記導光板を押圧するリブを有するトップフレーム、を備える、
    請求項１～５のいずれか一つに記載の面状照明装置。     A top frame, which is fitted to the opening side of the bottom frame and has ribs on the back side of the frame portion to press the light guide plate via a cushion material, is provided.
    The planar lighting device according to any one of claims 1 to 5.
  7. 　入光側の辺の略中央の端部から所定の距離の位置に前記センターピンに嵌合する孔部を有し、前記入光側の辺の両端部に前記ボトムフレームの側壁または光源の基板に当接する爪部を有し、前記導光板の出射側に積層される１以上の光学シート、を備える、
    請求項１～６のいずれか一つに記載の面状照明装置。     A hole that fits into the center pin is provided at a position at a predetermined distance from the substantially central end of the side that enters the light, and the side wall of the bottom frame or the substrate of the light source is located at both ends of the side that enters the light. It is provided with one or more optical sheets, which have a claw portion in contact with the light guide plate and are laminated on the emission side of the light guide plate.
    The planar lighting device according to any one of claims 1 to 6.
  8. 　前記ボトムフレームの開口側に嵌合し、額縁部の裏側にクッション材を介して前記導光板を押圧するリブを有するトップフレームと、
    　入光側の辺の略中央の端部から所定の距離の位置に前記センターピンに嵌合する孔部を有し、入光側の辺に前記リブを避ける切欠部を有し、前記入光側の辺の両端部に前記ボトムフレームの側壁または光源の基板に当接する爪部を有し、前記導光板の出射側に積層される１以上の光学シートと、を備える、
    請求項１～５のいずれか一つに記載の面状照明装置。     A top frame fitted to the opening side of the bottom frame and having ribs on the back side of the frame portion to press the light guide plate via a cushion material.
    It has a hole that fits into the center pin at a position at a predetermined distance from the substantially central end of the side that enters the light, and has a notch that avoids the rib on the side that enters the light. It is provided with one or more optical sheets laminated on the emission side of the light guide plate, having claws abutting on the side wall of the bottom frame or the substrate of the light source at both ends of the side.
    The planar lighting device according to any one of claims 1 to 5.
  9. 　前記クッション材の前記導光板に対向する面は、反射処理が施されている、
    請求項６または８に記載の面状照明装置。     The surface of the cushion material facing the light guide plate is subjected to a reflection treatment.
    The planar lighting device according to claim 6 or 8.
PCT/JP2021/018548 2020-07-07 2021-05-17 Planar illumination device WO2022009525A1 (en)

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WO2014073425A1 (en) * 2012-11-06 2014-05-15 シャープ株式会社 Illumination device, display device, and television receiver device
JP2017117520A (en) * 2015-12-21 2017-06-29 シャープ株式会社 Surface light emitting device and liquid crystal display device

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JP2012028142A (en) 2010-07-22 2012-02-09 Sharp Corp Light source module and electronic equipment equipped with it
JP2012084304A (en) 2010-10-08 2012-04-26 Sharp Corp Light source module and electronic apparatus
JP2020004692A (en) 2018-06-21 2020-01-09 ミネベアミツミ株式会社 Planar luminaire

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WO2012020592A1 (en) * 2010-08-09 2012-02-16 シャープ株式会社 Illumination device and display device
WO2014073425A1 (en) * 2012-11-06 2014-05-15 シャープ株式会社 Illumination device, display device, and television receiver device
JP2017117520A (en) * 2015-12-21 2017-06-29 シャープ株式会社 Surface light emitting device and liquid crystal display device

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