WO2020066220A1

WO2020066220A1 - Planar lighting device

Info

Publication number: WO2020066220A1
Application number: PCT/JP2019/027342
Authority: WO
Inventors: 和正安達; 暢彦吉垣
Original assignee: ミネベアミツミ株式会社
Priority date: 2018-09-28
Filing date: 2019-07-10
Publication date: 2020-04-02
Also published as: CN112236696A; JP2020057459A; JP7050641B2; CN112236696B

Abstract

A planar lighting device (1) is provided with: a light guide plate (5); a frame body (2); and a pair of elastic members (11A, 11B). The light guide plate (5) guides incident light. The frame body (2) houses the light guide plate (5). The pair of elastic members (11A, 11B) are each disposed between the light guide plate (5) and the frame body (2) and sandwich the light guide plate (5) in the width direction of the light guide plate (5), and contact the light guide plate (5) and the frame body (2) in a compression state. The pair of elastic members (11A, 11B) each include: a first contact part (111) which contacts the light guide plate (5) and the frame body (2) in the width direction; and a second contact part (112) which contacts the light guide plate (5) and the frame body (2) in a crossing direction crossing the width direction.

Description

Planar lighting device

The present invention relates to a planar lighting device.

面 There is a planar lighting device as a vehicle-mounted backlight used for a display device of a vehicle such as an automobile. Some planar illumination devices include a light guide plate that receives light from a light source such as an LED and guides the light, and a frame that houses the light guide plate. The light guide plate and the frame are generally made of materials having different thermal expansion coefficients. Therefore, when the light guide plate is fixed to the frame, the relative movement of the light guide plate relative to the frame in the width direction and the vertical direction orthogonal to the width direction is taken into consideration. Therefore, conventionally, in a planar lighting device, an elastic member is used to fix the light guide plate to the frame (see Patent Document 1). The elastic member is arranged between the side walls and the frame in the width direction of the light guide plate, and between the side wall and the frame opposite to the light source side in the vertical direction of the light guide plate.

JP 2012-138345 A

面 By the way, in recent years, a planar lighting device as a vehicle-mounted backlight is required to have a narrower frame from the viewpoint of designability, enlargement of a display screen, and space saving. In the case of an installation type such as a vehicle-mounted backlight, there is a case where a narrow frame of three sides excluding one side required for fixing is required.

The present invention has been made in view of the above circumstances, and has as its object to provide a spread illuminating apparatus capable of narrowing a frame.

In order to achieve the above object, the planar lighting device according to the present invention includes a light guide plate that guides incident light, a frame that houses the light guide plate, and the light guide plate in a width direction of the light guide plate. A pair of elastic members that are respectively disposed between the light guide plate and the frame with the light guide plate and the frame in contact with each other in a compressed state. It has a 1st contact part which contacts a light board and the above-mentioned frame, and a 2nd contact part which contacts the above-mentioned light guide plate and the above-mentioned frame in the crossing direction which intersects with the above-mentioned width direction.

In order to achieve the above object, a spread illuminating apparatus according to the present invention has a light guide plate for guiding incident light, a spacer fixed to the light guide plate, and a light guide plate stacked on an emission surface side of the light guide plate. One or more intermediate optical members, an outermost optical member laminated on the lamination direction side of the intermediate optical member, and a fixing tape for fixing each optical member to the spacer, and each optical member is A fixing piece is formed at a position facing the fixing tape in the laminating direction, and the fixing tape has a recess formed on the laminating direction side, and the fixing piece of the intermediate optical member is formed in the recess. The fixing piece of the outermost optical member is in contact with the fixing tape, and the fixing piece of the intermediate optical member of the fixing tape is exposed in a contact state where the fixing piece contacts the fixing tape in the recess. Touch , Characterized in that.

面 The planar lighting device according to the present invention can achieve a narrow frame.

FIG. 1 is a front view of the spread illuminating apparatus according to the embodiment. FIG. 2 is an exploded perspective view of the spread illuminating apparatus according to the embodiment. FIG. 3 is a cross-sectional perspective view of a main part of the spread illuminating apparatus according to the embodiment. FIG. 4 is a cross-sectional view of a main part of the spread illuminating apparatus according to the embodiment. FIG. 5 is a perspective view of an elastic member of the spread illuminating apparatus according to the embodiment. FIG. 6 is a perspective view illustrating the assembly of the planar lighting device according to the embodiment. FIG. 7 is a perspective view illustrating the assembly of the planar lighting device according to the embodiment. FIG. 8 is a perspective view illustrating the assembly of the planar lighting device according to the embodiment. FIG. 9 is a perspective view illustrating the assembly of the planar lighting device according to the embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the dimensional relationships of the components, the ratios of the components, and the like in the drawings may differ from reality. Even in the drawings, there may be cases where portions having different dimensional relationships and ratios are included.

[Embodiment]
The spread illuminating apparatus according to the embodiment will be described. FIG. 1 is a front view of the spread illuminating apparatus according to the embodiment. FIG. 2 is an exploded perspective view of the spread illuminating apparatus according to the embodiment. FIG. 3 is a sectional perspective view of a main part of the spread illuminating apparatus according to the embodiment. FIG. 4 is a cross-sectional view of a main part of the spread illuminating apparatus according to the embodiment. FIG. 5 is a perspective view of an elastic member of the spread illuminating apparatus according to the embodiment. FIG. 3 is a view in which the spacer 6, the first intermediate optical member 7, the second intermediate optical member 8, the outermost optical member 9, and the cover 10 are omitted. FIG. 4 is a sectional view taken along line AA of FIG.

Here, the X direction in each drawing is the width direction of the planar lighting device (light guide plate) in the present embodiment. The Y direction is a direction orthogonal to the width direction in the present embodiment, and is a vertical direction. The Z direction is a thickness direction orthogonal to the width direction and the vertical direction in the present embodiment. The Y1 direction is the upward direction, the direction of light incidence on the light guide plate, and the Y2 direction is the downward direction. The Z1 direction is the stacking direction, which is the emission direction of the planar lighting device (light guide plate), and the Z2 direction is the opposite direction. Unless otherwise specified, each direction used in the following description represents a direction in a state where the respective parts are assembled to each other.

面 The planar illumination device 1 in the present embodiment is used as a backlight of a liquid crystal display device. The liquid crystal display device is mounted on a vehicle such as an automobile, for example, and is mainly used as a display device visually recognized by a driver or a display terminal device such as a smartphone.

As shown in FIGS. 1 and 2, the spread illuminating device 1 includes a frame 2, a reflecting member 3, a light source 4, a light guide plate 5, a spacer 6, a first intermediate optical member 7, a second It includes an intermediate optical member 8, an outermost optical member 9, a cover 10, a pair of

elastic members

11A and 11B, and a fixing tape 12. The planar lighting device 1 according to the present embodiment is formed in a rectangular shape having a longitudinal direction in the width direction and a lateral direction in the vertical direction when viewed from the thickness direction.

As shown in FIG. 2, the frame body 2 accommodates components constituting the planar lighting device 1 including the light guide plate 5. The frame 2 is made of, for example, a metal such as aluminum or an aluminum alloy, and is formed by die casting or press working. The frame 2 in the present embodiment includes a rectangular bottom plate 21 having a longitudinal direction in the width direction, and a pair of long sides projecting from both ends of the bottom plate 21 in the vertical direction in the stacking direction and extending in the width direction.

Side walls

22 and 23 and a pair of

short side walls

24 and 25 projecting from both ends in the width direction of the bottom plate 21 in the laminating direction and extending in the up-down direction. The frame 2 has an accommodation space 2a formed by surrounding the outer periphery of the bottom plate 21 with the

long side walls

22 and 23 and the

short side walls

24 and 25. The accommodation space 2a communicates with the outside via an opening formed on the lamination direction side. The frame 2 in the present embodiment includes a reflecting member 3, a light source 4, a light guide plate 5, a spacer 6, a first intermediate optical member 7, a second intermediate optical member 8, an outermost optical member 9, and a pair of

elastic members

11A and 11B. , And the fixing tape 12 are accommodated in the accommodation space 2a.

As shown in FIG. 2 or 3, the frame 2 has cutouts 2b and 2c formed at the lower end portions of the

short side walls

24 and 25, respectively. The cutouts 2b and 2c connect the two side walls in the width direction of the

short side walls

24 and 25. The accommodation space 2a communicates with the outside via the notches 2b and 2c. The

short side walls

24 and 25 are formed with frame-

side protruding portions

26A and 26B above the notches 2b and 2c, respectively. Here, the frame-

side protruding portions

26A and 26B form a dead space in the planar lighting device 1 above the notches 2b and 2c, that is, the light guide plate when the planar lighting device 1 is viewed from the thickness direction. 5 is formed in an area on the lower side (light source 4 side) than the effective light emitting region R on the emission surface 51 described later. The frame-

side protruding portions

26A and 26B are formed to protrude inward in the width direction. The inner side in the width direction refers to a side toward the center of the planar illumination device 1 in the width direction when the planar illumination device 1 is viewed from the thickness direction. The frame-

side protruding portions

26A and 26B are contacted by the

elastic members

11A and 11B, respectively, and as shown in FIGS. 3 and 4, a first inner wall surface 261, a second inner wall surface 262, an insertion hole 263, and the like. Respectively. The first inner wall surface 261 comes into contact with a first contact portion 111 described later of the

elastic members

11A and 11B. The first inner wall surface 261 is a surface extending in the up-down direction, and is formed on the innermost side in the width direction among the frame-

side protrusions

26A, 26B. The second inner wall surface 262 comes into contact with a second contact portion 112 of the

elastic members

11A and 11B, which will be described later. The second inner wall surface 262 is formed from the lower end of the first inner wall surface 261 outward in the width direction. The second inner wall surface 262 in the present embodiment has a crossing direction intersecting the width direction between the width direction and a vertical direction orthogonal to the width direction, and has a width from the lower end of the first inner wall surface 261. It is an inclined surface along the outward direction in the direction. The insertion hole 263 is for inserting an insertion protrusion 113 described later of the

elastic members

11A and 11B, and is formed at a position facing the

elastic members

11A and 11B in the width direction. The insertion hole 263 in the present embodiment is formed in the first inner wall surface 261 and is formed to penetrate the

short side walls

24 and 25 in the width direction. In addition, the insertion hole 263 does not need to be a through hole and may be formed as a bottomed hole.

(2) The reflection member 3 is located on the opposite side of the light guide plate 5 and is disposed between the light guide plate 5 and the bottom plate 21 of the frame 2 as shown in FIG. The reflection member 3 mainly guides the light incident on the light guide plate 5 from the surface on the opposite side (the surface opposite to the emission surface 51 described later) among both surfaces in the thickness direction of the light guide plate 5. A part of the light leaked to the outside of the light plate 5 is reflected and returned to the inside of the light guide plate 5. The reflecting member 3 in the present embodiment includes a rectangular bottom plate 31, a long side wall 32 protruding from the upper end of the bottom plate 31 in the stacking direction and extending in the width direction, and a width of the bottom plate 21. And a pair of

short side walls

33, 34 protruding from both ends in the direction in the stacking direction and extending in the up-down direction.

(2) The light source 4 emits light to the light guide plate 5, as shown in FIG. The light source 4 in the present embodiment has a substrate 41 and an LED (Light Emitting Diode) 42.

The substrate 41 is formed in a band shape extending in the width direction. The board 41 is, for example, a flexible printed board, and an upper surface of the upper and lower surfaces is a mounting surface on which the LEDs 42 are mounted. The substrate 41 is fixed to the long side wall 23 of the frame 2 on the lower surface by a fixing member (fixing tape, adhesive, or the like).

The LED 42 is for irradiating light, and is, for example, a pseudo white LED including a blue LED and a phosphor. A plurality of LEDs 42 in the present embodiment are mounted on the board 41 in the width direction. The number of the LEDs 42 may be one or more, and an arbitrary number of the LEDs 42 are mounted on the substrate 41 according to the required performance of the planar lighting device 1. As shown in FIGS. 3 and 4, the LED 42 is mounted on the substrate 41, so that the light emitting surface 42a is on the upper side, that is, on the side facing the light guide plate 5 in the vertical direction, and the light is emitted upward. Emit. That is, the light source 4 is a top-view type light source mounted on the substrate 41 on which the surface of the LED 42 opposite to the light emitting surface 42a in the up-down direction is mounted, but is not limited thereto. Among them, a side view type in which a surface orthogonal to the light emitting surface 42a is mounted may be used.

(2) As shown in FIG. 2, the light guide plate 5 receives light from the light source 4 and guides the incident light. The light guide plate 5 is made of a transparent synthetic resin such as a transparent polycarbonate. The light guide plate 5 is a rectangular plate-shaped member whose longitudinal direction is the width direction, and includes an emission surface 51, a light incident surface 52,

legs

53A and 53B,

width side surfaces

54A and 54B, and a light guide plate side. It has

protrusions

55A and 55B. Here, the light guide plate 5 is housed in the frame 2 and is separated from the frame 2 in a fixed state where the light guide plate 5 is fixed by the pair of

elastic members

11A and 11B. The light guide plate 5 in the present embodiment is designed with respect to the frame 2 so that gaps are formed in the width direction and the upward direction with respect to the frame 2.

(4) The emission surface 51 is a surface on the lamination direction side of both surfaces in the thickness direction. The light exit surface 51 is a flat surface from which light guided by the light guide plate 5 is emitted, and forms a main surface of the light guide plate 5 together with the surface on the opposite side. Here, the surface on the opposite side may be a flat surface, or an optical path changing pattern including a plurality of dots may be formed. When the optical path changing pattern is formed on the surface on the opposite side, the traveling direction of the light guided inside the light guide plate 5 can be intentionally changed, so that more light is emitted from the emission surface 51. Can be emitted.

(3) The light incident surface 52 is a surface facing the light source 4 and a surface on which light from the light source 4 is incident, as shown in FIGS. The light incident surface 52 is a surface on the lower side among the upper and lower surfaces of the light guide plate 5 and is a surface facing the light emitting surface 42a of each LED 42.

The

legs

53A and 53B adjust the distance between the light incident surface 52 and the light emitting surface 42a in the vertical direction. The

legs

53A and 53B are formed at both ends in the width direction of the light incident surface 52, and are formed to protrude downward. That is, each LED 42 faces the light incident surface 52 in the up-down direction between the

legs

53A and 53B. The

leg portions

53A and 53B restrict the downward movement of the light guide plate 5 with respect to the long side wall 23 by contacting the substrate 41 in a downward direction in a state where the light guide plate 5 is housed in the frame 2. . Note that the

legs

53A and 53B may be in direct contact with the long side wall 23 without contacting the substrate 41. That is, the light guide plate 5 is only in contact with the frame 2 by the

legs

53A and 53B, and the other parts except the

legs

53A and 53B are not in contact with the frame 2, that is, the frame 2 2 may be separated from each other.

(4) The width direction side surfaces 54A and 54B are surfaces along the vertical direction, and are both outer circumferential surfaces in the width direction among the outer circumferential surfaces of the light guide plate 5. The side surfaces 54A and 54B in the width direction come into contact with the first contact portions 111 of the

elastic members

11A and 11B.

The light guide plate-

side protrusions

55A and 55B are formed at the lower end portions of the width direction side surfaces 54A and 54B, and are formed to protrude outward in the width direction. The outer side in the width direction refers to a side of the spread illuminating device 1 that is outside the spread illuminating device 1 in the width direction when viewed from the thickness direction. The light guide plate-

side protrusions

55A and 55B are contacted by the

elastic members

11A and 11B, respectively, and each have a first outer peripheral surface 551. The first outer peripheral surface 551 comes into contact with the second contact portions 112 of the

elastic members

11A and 11B. The first outer peripheral surface 551 is formed from the lower end of the width direction side surfaces 54A and 54B toward the outside in the width direction. The first outer peripheral surface 551 in the present embodiment is configured such that an intersecting direction intersecting the width direction is a direction between the width direction and an up-down direction orthogonal to the width direction, and from the lower side ends of the

width side surfaces

54A and 54B. It is an inclined surface along a direction toward the outside in the width direction.

The spacer 6 is disposed over the light source 4 and the light guide plate 5 on the emission direction side as shown in FIGS. The spacer 6 is made of, for example, a synthetic resin having a reflection function such as a white resin plate. The spacer 6 is a band-shaped plate-shaped member whose longitudinal direction is the width direction, and covers at least the light emitting surface 42a and the light incident surface 52 when viewed from the thickness direction. The spacer 6 has a fixing member (fixing tape, adhesive, or the like) on the opposite side of the both surfaces in the thickness direction, for example, at a lower end portion of the light guide plate 5 or a front portion between the adjacent LEDs 42. Fixed. The spacer 6 can suppress the light leaked from between the light emitting surface 42a and the light incident surface 52 from being emitted to the outside of the spread illuminating device 1 and reduce the light leaked by the reflection function to the light incident surface. 52.

As shown in FIG. 2, the first intermediate optical member 7 constitutes an intermediate optical member, and controls light emitted from the light guide plate 5. The first intermediate optical member 7 is, for example, a diffusion sheet as an optical member, and diffuses light emitted from the emission surface 51. The first intermediate optical member 7 is stacked on the emission surface 51 side of the light guide plate 5, that is, on the stacking direction side. That is, the first intermediate optical member 7 is the innermost, that is, the optical member closest to the emission surface 51 among the plurality of optical members. The first intermediate optical member 7 has a main body 71 and a plurality of fixing

pieces

72 and 73. The main body 71 has a sheet shape, and emits light incident on the surface on the opposite side in the thickness direction from the surface on the stacking direction side. The fixing

pieces

72 and 73 are for fixing the first intermediate optical member 7 to the light guide plate 5 via the spacer 6. The fixing

pieces

72 and 73 are formed to protrude downward from the lower end of the main body 71 and are formed at positions facing the spacer 6 in the stacking direction. The fixing

pieces

72 and 73 in the present embodiment are arranged at intervals in the width direction, and are not formed at the center and both ends in the width direction. The fixing piece 72 is formed as a pair at the center in the width direction, and comes into contact with the fixing tape 12 in a first concave portion 121 of the fixing tape 12 which will be described later. A plurality of the fixing pieces 73 are formed at both ends in the width direction, that is, outside the fixing pieces 72 in the width direction, and come into contact with the fixing tape 12 in a third concave portion 123 of the fixing tape 12 described later. Here, the fixed piece 72 has a shorter length in the width direction than the fixed piece 73. That is, the first intermediate optical member 7 can increase the length in the width direction of the central portion in the width direction where the fixing

pieces

72 and 73 are not provided.

The second intermediate optical member 8 constitutes an intermediate optical member as shown in FIG. 2, and controls light emitted from the light guide plate 5. The second intermediate optical member 8 is, for example, a prism sheet as an optical member, and controls light distribution of light emitted from the first intermediate optical member 7. The second intermediate optical member 8 is laminated on the first intermediate optical member 7 on the laminating direction side. That is, the second intermediate optical member 8 is an optical member sandwiched between two optical members in the middle of the plurality of optical members, that is, in the thickness direction. The second intermediate optical member 8 has a main body 81 and a plurality of fixing

pieces

82 and 83. The main body portion 81 has a sheet shape, and emits light incident on the surface on the opposite direction in the thickness direction from the surface on the stacking direction side. The fixing

pieces

82 and 83 are for fixing the second intermediate optical member 8 to the light guide plate 5 via the spacer 6. The fixing

pieces

82 and 83 are formed to protrude downward from the lower end of the main body 81 and are formed at positions facing the spacers 6 in the stacking direction. The fixing

pieces

82 and 83 are formed at positions that do not overlap the fixing

pieces

72 and 73 in the stacking direction. The fixing

pieces

82 and 83 in the present embodiment are arranged at intervals in the width direction, and are not formed at the center and both ends in the width direction. The fixing piece 82 is formed as a pair at the center in the width direction, and comes into contact with the fixing tape 12 in a second concave portion 122 of the fixing tape 12 described later. A plurality of the fixing pieces 83 are formed at both ends in the width direction, that is, on the outer side in the width direction than the fixing pieces 82, and come into contact with the fixing tape 12 in a fourth recess 124 described later of the fixing tape 12. Here, the fixing piece 82 has a shorter length in the width direction than the fixing piece 83. That is, the length of the second intermediate optical member 8 in the width direction of the central portion in the width direction where the fixing

pieces

82 and 83 are not provided can be increased.

(2) The outermost optical member 9 controls the light emitted from the light guide plate 5, as shown in FIG. The outermost optical member 9 is, for example, a DBEF (Dual Brightness Enhancement Film) as an optical member, and increases the intensity of light emitted from the second intermediate optical member 8. The outermost optical member 9 is laminated on the second intermediate optical member 8 on the laminating direction side. That is, the outermost optical member 9 is the outermost optical member of the plurality of optical members, that is, the optical member on the opposite side (the laminating direction side) from the exit surface 51 side. The outermost optical member 9 has a main body 91 and a fixing piece 92. The main body portion 91 has a sheet shape, and emits light incident on the surface on the opposite side in the thickness direction from the surface on the stacking direction side. The fixing piece 92 fixes the outermost optical member 9 to the light guide plate 5 via the spacer 6. The fixing piece 92 is formed to protrude downward from the lower end of the main body 91 and is formed at a position facing the spacer 6 in the laminating direction. Further, the fixing piece 92 is formed to extend in the width direction, and is formed so as to extend to the center and both ends in the width direction. The fixing piece 92 is formed at a position overlapping with the fixing

pieces

72, 73, 82, 83 in the stacking direction. The fixing piece 92 in the present embodiment is opposed to exposed

regions

125 and 126 of the fixing tape 12 described later in the laminating direction, and is in contact with the exposed

regions

125 and 126. Here, the thermal expansion coefficients of the optical members 7 to 9 in the present embodiment are the same or almost the same for the first intermediate optical member 7 as the diffusion sheet and the second intermediate optical member 8 as the prism sheet. DBEF, which is the outermost optical member 9, is larger than 7 and 8. In addition, the mass of the optical members 7 to 9 in the present embodiment becomes heavier in the order of the first intermediate optical member 7 as the diffusion sheet, the second intermediate optical member 8 as the prism sheet, and the outermost optical member 9 as the DBEF. .

(2) The cover 10 is a cover of the spread illuminating device 1 as shown in FIG. 2, and covers the frame 2 in a state in which the components are accommodated. The cover 10 has an opening 10a formed therein, and exposes the outermost optical member 9 to the outside through the opening 10a. Here, the opening 10 a is formed to be narrower than a region for emitting light from the light guide plate 5 on the surface of the outermost optical member 9 on the lamination direction side. That is, the cover 10 defines a light emitting area of the planar lighting device 1.

The

elastic members

11A and 11B fix the light guide plate 5 to the frame 2. The

elastic members

11A and 11B are arranged between the light guide plate 5 and the frame 2 with the light guide plate 5 interposed therebetween. The

elastic members

11A and 11B come into contact with the light guide plate 5 and the frame 2 in an elastically compressed state, that is, in a compressed state. The

elastic members

11A and 11B are made of, for example, rubber or synthetic resin having elasticity, and can be elastically compressed and elastically restored. As shown in FIG. 5, the

elastic members

11A and 11B have a first contact portion 111, a second contact portion 112, and an insertion protrusion 113.

The first contact portion 111 contacts the light guide plate 5 and the frame 2 in the width direction. The first contact portion 111 is formed to extend in the up-down direction. The first contact portion 111 is configured such that, of both side surfaces in the width direction, one side surface, that is, the first frame body side surface 114 is in contact with the first inner wall surface 261, and the other side surface, that is, the first light guide plate side surface 115, is elastic. In the case of the member 11A, it comes into contact with the width side surface 54A, and in the case of the elastic member 11B, it comes into contact with the width direction side surface 54B.

The second contact portion 112 contacts the light guide plate 5 and the frame 2 in the cross direction. The second contact portion 112 is located outside the first contact portion 111 in the width direction, and is formed to extend in the cross direction. The second contact portion 112 is configured such that, of the two side surfaces in a direction orthogonal to the cross direction, the second frame body side surface 116 that is one side is in contact with the second inner wall surface 262, and the second light guide plate side that is the other side surface. The side surface 117 contacts the first outer peripheral surface 551.

The insertion protrusion 113 is inserted into the insertion hole 263. The insertion protrusion 113 is formed to protrude outward from the first contact portion 111 in the width direction. The insertion protrusion 113 in the present embodiment is formed to protrude from the first frame body side surface 114 toward the frame 2. The insertion protrusion 113 may be provided on the first contact portion 112.

(2) The fixing tape 12 fixes the optical members 7 to 9 to the spacer 6 as shown in FIGS. The fixing tape 12 is formed in a strip shape extending in the width direction, and contacts the optical members 7 to 9 on the lamination direction side in the thickness direction and contacts the spacer 6 on the opposite direction side. The fixing tape 12 has a plurality of recesses 121 to 124 and a plurality of exposed

regions

125 and 126.

凹部 Each of the recesses 121 to 124 is formed so as to be recessed from the surface on the lamination direction side to the opposite direction side of the both surfaces in the thickness direction of the fixing tape 12. Each of the first recesses 121 corresponds to each of the fixing pieces 72, and is formed inside each of the second recesses 122. The first concave portion 121 is formed so as to sandwich the exposed region 125 in the width direction, and is formed so as to be concave toward the opposite side to the second concave portion 122. Here, the first concave portion 121 is formed such that the surface of the fixing piece 72 on the stacking direction side does not protrude further in the stacking direction than the first concave portion 121 when the fixing piece 72 is in contact with the first concave portion 121. Each of the second concave portions 122 respectively corresponds to the fixing piece 82, and is formed between the exposed

regions

125 and 126 adjacent in the width direction. Here, in the state where the fixing piece 82 is in contact with the second concave portion 122, the surface of the fixing piece 82 on the stacking direction side does not protrude toward the stacking direction side than the second concave portion 122, that is, on the stacking direction side of the fixing tape 12. It is formed so as not to protrude from the surface in the stacking direction. Each of the third recesses 123 corresponds to each of the fixing pieces 73, and is formed inside each of the fourth recesses 124. The third concave portion 123 is formed between the exposed regions 126 adjacent to each other in the width direction, and is formed so as to be concave toward the opposite direction side than the fourth concave portion 124. Here, the third concave portion 123 is formed such that the surface of the fixing piece 73 on the stacking direction side does not protrude further in the stacking direction than the third concave portion 123 when the fixing piece 73 is in contact with the third concave portion 123. Each of the fourth concave portions 124 corresponds to each of the fixing pieces 83, and is formed between the exposed regions 126 adjacent in the width direction. Here, in the state where the fixing piece 83 is in contact, the surface of the fixing piece 83 on the stacking direction side does not protrude further than the fourth recess 124 in the stacking direction. It is formed so as not to protrude from the surface in the stacking direction.

The exposed

areas

125 and 126 are areas where the fixing

pieces

72, 73, 82 and 83 of the intermediate

optical members

7 and 8 are exposed in the contact state where the fixing

pieces

72, 73, 82 and 83 come into contact with the fixing tape 12 in the recesses 121 to 124. The exposed region 125 is located at the center of the fixing tape 12 in the width direction. The exposed region 125 is formed to have a longer length in the width direction than the fixing

pieces

72, 73, 82, 83 of the intermediate

optical members

7, 8 and the exposed region 126. That is, the exposed region 125 has the longest length in the width direction. The exposed area 126 is located at both ends in the width direction of the fixing tape 12, that is, except for the central part. The exposed regions 126 are located at intervals in the width direction. The exposed areas 126 in the present embodiment are also located at both ends of the fixing tape 12, respectively. The fixing tape 12 in the present embodiment is a double-sided tape, and is formed in a three-layer structure corresponding to each of the recesses 121 to 124 by being laminated in the laminating direction, but may have a single-layer structure. In addition, the fixing tape 12 is to optimally adjust the length, pitch, and the like in the width direction of each of the recesses 121 to 124 and each of the exposed

regions

125 and 126 according to the thermal expansion coefficients and the masses of the optical members 7 to 9. Can be.

Next, assembly of the spread illuminating apparatus 1 in the present embodiment will be described. First, a worker or a worker such as an assembling machine accommodates the reflecting member 3 in the frame 2 as shown in FIG. Next, the worker accommodates the light source 4 in the frame 2. The worker or the like attaches the fixing member to the lower surface of the substrate 41 in advance by contacting the fixing member in advance, and contacts the fixing member to the long side wall 23 of the frame body 2 so that the fixing member contacts the frame 2. Fix the light source.

(4) Next, the worker accommodates the

elastic members

11A and 11B in the frame 2. The worker inserts the insertion protrusions 113 of the

elastic members

11A and 11B into the insertion holes 263, respectively. The

elastic members

11A and 11B face the frame 2 in the width direction, respectively. Next, the worker accommodates the light guide plate 5 in the frame 2. An operator or the like causes the light guide plate 5 to face the frame 2 in the thickness direction such that the emission surface 51 is on the stacking direction side. Then, with the

elastic members

11A and 11B elastically compressed, the light guide plate 5 is opposed to the

elastic members

11A and 11B in the width direction, respectively. At this time, the first frame side surface 114 contacts the first inner wall surface 261, the first light guide plate side surface 115 contacts the width direction side surfaces 54A and 54B, respectively, and the second frame body side surface 116 contacts the second inner wall surface 262. When the second light guide plate side surface 117 is in contact with the first outer peripheral surface 551, the first contact portion 111 is connected to the light guide plate 5 and the frame in the width direction in a state where the

elastic members

11A and 11B are elastically compressed. The second contact portion 112 contacts the light guide plate 5 and the frame 2 in the cross direction. As a result, the light guide plate 5 is fixed in a state where relative movement with respect to the frame body 2 in the width direction and the vertical direction is restricted.

Next, the worker and the like fix the spacer 6 to the light guide plate 5. The worker or the like attaches the fixing member to the surface on the opposite side of the spacer 6 in advance by bringing the fixing member into contact with the light exit surface 51 of the light guide plate 5. Is fixed. Next, the worker attaches the fixing tape 12 to the spacer 6 as shown in FIG. The worker or the like contacts the fixing tape 12 on the surface of the spacer 6 on the laminating direction side, that is, laminates the double-sided tape so that the concave portions 121 to 124 are formed. The fixing tape 12 may be attached to the spacer 6 before the spacer 6 is fixed to the light guide plate 5.

Next, the worker accommodates the first intermediate optical member 7 in the frame 2. The worker or the like moves the first intermediate optical member 7 with respect to the light guide plate 5 such that the fixing piece 72 faces the first recess 121 in the thickness direction and the fixing piece 73 faces the second recess 122 in the thickness direction. Are opposed in the thickness direction. Then, the worker or the like brings the fixing piece 72 and the fixing piece 73 into contact with the fixing tape 12 in the first recess 121 and the second recess 122, respectively, as shown in FIG. Is fixed to the light guide plate 5. Next, the worker accommodates the second intermediate optical member 8 in the frame 2. The worker or the like moves the second intermediate optical member 8 with respect to the light guide plate 5 so that the fixing piece 82 faces the third recess 123 in the thickness direction and the fixing piece 83 faces the fourth recess 124 in the thickness direction. Are opposed in the thickness direction. Then, the worker or the like brings the fixing piece 82 and the fixing piece 83 into contact with the fixing tape 12 in the third concave portion 123 and the fourth concave portion 124, respectively, as shown in FIG. Is fixed to the light guide plate 5. Next, the worker accommodates the outermost optical member 9 in the frame 2. The worker or the like causes the outermost optical member 9 to face the light guide plate 5 in the thickness direction such that the fixing piece 92 faces the exposed

regions

125 and 126 in the thickness direction. Then, the worker or the like fixes the outermost optical member 9 to the light guide plate 5 as shown in FIG. 9 by bringing the fixing pieces 92 into contact with the exposed

regions

125 and 126, respectively.

Next, the worker or the like fixes the cover 10 to the frame 2. An operator or the like locks the cover 10 to the frame 2 by inserting a locking claw formed on the outer circumference of the frame 2 into a locking hole formed on the outer circumference of the cover 10. Thereby, the assembly of the planar lighting device 1 in the present embodiment is completed.

As described above, the spread illuminating apparatus 1 in the present embodiment is pressed inward in the width direction by the pair of

elastic members

11A and 11B in the elastically compressed state, and is pressed downward, that is, toward the light incident surface 52 (the light guide surface). By pressing the light guide plate 5 toward the light plate 5 (the side where light is incident), the light guide plate 5 can be fixed to the frame body 2 in a state where the light guide plate 5 is separated in the width direction and the upward direction. Therefore, the light guide plate 5 can be arranged at the center with respect to the frame 2, that is, the centers of the light guide plate 5 and the frame 2 in the width direction can be matched or approached. Thus, the gap between the light guide plate 5 and the frame 2 is made small and equal to the left and right, so that the frame can be narrowed.

In addition, in the planar illumination device 1 according to the present embodiment, the lower end of the light guide plate 5 and both ends in the width direction, that is, both ends in the width direction of the light incident surface 52 have inherently poor optical characteristics. Since the area is uniform and deviates from the light emitting area, the optical effect of the arrangement of the pair of

elastic members

11A and 11B is small, and the frame width does not increase. In addition, since it is possible to avoid fixing the light guide plate 5 to the frame body 2 on the three sides except the side on the light incident surface 52 side, it is possible to narrow the frame on the three sides except the side on the light incident surface 52 side. Can be planned. In addition, in the spread illuminating device 1 according to the present embodiment, the relative movement of the light guide plate 5 in the width direction and the vertical direction with respect to the frame 2 can be restricted by the pair of

elastic members

11A and 11B. , The number of parts can be reduced. In addition, assembling of the spread illuminating device 1 becomes easy, and assembling workability can be improved.

In the spread illuminating apparatus 1 according to the present embodiment, the direction in which the second contact portion 112 extends between the pair of

elastic members

11A and 11B is the direction between the width direction and the vertical direction. Therefore, in the pair of

elastic members

11A and 11B, the first contact portion 111 and the second contact portion 112 are not bent at a right angle when viewed from the thickness direction. That is, the width direction side surfaces 54A and 54B of the light guide plate 5 and the first outer peripheral surface 551 do not bend at a right angle. The portion of the light guide plate 5 that is bent at a right angle has poor moldability (die cutting), and the light inside tends to leak to the outside. Therefore, the optical effect on the light guide plate 5 can be reduced by fixing the light guide plate 5 to the frame 2 by the pair of

elastic members

11A and 11B. In the present invention, from the viewpoint of fixing the light guide plate 5 to the frame 2, the first contact portion 111 and the second contact portion 112 may be bent at a right angle.

In the planar lighting device 1 according to the present embodiment, the pair of

elastic members

11A and 11B can move relative to the frame 2 in the thickness direction by inserting the insertion protrusion 113 into the insertion hole 263. Be regulated. Therefore, when the light guide plate 5 is accommodated in the frame 2 during assembly of the planar lighting device 1, the pair of elastic members 11 </ b> A and 11 </ b> B is prevented from being displaced in the thickness direction with respect to the frame 2. be able to. Thereby, since the light guide plate 5 can be accommodated in the frame body 2, the assembly of the planar lighting device 1 is facilitated, and the assembling workability can be improved. Further, even if the light guide plate 5 is repeatedly expanded and contracted due to a temperature change or the like, relative movement of the pair of

elastic members

11A and 11B relative to the frame 2 in the thickness direction is restricted.

In the spread illuminating apparatus 1 according to the present embodiment, the intermediate

optical members

7 and 8 come into contact with the fixing tape 12 in the recesses 121 to 124, and the outermost optical member 9 contacts the exposed

regions

125 and 126. The contact and the fixing tape 12 are attached to the spacer 6 fixed to the light guide plate 5. Therefore, all the optical members 7 to 9 are fixed to the light guide plate 5 via the spacer 6 having a reflection function. Thus, since all the optical members 7 to 9 are directly fixed to the light guide plate 5, the leaked light can be returned as compared with the case where the fixing tape 12 is directly attached to the light guide plate 5. It is possible to suppress a decrease in luminance of the spread illuminating device 1. Further, in the side of the planar illumination device 1 on the light incident surface 52 side, the fixing structure of the optical members 7 to 9 to the light guide plate 5 by the pair of

elastic members

11A and 11B and the fixing tape 12 is concentrated. The frame can be narrowed on three sides except the side on the surface 52 side. Further, by providing the fixing structure of the optical members 7 to 9 over the region of the light source 4 which is originally a dead space on the lamination direction side (by effectively utilizing the dead space as a fixing base), the light incident surface 52 side is provided. Can be promoted.

Further, in the spread illuminating apparatus 1 according to the present embodiment, since the outermost optical member 9 is in contact with the exposed region 125 located at the center in the width direction and is fixed to the light guide plate 5, the outermost optical member 9 is fixed. 9 expands and contracts based on the central portion in the width direction. Therefore, the outermost optical member 9 has a larger thermal expansion coefficient than the light guide plate 5 and the intermediate

optical members

7 and 8, and the outermost optical member 9 expands in the width direction with respect to the light guide plate 5 and the intermediate

optical members

7 and 8. Even if the contraction is large, the followability of the fixing tape 12 in the exposed region 125 located at the center in the width direction where the influence of the expansion and contraction is small is enhanced. Therefore, it is possible to prevent the fixing tape 12 from peeling off from the light guide plate 5 and the optical members 7 to 9 due to the expansion and contraction of the outermost optical member 9, and to prevent the optical members 7 to 9 from wrinkling due to expansion and contraction. Can be suppressed.

In the spread illuminating apparatus 1 according to the present embodiment, the exposed region 125 located at the center in the width direction has a longer length in the width direction than the fixing

pieces

72, 73, 82, 83 of the intermediate

optical members

7, 8. Thus, the length in the width direction of the exposed region 125 can be formed to be the longest. Further, in the spread illuminating apparatus 1 according to the present embodiment, the fixing

pieces

72 and 82 located at the center in the width direction have shorter lengths in the width direction than the fixing

pieces

73 and 83 located at both ends. As a result, the length in the width direction of the exposed region 125 located at the center in the width direction can be formed to be the longest. Therefore, even if the outermost optical member 9 has a large mass, it can be securely fixed to the light guide plate 5. Also, if necessary, the outermost optical member 9 is fixed also in the exposed region 126 which is disposed on both end sides (outside in the width direction) of the exposed region 125 and has a shorter width than the exposed region 125, thereby causing wrinkles. In this state, the strength of fixing the outermost optical member 9 to the spacer 6 (light guide plate 5) can be supplemented, and the rotational displacement in the plane (with the Z axis as the rotation axis) can be suppressed.

In the planar lighting device 1 according to the present embodiment, the intersecting direction is the direction between the width direction and the vertical direction, but the present invention is not limited to this, and may be the vertical direction. Further, the

elastic members

11A and 11B may have, for example, a shape in which the second contact portion has a curved portion.

In addition, in the planar lighting device 1 according to the present embodiment, the intermediate

optical members

7 and 8 are configured by two optical members, but may be one optical member.

The invention is not limited by the above embodiment. The present invention also includes a configuration in which the above-described components are appropriately combined. Further, further effects and modified examples can be easily derived by those skilled in the art. Therefore, the broader aspects of the present invention are not limited to the above embodiments, and various modifications are possible.

1 surface illumination device, 2 frame, 263 insertion hole, 3 reflection member, 4 light source, 5 light guide plate, 51 emission surface, 6 spacer, 7 first intermediate optical member, 72, 73 fixing piece, 8 second intermediate optical Member, 82, 83 fixing piece, 9 outermost optical member, 92 fixing piece, 10Ａ cover, 11A, 11B elastic member, 111 first contact portion, 112 second contact portion, 113 insertion protrusion 12 fixing tape, 121, 122, 123, 124 concave, 125, 126 exposed area

Claims

A light guide plate for guiding incident light;
A frame housing the light guide plate;
In the width direction of the light guide plate, a pair of elastic members arranged between the light guide plate and the frame with the light guide plate interposed therebetween, and in contact with the light guide plate and the frame in a compressed state,
With
The elastic member,
A first contact portion that contacts the light guide plate and the frame body in a width direction;
A second contact portion that contacts the light guide plate and the frame in a cross direction that intersects the width direction;
Having,
Planar lighting device.
The second contact portion is located outside the first contact portion in the width direction,
The cross direction is a direction between the width direction and a vertical direction orthogonal to the width direction.
The planar lighting device according to claim 1.
The elastic member is a light incident side of the light guide plate, and is in contact with the light guide plate at both ends in the width direction.
The planar lighting device according to claim 1.
The frame has an insertion hole formed at a position facing the elastic member in the width direction,
The elastic member protrudes outward in the width direction from the first contact portion, and has an insertion protrusion inserted into the insertion hole.
The planar lighting device according to any one of claims 1 to 3.
A spacer disposed on the light guide plate;
One or more intermediate optical members laminated on the emission surface side of the light guide plate,
An outermost optical member laminated on the lamination direction side of the intermediate optical member,
A fixing tape for fixing each of the optical members to the spacer,
With
Each of the optical members has a fixing piece formed at a position facing the fixing tape in the stacking direction,
The fixing tape has a concave portion formed on the lamination direction side,
The fixing piece of the intermediate optical member contacts the fixing tape in the concave portion,
The fixing piece of the outermost optical member, of the fixing tape, is in contact with an exposed area exposed in a contact state in which the fixing piece of the intermediate optical member is in contact with the fixing tape in the recess.
The planar lighting device according to any one of claims 1 to 4.
The light guide plate further includes a light source for irradiating the light,
The fixing piece of the optical member, at least a part of the light source, and a side of the light guide plate where the light is incident, is opposed in the stacking direction,
The planar lighting device according to claim 5.
A light guide plate for guiding incident light;
A spacer disposed on the light guide plate;
One or more intermediate optical members laminated on the emission surface side of the light guide plate,
An outermost optical member laminated on the lamination direction side of the intermediate optical member,
A fixing tape for fixing each of the optical members to the spacer,
With
Each of the optical members has a fixing piece formed at a position facing the fixing tape in the stacking direction,
The fixing tape has a concave portion formed on the lamination direction side,
The fixing piece of the intermediate optical member contacts the fixing tape in the concave portion,
The fixing piece of the outermost optical member, of the fixing tape, is in contact with an exposed area exposed in a contact state in which the fixing piece of the intermediate optical member is in contact with the fixing tape in the recess.
Planar lighting device.
The light guide plate further includes a light source for irradiating the light,
The fixing piece of the optical member, at least a part of the light source, and a side of the light guide plate where the light is incident, is opposed in the stacking direction,
The planar lighting device according to claim 7.
The exposed region is located at least at a central portion in the width direction of the fixing tape,
A spread illuminating device according to claim 7.
The exposed region located at the center in the width direction has a longer length in the width direction than the fixing piece of the intermediate optical member,
The planar lighting device according to claim 9.
The fixing piece of the intermediate optical member is formed in a plurality in the width direction,
The fixed piece located on the center portion side in the width direction has a shorter length in the width direction than the fixed piece located on both ends.
The planar lighting device according to claim 10.