JP2002133935A - Surface light source device and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent uneveness in brightness of the exit light caused by deformation of a light control sheet. SOLUTION: A reflector 13 of a light source unit 11 comprises a first plate- like part 37 tightly contacting an exit surface 36 end part on an incident surface 10 side of a light guide plate 4, and a second plate-like part 38 supported by a reflector support 14. A projection 41 formed at the second plate-like part 38 of the reflector 13 hooks with a hole formed at a plate-like base part 43 of the reflector support 14 so that the reflector 13 is aligned with the reflector support 14. Thus the deflection of the reflector 13 is corrected, keeping an appropriate interval between a fluorescent lamp 12 and the incident surface 10 of the light guide plate 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface for illuminating an image display unit such as a liquid crystal display panel used for a portable personal computer, a navigation device, a portable information communication terminal, an electronic dictionary, various monitors and the like. The present invention relates to a light source device and an image display device including the surface light source device.

[0002]

2. Description of the Related Art For example, a liquid crystal display device as an image display device is used in a portable personal computer or the like and irradiates a liquid crystal display panel (image display unit) with planar illumination light emitted from a surface light source device. An image is displayed on the surface of the liquid crystal display panel.

FIGS. 16 and 18 show a surface light source device 101 used in such a liquid crystal display device 100. FIG. As shown in these drawings, the surface light source device 101 includes:
The reflection sheet 3, the light guide plate 4 and the plurality of light control sheets 5 to 8 are sequentially accommodated in the resin frame 2, and the light source unit 11 is disposed on the incident surface 10 (side surface) of the light guide plate 4. It has become. The light source unit 11 includes a fluorescent lamp 12 as a rod-shaped light source disposed to face the side surface of the light guide plate 4, a reflector 13 that reflects light of the fluorescent lamp 12 and guides the light to the incident surface 10 of the light guide plate 4, And a metal reflector support 14 fixed to the frame 2 while supporting the reflector 13 containing the fluorescent lamp 12.

The surface light source device 101 configured as described above emits light from the fluorescent lamp 12 in a planar manner from the emission surface 36 of the light guide plate 4, and outputs the light emitted from the light guide plate 4 to a plurality of sheets. By passing the light control sheets 5 to 8, the light guide plate 4
Out of the liquid crystal display panel 16 is condensed in a direction toward the liquid crystal display panel 16 to form uniform and bright planar illumination light, and the planar illumination light illuminates the liquid crystal display panel 16. ing.

In recent years, the liquid crystal display device 100 used especially for portable personal computers is required to be more portable and easier to see on the screen. At the same time, the effective display area (display screen) is enlarged. As a result, in such a liquid crystal display device 100, the frame of the liquid crystal display panel 16 is narrowed, and the peripheral portion of the liquid crystal display panel 16 is reduced.

As a result, the liquid crystal display device 10 as described above
The surface light source device 101 used for the liquid crystal display panel 1
6, the thickness of the resin frame 2 is reduced, and in particular, the rigidity of the portion (first side 21) of the resin frame 2 in which the fluorescent lamp 12 is accommodated is small. Therefore, the plate-like base 4 of the reflector support 14
3 is fixed to a lower surface of a pair of sides (a second side 30 and a third side 31) substantially orthogonal to the first side 21 of the frame 2 with screws (not shown), and the plate base 43 of the reflector support 14 The upright side wall portions 44 to 46 are connected to the first to third sides 21,
The outer surface of the frame 2 is engaged with the outside of the frame 30, 31, and the frame 2 is reinforced by the reflector support 14.

[0007]

However, in the resin frame 2 of such a surface light source device 101, since the thickness of the first side 21 is extremely thin as compared with the thickness of the other side, injection molding is performed. The subsequent contraction amount is larger on the other side than on the first side 21, and the first side 21 may be slightly curved and deformed inward as shown by the two-dot chain line in FIG. 16 and FIG. In FIG. 16, the amount of deformation is exaggerated to emphasize the deformation of the frame 2.

In such a case, if the amount of bending deformation of the first side 21 of the frame 2 is larger than the gap between the frame 2 and the light control sheets 5 to 8, the light control sheets 5 to 8 Are compressed, and wrinkles are generated in the light control sheets 5 to 8, and luminance unevenness of emitted light due to the wrinkles of the light control sheets 5 to 8 may occur.

The reflector 13 is formed in a substantially U-shaped cross section as shown in FIGS. 17 and 18 by sheet metal working of a thin metal plate, and is formed in a long shape. The rigidity is smaller than that of the functioning reflector support 14. Moreover, such a reflector 13 has fluorescent lamps 12 at both ends thereof.
The lamp holders 22 and 23 made of rubber are engaged with each other, and both ends of the lamp holders 22 and 23 are held by the frame 2 together with the lamp holders 22 and 23. Are not locked to the frame 2 or the reflector support 14.

Therefore, when the reflector 13 is warped during sheet metal processing as shown by a two-dot chain line in FIG. 17, the intermediate portion of the reflector 13 is connected to the light guide plate as shown in FIGS. 4 side of the fluorescent lamp 12 and the light guide plate 4 (incident surface 1).
0), the light L of the fluorescent lamp 12 enters the inside of the light guide plate 4 also from the exit surface 36 side of the light guide plate 4,
Emitted light having high brightness is generated partially by the amount of light incident from the exit surface 36 side. Further, the light control sheets 5 to 8 are compressed by the reflector 13, and the light control sheets 5 to 8 are compressed.
The light control sheets 5 to 8 may be wrinkled, resulting in uneven brightness of emitted light due to the wrinkles of the light control sheets 5 to 8.

Therefore, the present invention provides a surface light source device capable of effectively preventing luminance unevenness of emitted light due to deformation of a frame or a reflector and enabling uniform and bright illumination, and an image display provided with the surface light source device. It is intended to provide a device.

[0012]

The surface light source device according to the present invention comprises:
Light from the light source unit attached to the frame is emitted in a planar manner through the light guide plate and the light control sheet housed in the frame. The light source unit of the surface light source device includes a rod-shaped light source arranged to face the side surface of the light guide plate, and the rod-shaped light source is housed, and the light of the rod-shaped light source is guided to the side surface of the light guide plate. It includes a reflector made of sheet metal processing, and a reflector support attached to the frame while supporting the reflector. The reflector of the light source unit includes a first plate-shaped portion that is in close contact with an end surface of the light guide plate on the side surface of the light-emitting plate, and a second plate-shaped portion supported by the reflector support. Have. Among them, the second plate-shaped part and the reflector support are positioned so as to be engaged and recessed.

According to the surface light source device having such a configuration, even if the reflector is warped, the reflector is positioned relative to the reflector support by the concave and convex engagement between the reflector and the reflector support.
The warpage of the reflector is corrected, and the distance between the rod-shaped light source and the side surface (incident surface) of the light guide plate can be maintained at an appropriate size. As a result, according to the surface light source device of the present invention, the light control sheet can be effectively prevented from being deformed (wrinkled) by being compressed by the reflector.

Further, in the surface light source device according to the present invention, light from the light source unit mounted on the frame is emitted in a planar manner through the light guide plate and the light control sheet housed in the frame. ing. The light source unit includes a rod-shaped light source disposed to face the side surface of the light guide plate, a reflector that accommodates the rod-shaped light source, and guides the light of the rod-shaped light source to the side surface of the light guide plate. And a reflector support attached to the frame while supporting the reflector. At least a pair of annular members are fitted to the rod-shaped light source, and a plurality of annular members are fitted between the annular members so as to be adjacent to each other. Further, the rod-shaped light source is supported in the reflector via the annular member. Here, the annular member includes an O-ring and a substantially C-shaped ring. Further, the annular member may be formed so that the outer shape is formed to be substantially in contact with the inner surface of the reflector and the side surface of the light guide plate, and the inner surface is formed to have a shape to be fitted to the annular light source. That is, the annular member may be disposed so as to surround the outer periphery of the rod-shaped light source, and may be capable of supporting the rod-shaped light source in the reflector.

According to the present invention having such a configuration, even if the reflector is warped and the rod-shaped light source is curved and deformed by the reflector so as to approach the side surface (incident surface) of the light guide plate, a pair of the light sources can be formed. The warpage of the reflector can be corrected by the elastic force of the plurality of annular members arranged between the annular members, a sufficient space can be secured between the fluorescent lamp and the light guide plate, and the light guide plate excessively approaches the rod-shaped light source. Can not be. As a result, there is no possibility that the light control sheet is compressed by the reflector to generate wrinkles.

Further, in the surface light source device according to the present invention, light from the light source unit mounted on the frame is emitted in a plane through the light guide plate and the light control sheet housed in the frame. ing. The light source unit includes a rod-shaped light source disposed to face the side surface of the light guide plate, a reflector that accommodates the rod-shaped light source, and guides the light of the rod-shaped light source to the side surface of the light guide plate. And a reflector support attached to the frame while supporting the reflector. At least a pair of annular members are fitted to the rod-shaped light source, and a substantially cylindrical elastic member is fitted between the annular members. Further, the rod-shaped light source is supported in the reflector via the annular member and the substantially cylindrical elastic member.

According to the present invention having such a configuration, the substantially cylindrical elastic members correspond to the plurality of adjacent annular members in the above invention, and can correct the warpage of the reflector. As a result, there is no possibility that the light control sheet is compressed by the reflector to generate wrinkles.

[0018] The surface light source device according to each of the above inventions may be configured such that a hook formed on the reflector support is engaged with one side of the frame on which the light source unit is mounted.

Further, in the surface light source device according to the present invention, light from the light source unit mounted on the frame is emitted in a plane through the light guide plate and the light control sheet housed in the frame. ing. The light source unit includes a rod-shaped light source disposed to face the side surface of the light guide plate, a reflector that accommodates the rod-shaped light source, and guides the light of the rod-shaped light source to the side surface of the light guide plate. And a reflector support attached to the frame while supporting the reflector. Then, on one side of the frame on which the light source unit is mounted,
A hook formed on the reflector support is engaged with the concave and convex.

According to the present invention having such a configuration, even if one side of the frame expands due to the heat of the rod-shaped light source and the like, which causes deformation, the hook of the reflector support is attached to one side of the frame. Engaged and deformation of the frame is prevented by hooks on the reflector support. As a result, the surface light source device of the present invention can properly maintain the interval between the rod-shaped light source and the side surface (incident surface) of the light guide plate, and can cause wrinkles in the light control sheet due to deformation of the frame. And bright surface illumination without luminance unevenness becomes possible.

Further, an image display device according to the present invention is characterized by comprising any one of the above-described surface light source devices and an image display panel illuminated with light emitted from the surface light source device. I have.

According to the image display device having such a configuration,
The image display panel is illuminated by the uniform and bright planar illumination light emitted from the surface light source device, so that the display quality of an image can be improved.

[0023]

Embodiments of the present invention will be described below in detail with reference to the drawings.

[First Embodiment] FIGS. 1 to 3 show a surface light source device 1 according to a first embodiment of the present invention. FIG. 1 is a plan view of the surface light source device 1. FIG. 2 is an exploded plan view showing the surface light source device 1. FIG. 3 is an enlarged cross-sectional view of the surface light source device 1 taken along line AA of FIG.

(Schematic Configuration of Surface Light Source Device) As shown in these drawings, a surface light source device 1 comprises a frame 2 for housing the components, a reflection sheet 3 which is sequentially stacked and housed in the frame 2, and a light guide 3. Light plate 4, and a plurality of light control sheets 5 to 8
A light source unit 11 attached to the frame 2 so as to face the incident surface (one side surface) 10 of the light guide plate 4,
It has. The light source unit 11 includes a fluorescent lamp 12 as a rod-shaped light source, a reflector 13 that houses the fluorescent lamp 12, a reflector support 14 that supports the reflector 13 that houses the fluorescent lamp 12,
It has. The reflector 13 reflects the light of the fluorescent lamp 12 and guides the light to the incident surface 10 of the light guide plate 4.

(Frame) Of these, as shown in FIGS. 1 to 8, a frame 2 is a PC (polycarbonate) or P
It is formed in a substantially rectangular shape by injection molding a white synthetic resin such as MMA (polymethyl methacrylate), and accommodates and supports the reflection sheet 3, the light guide plate 4, and the plurality of light control sheets 5 to 8. A light guide plate accommodating portion 15; an image display panel accommodating portion 17 for accommodating and supporting an image display panel 16 such as a liquid crystal display panel with a small gap with respect to the surface of the uppermost light control sheet 8; Light source accommodating section 1 accommodating 12 and reflector 13
8 are formed. And this frame 2
In order to reduce the size and weight of the surface light source device 1, the thickness is formed as thin as possible, and the bottom surface 20 of the light guide plate housing portion 15 is hollowed out. The bottom surface 20 of the light guide plate housing 15 is
The shape is such that it can support the reflection sheet 3, the light guide plate 4, and the like, and can attach control components (not shown) of the image display panel 16 and the like.

As shown in detail in FIGS. 4 to 7, the frame 2 has one side (first side) of the light guide plate 4 on the side of the incident surface 10.
Sides) of the lower surface side of the fluorescent lamp 12 to be described later.
Are formed with lamp holding body accommodating recesses 24 and 25, respectively, with which the lamp holding bodies 22 and 23 at both ends thereof are engaged.
The reflector 13 is accommodated on the lower surface side of the first side 21 of the frame 2. Therefore, the first side 21 of the frame 2 is formed thinner than the other sides, and has a lower rigidity than the other sides. Therefore, the first side 21 is reinforced by the reflector support 14. That is, as shown in detail in FIGS. 3 and 8, on the upper surface of the first side 21, a hook receiving recess 27 of a substantially rectangular shape with which the plurality of hooks 26 of the reflector support 14 are engaged, and the reflector support A projection 28 is formed which engages with the plurality of hooks 26 of the body 14. The hook 26 of the reflector support 14 is accommodated in the hook accommodating recess 27 of the first side 21, and the hook 2 of the reflector support 14 is accommodated in the projection 28 of the first side 21.
16, the first side 21 of the frame 2 and the reflector support 14 can be detachably integrated with each other, so that the first side 21 of the frame 2 is curved and deformed to the inside of the first side 21 (FIG. 16). Two-dot chain line) can be prevented. The shape of the hook 26 and the hook receiving recess 27 are so set that the upper surface of the hook 26 does not protrude upward from the upper surface of the first side 21.
Is preferably determined. This makes it difficult for other components or the like to be hooked on the hook 26, and the hook 26 is unlikely to come off the projection 28.

The frame 2 includes a light guide plate 4 inside a second side 30 and a third side 31 substantially orthogonal to the first side 21.
In addition, positioning projections 34 are formed to be engaged with cutouts 32 and 33 of substantially rectangular shape formed at both ends of the reflection sheet 3. Thus, even if vibration or impact acts on the surface light source device 1, the light guide plate 4 can be prevented from moving in the frame 2, and the light guide plate 4 can be prevented from colliding with the fluorescent lamp 12. Damage can be prevented.

(Light Source Unit) As shown in FIGS. 1 to 3 and FIGS. 9 to 12, the light source unit 11 includes a fluorescent lamp 12 as a rod-shaped light source and a reflector 13 for accommodating the fluorescent lamp 12. 10), and a reflector support 14 that supports the reflector 13 (see FIG. 10).
reference). Of these, the fluorescent lamp 12 has rubber lamp supports 22 and 23 engaged at both ends thereof, and a pair of rubber O-rings 35 are spaced substantially symmetrically with respect to the center thereof. They are fitted apart (see FIG. 2). The reflector support 14 is engaged with an end of the reflector 13 and is engaged with lamp support accommodating recesses 24 and 25 formed on the first side 21 of the frame 2 (FIG. 5, see FIG. 6). O-ring 35,
Numeral 35 is to elastically support the fluorescent lamp 12 inside the reflector 13 to prevent the fluorescent lamp 12 from directly contacting the inner surface of the reflector 13 and protect the fluorescent lamp 12 from impact. . The cable 39 on the ground side is accommodated in the space between the first side 21 and the reflector 13 (see FIG. 3).

The reflector 13 is formed by processing a thin metal plate such as a stainless steel plate into a sheet metal, and has a first plate-shaped portion 37 in close contact with an end of the light exit surface 36 of the light guide plate 4 and a lower surface of the reflection sheet 3. Close to the reflector support 14
And a rising wall 40 connecting the first plate 37 and the second plate 38 to each other, and a first side of the frame 2. It is a long body formed to have a length substantially the same as 21. this house,
The first plate-like portion 37 is provided on the light incident surface 1 of the light exit surface 36 of the light guide plate 4.
Light is prevented from entering the light guide plate 4 from the 0-side (side surface) end. Further, a projection 41 projecting to the lower surface side is formed at a substantially central portion of a distal end of the second plate-shaped portion 38 in a longitudinal direction (a direction along the axis of the fluorescent lamp 12). The hole 42 that engages with the projection 41 of the reflector 13 is provided in the plate-like base 43 of the reflector support 14.
Is formed. Therefore, by engaging the projections 41 of the reflector 13 with the holes 42 of the reflector support 14, even if the reflector 13 is warped due to sheet metal processing (see the two-dot chain line in FIG. 17), the warp is corrected. Even if an action that causes the deformation of the reflector 13 occurs, the reflector 13 is not deformed and the reflector 13
Can be positioned.

The reflector support 14 includes a plate-like base 43 fixed to the lower surface of the second side 30 and the third side 31 of the frame 2 with screws (not shown), and a first side 2 of the frame 2.
Side walls 44 to 46 rising from the plate-shaped base 43 so as to support the outer surface of the first side, the outer surface of the second side 30, and the outer surface of the third side 31, respectively. The reflector support 14 is made of a metal plate such as a stainless steel plate formed by sheet metal processing similarly to the reflector 13 described above. However, the reflector support 14 is thicker and more rigid than the reflector 13 described above, and reinforces the frame 2. It is supposed to. Further, the reflector support 14 is provided on the first
The first end of the side wall portion 44 located on the outer surface side of the side 21
The hook 26 that engages with the projection 28 formed on the side 21 is bent in a pair. By engaging the hook 26 of the reflector support 14 with the projection 28 of the frame 2, it is possible to prevent the first side 21 of the frame 2 from being bent inward. The hook 26 is provided with a first side 21 inside a substantially rectangular frame 26a.
A hole 26b that engages with the projection 28 is formed.

In such a light source unit 11, first, as shown in FIGS. 3 and 9, the fluorescent lamp 12 is accommodated in a reflector 13, and then, as shown in FIG. Is combined with At this time, the projection 41 of the reflector 13 is engaged with the hole 42 of the reflector support 14 as described above.
That is, the second plate-shaped portion 38 of the reflector 13 and the plate-shaped base 43 of the reflector support 14 are engaged with each other. Thus, the reflector 13 and the reflector support 14 can be positioned, and the bending deformation of the reflector 13 can be corrected. Next, as shown in FIG.
6 are engaged with the projections 28 of the first side 21 of the frame 2, and screws (not shown) are inserted into the screw holes 47 and 48 of the second plate-shaped portion 38 of the reflector 13 and the plate-shaped base 43 of the reflector support 14. Then, the reflector 13 and the reflector support 14 are fixed to the lower surfaces of the second side 30 and the third side 31 of the frame 2 with the screws. Thereby, the frame 2 and the light source unit 11 are integrated. Thereafter, the reflection sheet 3, the light guide plate 4, and the plurality of light control sheets 5 to 8 are accommodated in the light guide plate accommodating portion 15 of the frame 2, and the surface light source device 1 is assembled (see FIGS. 1 to 3). Further, the liquid crystal display panel 16 is accommodated in the image display panel accommodation portion 17 of the frame 2, and the liquid crystal display device 5 as an image display device is provided.
0 is assembled (see FIG. 3).

(Light Guide Plate) The light guide plate 4 is made of PC, PMMA, cycloolefin resin material or the like having excellent light transmittance, and has a vertical cross section perpendicular to the fluorescent lamp 12. It has a wedge-shaped shape that becomes thinner as it goes away, and the shape of the exit surface (upper surface) 36 has a substantially rectangular shape. The light guide plate 4 has substantially rectangular cutouts 32 formed at both ends on the incident surface 10 side, and the cutouts 32 are formed on the second side 30 and the third side of the frame 2. The positioning projection 34 formed on the inside of the base 31 is engaged with the positioning projection 34. The outer dimensions of the light guide plate 4 are determined in consideration of the difference in the temperature expansion and the difference in the hygroscopic expansion between the light guide plate 4 and the frame 2 and the manufacturing error, and the conditions under which the surface light source device 1 is used. Below, a slight gap is formed between the side surface other than the incident surface 10 and the side wall of the light guide plate housing 15. The light guide plate 4 has sufficient rigidity so that it is not easily deformed unlike a flexible sheet member such as a reflection sheet 3 and light control sheets 5 to 8 described later. In such a light guide plate 4, light from the fluorescent lamp 12 that has entered the inside from the incident surface 10 propagates inside the light guide plate 4,
In the course of the propagation, light that enters the emission surface 36 at an angle equal to or less than the critical angle is emitted from the emission surface 36. Various means for emitting light from the light exit surface 36 of the light guide plate 4 have been known in the related art.

(Reflection Sheet) The reflection sheet 3 is formed of a resin material having excellent light reflectivity (for example, white PET (polyethylene terephthalate)) in a sheet shape. It has a rectangular shape corresponding to the opposite surface (lower surface) 51 and functions to reflect light emitted from the lower surface 51 of the light guide plate 4 and return the light to the inside of the light guide plate 4. The reflecting sheet 3 has cutouts 33 formed at both ends of the front end of the fluorescent lamp 12 side, corresponding to the cutouts 32 of the light guide plate 4.
3 is engaged with a positioning projection 34 formed inside the second side 30 and the third side 31 of the frame 2.

(Light Control Sheet) A diffusion sheet (first light control sheet) 5 arranged to face the emission surface 36 of the light guide plate 4, and is arranged to face the upper surface of the diffusion sheet 5. A pair of prism sheets (second and third light control sheets) 6 and 7, and a light-diffusing protective sheet (fourth light control sheet) disposed on the upper surface side of the pair of prism sheets 6 and 7. The sheet 8 constitutes a light control sheet. These first to fourth light control sheets 5 to 8 are formed of a resin material having excellent light transmittance (for example, PET (polyethylene terephthalate)), and correspond to the emission surface 36 of the light guide plate 4. It is formed in a substantially rectangular shape. The first to fourth light control sheets 5 to 8
Are sequentially accommodated in the light guide plate accommodating portion 15 above the light guide plate 4 and are locked to the frame 2 by fixing means such as a tape or a clip (not shown), so that the shift movement in the frame 2 is prevented.

(Operation / Effect of First Embodiment) The surface light source device 1 according to the present embodiment configured as described above has the following features.
The protrusion 28 formed on the first side 21 of the frame 2 is engaged with the hook 26 of the reflector support 14 and the first side 2
1 is corrected, the light control sheets 5 to 8 are not pressed by the first side 21 to form wrinkles, and the light control sheets 5 to 8 are caused by wrinkles. There is no uneven brightness of the emitted light.

The surface light source device 1 according to the present embodiment
Is to engage the projection 41 formed on the second plate-shaped portion 38 of the reflector 13 with the hole 42 formed on the plate-shaped base 43 of the reflector support 14 to position the reflector 13 with respect to the reflector support 14. Even if the reflector 13 is curved and deformed inward as shown in FIG. 17 (even if warpage is caused by sheet metal processing), the deformation of the reflector 13 can be corrected.
The gap between the light guide plate 2 and the light incident surface 10 of the light guide plate 4 can be maintained in an appropriate state, and the end of the light exit surface 36 of the light guide plate 4 on the light incident surface 10 side can be reliably shielded by the first plate portion 37 of the reflector 13. The light of the fluorescent lamp 12 is transmitted from the light exit surface 36 of the light guide plate 4 to the light guide plate 4.
Can be effectively prevented from entering the inside of the device. Moreover, as described above, since the deformation of the reflector 13 can be corrected and the distance between the fluorescent lamp 12 and the incident surface 10 of the light guide plate 4 can be maintained in an appropriate state, the light control sheets 5 to 8 are pressed by the reflector 13. No wrinkles occur. Therefore, according to the present embodiment, the emission surface 36 of the light guide plate 4
It is possible to prevent the occurrence of uneven brightness of the emitted light due to the incident light from the light source.

The surface light source device 1 according to the present embodiment
The projections 41 of the reflector 13 and the holes 42 of the reflector support 14 that engage with the projections 41 are
Therefore, the projections 41 of the reflector 13 and the holes 42 of the reflector support 14 are not visible from the light exit surface 36 side of the light guide plate 4, and troubles such as light leakage do not occur.

The liquid crystal display device 1 according to the present embodiment
In this case, the liquid crystal display panel 16 is illuminated by the above-described surface light source device 1 with a uniform illumination light having a planar shape, so that an even brighter and easier-to-view image can be displayed.

In this embodiment, the mode in which the projection 41 of the reflector 13 and the hole 42 of the reflector support 14 are formed at one place is exemplified. However, the present invention is not limited to this, and the projection 41 of the reflector 13 and the reflector support 14 are formed. 14 holes 42
May be formed in plurality.

In this embodiment, the protrusion 41
Is formed at the tip of the second plate-shaped portion 38 of the reflector 13, but is not limited thereto, and is formed at a portion (a part of the second plate-shaped portion 38) located on the lower surface side of the reflection sheet 3. I just need.

In the present embodiment, the protrusion 41
Is formed so that the tip of the second plate-shaped portion 38 of the reflector 13 is cut and raised toward the lower surface (toward the plate-shaped base 43 of the reflector support 14). It may be formed so as to partially bulge out.
In this case, a recess or a hole is formed in the plate-like base 43 of the reflector support 14 so as to engage with the bulging projection.
In addition, the projection is formed on the plate-like base 43 of the reflector support 14.
And a hole or a concave portion that engages with the projection may be formed in the second plate-shaped portion 38 of the reflector 13. In this case, it is desirable that the protrusion does not protrude toward the upper surface of the second plate-shaped portion 38.

In the present embodiment, a projection is formed on the lower surface side of the hook 26 of the reflector support 14, and a recess for engaging with the projection is formed on the first side 21 of the frame 2. By making the protrusions and the recesses of the first side 21 engage with the concave and convex, the curved deformation of the first side 21 of the frame 2 may be corrected.

In this embodiment, the hooks 26 are formed on the reflector support 14 at two places. However, as long as the bending deformation of the first side 21 of the frame 2 can be corrected, the hooks 26 and the hooks 26 may be formed. Only one projection 28 may be engaged, and three or more hooks 26 and projections 28 engaged with the hook 26 may be formed.

In the present embodiment, a rib extending substantially along the axial direction of the fluorescent lamp 12 is provided on a portion of the reflector support 14 which is located on the tip side of the plate-like base 43 and on the lower surface side of the reflection sheet 3. 52 and 53 are formed, thereby increasing the rigidity of the reflector support 14.

[Second Embodiment] This embodiment exemplifies a mode different from that of the above-described first embodiment as a means for correcting the warpage of the reflector 13. That is, as shown in FIG. 13, the surface light source device 1 according to the present embodiment has a substantially central portion between a pair of O-rings (annular members) 35 fitted to the fluorescent lamp 12,
A plurality of O-rings (annular members) 54 are arranged in close contact.

With such a configuration, when the reflector 13 is warped such that the reflector 13 is bent inward (see FIG. 17), the rod-shaped fluorescent lamp 12 is also bent and deformed by the reflector 13, and the fluorescent lamp 12 is bent. Of the fluorescent lamp 1 has the largest deformation at the substantially central portion of the
It is also conceivable that a plurality of O-rings 54 arranged substantially at the center of the light guide 2 are pressed against the incident surface 10 of the light guide plate 4. However, according to the present embodiment, since the pressing force received from the incident surface 10 of the light guide plate 4 can be dispersed by the plurality of O-rings 54, the same O-ring 35 as the pair of O-rings 35, 35 is used. Compared to the case where only one lamp is disposed at the center of the fluorescent lamp 12, the amount of elastic deformation of each O-ring 54 is reduced, and a sufficient space between the light guide plate 4 and the fluorescent lamp 12 can be secured. In other words, reflector 1
The warp 3 is corrected by the plurality of O-rings 54 arranged substantially at the center of the fluorescent lamp 12, and a sufficient space can be secured between the fluorescent lamp 12 and the light guide plate 4. The width W of the plurality of O-rings 54 arranged substantially at the center of the fluorescent lamp 12 is equal to the pair of O-rings 35 and 3.
When the wire diameter of 5 is d, it is preferable that W = 2d to 4d. If W <2d, the effect of correcting the reflector 13 cannot be sufficiently obtained, and if W> 4d, the light-blocking portion becomes too large, and the light-blocking portion may be visually recognized as a variation in the luminance of the emitted light. is there.

According to the present embodiment having such a configuration,
Since the deformation of the reflector 13 can be corrected by the plurality of O-rings 54 arranged substantially at the center of the fluorescent lamp 12, a sufficient space between the fluorescent lamp 12 and the incident surface 10 of the light guide plate 4 can be ensured, and the light guide plate 4 can be secured. The end of the light exit surface 36 on the incident surface 10 side can be reliably shielded by the first plate-shaped portion 37 of the reflector 13, and the light of the fluorescent lamp 12 enters the light guide plate 4 from the light exit surface 36 of the light guide plate 4. Can be effectively prevented. Moreover, as described above, the deformation of the reflector 13 is corrected, and a sufficient space between the fluorescent lamp 12 and the incident surface 10 of the light guide plate 4 can be ensured.
No. 8 is not pressed by the reflector 13 to cause wrinkles. Therefore, according to the present embodiment, the emission surface 36 of the light guide plate 4 is similar to the first embodiment.
It is possible to prevent the occurrence of uneven brightness of the emitted light due to the incident light from the light source.

In the second embodiment, a plurality of Os
Although the mode in which the ring 54 is arranged close to the approximate center of the fluorescent lamp 12 is illustrated, the present invention is not limited to this.
As shown in FIG. 4 and FIG. 15A, a substantially cylindrical rubber ring (elastic member) 55 may be fitted to a substantially intermediate portion between the pair of O-rings 35. Here, as shown in FIG. 15B, the ring 55 may form a slit 56 over the entire length in the width direction to facilitate the fitting operation to the fluorescent lamp 12. With such a configuration, the same effect as that of the above-described second embodiment can be obtained.
The width W of the ring 55 is W = 2d, where d is the wire diameter of the O-ring 35, as in the second embodiment.
To 4d is preferred.

Further, in the above-described second embodiment,
With the plurality of O-rings 54 in close contact with each other,
Of the O ring 5
4 may be arranged slightly apart from each other.

(Other Embodiments) In the surface light source device 1 according to each of the above embodiments, the first light control sheet 5 diffuses the light emitted from the light exit surface 36 of the light guide plate 4 to distribute the luminance. Then, the light is condensed by the second and third light control sheets 6 and 7 in the normal direction of the light exit surface 36 of the light guide plate 4 to increase the ratio of light that can be effectively used for illumination. , And provide bright and uniform surface illumination. In the surface light source device 1 according to each of the embodiments, for example, the second light control sheet 6 has a prism surface having a substantially triangular cross section extending in a direction substantially parallel to the fluorescent lamp 12 in a direction orthogonal to the fluorescent lamp 12. The third light control sheet 7 has a large number of prism surfaces having a substantially triangular cross section and extending in a direction substantially perpendicular to the prism surface of the second light control sheet 6. The fourth light control sheet 8 is mainly used as a protective sheet for preventing the above-mentioned scratches on the prism surface. However, the fourth light control sheet 8 needs to function as a diffusion sheet in order to further uniform the illumination light. Will be given accordingly.

The present invention is not limited to the mode of the surface light source device 1 according to each of the embodiments.
A prism surface similar to the prism surface of the second light control sheet 6 is formed on the lower surface 51 of the light guide plate 4, and the second light control sheet 6 is formed.
May be omitted. In addition, the present invention only needs to have a configuration in which at least one light control sheet is disposed on the emission surface 36 side of the light guide plate 4. That is, as a specific configuration of the light guide plate 4 and the light control sheets 5 to 8, various configurations conventionally known in this type of the surface light source device 1 can be adopted.

In each of the above embodiments, the light guide plate 4 has a vertical cross section perpendicular to the light incident surface 10 in a substantially wedge shape. However, the present invention is not limited to this. For example, the light incident surface 10 of the light guide plate 4 may be used. The vertical cross-sectional shape orthogonal to the above may be substantially rectangular, or another cross-sectional shape may be used.

Further, in the above embodiment, the light source unit 11 is arranged only on the incident surface 10 side of the light guide plate 4, but is not limited to this, and may be arranged on a plurality of side surfaces of the light guide plate 4. You may.

[0055]

As described above, in the surface light source device according to the present invention, by correcting the bending deformation of the frame and the warpage of the reflector, it is possible to prevent the light control sheet from being pressed by the frame or the reflector and causing wrinkles. In addition to this, it is possible to prevent light from the fluorescent lamp from being incident from the emission surface side of the light guide plate, so that uneven brightness of planar light emitted from the light guide plate can be suppressed, and uniform and bright surface illumination can be achieved.

Further, in the image display device according to the present invention, the image display panel is illuminated by the uniform and bright planar illumination light emitted from the surface light source device as described above. Image display quality is improved.

[Brief description of the drawings]

FIG. 1 shows a plan view of a surface light source device according to a first embodiment of the present invention.

FIG. 2 is an exploded plan view showing the surface light source device according to the first embodiment.

FIG. 3 is an enlarged cross-sectional view of the surface light source device cut along the line AA of FIG.

FIG. 4 is a plan view of a frame.

FIG. 5 is a view (side view) as viewed from a direction B in FIG. 4;

FIG. 6 is a diagram viewed from a direction C in FIG. 5 (a diagram illustrating a lower surface on a first side of the frame).

FIG. 7 is an enlarged sectional view taken along line DD of FIG. 5;

FIG. 8 is a view showing an engagement state between a hook of a reflector support and a projection of a frame.

FIG. 9 is a plan view of a reflector accommodating a fluorescent lamp.

FIG. 10 is a plan view of a light source unit.

FIG. 11 is a plan view of a frame to which the light source unit is attached.

FIG. 12 is a perspective view partially showing a reflector and a reflector support.

FIG. 13 is a view showing a fluorescent lamp according to a second embodiment of the present invention.

FIG. 14 is a diagram showing a fluorescent lamp according to a modification of the second embodiment.

FIG. 15 is a view showing a ring. FIG. 15A is a perspective view showing a first example of the ring, and FIG. 15B is a perspective view showing a second example of the ring.

FIG. 16 is a plan view showing a conventional surface light source device.

FIG. 17 is a plan view showing a conventional fluorescent lamp and a reflector.

FIG. 18 is an enlarged sectional view taken along line EE of FIG. 16;

FIG. 19 is a cross-sectional view of the surface light source device showing a curved deformation state of the frame.

FIG. 20 is a cross-sectional view showing a state in which a defect of the conventional surface light source device occurs due to the warpage of the reflector.

FIG. 21 is an enlarged sectional view showing a part of FIG. 20;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Surface light source device, 2 ... Frame, 4 ... Light guide plate, 5
... 8 ... light control sheet, 10 ... incident surface (side surface), 11
…… Light source unit, 12 …… Fluorescent lamp (bar-shaped light source),
13 ... reflector, 14 ... reflector support,
16: Liquid crystal display panel (image display panel), 26:
Hook, 35 O-ring, 36 Outgoing surface, 37
First plate portion, 38 second plate portion, 50 liquid crystal display device (image display device), 54 O-ring, 55
ring

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Tsutomu Arihara 2-30-1 Namiki, Kawaguchi-shi, Saitama F-term in Enplas Co., Ltd. (Reference) 2H091 FA14Z FA23Z FA32Z FA41Z FD13 LA02 LA18

Claims (6)

[Claims] 1. A surface light source device in which light from a light source unit attached to a frame is emitted in a planar manner via a light guide plate and a light control sheet housed in the frame, wherein the light source unit comprises: A rod-shaped light source arranged to face the side surface of the light guide plate, a sheet metal processing reflector that accommodates the rod-shaped light source and guides the light of the rod-shaped light source to the side surface of the light guide plate, and a state where the reflector is supported. A reflector support attached to the frame, wherein the reflector is a first plate-shaped portion that is in close contact with an end surface of the light guide plate on the side surface of the light guide plate, and a second plate that is supported by the reflector support. A planar light source device, comprising: a second plate-shaped portion and the reflector support body are positioned by being engaged and recessed. 2. A surface light source device in which light from a light source unit attached to a frame is emitted in a planar manner through a light guide plate and a light control sheet housed in the frame, wherein the light source unit comprises: A rod-shaped light source disposed so as to face the side surface of the light guide plate; a reflector accommodating the rod-shaped light source and guiding the light of the rod-shaped light source to the side surface of the light guide plate; and a frame supporting the reflector on the frame. A reflector support to be attached, at least a pair of annular members are fitted to the rod-shaped light source, and a plurality of annular members are fitted between these annular members so as to be adjacent to each other; Is supported in the reflector via the annular member. 3. A surface light source device in which light from a light source unit attached to a frame is emitted in a planar manner through a light guide plate and a light control sheet housed in the frame, wherein the light source unit comprises: A rod-shaped light source disposed so as to face the side surface of the light guide plate; a reflector accommodating the rod-shaped light source and guiding the light of the rod-shaped light source to the side surface of the light guide plate; and a frame supporting the reflector on the frame. A reflector support to be attached, and the rod-shaped light source is fitted with at least a pair of annular members, and a substantially cylindrical elastic member is fitted between these annular members. A surface light source device supported in the reflector via an annular member and a substantially cylindrical elastic member. 4. A hook formed on the reflector support body is engaged with one side of the frame on the side on which the light source unit is mounted.
4. The surface light source device according to 2 or 3. 5. A surface light source device in which light from a light source unit attached to a frame is emitted in a planar manner via a light guide plate and a light control sheet housed in the frame, wherein the light source unit comprises: A rod-shaped light source disposed so as to face the side surface of the light guide plate; a reflector accommodating the rod-shaped light source and guiding the light of the rod-shaped light source to the side surface of the light guide plate; and a frame supporting the reflector on the frame. And a reflector support attached thereto, wherein a hook formed on the reflector support is unevenly engaged with one side of the frame on the side on which the light source unit is attached. 6. An image display device comprising: the surface light source device according to claim 1; and an image display panel illuminated with light emitted from the surface light source device.