KR100417025B1 - surface light source device, liquid crystal display and reflecting member - Google Patents

Abstract

In the surface light source device, it is possible to prevent the occurrence of the linear shape and to make the effective area to obtain a uniform output on the exit surface wide. As a result, the size and weight of the surface light source device and the liquid crystal display device can be reduced. The end 42 of the reflector 10 surrounding the primary light source is formed by shearing. The corner portion of the end portion 42 is sharp, and the end portion 42 securely engages the edge 41 of the light guide plate 4. A rubber piece 13 is disposed on the end face of the light guide plate 4 and the gap 12 of the frame 2, and the light guide plate 4 is pressed against the end portion 42. The incident surface 7 of the light guide plate 4 is in close contact with the end 42, so that light of the fluorescent lamp 8 is reliably blocked at the end 42. As a result, light does not enter the light guide plate 4 via the edge 41, and therefore, abnormal light emission in a linear shape is avoided. An inclined surface may be formed at the tip of the reflector surrounding the primary light source, and the inclined surface may contact the edge of the light guide plate to prevent abnormal light emission.

Description

Surface light source device, liquid crystal display and reflecting member

The present invention relates to a surface light source device, a display device and a reflective member used in these devices. In more detail, in the surface light source device or liquid crystal display device using a light-guide plate, it is related with the technique which prevents a luminance nonuniformity or abnormal light emission in the output surface of a light-guide plate. The present invention can be applied to, for example, a liquid crystal display device for a portable personal computer or a navigation system and a surface light source device used for illumination of the liquid crystal display panel or a reflection member used therein.

Illumination of a liquid crystal display panel of a liquid crystal display device with a surface light source device is already known, and is widely applied to image display of, for example, a portable personal computer or a navigation system. 21 shows an example thereof.

Referring to FIG. 21, the surface light source device 101 used in the liquid crystal display device 100 includes a light guide plate 102 and a fluorescence disposed so as to face one side surface (incident surface) 103 of the light guide plate 102. Lamp (primary light source) 104.

The reflective sheet 105 is disposed on the rear (lower surface) 102a side of the light guide plate 102, and the prism sheet 106 is disposed on the emission surface (upper surface) 102b side. In addition, a reflector (reflective member) 107 is disposed so as to surround the fluorescent lamp 104.

The operating mode of this type of surface light source device is already known. That is, the light emitted from the fluorescent lamp 104 is introduced into the light guide plate 102 through the incident surface 103, and the internal reflection at the back surface 102a and the exit surface 102b and the reflective sheet 105 are reflected. It exits from the exit surface 102b through reflection etc. The outgoing light is directionally corrected in the prism sheet 106 toward the object to be illuminated (the liquid crystal display panel 108 here).

One problem with such a surface light source device is that light entering the light guide plate 102 through the vicinity of an edge (also called a first edge) 110 where the exit surface 102b and the incident surface 103 meet each other is uneven in brightness. It causes abnormal light emission. As shown in FIG. 22A, the light H passing through the first edge 110 is locally emitted from the exit surface 102b near the incident surface 103 and correspondingly to the prism sheet ( It is easy to cause abnormal light emission to the exit surface 106a of the 106. This abnormal light emission is usually shown in the form of the bright line 111 parallel to the incident surface 103.

Such luminance unevenness significantly impairs the quality of the emitted light. Moreover, when such output light is supplied to the liquid crystal display panel 108, the image of the liquid crystal display panel 108 becomes difficult to see.

This damage is avoided if the vicinity of the incident surface 103 is shielded from the exit surface 102b and only the remaining area is used as the actual illumination light output area. However, if this method is taken, the effective light emitting area is narrowed. Moreover, even in view of light utilization efficiency, waste is generated, which is not preferable. Moreover, it is not suitable for the request of the weight reduction and the miniaturization of the portable personal computer etc. which are increasing recently.

An object of the present invention is to provide an improved surface light source device, a liquid crystal display device using the same, and a reflection member used therein, so as not to cause the above problems. Specifically, the present invention provides a surface light source device capable of widening an effective light emitting area without luminance unevenness, a liquid crystal display device using the same, and a reflective member used therein.

The present invention is, firstly, an emission surface for outputting light, a back surface opposite to the emission surface, an entrance surface for inputting light from a side, a first edge where the emission surface and the entrance surface meet, and A light guide plate having an end surface positioned on an opposite side to the incident surface;

A primary light source disposed opposite the incident surface,

It is applied to a surface light source device including a reflection member disposed to introduce the supply light of the primary light source to the incident surface.

According to the present invention, the reflective member includes a metal base material and a reflective layer formed on an inner surface of the base material,

A portion of the reflective layer and the base material is sheared, thereby forming an end engaging at least with the first edge.

According to such a structure, since the edge part of a reflective member is formed by shearing, the corner part of the edge part of a reflective member is sharply formed compared with the case where the edge part of a reflective member is formed by bending by press. Thus, the end of the reflective member is engaged so as to cover the first edge of the light guide plate so that the end is surely in close contact with the incident surface of the light guide plate.

As a result, the light of the primary light source is blocked by the end of the reflecting member, and the light is prevented from entering the inside of the light guide plate from the first edge of the light guide plate, thereby avoiding the above-described linear abnormal light emission.

In general, the light guide plate, the primary light source, and the frame accommodating the reflective member are often disposed. In this case, a gap between the end face and the frame is provided with a gap for allowing thermal expansion of the light guide plate, and between the ends, an elastic support means for pressing the light guide plate at the end and allowing thermal expansion of the light guide plate. It is preferable to arrange this.

In this way, when the elastic support means is formed, the incidence surface of the light guide plate is elastically pressed to the end of the reflective member, so that even if the surface light source device is used in an environment where vibration or posture change is large, The gap is hard to occur in between. Therefore, the edge is reliably shielded by the end of the reflecting member, and the occurrence of the above-described linearity luminance unevenness is more reliably prevented.

In addition, since the gap between the light guide plate and the frame is formed to allow thermal expansion of the light guide plate, and the elastic support means disposed between the gaps allows the thermal expansion of the light guide plate, such as bending caused by thermal expansion of the light guide plate. There is no problem.

In addition, the metal base material at the end of the reflective member can receive the elastic force of the elastic support means acting on the light guide plate. It is also possible to employ a reflecting member having a material configuration other than the combination of the metal base material and the reflecting layer.

Usually, although a reflective sheet is arrange | positioned along the said back surface of the said light guide plate, it is preferable that this reflective sheet protrudes to the said light source side beyond the 2nd edge where the said incidence surface and said back surface meet. This also suppresses the phenomenon that luminance unevenness occurs due to light entering through the second edge.

In addition, it is preferable that the surfaces of the elastic support means and the frame are colored black or gray. This is effective to eliminate the possibility that the elastic support means or the surface of the frame will generate harmful reflected light. Further, since the light emitted from the end face of the light guide plate is absorbed by the elastic support means and the black or gray colored portion of the frame, the light emitted from the portion where the elastic support means of the light guide plate is in close contact with the elastic support means is not. The difference in luminance becomes less likely to occur.

It is preferable that the corner of the said edge part of the said reflection member is formed in substantially circular arc shape with a curvature radius of 10 micrometers or less. Taking this aspect, the gap between the end of the reflecting member and the incident surface of the light guide plate becomes particularly difficult to occur. As a result, the possibility of light penetrating into the edge of the light guide plate from between the electrodes is further lowered.

In the case where the light guide plate is injection molded, in general, the edge of the light guide plate has a substantially circular arc shape having a radius of curvature of 10 µm or more. Therefore, when the corner part of the edge part which engages the edge of a light guide plate is 10 micrometers or less, it becomes possible to make an edge close to the incident surface of a light guide plate reliably.

The present invention also applies to a liquid crystal display device. In that case, the liquid crystal display panel equipped in the liquid crystal display device is illuminated by the surface light source device improved according to the present invention as described above. Advantages of the improved surface light source device (resolution of luminance unevenness) are naturally reflected in the liquid crystal display device used for illumination, so that easy-to-view image display without light and shade unevenness is achieved.

The present invention can also be applied to a reflective member that plays an important role in the above improvement. That is, the present invention provides a light source for supplying light through the incident surface to a light guide plate having an emission surface, a back surface, an incident surface provided by a cross section, and an edge where the emission surface and the incident surface meet. It is applied to the reflecting member arranged enclosed.

According to an improvement according to the present invention, the reflecting member includes a metal base material and a reflecting layer formed on the inner surface side of the reflecting member, the end face of which is in contact with the exit surface and the back surface, and the reflecting layer and a part of the base material are sheared. As a result, an end portion for engaging with the edge is formed.

When the reflective member having such a structure is used, it has an end that is sharply formed by the front end, so that it is engaged with the light guide plate so as to cover the first edge, and close to the incident surface of the light guide plate, and effectively intrudes light therefrom. You can prevent it.

According to another aspect of the present invention, an emission surface for outputting light, a back surface opposite to the emission surface, an entrance surface for inputting light from the side, and a first surface where the emission surface and the entrance surface meet A light guide plate having an edge,

A primary light source disposed opposite the incident surface,

A surface light source device including a support member for supporting the primary light source facing the incident surface is improved as follows.

The support member used here is formed with the inclination so that it may contact the said 1st edge and may cross the said 1st edge. The said support member may be formed by bending a metal plate material, and may be a reflector which reflects the light supplied from the said primary light source.

Moreover, the said support member may comprise a part of the frame which integrally supports the said light guide plate and another structural member. If the improved surface light source device is used for illumination of the liquid crystal display panel, an improved liquid crystal display device is provided.

This improvement also reliably achieves light shielding at the first edge of the light guide plate, and prevents luminance unevenness in the linear form caused by light entering the light guide plate via the same edge.

1 is an exploded perspective view of a surface light source device according to a first embodiment of the present invention.

2 is a cross-sectional view taken along the line A-A of FIG.

FIG. 3 is an enlarged cross-sectional view of the periphery of the primary light source in the surface light source device shown in FIG. 2.

4 is a view showing the reflector in detail. (a) is a front view of a reflector, (b) is an enlarged view of the B part of (a).

5 is a view showing a state of use of the rubber piece of the surface light source device. (a) is an enlarged view of the vicinity of the right end part of the surface and circle apparatus of FIG. 2, and FIG. 5 (b) is a perspective view of a rubber piece.

6 is a view illustrating an engagement state between an end portion and a light guide plate. (a) is a figure explaining the engagement state of the edge part and the light-guide plate in this invention, and FIG. 6 (b) is a figure explaining the state of the bad engagement of an edge part and a light guide plate.

7 is an exploded perspective view of the surface light source device according to the second embodiment of the present invention.

FIG. 8 is a cross-sectional view taken along the line C-C of FIG. 7.

FIG. 9 is an enlarged view illustrating a light source periphery of the surface light source device of FIG. 8.

10 is a front view of a second example of the reflector according to the present invention.

It is a figure which shows the use state of the rubber piece of the surface light source device which concerns on 2nd Embodiment of this invention. (a) is an enlarged view of the right end part of the surface light source device of FIG. 8, (b) is a perspective view of a rubber piece.

12 is a cross-sectional view of the surface light source device according to the third embodiment of the present invention.

FIG. 13 is an enlarged view of the left end of FIG. 12.

14 is a diagram showing a surface light source device according to a modification of the first embodiment of the present invention, (a) is an enlarged sectional view of the main portion of the coplanar light source device, and (b) is a partially enlarged view of the reflector.

Fig. 15 is an enlarged cross-sectional view of a main portion of a surface light source device showing a modification of the second embodiment of the present invention.

Fig. 16 is an enlarged view of the main portion of the surface light source device showing another modification of the first embodiment of the present invention.

17 is an enlarged cross-sectional view of a main portion of the surface light source device 231 showing another modification of the second embodiment of the present invention.

18 is a plan view showing a first application example of the elastic support means.

19 is a view showing a second application example of the elastic support means. (a) is sectional drawing along the D-D line of (b), (b) is sectional drawing which shows the mounting state of the rubber piece as elastic support means.

20 is a view showing a third application example of the elastic support means. (a) is sectional drawing along the E-E line of (b), (b) is sectional drawing which shows the mounting state of the rubber piece as elastic support means.

It is sectional drawing explaining the conventional surface light source device.

22 is a diagram illustrating a situation in which abnormal light emission occurs in the conventional example. (a) is sectional drawing which expanded the vicinity of the light source of FIG. 21 in order to demonstrate the situation, (b) shows the figure seen from the arrow of the G direction of (a) in order to demonstrate the same situation.

Fig. 23 is an enlarged cross-sectional view showing the periphery of the primary light source of the surface light source device according to the sixth embodiment of the present invention.

24 is an exploded perspective view showing the outline of the surface light source device shown in FIG. 23.

FIG. 25 is a cross-sectional view showing the reinforcing material used in the surface light source device shown in FIG. 23.

Fig. 26 is an enlarged cross-sectional view showing the surface light source device according to the seventh embodiment.

27 is an enlarged cross-sectional view showing a surface light source device according to an eighth embodiment.

28 is an enlarged cross-sectional view showing the periphery of the light source of the conventional surface light source device in order to explain the advantages of the sixth to eighth embodiments.

* Description of the symbols for the main parts of the drawings *

1, 61, 91, 201, 211, 221, 231, 301. 311, 341: surface light source device

2, 62, 94, 96, 305, 312, 332: Frame

3, 92: reflective sheet

4, 302, 314: Light guide plate

7: incident surface of the light guide plate

8, 306, 324: fluorescent lamp (primary light source)

10, 64: reflector

11: end surface of the light guide plate

12, 65: gap

13, 66, 93: rubber pieces (elastic support means)

23 liquid crystal display panel (image display unit)

27: metal base material

32: reflective layer

40: exit surface of the light guide plate

41: first edge

80: second edge

42, 78, 81: end

44, 83, 95, 97: elastic support means receiving portion

51, 84: image display device

92a: end

98: plate-shaped spring member (elastic support means)

305A, 320A: main body of the frame

323: Rubber Bushing

R1: corner

Example

Hereinafter, with reference to the accompanying Figures 1 to 20 and 23 to 28 will be described an embodiment. In addition, in each figure, the dimension, shape, etc. of each element are exaggerated as needed in order to make understanding easy.

[First Embodiment]

1-3 shows the outline | summary of the side light type surface light source device 1 which concerns on this embodiment. 1 is an exploded perspective view of the surface light source device 1, and FIG. 2 is a sectional view taken along the line A-A. 3 is a partially enlarged view of FIG.

Referring to these drawings, the reflective sheet 3, the light guide plate 4, the prism sheet 5, and the protective sheet 6 are sequentially stacked and accommodated in the frame 2 produced in a substantially rectangular shape. A fluorescent lamp (primary light source) 8 is disposed so as to face the side (incident surface) 7 side on one side of the light guide plate 4.

The fluorescent lamp 8 is housed in a metal reflector (reflective member) 10 fixed to the frame 2. Further, the light guide plate 4 is elastically directed toward the fluorescent lamp 8 in the gap 12 between the side face (end face) 11 and the frame 2 located on the reflection side with respect to the incident surface 7 of the light guide plate 4. A pair of rubber pieces (elastic support means) 13 and 13 to support are accommodated.

The frame 2 is formed into a substantially rectangular shape by injection molding white synthetic resin. The said metallic reflector 10 is being fixed to the edge part E1 of the one side. A metal support plate 14 is fixed to the end E2 so as to face the reflector 10.

Here, the frame 2 includes a first side 15 to which the reflector 10 is fixed, a second side 16 substantially perpendicular to an end of one side of the first side 15, and the first side. The 3rd side 17 orthogonal to the other edge part of (15) and the 4th side 18 substantially orthogonal to these 2nd side 16 and the 3rd side 17 are provided.

And inside the second side 16 and the third side 17, tongue pieces 20, 20 supporting the lower surface 3a of the reflective sheet 3 are formed. In addition, a pair of reflector fixing parts 21 is formed at both ends of the first side 15. In addition, a pair of support plate fixing parts 22 is formed at both ends of the fourth side 18.

On the other hand, a panel engaging portion 24 for accommodating the liquid crystal display panel (image display portion) 23 is formed at the upper periphery of the frame 2. And the 1st engagement part 25 which engages with the reflector 10, and the 2nd engagement part 26 which engages with the support plate 14 are formed in the lower surface side of the frame 2, respectively.

As shown in detail in Figs. 4A and 4B, the reflector 10 includes a metal base material 27, such as stainless steel or an aluminum alloy, and a reflective layer 32. The reflective layer 32 is formed over the entire inner surface of the base material 27, and is formed by sequentially overlapping the adhesive 28, the silver 30, and the synthetic resin film (for example, PET) 31.

The reflector 10 stands up from the base 34, which is fixed to the reflector fixing portions 21, 21 on the side of the first side 15 of the frame 2 with screws 33, 33. The standing wall part 35 and the sunshade (flange) part 36 bent to the light guide plate 4 side so that it may become substantially parallel to the base 34 from this standing wall part 35. As shown in FIG.

The lower base 34 is formed longer than the upper shading portion 36, and is closer to the lower surface 3a side of the reflective sheet 3, and the reflective sheet 3, the light guide plate 4, and the prism sheet. One end of the side 5 and the protective sheet 6 can be stably supported.

Moreover, the upper shading part 36 is provided with the panel paper surface part 37 which supports the surface side of the liquid crystal display panel 23, and the light guide plate press part 38 bent from this panel paper surface part 37. Doing.

The light guide plate pressing portion 38 is located on the exit surface 40 side of the light guide plate 4. Further, the light guide plate pressing portion 38 has an edge at which the entrance surface 7 and the exit surface 40 of the light guide plate 4 meet each other. An end portion 42 engaged with the (first edge) 41 is formed.

The end part 42 is formed by shearing a part of the reflective layer 32 of the reflector 10 and the metal base material 27. It is sharply formed to engage the edge 41 of the light guide plate 4 and to be in close contact with the incident surface 7.

That is, the corner portion R1 of the end portion 42 has the same shape as the edge 41 of the substantially arcuate shape of the light guide plate 4, as shown in Fig. 6 (a), or does not touch the edge 41. It is formed by a shearing process with the dimension of the grade.

Since the edge 41 of the light guide plate 4 is formed by injection molding, eggs are formed (rounded), and are generally formed in a substantially circular arc shape having a radius of curvature of 10 µm or more. On the other hand, the corner part R1 of the edge part 42 is formed in substantially circular arc shape of the magnitude | size of 10 micrometers or less. The end part 42 of the reflector 10 formed in such a magnitude | size is easily intimately connected with the incident surface 7 of the light guide plate 4, without generating a gap.

Thus, the edge 41 is completely shielded at the end 42, and the light of the fluorescent lamp 8 does not enter the inside of the light guide plate 4 via the edge 41 of the light guide plate 4. Thereby, generation | occurrence | production of the bright line originating in the entrance light via the edge 41 is prevented. On the other hand, as shown in FIG. 6B, when the corner portion R1 of the end portion 42 is formed with a curvature that is gentler than that of the edge 41 of the light guide plate 4, the end portion 42 and the incident surface 7 are formed. It is not preferable because a gap tends to occur between the parts. If the light of the fluorescent lamp 8 penetrates into the vicinity of the edge 41 of the light guide plate 4 from this gap, there is a possibility that bright lines are generated.

1 to 3 and 5, the incidence surface 7 is pressed by the elastic force F of the rubber piece 13 described above at the end portion 42. Thereby, even if vibration acts on the surface light source device 1, and even if the attitude | position of the surface light source device 1 changes, the close state with respect to the incident surface 7 of the edge part 42 is maintained. Therefore, since the edge 41 is always shielded by the end part 42, the bright line which arises from the light which enters from the edge 41 is reliably prevented.

The frame 2 has a gap 12 that can absorb the thermal expansion of the light guide plate 4 between the end face 11 of the light guide plate 4. And the pair of rubber pieces 13 and 13 is accommodated in this clearance gap 12. The rubber piece 13 is substantially L-shaped in cross section, and the engaging projection 43 is engaged with the receiving portion (elastic support means containing portion) 44 formed in the frame 2. Thereby, the rubber piece 13 is being fixed so that it cannot escape from the frame 2. As shown in FIG.

On the other hand, the rubber piece 13 elastically deforms when the light guide plate 4 thermally expands, absorbs the deformation of the light guide plate 4, and prevents warping of the light guide plate 4. In addition, the reflector 10 is fixed to the frame 2 so that the base 34 functions as a beam member of the frame 2 and supports the reflective sheet 3, the light guide plate 4, and the prism sheet 5. It functions as a supporting plate member to reinforce the frame 2.

Therefore, the frame 2 can be designed to be thin and light as thin as the one reinforced with the reflector 10. In addition, since the reflector 10 can hold the reflection sheet 3 and the light guide plate 4 at the base 34 and the shade portion 36, the reflecting sheet 3 and the light guide plate 4 on the frame 2 side. ), There is no need to form a portion to sandwich the support. Therefore, also in this point, the frame 2 can be thinned and downsized.

Similar to the reflector 10, the support plate 14 is formed of a metal plate such as stainless steel or an aluminum alloy in a substantially L-shaped cross section (see FIG. 1), and is provided on the fourth side 18 side of the frame 2. The support plate fixing parts 22 and 22 are fixed with screws 45 and 45. Here, the support plate 14 is fixed to the support plate fixing portion 22, and stands on the base 46 supporting the lower surface 3a side of the reflective sheet 3, and stands up from the base 46 to form a fourth A back plate 47 engaged with the outside of the side 18 is provided. In this way, since the supporting plate 14 is integrated with the fourth side 18 of the frame 2 to reinforce the frame 2, the frame 2 is thinned together with the function of the reflector 10. · Miniaturization is facilitated.

The reflective sheet 3 is formed of a white PET sheet having excellent reflectivity, and returns the light emitted from the rear surface (lower surface) 48 of the light guide plate 4 to the light guide plate 4. In addition, a dot-like paint layer or a wrinkled surface for light diffusion may be formed on the surface 3b of the reflective sheet 3 that faces the rear surface 48 of the light guide plate 4.

The light guide plate 4 is manufactured by injection molding synthetic resin such as acrylic resin. The exit surface 40 is substantially rectangular shape, and the cross-sectional shape is formed in substantially wedge shape. The incident surface 7 is located on the thick side. In addition, the incident surface 7 is roughened, and the amount of emitted light near the incident surface 7 is adjusted to suppress a phenomenon (so-called phenomena) in which the contrast of the emitted light repeatedly occurs. do.

In addition, the light diffusing ink (for example, ink using magnesium carbonate, titanium oxide, etc. as a pigment) is selectively attached to the emission surface 40 or the back surface 48, or the uneven surface (wrinkle surface) is partially attached. The amount of emitted light may be adjusted by diffusing light.

The prism sheet 5 is formed of a light-transmitting sheet material such as polycarbonate, and a plurality of prism faces 50 having substantially triangular cross sections are formed continuously on the surface (lower surface) facing the light guide plate 4. In addition, the prism surface 50 of the prism sheet 5 extends in a direction substantially parallel to the incident surface 7 of the light guide plate 4, and corrects the advancing direction of light emitted from the light guide plate 4, The liquid crystal display panel 23 has been studied so that it can be efficiently irradiated in a planar shape.

The protective sheet 6 is formed of a light-transmitting sheet material such as polycarbonate, and used to protect the exit surface of the prism sheet 5, but forms a wrinkled surface for light diffusion and the like to diffuse the exit light. You may make it allow.

In addition, in order to form the image display apparatus 51, the liquid crystal display panel (image display part) 23 is accommodated in the panel engaging part 24 of the frame 2, and this liquid crystal display panel 23 is accommodated. It can be attached to the frame 2.

In the surface light source device 1 having the above-described structure, when the fluorescent lamp 8 is turned on, the light is directly or reflected by the reflector 10 and then guided to the incident surface 7 to form the interior of the light guide plate 4. Is introduced. As already known, this introduction light is gradually emitted from the exit surface 40 while propagating in the light guide plate. The exiting light is corrected in the prism sheet 5, and after passing through the protective sheet, the liquid crystal display panel 23 is illuminated in a planar shape.

The advantages of the surface light source device 1 of the present embodiment are summarized as follows.

(1) Since the end portion 42 of the reflector 10 is engaged with the edge 41 of the light guide plate 4 and is in close contact with the incidence surface 7, the fluorescent lamp 8 facing the edge 41 is formed. Light is shielded by the end 42 of the reflector 10. As a result, the light entering the light guide plate via the edge 41 is eliminated, and the occurrence of bright lines is thus prevented.

(2) Deriving from this, the exit surface 40 can be used widely and effectively. Then, the size of the light guide plate 4, the frame 2, etc. can be reduced. The entire apparatus is also downsized and lightweight.

(3) The reflective layer 32 of the reflector 10 and a part of the metal base material 27 are sheared to form an end portion 42, and the incidence surface 7 near the edge 41 is formed at the end portion 42. It is pressed by the elastic force of the rubber piece 13. For this reason, the elastic force of the rubber piece 13 which acts on the light guide plate 4 can be accommodated in the metal base material 27 of the edge part 42. FIG. As a result, the reflection layer 32 is prevented from coming off the light guide plate 4.

Second Embodiment

7-9, the outline | summary of the side light type surface light source device 61 which concerns on this embodiment is shown. FIG. 7 is an exploded perspective view of the surface light source device 61, and FIG. 8 is a sectional view along the line C-C in FIG. 9 is an enlarged cross-sectional view of a portion of FIG. 8. In addition, the description which attaches | subjects the same code | symbol and overlaps about all the elements common to 1st Embodiment is abbreviate | omitted.

In these drawings, the reflective sheet 3, the light guide plate 4, the prism sheet 5, and the protective sheet 6 are sequentially stacked and accommodated in the frame 62 produced in a substantially rectangular shape. The fluorescent lamp (primary light source) 8 is disposed so as to face the incident surface 7 side of the light guide plate 4. Both ends of the fluorescent lamp 8 are fixed to the frame 63 of the frame 62 in a detachable state.

The circumference | surroundings of the fluorescent lamp 8 are covered with the reflector 64, and the light of the fluorescent lamp 8 is reflected by the reflector 64, and is introduce | transduced into the incident surface 7. As shown in FIG. Then, a pair of rubber pieces 66 is provided between the end 11 of the light guide plate 4 and the gap 65 of the frame 62 as elastic support means for elastically supporting the light guide plate 4 toward the fluorescent lamp 8 side. It is arranged.

The frame 62 is formed by injection molding white synthetic resin. The frame 62 includes a frame 63 made of a synthetic resin having a substantially rectangular shape, extension portions 67 and 68 for supporting the reflective sheet 3 and the like from below, and an upper cutout portion 70 of the frame 63. ), Plate members 72 fixed with screws 71 and 71 are provided.

On the upper surface side of the frame 63 and the plate member 72, panel engaging portions 73 and 74 for engaging the liquid crystal display panel (image display portion 23) are formed.

As shown in FIG. 10, the reflector 64 is formed of a substantially U-shaped metal base material 27, such as stainless steel or aluminum alloy, and a reflective layer 32, as is the fluorescent lamp 8. It is. The reflective layer 32 has a structure in which the adhesive 28, the silver 30, and the synthetic resin film 31 are formed in order on the inner surface of the base material 27. The reflector 64 is housed together with the fluorescent lamp 8 in the frame 62 (see Fig. 4 (b)).

The upper end 75 of the opening of the reflector 64 is in contact with the exit surface of the light guide plate 4, and the lower end 76 of the opening of the reflector 64 is in contact with the back surface 48 of the light guide plate 4. . In addition, the lower end portion 76 of the reflector 64 is supported by the extension portion 68 of the frame 62.

In the upper end portion 75 of the reflector 64, an end portion 78 which is engaged with the edge (first edge; 41) where the entrance face 7 and the exit face 40 meet and is in close contact with the entrance face 7 is formed. It is. Moreover, the lower end part 76 of the reflector 64 engages with the edge (second edge; 80) where the incident surface 7 and the rear surface 48 meet and end portions 81 which are in close contact with the incident surface 7. Is formed.

In the same manner as in the first embodiment, both end portions 78 and 81 are sheared by a portion of the reflective layer 32 and the metal member 27, are engaged with the edges 41 and 80, and are in close contact with the incident surface 7. It is formed to be sharp. 7, 8, and 11, the incidence surface 7 is pressed by the elastic force of the rubber piece 66 on both ends 78, 81 of the reflector 64. As shown in FIG. Thereby, even if the surface light source device 61 vibrates or changes a posture, the state which always shields the upper and lower edges 41 and 80 to the edge parts 78 and 81 of the reflector 64 is maintained. Therefore, bright lines generated due to light incident from the upper and lower edges 41 and 80 are reliably prevented.

Here, the rubber piece 66 is provided with the round bar engaging protrusion 82 on the back side. The engaging projection 82 is engaged with the receiving portion 83 formed in the frame 62 and is fixed so as not to be pulled out of the frame 62. The rubber piece 66 is elastically deformed when the light guide plate 4 is thermally expanded, thereby preventing the warpage of the light guide plate 4 from occurring.

In the surface light source device 61 configured as described above, since the upper and lower edges 41 and 80 are shielded by the ends 78 and 81 of the reflector 64, the bright line due to the light incident from the upper and lower edges 41 and 80 is provided. Can be prevented. As a result, generation | occurrence | production of a bright line can be prevented more effectively compared with the 1st Embodiment in which only the edge 41 of the light guide plate 4 is shielded. Therefore, by enlarging the area of the exit surface which can be used effectively, the whole apparatus can be reduced in size and weight.

Here, the liquid crystal display panel (image display unit) 23 is accommodated in the panel engaging portions 73 and 74 of the frame 62, and the liquid crystal display panel 23 is attached to the frame 62, thereby providing a surface light source device. The image display apparatus 84 which displays an image on the liquid crystal display panel 23 by the planar illumination light emitted from 61 can be comprised.

[Third Embodiment]

FIG.12 and FIG.13 has shown the outline of the side light type surface light source device 91 which concerns on 3rd Embodiment. In addition, the description which attaches | subjects the same code | symbol and it overlaps about all the elements common to the said 1st Embodiment or 2nd Embodiment is abbreviate | omitted.

Although the surface light source device 91 has a structure substantially the same as that of the first embodiment, research is being conducted on the reflective sheet 92 disposed along the back surface 48 of the light guide plate 4. In other words, the end portion 92a of the reflective sheet 92 protrudes toward the fluorescent lamp 8 side (left side in the drawing) over the second edge 80 where the rear surface 48 meets the incident surface 7. .

By this study, shading of the second edge 80 is assuredly performed. Since the 1st edge 41 is shielded by the edge part 42 of the reflector 10 similarly to 1st Embodiment, eventually, the light shielding of both edges 41 and 80 is made reliably. In this respect, generation of bright lines is more effectively prevented than in the first embodiment where only the first edge is shielded. In addition, the effective light emitting area can be enlarged, the device can be reduced in size, and the weight can be reduced.

Fourth Embodiment

14 and 15 show the outline of the side light type surface light source device according to the fourth embodiment. The surface light source devices 201 and 211 shown in FIG. 14, FIG. 15 correspond to the modified example of 1st Embodiment, and the modified example of 2nd Embodiment, respectively.

First, referring to FIG. 14, in the surface light source device 201, the light guide plate pressing portion 38 of the reflector 10 is composed of a first portion 38a and a second portion 38b. The first portion 38a is bent from the panel supporting ground portion 37 of the reflector 10. At least the lower edge 39a of the distal end face 39, in some cases, the entire region is formed to be in close contact with the incident face 7.

Moreover, the 2nd part 38b is fixed to the upper surface of the 1st part 38a by welding, adhesion | attachment, etc., and is in contact with the exit surface 40. FIG. And the 1st edge 41 is engaged with the edge part 42 formed from the front end surface 39 of the 1st part 38a, and the 2nd part 38b.

According to such a structure, the light incident on the edge 41 is interrupted | blocked by the front end surface 39 of the 1st part 38a which abuts on the incidence surface 7, and the bright line generate | occur | produces similarly to 1st Embodiment. This is avoided.

Moreover, as shown in detail in FIG. 14 (b), the corner portion R1 of the end portion 42 having the first portion 38a and the second portion 38b forms a sharp edge that is substantially perpendicular. Therefore, the light shielding of the edge 41 by the edge part 42 is performed reliably.

If the corner portion R1 forms a dull edge, as shown in Figs. 6A and 6B, shading of the edge 41 by the end portion 42 may be unstable, which is not preferable. not.

In addition, the technique shown in FIG. 14 can also be applied to 2nd Embodiment, as shown in FIG. That is, in the reflector 64, the upper end part 75 consists of the 1st part 75a and the 2nd part 75b, and the lower end part 76 consists of the 1st part 76a and the 2nd part 76b. have.

Then, at least the bottom edge 79a of the tip surface 79 of the first portion 75a, in some cases the entire region, is in close contact with the incident surface 7, and the first edge 41 and the second edge 80. Light incidence is blocked. Therefore, the same effects as in the second embodiment can be obtained.

In addition, as shown in FIG. 15, the second portion 75b of the upper end 75 abuts on the exit face 40, and the second portion 76b of the lower end 76 abuts on the back 48. . And the edge part 78 is formed by the front end surface 79 and the 2nd part 75b of the 1st part 75a, and the front end surface 79 and the 2nd part 76b of the 1st part 76a are formed. The edge part 81 is formed by this.

[Fifth Embodiment]

16 and 17 show the outline of the side light type surface light source device according to the fifth embodiment.

FIG. 16 corresponds to the modified example of the first embodiment and the modified example of the second embodiment, respectively, of the surface light source devices 221 and 231 shown in FIG.

First, referring to FIG. 16, in the surface light source device 221, the light guide plate pressing portion 38 of the reflector 10 includes a first portion 38a and a second portion 38b. Moreover, the edge part 38c of the 2nd part 38b is being fixed by welding, adhesion | attachment, etc. in the state engaged with the front-end | tip of the 1st part 38a.

And the front end surface 39 (end part 42) of the 1st part 38a is surface-contacted to the incidence surface 7, or at least the lower edge 39a of the front end surface 39 (end part 42) is Light incidence to the first edge 41 is interrupted by linear contact with the incident surface 7. In addition, the second portion 38b is configured to abut the emission surface 40.

According to such a structure, the 1st edge 41 is shielded by the front end surface 39 of the 1st part 38a which abuts on the incident surface 7, and generation | occurrence | production of a bright line is prevented. That is, the same effects as in the first or fourth embodiment can be obtained.

Further, the end portion 38c of the second portion 38b is engaged with the distal end of the first portion 38a, and the welding or bonding is performed while the relative positions of the first portion 38a and the second portion 38b are positioned. Etc., the fixing work of the first portion 38a and the second portion 38b becomes easy.

In addition, the technique shown in FIG. 16 is applicable also to 2nd Embodiment. The example is shown in FIG. Referring to FIG. 17, the reflector 64 has a top portion 75 composed of a first portion 75a and a second portion 75b, and a bottom portion 76 has a first portion 76a and a second portion ( 76b). In a state where the end portion 75c of the second portion 75b is engaged with the tip of the first portion 75a, the first portion 75a and the second portion 75b are fixed by welding or the like.

Moreover, the 1st part 76a and the 2nd part 76b are being fixed by welding etc. in the state which the edge part 76c of the 2nd part 76b engaged with the front-end | tip of the 1st part 76a. Further, the front end surface 79 of the first portion 75a is in planar contact with the incident surface 7, or the lower edge 79a of the front end surface 79 of the first portion 75a is formed of a light guide plate ( Line contact is made with the incident surface 7 of 4). Further, the front end surface 79 of the first portion 76a is in planar contact with the incident surface 7, or the lower edge 79b of the front end surface 79 of the first portion 76a is the incident surface. Line contact with (7).

As a result, light incidence to the first edge 41 and the second edge 80 is blocked at the front end face 79 of the first portions 75a and 76a. Therefore, the same effects as in the second embodiment can be obtained. In addition, the second portion 75b of the upper end portion 75 abuts the exit surface 40, and the second portion 76b of the lower end portion 76 abuts the back surface 48.

And the edge part 78 is formed by the front end surface 79 and the 2nd part 75b of the 1st part 75a, and the front end surface 79 and the 2nd part 76b of the 1st part 76a are formed. The edge part 81 is formed by this.

[Other Modifications to First to Fifth Embodiments]

The first to fifth embodiments described so far do not limit the present invention. For example, the following modifications are allowed.

(1) In each embodiment, although the aspect which arrange | positions a pair of rubber pieces 13 and 66 as an elastic support means was shown, other forms of elastic support means are employable. For example, as shown in FIG. 18, the side opposite to the end 11 of the light guide plate among the frames 2 and 62 is bent toward the side of the coplanar surface 11, and the coplanar surface 11 is fluorescent by the elastic force of the curved side. You may make it elastically support to the side (left side in drawing).

In addition, the shape of the rubber pieces 13 and 66 as elastic support means is not limited to the shape of 1st and 2nd embodiment. What is necessary is just to be able to elastically support the light guide plate 4 to the fluorescent lamp 8 side, and to be able to absorb the thermal expansion of the light guide plate 4. For example, as shown in FIG. 19, the shape of a square bar may be sufficient. In such a case, the rubber piece 93 may be fixed to the frame 94 by pressing a part of the rectangular bar-shaped rubber piece 93 to the spring receiving portion 95 formed in the frame 94.

As the elastic support means, as shown in Fig. 20, a metal or resin plate-like spring member which is accommodated in the receiving portion 97 of the frame 96 and curved in an arc shape on the end face 11 side ( 98) may be used.

(2) In each said embodiment, the light guide plate 4 which has a substantially wedge-shaped cross section is used. However, this does not limit the present invention. For example, the light guide plate in which the exit surface 40 and the back surface 48 were formed in parallel, and the other suitable light guide plate of cross-sectional shape may be used.

(3) In each of the above embodiments, the fluorescent lamp 7 is employed as the primary light source. However, this does not limit the present invention. For example, a plurality of light emitting diodes arranged in a row may be used as the primary light source.

(4) In each said embodiment, the one prism sheet 5 is arrange | positioned at the emission surface 40 side of the light guide plate. However, a prism sheet may be arrange | positioned in another aspect and other types of additional sheets, such as a light-diffusion sheet, may be arrange | positioned. For example, two prism sheets may be arranged so that the prism rows are perpendicular to each other.

From the above description, it can be seen that the edges (particularly, the first edge) above and below the incident surface of the light guide plate may be shielded reliably in order to avoid the occurrence of bright lines. Thus, an example in which the first edge of the light guide plate is shielded in a slightly different manner from the various embodiments described above will be described below in the sixth embodiment.

A common important role in these embodiments is an inclined surface formed near the tip of the member supporting the primary light source. By utilizing the function of this inclined surface, the first edge is reliably shielded and effective in preventing the bright line. In addition, although the following embodiment is described as a surface light source device, it is the same as the various embodiment demonstrated so far, and it can arrange | position to illumination of a liquid crystal display panel, and can comprise a liquid crystal display device.

[Sixth Embodiment]

The scheme of the side light type surface light source device according to the present embodiment is shown in exploded perspective view in FIG. The surface light source device 311 has a frame 312 in which the primary light source is disposed, and also includes a reflective sheet 313, a light guide plate 314, a light diffusion sheet 317, a prism sheet 315, 316, and a protective sheet 318. It is configured by placing.

The reflective sheet 313 is a sheet-shaped diffuse reflection member made of a white PET film or the like. The reflective sheet 313 reflects the light exiting from the rear surface 314C of the light guide plate 314 and reenters the light guide plate 314 to prevent loss of light.

The light guide plate 314 has the same material and shape as the light guide plate 4 described above. One cross section provides an incidence surface 314A, and two large surfaces provide an exit surface 314B and a back surface 314C, respectively. In addition, according to the known art, the light scattering pattern for promoting the emission can be formed in various forms on one or both of the emission surface 314B, the rear surface 314C. The light scattering pattern is well known and detailed descriptions that are not particularly relevant to the features of the present invention are omitted.

The prism sheets 315 and 316 are well-known elements, and act on the in-plane and perpendicular in-plane parallel to the incidence surface 314A with respect to the light emitted obliquely from the emission surface 314B, It provides output light for almost the front direction.

The same effect can be obtained by employing a so-called double-sided prism sheet instead of the prism sheets 315 and 316. The structure, function, etc. of the prism sheet are well known, and detailed descriptions that are not particularly relevant to the features of the present invention are omitted.

The light diffusion sheet 317 diffuses the light emitted from the emission surface 314B, achieves uniformity in luminance, and makes the luminance uneven uniform.

The protective sheet 318 is a sheet material having weak light diffusivity to protect the surface of the light diffusing sheet 317 from damage or the like.

The frame 312 is formed by screwing the reinforcing materials 321 and 322 to the frame main body 320 by screws 319. The frame main body 320 is formed in a rectangular rim as shown in an injection molded body of white resin that reflects light efficiently. This structure can form each part with a thin film compared with the case where the whole frame is integrated by resin. Therefore, it is suitable for weight reduction of the whole surface light source device 311. FIG.

The frame main body 320 is provided with the shade 320A on the outer surface, the reinforcement materials 321 and 322 are screw-locked to the shade 320A, and attached to the liquid crystal display panel with the shade 320A interposed therebetween. have. In this way, the frame 312 constitutes a support member for supporting the constituent members of the surface light source device 311 and at the same time forms a part of the support mechanism for supporting the surface light source device 311 on the back of the liquid crystal display panel.

Moreover, the protrusion piece 320 is formed in auxiliary | assistance in each of the side edges in which the reinforcement materials 321 and 322 of the frame main-body part 320 are not arrange | positioned. The projection piece 320C protrudes inward from the back surface 314C side, and prevents looseness of the reflection sheet 313, and the like.

The reinforcing materials 321 and 322 are formed by bending a metal plate made of a light metal such as stainless steel or aluminum. The reinforcing materials 321, 322 are disposed along the frame main body 320 in correspondence with the incident surface 314A side and the wedge end (hereinafter, simply referred to as "end") side. By doing in this way, the intensity | strength of the frame main-body part 320 is reinforced, and also the deformation and damage of the frame main-body part 320 can be prevented.

The reinforcing material 321 disposed on the end side is formed by bending a cross section into an L shape. Then, one end side which is erected in an L shape is arranged to contact the outer surface of the frame main body 320, and the other end side is formed so as to protrude to the inside of the frame main body 320 from the rear surface 314C side.

By doing so, the reinforcing material 321 reinforces the strength of the frame main body 320 with respect to the distal side of the light guide plate 314 and prevents deformation or damage thereof. In addition, the dropping of the reflective sheet 313 and the like on the back side is prevented. In addition, the reinforcing material 321 disposed on the distal side may be integrated with the frame body portion 320 by insert molding. In that case, the assembling process of the frame is simplified.

On the other hand, the reinforcing material 322 disposed on the incidence surface 314A side is configured to function as a support member that supports the primary light source facing the incidence surface while serving as a reflector in addition to these functions. That is, as shown in FIG. 23 in the cross section along the D-D line, the reinforcing material 322 is formed into a nearly C-shaped cross-section by bending a metal and disposed inside the frame main body 320.

As shown in FIG. 24, the inside of the both ends of the reinforcing material 322 is supported by the rubber bushing 323 of a square shape. The fluorescent lamp 324 is disposed inside the reinforcing material 322 with the rubber bushing 323 interposed therebetween.

Moreover, it arrange | positions so that the opening side of the reinforcing material 322 may be the incident west side of the light guide plate 314. Therefore, the reinforcing material 322 is configured to reflect the illumination light emitted from the fluorescent lamp 324 to configure a reflector for supplying the illumination light to the incident surface of the light guide plate 314, and at the same time constitute a support member of the fluorescent lamp 324 have.

The rubber bushing 323 is elastically supported inside the reinforcement 322 by rubber, which is an elastic member. The rubber bushing 323 also has an insertion hole into which the fluorescent lamp 324 is to be inserted, and an outlet for taking out the lead wire connected to the electrode 324A of the fluorescent lamp 324 from the insertion hole. The rubber bushing 323 is inserted into the insertion hole by the fluorescent lamp 324, and is supported inside the reinforcing material 322 in a form in which the lead wire is drawn out from the outlet. In this way, the fluorescent lamp 324 is disposed inside the reinforcing material 322.

In other words, the rubber bushing 323 constitutes a support member for supporting the fluorescent lamp 324 to the reinforcing member 322 which is a reflector and at the same time constitutes an impact member for alleviating the impact on the fluorescent lamp 324. Moreover, the insulating member which insulates the metal reinforcement 322 and the electrode 324A is comprised.

In addition, the fluorescent lamp 324 is fitted into the rubber bushing 323 in a state in which the connecting portion of the lead wire is covered with the electrode 324A by the non-contraction tube. That is, in this embodiment, the rubber bushing 323 comprises an insulation member with a non-shrink tube.

The reinforcing material 322 is formed by bending one end side of the exit surface 314B side inward at a right angle to the stairway direction. For this reason, the rubber bushing 323 is supported on the light guide plate 314 side without being out of position. In this way, the reinforcing material 322 also serves as a supporting member for supporting the primary light source.

As the reinforcing material 322 is enlarged by the addition of the symbol E, the bending with respect to the inner side is set at the inner position toward the primary light source side at the incident surface 314A. In addition, the angle of bending is set to almost 90 degrees. Further, the reinforcing material 322 is folded back at an angle of more than 90 degrees at the tip side at a position tilted toward the back surface 314C by a slight distance from the first edge where the incidence surface 314A meets the exit surface 314B. .

That is, one end of the reinforcing material 322 located on the emission surface 314B side is bent inward at the site which becomes the primary light source side than the entrance surface 314A when the surface light source device is assembled. Moreover, the tip side is folded back toward the direction away from the light source.

Here, the angle formed by the suspension piece indicated by reference numeral 322B and the bending piece indicated by reference numeral 322C is set to less than 90 degrees. In addition, the continuous portion 322D of the hanging piece 322B and the bending piece 322C is positioned downward from the exit surface 314B of the light guide plate 314 (back side 314C side).

That is, at one end side of the reinforcing material 322, a slope 322A is formed, and the slope 322A abuts against the first edge and extends to cover the same edge. In other words, the slope 322A extends closer to the rear surface 314C side on the primary light source side on the first edge and away from the rear surface 314C and the exit surface 314B on the light guide plate 314 side. .

The reinforcing material 322 sandwiches the reflective sheet 313 and the light guide plate 314 by the slope 322A and the front end portion on the rear surface 314C side. Thereby, the shaking of the light guide plate 314 and the reflective sheet 313 in the up-down direction is prevented. The slope 322A functions as a stopper so that the light guide plate 314 is folded back with the hanging piece 322B and is not displaced to the fluorescent lamp 324 side beyond the junction 322D of the bending piece 322C. In this way, the first edge is always shielded so that abnormal light emission generated when illumination light enters the light guide plate 314 from the incident surface 314A is prevented.

Referring to FIG. 25 here, the outline when assuming that the reinforcing material 322 is bent at an angle of 90 degrees is shown by a broken line. As can be seen from this outline, the reinforcing material 322 in the present embodiment is formed on the rear surface 314C so that the tip thereof falls inward (see angle θ). Here, since the reinforcing material 322 has elasticity, in this state, the reflection sheet 313 and the light guide plate 314 can be sandwiched.

Moreover, on the protective sheet 318, black paint is affixed and the edge 318A is formed. This edge 318A is formed in the range which spans the front-end | tip of the emission surface 314B side of the reinforcing material 322, and the entrance surface 314A. This makes it possible to more reliably prevent light leakage and abnormal light emission.

Here, the advantages of the present embodiment are summarized and rewritten as follows.

(1) Since the reinforcing material 321 is attached to the frame main body 320 formed of the injection molded body by the screw 319, even if the frame main body 320 is designed thin, the end of the light guide plate 314 Deformation or breakage of the frame main body 320 on the side is prevented.

(2) On the incident surface 314A side, by using the rubber bushing 323, the fluorescent lamp 324 is disposed inside the reinforcing material 322 in a state where lead wires are connected to both electrodes 324A. The reinforcing material 322 is attached to the frame main body 320 by the screw 319. Thereby, also in the incident surface 314A side, the intensity | strength required in order to prevent the deformation | transformation or damage of the frame main-body part 320 can be easily ensured.

(3) Using the bent shape reinforcing materials 321 and 322, dropping to the back surface 314C side of the reflective sheet 313 or the like is prevented. Compared with the case where the fall prevention mechanism is formed by the integral formation of the resin, the thickness on the back surface 314C side can be made thin, and the weight of the entire frame can be easily reduced.

In addition, since the reinforcing material 322 also serves as a reflector of the primary light source also on the incident surface 314A side, the structure can be simplified and the thickness of the entire apparatus can be reduced as compared with the case of separately preparing the reflector.

(4) The reinforcing material 322 is bent stepwise on the exit surface 314B side, and the rubber bushing 323 is caught therein, whereby the position shift of the fluorescent lamp 324 to the light guide plate 314 side is prevented. .

(5) Due to the elasticity of the rubber bushing 323, even when an external force is applied to the fluorescent lamp 324, the impact is alleviated and the breakage of the fluorescent lamp 324 is prevented.

(6) Since the periphery of the electrode of the fluorescent lamp 324 is insulated by the rubber bushing 323 and the non-shrinkable tube, it is safe to use a metal reinforcing material 322 for the reflector, and the lighting state of the fluorescent lamp 324 is confused. This does not happen.

(7) Since the slope 322A which stably abuts on the first edge on the emission surface 314B side of the reinforcing material 322 and always serves as a light shielding function is formed, abnormal emission of the emission surface 314B is sure. Is prevented. Since the reinforcement material 322 which is a reflector is in contact with a surface by the 1st edge, abnormal light emission by the entrance of the light from the emission surface 314B side is also prevented.

In addition, since the light guide plate 314 and the reflective sheet 313 are sandwiched and held by the reinforcing material 322, even if the finishing precision of the reinforcing material 322 is uneven, no gap is generated between the light guide plate 314 and the reflector. Therefore, light leakage from such a gap can be avoided, and luminance unevenness is prevented.

(8) In the case where the light guide plate 314 is displaced to the primary light source side due to an impact or the like, the first edge acts to push up the slope 322A. Since the reinforcing material 322 has elasticity, the reinforcing material 322 is pressed against the edge to prevent the light guide plate 314 from shifting. This also prevents damage to the fluorescent lamp 324 in advance.

(9) When the reinforcing material 322 is folded back at an angle larger than 90 degrees, deformation due to handling after processing is less likely to occur compared to the case where it is folded back to about 90 degrees. This is also advantageous in preventing abnormal light emission and light leakage.

Among the above advantages, (7) is particularly important. Here, in order to understand this better, the prior art example which bends a metal plate 90 degrees and used as a reflector is briefly demonstrated with reference to FIG.

As shown in FIG. 28, the surface light source device 301 includes a light guide plate 302 and a reflection sheet 304. The light guide plate 302 is not particularly changed from the light guide plate used in the present invention and includes an entrance face 302A, an exit face 302B, and a back face 302C.

The frame 305 includes all members other than the light guide plate 302, the side plates surrounding these members so as to integrally hold the primary light source 3, and the like, and a back side member which prevents the members from falling off to the back side. Consists of

In the case where a part of the frame 305 is made of metal, for example, the frame body portion 305A is formed of an injection molded body of white resin, and the reinforcing material 305B that is bent and processed by the metal plate is combined with the frame body portion 305A. Use it.

The reinforcing material 305B is configured to reinforce the strength of the frame main body 305A and to serve as the back side member. Thereby, even if the frame 305 is formed relatively thin as a whole, the risk of deformation, damage, etc. is relatively small.

Here, the reinforcing material 305B also serves as a reflector of the primary light source. The reflector is arrange | positioned so that the fluorescent lamp 306 equipped with the primary light source 303 may be reflected, and the light L may be reflected and not missed.

Here, as indicated by the partial enlargement of the arrow A, the inner wall surface of the reinforcing material 305B closely adheres to the exit surface 302B, and no light enters the light guide plate 302 from the entrance surface 302A at all. Ideally it should not be possible.

In practice, however, it is difficult to maintain such an abnormal state. Because of this, there is a limit to the finish degree of the reinforcing material 305B, and deformation after production cannot be avoided. For example, when metal bending is applied, it is difficult to avoid unevenness in the shape of a product due to pressing force during bending, abrasion of a mold, and the like.

Moreover, since the reflector itself is an elongate bent product which is almost the same length as a fluorescent lamp, it is easy to bend at the time of assembling a surface light source device.

Therefore, in practice, as indicated by the partial enlargement of the arrow B or C, light leaks near the first edge, abnormal light emission occurs, and the quality of the emitted light is often lowered.

That is, in the case of arrow B, the leading edge of the reinforcing material 5B abuts the emission surface 302B, but the upper edge is separated from the inner wall surface of the reinforcing material 5B, and a gap is generated.

In such a case, the light of the primary light source enters along the exit surface 302B from the gap and enters the light guide plate 302. This entrance light is reflected locally at the back surface 302C and then exits locally at the exit surface 302B. This is observed as a local rise in brightness.

In the case of arrow C, the whole front-end | tip part of the reinforcing material 305B will float from the exit surface 302B. Therefore, in addition to the phenomenon that occurs in the case of arrow B, light leakage from this gap occurs. Since the light is output to the outside without passing through the light guide plate 302, a strong brightness nonuniformity is caused.

Although not particularly shown, when the reflector is curved, the incident surface 302A side of the light guide plate 302 enters the reflector, whereby a part of the exit surface 302B is exposed in the reflector. Light may also enter the exposed portion to locally increase the luminance near the incident surface.

It will be apparent from the description of the sixth embodiment that these problems are solved in the surface light source device of the sixth embodiment of the present invention.

Although it is repeated, since the slope 322A abuts on the first edge as if it is a point, the abutment relationship between the slope 322A and the first edge is maintained even if there is some unbalance or deformation of the finish on the reflector. do. Moreover, this contact relationship is also hard to be broken about vibration and shock.

Seventh Embodiment

The characteristic of the side light type surface light source device which concerns on this embodiment is shown in FIG. This embodiment mentions only this difference, since it has the structure similar to 6th Embodiment except the structure of the reinforcing material 332. FIG.

The reinforcing material 332 employed here is formed at the exit surface 314B side by bending at an angle greater than 90 ° inward. Thereby, even if a deviation generate | occur | produces in the finishing of a reinforcement material with respect to the position bent inwardly, the same advantage as 5th Embodiment can be acquired. And the strength of the reinforcing material 332 is also increased.

[Eighth Embodiment]

The characteristic of the side light type surface light source device which concerns on this embodiment is shown in FIG. The surface light source device 341 employs a frame 342 made of a white resin molded body. The frame 342 also serves as a reflector. The frame 342 is configured in a cross-sectional U-shape so as to support the fluorescent lamp 324 inward. And the frame 342 is provided with the inclined surface 342A which abuts on the 1st edge in the emission surface 314B side, and extended beyond this.

In other words, the slope 342A is extended so as to be close to the back surface 314C side on the primary light source side and away from the back surface 314C and the exit surface 314B on the light guide plate 314 side with the first edge as a boundary.

The frame 342 acts to suppress the light guide plate 314 toward the fluorescent lamp 324 in a state where the light guide plate 314 and the reflective sheet 313 are integrally inserted into the U-shaped recess. Thus, a pressing member (not shown) is used.

Also in this embodiment, the slope 342A is stably in contact with the first edge. Therefore, of course, the same light shielding effect as that of the sixth embodiment is achieved. As a result, similarly to the sixth embodiment, occurrence of luminance deviation in the vicinity of the incident surface 314A is effectively prevented.

[Other Modifications to Sixth to Eighth Embodiments]

The sixth to eighth embodiments are not intended to limit the present invention. For example, the following modifications are allowed.

(1) In the eighth embodiment, the frame also serves as a reflector. However, this does not limit the present invention. For example, you may arrange | position a sheet material etc. separately and use this for a reflector.

(2) The same thing as the slope for light shielding formed in the 1st edge side can be formed also in a 2nd edge (edge where a back surface and an incident surface meet). In that case, by pressing the light guide plate toward the primary light source side, the state where the first edge and the second edge are pressed against the corresponding slope, respectively, can be further stabilized.

(3) With respect to the additional sheet member disposed on the emission surface side of the light guide plate, there are no particular restrictions such as type and number of copies.

(4) As a material of the light guide plate, a light scattering light guide may be used. The light scattering light guide is a resin material having a uniform scattering ability therein as is well known. This also applies to the fifth embodiment in the first embodiment.

(5) The light guide plate does not necessarily have a wedge shape. For example, a light guide plate in which the exit surface and the rear surface are formed in parallel, or other suitable cross-sectional light guide plate may be used.

(6) A plurality of side cross-sections of the light guide plate may be used as the incident surface. In that case, a primary light source is formed to face each incident surface, and the light shielding measures by the slopes described in the sixth to eighth embodiments are adopted for each.

(7) The illumination target by the surface light source device is not limited to the liquid crystal display panel. The present invention can be widely applied to a surface light source device that provides illumination light to various other apparatuses. This also applies to the fifth embodiment in the first embodiment.

In the present invention, since the elastic support means disposed between the poles can allow thermal expansion of the light guide plate, there is no problem such as warping due to thermal expansion of the light guide plate.

Moreover, the reflecting layer of a reflector and a part of metal base material are sheared, and an edge part is formed, and the incidence surface near an edge is pressed by this elastic force of a rubber piece at this edge part. For this reason, the elastic force of the rubber piece which acts on a light guide plate can be received by the metal base material of an edge part. This prevents the reflective layer from peeling off the light guide plate.

Moreover, in the surface light source device of the present invention, since the edge is shielded to the end of the reflector, it is possible to prevent the generation of bright lines due to light incident from the edge. Therefore, by enlarging the area of the exit surface which can be used effectively, the whole apparatus can be reduced in size and weight.

In addition, by bending the cross section of the reinforcing member disposed on the distal end in an L shape, the strength of the frame main body portion is reinforced and the deformation and damage are prevented. In addition, the fall of the reflection sheet or the like on the back side is prevented, and the reinforcing material disposed on the distal side can be integrated with the frame main body by insert molding, thereby simplifying the assembly process of the frame.

Claims (25)

A light guide plate having an emission surface for outputting light, a back surface opposite to the emission surface, an entrance surface for inputting light from the side, and a first edge where the emission surface and the entrance surface meet; A primary light source disposed opposite the incident surface, A surface light source device including a reflection member arranged to guide the supply light of the primary light source to the incident surface; The reflective member includes a metal base material and a reflective layer formed on an inner surface of the base material, And a part of the reflective layer and the base material is sheared, whereby an end portion engaging at least the first edge is formed. A light guide plate having an emission surface for outputting light, a back surface opposite to the emission surface, an entrance surface for inputting light from the side, and a first edge where the emission surface and the entrance surface meet; A primary light source disposed opposite the incident surface, A surface light source device comprising: a reflection member disposed to guide the supply light of the primary light source to the incident surface; and a frame for receiving the light guide plate, the primary light source, and the reflection member; The reflective member includes a metal base material and a reflective layer formed on an inner surface of the base material, A portion of the reflective layer and the base material is sheared, thereby forming an end engaging at least the first edge, Between the end surface of the said light guide plate and the said frame, the clearance gap which allows thermal expansion of the said light guide plate is formed, The surface light source device according to claim 1, wherein elastic support means for pressing the light guide plate at the end and allowing thermal expansion of the light guide plate are arranged at the ends. A light guide plate having an emission surface for outputting light, a back surface opposite to the emission surface, an entrance surface for inputting light from the side, and a first edge where the emission surface and the entrance surface meet; A primary light source disposed opposite the incident surface, A surface light source device comprising: a reflection member disposed to guide the supply light of the primary light source to the incident surface; and a frame for receiving the light guide plate, the primary light source, and the reflection member; The reflective member has an end portion engaged with the first edge, Between the end surface of the said light guide plate and the said frame, the clearance gap which allows thermal expansion of the said light guide plate is formed, The surface light source device according to claim 1, wherein elastic support means for pressing the light guide plate at the end and allowing thermal expansion of the light guide plate are arranged at the ends. The light guide plate of claim 1, wherein the light guide plate has a second edge where the incident surface and the rear surface meet each other. A reflective sheet is disposed opposite the rear surface, One end portion of the reflective sheet protrudes toward the light source side beyond the second edge. The light guide plate of claim 2, wherein the light guide plate has a second edge where the incident surface and the rear surface meet each other. A reflective sheet is disposed opposite the rear surface, One end portion of the reflective sheet protrudes toward the light source side beyond the second edge. The light guide plate of claim 3, wherein the light guide plate has a second edge where the incident surface and the rear surface meet each other. A reflective sheet is disposed opposite the rear surface, One end portion of the reflective sheet protrudes toward the light source side beyond the second edge. The surface light source device according to claim 2, wherein the surfaces of the elastic support means and the frame are colored black or gray. 4. The surface light source device according to claim 3, wherein the surfaces of the elastic support means and the frame are colored black or gray. The surface light source device according to claim 1, wherein the corner portion of the end portion is formed in a substantially arc shape having a radius of curvature of 10 µm or less. The surface light source device according to claim 2, wherein the corner portion of the end portion is formed in a substantially arc shape having a radius of curvature of 10 m or less. 4. The surface light source device according to claim 3, wherein the corner portion of the end portion is formed in a substantially arc shape having a radius of curvature of 10 m or less. The surface light source device according to claim 2, wherein the frame is provided with an elastic support means accommodating portion engaged with a portion of the elastic support means. 4. The surface light source device according to claim 3, wherein the frame is provided with an elastic support means accommodating portion engaged with a portion of the elastic support means. A liquid crystal display device comprising a liquid crystal display panel and a surface light source device disposed for illuminating the liquid crystal display panel; The surface light source device includes a light guide plate having an emission surface for outputting light, a rear surface opposite to the emission surface, an incident surface for inputting light from the side, and a first edge where the emission surface and the incident surface meet each other. and; A primary light source disposed opposite the incident surface, And a reflecting member disposed to guide the supply light of the primary light source to the incident surface; The reflective member includes a metal base material and a reflective layer formed on an inner surface of the base material, And a portion of the reflective layer and the base material is sheared, thereby forming at least an end portion engaging with the first edge. A liquid crystal display device comprising a liquid crystal display panel and a surface light source device disposed for illuminating the liquid crystal display panel; The surface light source device includes a light guide plate having an emission surface for outputting light, a rear surface opposite to the emission surface, an incident surface for inputting light from the side, and a first edge where the emission surface and the incident surface meet each other. and; A primary light source disposed opposite the incident surface, A reflection member disposed to guide the supply light of the primary light source to the incident surface; A frame for receiving the light guide plate, the primary light source and the reflective member; The reflective member includes a metal base material and a reflective layer formed on an inner surface of the base material, A portion of the reflective layer and the base material is sheared, thereby forming an end engaging at least with the first edge, Between the end surface of the said light guide plate and the said frame, the clearance gap which allows thermal expansion of the said light guide plate is formed, And said elastic support means is disposed at said end portion to press said light guide plate and to allow thermal expansion of said light guide plate. A liquid crystal display device comprising a liquid crystal display panel and a surface light source device disposed for illuminating the liquid crystal display panel; The surface light source device includes a light guide plate having an emission surface for outputting light, a rear surface opposite to the emission surface, an incident surface for inputting light from the side, and a first edge where the emission surface and the incident surface meet each other. and; A primary light source disposed to face the incident surface, A reflecting member disposed to guide the supply light of the primary light source to the incident surface, and a frame for receiving the light guide plate, the primary light source, and the reflecting member; The reflective member has an end portion engaged with the first edge, Between the end surface of the said light guide plate and the said frame, the clearance gap which allows thermal expansion of the said light guide plate is formed, And said elastic support means is disposed at said end portion to press said light guide plate and to allow thermal expansion of said light guide plate. A reflecting member disposed so as to surround a light source for supplying light through the incident surface to a light guide plate having an emission surface, a back surface, an entrance surface provided by a cross section, and an edge where the emission surface and the incident surface meet. In; The reflecting member includes a base material made of metal and a reflecting layer formed on an inner surface side thereof, having an end facing the emission surface and the rear surface. The reflective member, characterized in that an end portion for engaging with the edge is formed by shearing a portion of the reflective layer and the base material. A light guide plate having an emission surface for outputting light, a back surface opposite to the emission surface, an entrance surface for inputting light from the side, and a first edge where the emission surface and the entrance surface meet; A primary light source disposed to face the incident surface, A surface light source device comprising a support member for supporting the primary light source to face the incident surface; The surface light source device according to claim 1, wherein a slope is formed in the support member so as to contact the first edge and exceed the first edge. 19. The surface light source device according to claim 18, wherein the support member is formed by bending a metal plate material. The surface light source device according to claim 18 or 19, wherein the support member is a reflector reflecting light supplied from the primary light source. 19. The surface light source device according to claim 18, wherein the support member constitutes a part of a frame which integrally supports another component member to the light guide plate. A liquid crystal display device comprising a liquid crystal display panel and a surface light source device disposed for illuminating the liquid crystal display panel; The surface light source device includes a light guide plate having an emission surface for outputting light, a rear surface opposite to the emission surface, an entrance surface for inputting light from a side, and a first edge where the emission surface and the entrance surface meet each other. and, A primary light source disposed to face the incident surface, It includes a support member for supporting the primary light source facing the incident surface, The support member is characterized in that the inclined surface is formed to abut the first edge and beyond the first edge. 23. The liquid crystal display device according to claim 22, wherein the support member is formed by bending a metal plate material. 24. The liquid crystal display device according to claim 22 or 23, wherein the support member is a reflector reflecting light supplied from the primary light source. 23. The liquid crystal display device according to claim 22, wherein the support member constitutes a part of a frame which integrally supports the light guide plate and other constituent members.