JP2001084823A - Surface lignt source device, and image display device provided with same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of a bright line, to increase outgoing light quantity, and to provide bright and equalized surface illumination. SOLUTION: A protruded part 34 of a reflection sheet 3 is protruded toward a fluorescent lamp 7 over an incidental surface side edge 30 of a guide plate 4. On the protruded part 34 of the reflection sheet 3, a silver reflection layer 35 similar to a silver reflection layer 23 formed on an inner surface of a reflector 8 is formed. Light H incidental from the incidental surface side edge 30 of the guide plate 4 can thus be physically shielded by the reflection sheet 3. As a result, generation of a bright line can be prevented. The silver reflection layer 35 formed on the protruded part 34 of the reflection sheet 3 reflects light of the fluorescent lamp 7 at a similar reflectance to that of the silver reflection layer 23 of the reflector 8. As a result, light quantity incidental to an incidental surface 6 of the guide plate 4 is increased compared to conventional devices, thereby outgoing quantity from the guide plate 4 is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface light source device for illuminating an image display panel such as a portable personal computer or a navigation device, and an image display device provided with 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 panel) with planar illumination light emitted from a surface light source device. An image is displayed on the surface of the liquid crystal display panel.

FIG. 7 shows an example of a surface light source device 61 used in such a liquid crystal display device 60. The surface light source device 61 shown in FIG. 7 includes a flat light guide plate 62,
A fluorescent lamp (light source) 64 arranged to face one side surface (incident surface) 63 of the light guide plate 62; a reflection sheet 65 arranged on the lower surface 62a side of the light guide plate 62;
A prism sheet 66 disposed on the upper surface 62b side of
And a reflector (reflection member) 67 arranged so as to surround the fluorescent lamp 64.

[0004] The surface light source device 61 configured as above is
Light emitted from the fluorescent lamp 64 enters the inside of the light guide plate 62 from the incident surface 63 of the light guide plate 62, and the light that enters the inside of the light guide plate 62 forms the upper surface 62 b and the lower surface 62 of the light guide plate 62.
While the light propagates inside the light guide plate 62 while being reflected by the light guide plate 62, light having a critical angle or less with respect to the upper surface 62 b and the lower surface 62 a of the light guide plate 62 is reduced.
The light exits from the light guide plate 62 through 2a. Of the emitted light, the light emitted from the lower surface 62a side of the light guide plate 62 is reflected by the reflection sheet 65 and re-enters the inside of the light guide plate 62, and then directly or repeats the above-described operation to form the light guide plate 62. The light exits from the upper surface 62b to the outside of the light guide plate 62. Then, the light emitted from the upper surface 62b of the light guide plate 62 passes through the prism sheet 66, so that the traveling direction is corrected to the liquid crystal display panel 68 side, and efficiently irradiates the liquid crystal display panel 48.

A surface light source device 61 as shown in FIG.
Light H of the fluorescent lamp 64 also enters the inside of the light guide plate 62 from an incident surface side edge (light source side edge) 70 of the light guide plate 62.
The light H incident from the incident surface side edge 70 of the light guide plate 62
Is the incident surface 6 of the prism sheet 66 as shown in FIG.
A bright streak-shaped bright line 71 parallel to the incident surface 63 is generated on the exit surface (upper surface) 66a near the side 3. Since the bright line 71 is a cause of luminance unevenness, the quality of emitted light is significantly reduced. Therefore, even if the surface light source device 61 illuminates the liquid crystal display panel 68, the liquid crystal display panel 68
Is difficult to see.

Therefore, the applicant of the present invention, as shown in FIG. 9, attaches the reflection sheet 65 to the incident surface side edge 7 of the light guide plate 62.
0 to the fluorescent lamp 64 side, the light H entering the inside of the light guide plate 62 from the incident surface side edge 70 of the light guide plate 62.
Has been devised and a patent application has already been filed (Japanese Patent Laid-Open No. 10-112214).
Reference).

[0007]

In recent years, liquid crystal display devices 6
The surface light source device 61 used for the liquid crystal display panel 68
To make the upper screen brighter and easier to see (see Figure 7),
A silver coating layer is formed on the inner surface (reflection surface) of the reflector 67 to increase the reflection efficiency more than the conventional white reflector 67 and to more efficiently transmit the light of the fluorescent lamp 64 than the conventional light guide plate 6.
The technology leading to No. 2 has been developed. However, when such a technique is applied to the surface light source device 61 having the configuration shown in FIG.
The reflection sheet 65 protruding toward the fluorescent lamp 64 is formed of a white PET sheet and the reflectance of the white reflection sheet 65 is lower than the reflectance of the silver reflector 67. The amount of light entering the incident surface 63 of the light guide plate 62 decreases by the amount of 65, and the luminance of the outgoing light decreases.

Accordingly, the present invention provides a surface light source device capable of preventing the generation of bright lines and improving the luminance of emitted light, and an image display device provided with the surface light source device. The purpose is.

[0009]

According to a first aspect of the present invention, there is provided a light guide plate which emits light incident from a side surface in a planar shape, a light source arranged to face the side surface of the light guide plate, and a light source of the light source. A reflecting member that reflects light on a silver inner surface and guides the light to the side surface of the light guide plate, and a reflection sheet that is disposed on one surface side of the light guide plate and reflects light emitted from the light guide plate toward the light guide plate. The present invention relates to a surface light source device provided. The reflection sheet includes a protrusion protruding from a light source side edge of the light guide plate toward the light source, and a silver reflection layer is formed on a surface of the protrusion on the light source side.

[0010] According to the present invention having such a configuration, since the reflection sheet is provided with the protruding portion protruding toward the light source from the light source side edge of the light guide plate, the light incident from the light source side edge of the light guide plate is provided. Is physically shielded by the protruding portion of the reflection sheet to prevent the generation of a bright line caused by light incident from the light source side edge of the light guide plate. In addition, since the protruding portion of the reflection sheet is formed with a silver reflection layer of the same color as the reflection member, the reflectance is higher than that in the case where the protruding portion does not have a silver reflection layer. Therefore, the amount of light incident on the light guide plate increases, and the amount of light emitted from the light guide plate also increases. That is, according to the present invention,
Bright lines can be illuminated without bright lines.

According to a second aspect of the present invention, there is provided a light guide plate for emitting light incident from a side surface in a planar shape, a light source arranged to face the side surface of the light guide plate, and a light source for the light source on a silver inner surface. A reflecting member that reflects and guides the light to the side surface of the light guide plate; a reflection sheet that is disposed on one surface side of the light guide plate and reflects light emitted from the light guide plate toward the light guide plate; The present invention relates to a surface light source device including a member and a frame for housing a reflection sheet. The reflection member includes a base formed of a metal plate and fixed to the frame to function as a beam member of the frame and to function as a support plate member that supports the reflection sheet and the light guide plate. . Further, the reflection sheet includes a protruding portion that protrudes from the light source side edge of the light guide plate toward the light source,
It is characterized in that a silver reflective layer is formed on the surface of the projection on the light source side.

According to the present invention having such a configuration, the base of the metal reflecting member is fixed to the frame,
Since the base of the reflection member functions as a beam member for reinforcing the frame and also functions as a support plate member for supporting the reflection sheet and the light guide plate, the thickness of the frame can be reduced by the amount reinforced by the reflection member. . Therefore, according to the present invention, it is possible to reduce the thickness and size of the frame, and further to reduce the thickness and size of the surface light source device. In addition, according to the present invention, the projecting portion of the reflection sheet physically blocks the light incident from the light source side edge of the light guide plate, so that it is possible to prevent the generation of a bright line. Further, since a silver reflective layer similar to the reflective member is formed on the projecting portion of the reflective sheet, the amount of light incident on the light guide plate increases, and the amount of light emitted from the light guide plate increases.

According to a third aspect of the present invention, there is provided an image display device, comprising: the surface light source device according to the first or second aspect; and an image display panel illuminated in a planar shape by light emitted from the surface light source device. , Is provided.

According to the present invention having the above-described structure, the image display panel is uniformly illuminated with the high-brightness emitted light which does not generate a bright line, and is brighter and clearer than the conventional example. Image display becomes possible.

[0015]

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

[First Embodiment] FIGS. 1 to 3 relate to a surface light source device 1 according to an embodiment of the present invention. FIG. 1 is an exploded perspective view of the surface light source device 1 according to the embodiment of the present invention. FIG. 2 is a sectional view of FIG.
It is sectional drawing cut | disconnected and shown along A line. Also, FIG.
FIG. 3 is a partially enlarged view of FIG. 2. In these drawings, a reflection sheet 3, a light guide plate 4, and a prism sheet 5 are sequentially stacked and accommodated in a frame 2 formed in a substantially rectangular shape. A fluorescent lamp (light source) 7 is disposed so as to face one side surface (incident surface) 6 of the light guide plate 4.
The fluorescent lamp 7 is accommodated in a metal reflector (reflection member) 8 fixed to the frame 2.

The frame 2 is formed in a substantially rectangular shape by injection-molding a white synthetic resin. The metal reflector 8 is fixed to one end E1, and the other end is provided. A metal support plate 10 is fixed to E2 so as to face the reflector 8.

The frame 2 has a first side 11 to which the reflector 8 is fixed, a second side 12 substantially perpendicular to one end of the first side 11, and the first side 11 11 includes a third side 13 substantially perpendicular to the other end, and a fourth side 14 substantially perpendicular to the second side 12 and the third side 13. The tongue pieces 15, 15 for supporting the lower surface 3a of the reflection sheet 3 are formed inside the side 13 of FIG. A pair of reflector fixing portions 16 are formed at both ends of the first side 11. Further, a pair of support plate fixing portions 17 are formed at both ends of the fourth side 14.
A panel engaging portion 20 for accommodating a liquid crystal display panel (image display panel) 18 is formed on an upper peripheral edge of the frame 2. Note that a first engagement portion 21 that engages with the reflector 8 and a second engagement portion 22 that engages with the support plate 10 are formed on the lower surface side of the frame 2.

The reflector 8 is formed of a metal plate such as stainless steel or an aluminum alloy, and has a silver reflective layer 23 formed on the entire inner surface thereof (see FIG. 3). The reflector 8 includes a base 2 fixed to the reflector fixing portions 16 on the first side 11 side of the frame 2 with screws 24.
5, an upright wall 26 rising from the base 25, and a flange 27 bent from the upright wall 26 toward the light guide plate 4 so as to be substantially parallel to the base 25. The lower base portion 25 is formed longer than the upper flange portion 27, is in close contact with the lower surface 3a side of the reflection sheet 3, and stably holds one end side of the reflection sheet 3, the light guide plate 4 and the prism sheet 5. I can support it. The upper flange 27 includes a panel support surface portion 27a that supports the back surface side of the liquid crystal display panel 18, and a light guide plate pressing portion 27b that is bent from the panel support surface portion 27a. The light plate holding portion 27b is located on the upper surface (emission surface) 28 side of the light guide plate 4. The reflector 8 configured as described above reflects the light of the fluorescent lamp 7 on the silver reflective layer 23 and guides the reflected light to one side surface (incident surface) 6 of the light guide plate 4. .

The reflector 8 is fixed to the frame 2 so that the base 25 functions as a beam member of the frame 2 and the reflection sheet 3 and the light guide plate 4
In addition, the frame 2 functions as a support plate member that supports the prism sheet 5, and can reinforce the frame 2. Therefore, the frame 2 can be made thinner and smaller by the amount reinforced by the reflector 8. Also, the reflector 8
Since the reflection sheet 3 and the light guide plate 4 can be sandwiched between the base portion 25 and the flange portion 27, it is not necessary to form a portion for sandwiching the reflection sheet 3 and the light guide plate 4 on the frame 2 side.
Therefore, also in this respect, the frame 2 can be made thinner and smaller. The base 25 and the flange 27 of the reflector 8 hold the reflection sheet 3 and the light guide plate 4 with a small gap or hold them with a predetermined elastic force. Here, the base 25 and the flange 27 of the reflector 8
When the light guide plate 4 is sandwiched between the reflection sheet 3 and the light guide plate 4 with a predetermined elastic force, the incident surface side edge (light source side edge) 30 of the light guide plate 4
Is pressed against the reflection sheet 3 by the elastic force of the reflector 8 and the weight of the light guide plate 4 and the prism sheet 5. When the base portion 25 and the flange portion 27 of the reflector 8 are sandwiched with a small gap, the incident surface side edge 30 of the light guide plate 4 is pressed against the reflection sheet 3 by the weight of the light guide plate 4 and the prism sheet 5.

The support plate 10 is formed of a metal plate such as stainless steel or an aluminum alloy and has a substantially L-shaped cross section similarly to the reflector 8 (see FIG. 1).
The supporting plates 17 are fixed to the supporting plate fixing portions 17 by screws 31. Here, the support plate 10 is fixed to the support plate fixing portion 17 and supports the lower surface 3a side of the reflective sheet 3 and engages with the outside of the fourth side 14 rising from the base 32. A back plate 33 is provided, and is integrated with the fourth side 14 of the frame 2 to reinforce the frame 2. Therefore, the thickness of the frame 2 can be reduced in conjunction with the function of the reflector 8. It is possible to reduce the size.

The reflection sheet 3 is formed of a white PET sheet having excellent reflectivity, is large enough to be accommodated in the frame 2, and protrudes from the light incident surface 6 of the light guide plate 4 toward the fluorescent lamp 7. A protrusion 34 is formed. A silver reflective layer 35 is formed on the surface (upper surface) 3b of the protrusion 34 of the reflective sheet 3 on the fluorescent lamp 7 side (see FIGS. 1 to 3 and 6). For example, in the present embodiment, the length L of the protrusion 34 of the reflection sheet 3 is 1 to 2 mm, and the length of the silver reflection layer 35 is formed to be the same as the length of the protrusion 34. I have. The entire surface of the reflection sheet 3 facing the light guide plate 4 (reflection surface) 3b is covered with the silver reflection layer 3.
Although it is conceivable to form 5, in this case, although the luminance of the emitted light increases, a new problem arises in that a glare is generated and it is difficult to see.

The light guide plate 4 is formed by injection molding a synthetic resin such as an acrylic resin so that the upper surface (emission surface) 28 is substantially rectangular and the cross-sectional shape is substantially wedge-shaped. It is formed so that the plate thickness becomes thinner as it gets away from it. Note that the incident surface 6 of the light guide plate 4 may be roughened, the amount of emitted light in the vicinity of the incident surface 6 may be adjusted, and a phenomenon in which the emitted light is repeatedly bright and dark (a reflection phenomenon) may be suppressed. In addition, a light diffusing ink (for example, an ink using magnesium carbonate, titanium oxide, or the like as a pigment) is selectively adhered to the upper surface 28 or the lower surface (one surface) 37 of the light guide plate 4, Partly)
The emitted light amount may be adjusted by diffusing the light.

The prism sheet 5 is formed of a light-transmitting sheet material such as polycarbonate, and a large number of prism surfaces 38 having a substantially triangular cross section are continuously formed on a surface (lower surface) facing the light guide plate 4. I have. In addition, this prism sheet 5
The prism surface 38 extends in a direction substantially parallel to the incident surface 6 of the light guide plate 4, corrects the traveling direction of the light emitted from the light guide plate 4, and can efficiently irradiate the liquid crystal display panel 18 in a planar manner. It is devised as follows.

In the surface light source device 1 of the present embodiment configured as described above, light emitted from the fluorescent lamp 7 enters the inside of the light guide plate 4 from the incident surface 6 of the light guide plate 4, and the incident light The light propagates in the light guide plate 4, and is emitted from the light exit surface 28 when the light becomes a critical angle or less with respect to the light exit surface 28. And
The light emitted from the light guide plate 4 has its traveling direction corrected by the prism sheet 5 and illuminates the liquid crystal display panel 18 in a planar manner.

Here, the surface light source device 1 of the present embodiment
The projecting portion 34 of the reflecting sheet 3 projects more toward the fluorescent lamp 7 than the incident surface side edge 30, and the projecting portion 34 of the reflecting sheet 3 shields the incident surface side edge 30 of the light guide plate 4. Light H is prevented from entering from the edge 30. In the surface light source device 1 of the present embodiment, since the silver reflection layer 35 similar to the reflection layer 23 of the reflector 8 is formed on the projection 34 of the reflection sheet 3, the projection 34 of the reflection sheet 3 The reflection efficiency is higher than that of the white conventional example, and the amount of incident light from the incident surface 6 of the light guide plate 4 increases.

As described above, the surface light source device 1 of the present embodiment
Is that the projection 34 of the reflection sheet 3 protrudes toward the fluorescent lamp 7 side from the incident surface side edge 30 of the light guide plate 4, and the reflection sheet 3 and the incident surface side edge 30 of the light guide plate 4 come into close contact with each other,
Since the light H incident from the incident surface side edge 30 can be physically shielded by the reflection sheet 3, it is possible to prevent the generation of a bright line caused by the light H incident from the incident surface side edge 30 of the light guide plate 4. it can. Further, in the surface light source device 1 of the present embodiment, a silver reflective layer 35 similar to the reflective layer 23 of the reflector 8 is formed on the projecting portion 34 of the reflective sheet 3,
Since the reflection layer 35 of the projection 34 reflects the light of the fluorescent lamp 7 with the same reflectance as that of the reflection layer 23 of the reflector 8, the amount of light incident on the incident surface 6 of the light guide plate 4 is smaller than that of the conventional example. As a result, the amount of light emitted from the emission surface 28 of the light guide plate 4 increases. Therefore, according to the surface light source device 1 of the present embodiment, bright and uniform surface illumination can be performed without generating bright lines.

Here, the surface light source device 1 of the present embodiment
In this embodiment, a liquid crystal display panel (image display panel) 18 is accommodated in a panel engaging portion 20 of the frame 2, and the liquid crystal display panel 18 is assembled to the frame 2, so that planar illumination light emitted from the surface light source device 1 is obtained. LCD panel 1
The image display device 40 for displaying the image on the image 8 is configured.
Therefore, in the image display device 40, the liquid crystal display panel 18 is uniformly illuminated with the high-brightness emitted light having no bright line, and a brighter, clearer, higher-quality image can be displayed than in the conventional example.

[Second Embodiment] FIGS. 4 and 5 relate to a surface light source device 41 according to a second embodiment of the present invention. 4 is an exploded perspective view of the surface light source device 41 according to the embodiment of the present invention. FIG. 5 is a cross-sectional view taken along line BB of FIG. still,
In the present embodiment, the same components as those of the first embodiment are denoted by the same reference numerals, and the detailed description thereof will be omitted.

In these figures, a reflection sheet 3, a light guide plate 4 and a prism sheet 5 are successively accommodated in a frame 42 formed in a substantially rectangular shape. And
A fluorescent lamp (light source) 7 is disposed so as to face one side surface (incident surface) 6 of the light guide plate 4, and both ends of the fluorescent lamp 7 are detachable from the frame 43 of the frame 42. Fixed. Further, the periphery of the fluorescent lamp 7 is covered with a reflector 44, and the light of the fluorescent lamp 7 is reflected by the reflector 44, and the reflected light is guided to the incident surface 6 of the light guide plate 4 by the reflector 44.

The frame 42 is formed by injection-molding a white synthetic resin, and includes a frame 43 made of a substantially rectangular synthetic resin, and projecting portions 45 and 46 for supporting the reflection sheet 3 and the like from below. Notch 4 on the upper surface side of the frame 43
7 and a plate member 50 fixed by screws 48. On the upper surfaces of the frame 43 and the plate member 50, panel engaging portions 51a and 51b for engaging the liquid crystal display panel (image display panel) 18 are formed.

The reflector 44 is formed of a white PET film or a metal plate in a substantially U shape so as to surround the fluorescent lamp 7, and has a silver reflective layer 52 formed on the inner surface thereof. Are accommodated together with the fluorescent lamp 7. The upper end 53 of the opening of the reflector 44 contacts the upper surface 28 of the light guide plate 4 on the side of the fluorescent lamp 7, and the lower end 54 of the opening of the reflector 44.
Is in contact with the lower surface 3a of the reflection sheet 3 on the fluorescent lamp 7 side. As a result, the light emitted from the fluorescent lamp 7 is directly incident on the inside of the light guide plate 4 from the incident surface 6 of the light guide plate 4, and is reflected by the reflection layer 52 of the reflector 44 after being incident on the incident surface of the light guide plate 4. From 6, the light enters the light guide plate 4. The lower end 54 of the reflector 44 is
It is supported by the overhang portion 46 of the frame 42.

The reflection sheet 3 is formed of a white PET sheet having excellent reflectivity, is large enough to be accommodated in the frame 2, and protrudes from the incident surface 6 of the light guide plate 4 toward the fluorescent lamp 7. A protrusion 34 is formed. A silver reflective layer 35 is formed on a surface (upper surface) 3b of the protrusion 34 of the reflective sheet 3 on the fluorescent lamp 7 side (see FIGS. 4 to 6). For example, in the present embodiment, similar to the first embodiment, the projecting portion 34 of the reflection sheet 3 is used.
Has a length L of 1 to 2 mm, and the length of the silver reflective layer 35 is formed to be the same as the length of the protrusion 34.

The surface light source device 41 according to the present embodiment having the above-described structure does not generate a bright line, and enables bright and uniform surface illumination, similarly to the first embodiment.

In the surface light source device 41 according to the present embodiment, the liquid crystal display panel (image display panel) 18 is accommodated in the panel engaging portions 51a and 51b of the frame 42, and the liquid crystal display panel 18 is assembled to the frame 42. Thus, an image display device 55 that displays an image on the liquid crystal display panel 18 with planar illumination light emitted from the surface light source device 41 is configured. Therefore, in the image display device 55, the liquid crystal display panel 18 is uniformly illuminated with high-brightness emitted light having no bright line, and a brighter, clearer, higher-quality image can be displayed than in the conventional example.

In the second embodiment, the plate member 50 is fixed to the frame 43 with screws 48 and 48, and the reflection sheet 3 is pressed against the incident surface side edge 30, so that the reflection sheet 3 is formed. It can be slightly deformed to cover the incident surface side edge 30 reliably, and the incidence of the light H from the incident surface side edge 30 can be more reliably blocked by the reflection sheet 3.

In each of the above embodiments, the light guide plate 4 having a substantially wedge-shaped cross section has been described as an example. However, the present invention is not limited to this, and the upper surface (emission surface) 28 and the lower surface 37 of the light guide plate 4 may be formed. A light guide plate 4 formed in parallel or another appropriately shaped light guide plate 4
Is used.

The present invention is not limited to the above-described embodiments, but is also applicable to a case where the fluorescent lamps 7 are arranged on a plurality of side surfaces of the light guide plate 4.

In each of the above embodiments, the fluorescent lamp 7 has been described as an example of the light source. However, the present invention is not limited to this, and a light source in which a number of light emitting diodes are arranged in a line may be used. Good.

Further, in each of the above embodiments, only one prism sheet 5 is disposed on the upper surface 28 of the light guide plate 4. However, the present invention is not limited to this. Alternatively, two prism sheets combined such that the prism surfaces are substantially orthogonal to each other, a protective sheet, or the like may be appropriately disposed.

[0041]

As is apparent from the above description, in the surface light source device of the present invention, the projecting portion of the reflection sheet is projected to the light source side from the light source side edge of the light guide plate, and the light guide side end of the light guide plate is provided. The light incident from the edge can be physically shielded by the reflection sheet, and the reflection member is formed by forming a silver reflection layer similar to the reflection layer of the reflection member on the surface of the protrusion of the reflection sheet facing the light guide plate. Since the light reflection efficiency and the light use efficiency can be increased, bright uniform surface illumination can be achieved without generation of bright lines.

Further, since the image display device of the present invention is provided with the above-mentioned surface light source device, the image display panel is uniformly illuminated with high-brightness emitted light having no bright line.
A brighter, clearer, higher-quality image can be displayed than in the conventional example.

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view of the surface light source device taken along line AA of FIG.

FIG. 3 is an enlarged sectional view showing a light source side of the surface light source device shown in FIG. 2;

FIG. 4 is an exploded perspective view of a surface light source device according to a second embodiment of the present invention.

FIG. 5 is a light source side sectional view of the surface light source device cut along a line BB in FIG. 4;

FIG. 6 is a plan view showing a protruding portion of a reflection sheet.

FIG. 7 is a cross-sectional view cut along a line perpendicular to the light source of the first conventional surface light source device.

FIG. 8 is a diagram showing a failure occurrence state of the first conventional example. FIG. 7A is a front cross-sectional view (a cross-sectional view showing the light source side in FIG. 7 in an enlarged manner) showing a state of occurrence of a defect of the conventional surface light source device, and FIG. 7B is a sectional view of the same surface light source device. FIG. 4 is a plan view showing a state in which a failure has occurred.

FIG. 9 is a sectional view of a main part of a surface light source device showing a second conventional example.

[Explanation of symbols]

1, 41 surface light source device, 3 reflection sheet, 4 light guide plate, 6 incident surface (side surface), 7 fluorescent lamp (light source), 8, 44 reflector, 18 liquid crystal Display panel (image display panel), 25: base portion, 30: incident surface side edge (light source side edge), 34: projecting portion, 35 ...
Reflective layer, 37 ... Lower surface (one surface), 40, 55 ... Image display device

Claims (3)

[Claims] 1. A light guide plate for emitting light incident from a side surface in a plane, a light source arranged to face the side surface of the light guide plate, and a light guide for reflecting light from the light source on a silver inner surface. A reflecting member that guides to a side surface of the light plate; and a reflecting sheet that is disposed on one surface side of the light guide plate and reflects light emitted from the light guide plate toward the light guide plate. A surface light source device, comprising: a projection protruding from the light source side edge of the light guide plate toward the light source; and a silver reflective layer formed on the light source side surface of the projection. 2. A light guide plate for emitting light incident from a side surface in a planar shape; a light source arranged to face the side surface of the light guide plate; and a light guide for reflecting light from the light source on a silver inner surface. A reflection member that guides to a side surface of the light plate; a reflection sheet that is disposed on one surface side of the light guide plate and reflects light emitted from the light guide plate toward the light guide plate; and the light guide plate, the light source, the reflection member, and the reflection sheet. And a frame to be housed, wherein the reflection member is formed of a metal plate, and functions as a beam member of the frame by being fixed to the frame, and supports the reflection sheet and the light guide plate. The reflection sheet includes a base that functions as a support plate member, the reflection sheet includes a protrusion protruding from a light source side edge of the light guide plate toward the light source, and a silver reflective layer is formed on a light source side surface of the protrusion. Specially And a surface light source device. 3. An image display, comprising: the surface light source device according to claim 1 or 2; and an image display panel illuminated in a planar shape with light emitted from the surface light source device. apparatus.