KR100827774B1 - Back lighting device, light source cover constituting thereof, and light source reflector - Google Patents

Abstract

The present invention relates to a backlight and a light source cover and a light source judge plate constituting the backlight, and to provide a backlight and a light source cover and light reflector plate constituting the backlight capable of preventing bright lines caused by light introduced from the edge portion of the light guide plate. have.

The light reflecting plate 6 is a metal sheet, which has a thickness of about 0.1 mm, and surrounds its periphery at the rear side with a predetermined distance from the linear light source 5. The upper chassis 1 has a substantially L-shaped cross section, and ribs 1a are formed on the surface of the light source reflecting plate 6 substantially parallel to the longitudinal direction of the linear light source 5. The rib 1a has a predetermined height and is formed at a position having a predetermined interval between the light incident end face 4 of the light guide plate 10. The light source reflecting plate 6 is bent downward at the portion where the rib 1a of the upper chassis 1 abuts, so that the light reflecting plate 6 has an upper edge portion of the light incident end face 4 of the light guide plate 10. It covers (4E).

Description

BACK LIGHTING DEVICE, LIGHT SOURCE COVER CONSTITUTING THEREOF, AND LIGHT SOURCE REFLECTOR}

1 is a cross-sectional view showing the structure of a backlight of Example 1 according to the present invention.

FIG. 2 is a partially enlarged cross-sectional view of FIG. 1.

3 is a perspective view illustrating a process of mounting an image chassis of a backlight of Embodiment 1 according to the present invention;

4 is a graph showing the luminance distribution of the light emitting surface of the backlight of Example 1 according to the present invention.

5 is a cross-sectional view showing the structure of a backlight of Example 2 according to the present invention.

6 is a perspective view illustrating a process of mounting an image chassis on a backlight of Embodiment 2 according to the present invention.

7 is a partially enlarged cross-sectional view of a backlight showing the structure of a reflector for a light source of Example 3 according to the present invention.

Fig. 8 is a partially enlarged sectional view of the backlight showing the structure of the reflector for light sources of Example 4 according to the present invention.                 

9 is a partially enlarged cross-sectional view of a backlight showing the structure of a light source cover of Embodiment 5 according to the present invention;

10 is a perspective view showing the structure of a conventional backlight.

<Explanation of symbols for main parts of drawing>

1, 20: upper chassis 1a: rib

2: reflecting surface 3: emitting surface

4: light incident section 4E: upper edge part

5: linear light source 6, 16, 26, 36 light source reflector

6a: white tape 10: light guide plate

16a: embossed portion 26a: metal film

26b: PET film

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight and a light source cover and a reflector for light sources constituting the backlight, and to a backlight used for a display device such as a liquid crystal display, and a light source cover and a reflector for light sources constituting the same.

Background Art [0002] The edge light type backlight is widely used for liquid crystal display devices such as liquid crystal televisions and personal computers. The edge light method is a method in which light introduced from the side end surface (light receiving end surface) of the light guide plate included in the backlight unit is emitted from the light emitting end surface to irradiate the liquid crystal display device. As a light source, a linear light source (linear light source) is widely used, and is disposed opposite to the light incident end surface of the light guide plate.

10 is a perspective view showing the structure of a conventional edge light method. As shown in the figure, the backlight comprises a light guide plate 10, a reflecting plate 11, a prism sheet 12, and a protective sheet (not shown). The light guide plate 10 is a rectangular plate made of an acryl resin having a rectangular planar view, and has a wedge shape in which the upper surface (light emitting surface) 3 and the lower surface (reflecting surface) 2 are non-parallel. The thick edge of the light guide plate 10 is the light incident end face 4, and the linear light source (linear light source) 5 is disposed so as to face the light incident end face 4.

The light exit surface 3 of the light guide plate 10 is subjected to shatin processing, and its surface roughness has a predetermined gradation pattern. The reflecting surface 2 of the light guide plate 10 is formed on a prism surface in which a plurality of projecting portions of an isosceles triangle are formed in parallel with each other in cross-sectional shape, and the ridge direction thereof is the longitudinal direction of the linear light source 5, that is, the light incident end surface 4. The direction is orthogonal to the long direction of). In addition, a lens (lenticular) may be formed on the reflective surface 2 of the light guide plate 10 instead of the prism.

The prism sheet 12 is stacked on the light exit surface 3 side of the light guide plate 10. The prism sheet 12 is provided with a plurality of protrusions having a substantially isosceles cross section on the lower surface thereof, and the ridge direction thereof is substantially parallel to the longitudinal direction of the light incident end face 4, that is, the protrusion of the light guide plate 10. It is arranged to be almost perpendicular to the ridge direction.

Since the backlight having such a configuration applies a shading process to the light exit surface 3 of the light guide plate 10 and forms a prism or a lens on the reflective surface 2, the light collection efficiency of the light introduced into the light guide plate 10 is high. Thinning of the whole backlight is intended. When assembling the backlight, the light guide plate 10, each sheet, and the linear light source 5 are stored in a chassis not shown, and a light source cover (not shown) is mounted in such a manner as to cover the upper part of the linear light source 5. Irradiation light from the linear light source 5 is incident on the light incident end face 4 of the light guide plate 10, reflected on the reflecting surface 2 and the reflecting plate 11, and passes through the light guide plate 10. The display device is emitted from the light source and irradiates the display device arranged on the light emitting surface side of the backlight.

The light introduced from the light incident end face 4 into the light guide plate 10 is reflected by the reflecting face 2 and proceeds toward the light exit face 3 as described above, but the upper edge portion 4E of the light incident end face 4 is provided. The light introduced at) is larger in scattering at the time of light incidence than the light introduced at the central portion of the light incident end face 4. For this reason, the light introduced from the upper edge portion 4E becomes a curved line at a position slightly separated from the light incident end face 4 as indicated by '×××' on the light exit surface 3 in FIG. 10. appear. Since only the prism sheet 12 and the protective sheet are disposed on the light exit surface 3 of the light guide plate 10, the bright lines generated on the light exit surface 3 are reflected on the light exit surface of the backlight, which adversely affects the illumination of the display device. There was a problem of going crazy.

In order to solve this problem, as disclosed in the prior art of Japanese Patent Laid-Open No. 9-211450, a backlight having a white ink coated on the upper edge portion of a light guide plate has been proposed. Since light incident from the upper edge portion is blocked by the white ink, bright lines caused by light incident from the upper edge portion are prevented. However, this white ink is formed through a process of pushing the upper edge portion of the light guide plate onto a flat plate coated with ink, so that there is a problem that the process increases and labor is required. In addition, when the transparent ink is applied, the bright lines are not solved, and when the black ink is applied, there is a problem that dark lines (dark lines) are generated on the contrary.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and by using a light reflector for a light source, which is a constituent member of a backlight, a backlight capable of preventing bright lines caused by light incident from the edge of the light guide plate, and a light source cover and a light source constituting the backlight. It is an object to provide a reflector.

Moreover, it aims at providing the backlight which can prevent the bright line by light incident from the edge part of a light guide plate using a light source cover of a predetermined shape.

In the backlight according to the first aspect of the present invention, the irradiation light from the light source disposed opposite to the light incident end surface of the light guide plate having the light exit surface is reflected by the light reflector for light source disposed around the light source, and is introduced into the light guide plate from the light incident end face. And the backlight for emitting light from the light exiting surface, wherein the light source reflecting plate covers the edge portion on the light exiting surface side of the light incident end surface of the light guide plate.

In the first aspect of the invention, since the edge portion on the light exit surface side of the light incidence end surface of the light guide plate is covered with the light reflecting plate for light source, light is not incident from the edge portion. Since the light introduced from the edge portion has a large scattering degree, bright lines are generated on the light-emitting surface, but the bright portions can be prevented by shielding the edge portions by shielding the light reflector for light sources of the present invention.

In the first invention, the backlight according to the second aspect of the invention includes the edge of the light guide plate of the surface of the light guide plate which is in contact with the outer surface of the light source reflecting plate disposed around the light source and covers the light source and abuts the light source reflecting plate. It is characterized by further comprising a cover for a light source provided with a rib on the side close to the portion.

In the second invention, the rib of the light source cover presses the reflector for the light source by attaching the light source cover. Since the light reflector for the light source is in the form of a sheet, it is bent toward the light source side by pressing the rib to cover the edge portion of the light incident end face, and to block the irradiation light from the light source. As a result, light is not incident from the edge of the light guide plate, and bright lines are prevented.

The backlight according to the third invention further comprises a light source cover for covering the light source in contact with an outer surface of the light source reflector disposed around the light source in the first invention, wherein the light source reflector is the light source cover. A spacer having a predetermined height is installed on a side close to the edge portion of the light guide plate on a surface in contact with the surface.

In the third invention, the spacer of the light source reflector is pressed against the light source cover by mounting the light source cover. Since the reflector for the light source is in the form of a sheet, for example, by pressing a spacer such as a tape made of polyethylene terephthanlete (PET), it is bent toward the light source to cover the edge portion of the light incident end face to block the irradiation light from the light source. As a result, the irradiated light from the light source is not incident on the edge portion, and bright lines are prevented.

In the backlight according to the fourth aspect of the present invention, in the first aspect of the present invention, the light source reflecting plate has a shape in which a part of the backlight is in contact with the edge portion of the light exit surface side of the light guide plate.                         

In the fourth aspect of the invention, the edge portion of the light guide plate is covered with a light reflecting plate for the light source, whereby the light introduced from the edge portion is shielded. The reflector for a light source is embossed at the edge part which is near the said edge part of the light-guide plate, for example, or is changed in thickness so that a terminal may arise in the surface which faces a light source. By bringing the embossed portion or the stepped portion into contact with the edge portion of the light guide plate, the edge portion is covered with the light reflecting plate for shading.

In the backlight according to the fifth aspect of the present invention, in a backlight in which irradiation light from a light source disposed opposite to a light incidence end face of a light guide plate having a light exit face is introduced into the light guide plate at the light incidence end face, light is incident on the light guide plate. A light source cover provided with a rib that should be in contact with the end face on the surface facing the light source is disposed covering the light source.

In the fifth aspect of the invention, by attaching the light source cover, the rib is directly in contact with the light incident end face of the light guide plate, and the light source cover covers the edge portion to shield the light. As a result, the irradiated light from the light source is not incident on the edge portion, and bright lines are prevented.

A light source cover according to a sixth aspect of the present invention is a light source cover for a backlight covering a light source disposed opposite to a light incident end face of a light guide plate having a light exit face, the edge of the light exit face side of the light incident end face of the light guide plate facing the light source. A rib is provided on the side close to the part.

In the sixth aspect of the invention, by attaching the light source cover to the backlight, for example, by pressing the rib, the reflector for the light source is bent to cover the edge portion of the light guide plate, and the incoming light from the edge portion is shielded. Alternatively, the rib abuts directly on the edge portion of the light guide plate so that the light introduced from the edge portion is shielded. As a result, the irradiated light from the light source is not incident on the edge portion, and bright lines are prevented.

In the sixth invention, the light source cover according to the seventh aspect of the invention is characterized in that the ribs are formed at a height of 0.05 to 1.0 mm with an interval of about 0 to 2.5 mm between the light incident end face of the light guide plate.

In the seventh aspect of the invention, when the distance from the light incident end surface of the light guide plate to the rib is zero (zero), the rib directly contacts the edge portion of the light guide plate, and the light introduced from the edge portion is shielded. When the distance from the light incident end face of the light guide plate to the rib is about 0 to 2.5 mm, the light reflector for the light source can be pressed by the rib to cover the edge portion of the light guide plate. This distance is preferably 1.5 mm, and when it exceeds 2.5 mm, the light shielding effect is weakened. In addition, the height of the rib is preferably 0.5 mm, and when it is lower than 0.05 mm, the effect of light shielding is small, and when it is higher than 1.0 mm, dark portions are formed on the light exit surface.

A light source reflecting plate according to an eighth aspect of the present invention is a light source reflecting plate disposed around a light source facing away from a light receiving end face of a light guide plate having a light exiting surface, a part of which is an edge portion on the light exiting surface side of the light receiving end face of the light guide plate. It has a shape in contact with the.

In the eighth aspect of the invention, the edge portion of the light guide plate is covered with a light reflector for the light source, whereby the introduction light at the edge portion is shielded. The reflector for a light source is embossed at the edge part of the light guide plate near the edge part, for example, or is changed in thickness so that a step may arise in the surface which faces a light source. By bringing the embossed portion or the stepped portion into contact with the edge portion of the light guide plate, the edge portion is covered with the light reflecting plate for light shielding.

EMBODIMENT OF THE INVENTION Hereinafter, the specific Example is described, referring drawings for this invention.

Example 1

1 is a cross-sectional view showing the structure of a backlight of Embodiment 1 of the present invention. As shown in FIG. 1, the backlight stacks the reflecting plate 11, the light guide plate 10, the prism sheet 12, and the protective sheet (not shown) in this order in the lower chassis 7, and the linear light source 5 is arranged in the light guide plate ( The light source reflecting plate 6 is disposed to face the light incident end face 4 of FIG. 10, and surrounds the periphery at the rear side of the linear light source 5, and the light reflecting plate is disposed above the linear light source 5. It is comprised by attaching the light source cover 1 (henceforth an upper chassis) from the outer side of (6).

The light guide plate 10 is a rectangular plate made of a rectangular acryl resin having a planar view, and has a wedge shape in which the upper surface (light emitting surface) 3 and the lower surface (reflecting surface) 2 are non-parallel, and the thick side is the light incident surface (4). )to be. The light exit surface 3 of the light guide plate 10 is subjected to shatin processing, and the surface roughness is formed with a predetermined gradation pattern. The reflective surface 2 of the light guide plate 10 is formed with a prism surface provided with a plurality of parallel parallel projecting portions of an isosceles triangle, the ridge direction of which is the longitudinal direction of the linear light source 5, that is, the light incident end surface 4. The direction is orthogonal to the long direction of). In addition, a lens may be formed on the reflective surface 2 of the light guide plate 10 instead of the prism. In addition, the prism sheet 12 has a plurality of protrusions having a substantially isosceles triangle in cross-section on one surface thereof, and the ridge direction is substantially parallel to the long direction of the light incident end face 4, that is, of the light guide plate 10. It is arrange | positioned in the direction orthogonal to the ridge direction of a protrusion part.

The reflector 6 for the light source is a metal sheet and has a thickness of about 0.1 mm. The light source reflector 6 has a predetermined distance from the linear light source 5 and surrounds its periphery at the rear side, and both ends thereof are stacked on the light-emitting surface 2 side of the light guide plate 10, respectively, and the upper chassis 1 and lower It is fixed by the chassis 7. The upper chassis 1 is, for example, made of synthetic resin and has a substantially L-shaped cross section. The upper chassis 1 covers the linear light source 5 outside the light source reflector 6 so that one side is covered by the lower chassis 7. . Ribs 1a are formed on the surface of the upper chassis 1 facing the light source reflecting plate 6 in substantially the longitudinal direction of the linear light source 5. FIG. 2 is an enlarged cross-sectional view illustrating a vicinity of a light incident cross section of the light guide plate of FIG. 1. The rib 1a is formed in the position which has a space | interval of about 0.1 mm-2.5 mm between the light incident end surface 4 of the light guide plate 10, and the height of the rib 1a is 0.05 mm-1.0 mm. As shown in FIG. 2, the light source reflector 6 is bent toward the linear light source 5 at a portion where the rib 1a of the upper chassis 1 abuts, and the light reflector 6 for the light source reflects the light guide plate 10. The upper edge portion 4E of the light incident end face 4 is covered. In addition, although the rib 1a is integrally formed in the upper chassis 1 in this embodiment, it is not limited to this, For example, you may form the rib 1a by spreading the tape made from PET. .

3 is a perspective view illustrating a state in which the upper chassis 1 is mounted on the backlight. As shown in the figure, the sheet-shaped light source reflector 6 surrounds in three planes the upper, lower, and rear sides of the linear light source 5 until the upper chassis 1 is mounted, but the upper chassis 1 By attaching the ribs 1a, the light reflector 6 is pressed from above and bent downward. As a result, the upper edge portion 4E of the light guide plate 10 as shown in FIG. It becomes the state covered with.

In the backlight having the above-described configuration, the irradiation light from the linear light source 5 is directly reflected by the light reflecting plate 6 and the light source end face 4 of the light guide plate 10. The introduced light is reflected on the reflecting surface 2 and the reflecting plate 11 of the light guide plate 10, and is emitted from the light exit surface 3 while passing through the light guide plate 10. At this time, since the upper edge portion 4E of the light incident end face 4 of the light guide plate 10 is covered with the light reflecting plate 6, no irradiation light is introduced from the upper edge portion 4E, so that the upper edge It is possible to prevent the occurrence of bright lines caused by the portion 4E.

In addition, the light source reflecting plate 6 may use, for example, a white film or a vapor deposition film attached to a metal plate such as U series (manufactured by Mitsui-to-Atsu Chemical Co., Ltd.), and RW75CB, CR38W, RW75CB or GR25D (Kimomoto Co., Ltd.). Product) or a white film or a deposited film such as # 4596 (manufactured by Sumitomo 3M Co., Ltd.).

The luminance component of the light emitting surface was examined for the backlight of Example 1 described above. In luminance measurement, the area | region from the light incident end surface 4 side to 10 mm was measured in 1 mm space in the center of the light exit surface. 4 is a graph showing the result, where the vertical axis represents luminance (cd / m 2) and the horizontal axis represents position (mm) from the light incident end surface. The rib 1a of the upper chassis 1 was formed at a height of 0.5 mm at a position having an interval of about 1.5 mm between the light incident end face 4. In addition, luminance measurement was similarly performed for the conventional backlight using the light source cover without ribs. In the graph, '○' indicates the result of Example 1, and '×' indicates the result of the conventional example.

As can be seen from the graph, in the conventional example, so-called bright lines of higher luminance than the surroundings are generated at positions 2 mm away from the light incident end face 4. On the other hand, in the backlight of the first embodiment in which the rib 1a is provided in the upper chassis 1, the luminance is almost constant to a position 10 mm away from the light incident end surface, and it can be said that bright lines are prevented.

Further, the distance from the light incident end surface of the light guide plate to the ribs is such that when the thickness (mm) of the light source reflector is 2.5 mm to 2.5 mm, the light source reflector can be pressed by the ribs to cover the edge of the high light guide plate, preferably 1.5 mm. to be. When it exceeds 2.5 mm, the light shielding effect is weak. In addition, the rib height is preferably 0.5 mm, and when it is lower than 0.05 mm, the light shielding effect is small, and when it is higher than 1.0 mm, dark lines are formed on the light exit surface.

Example 2

5 is a cross-sectional view showing the structure of a backlight of Embodiment 2 of the present invention. The light source reflecting plate 6 is a metal sheet and has a thickness of about 0.1 mm. The surface of the light reflecting plate 6 facing the upper chassis 20 is made of PET almost parallel to the longitudinal direction of the linear light source 5. White tape (spacer) 6a is attached. The white tape 6a is attached to a position having an interval of about 0.1 to 2.5 mm between the light incident end face 4 of the light guide plate 10, and the thickness of the white tape 6a is 0.05. mm-1.0 mm. The upper chassis 20 has a substantially L-shaped cross section and covers one of the linear light sources 5 on the outside of the light source reflector 6 so that one side is covered by the lower chassis 7. As shown in FIG. 5, the light source reflecting plate 6 is bent toward the linear light source 5 at the portion where the upper chassis 20 abuts the white tape 6a. As a result, the light reflecting plate 6 is light guide plate (6). The upper edge portion 4E of the light incident end face 4 of 10 is covered. In addition, the shape and structure of the other member of a backlight are the same as that shown in Example 1, the same code | symbol is attached | subjected to the same part, and the description is abbreviate | omitted.

6 is a perspective view illustrating a state in which the upper chassis 20 is mounted on the backlight. As shown in the figure, the sheet-shaped light source reflecting plate 6 surrounds three directions of the upper, lower, and rear sides of the linear light source 5 in a planar manner until the upper chassis 20 is mounted, but the upper chassis 20 The white tape 6a is pressed from the upper side by the upper chassis 20 by attaching the upper surface, and the reflecting plate 6 for the light source is bent downward. As a result, as shown in FIG. 5, the upper edge portion 4E of the light guide plate 10 is covered with the light reflection plate 6.

In the backlight of Example 2 having the above-described configuration, since the upper edge portion 4E of the light incident end face 4 of the light guide plate 10 is covered with the light reflecting plate 6, the upper edge portion 4E is irradiated. Since light is not introduced, generation of bright lines caused by the upper edge portion 4E can be suppressed.

Example 3

7 is a partially enlarged cross-sectional view of a backlight showing the configuration of a light reflector for a light source of the present invention. The reflector plate 16 for light sources is formed by remerizing a metal film and a white PET film. The light source reflecting plate 16 is provided with an embossed portion 16a having a concave cross section substantially parallel to the longitudinal direction of the linear light source 5 at an end portion of the light guide plate 10 that is overlapped with the light exit surface 3 of the light guide plate 10. It is. The embossed portion 16a has a depth of 0.05 mm to 1.0 mm, and is formed by pressing at a position where the side surface thereof is in contact with the light incident end face 4 of the light guide plate 10. The upper chassis 2 has a substantially L-shaped cross section and covers one of the linear light sources 5 on the outside of the light source reflector 16 so that one side is covered by the lower chassis 7. As shown in FIG. 7, the embossed portion 16a of the light reflecting plate 16 covers the upper edge portion 4E of the light incident end face 4 of the light guide plate 10. In addition, the light reflection plate 16 may be processed with a metal film. In addition, the shape and structure of the other member of a backlight are the same as what was shown in Example 1, the same code | symbol is attached | subjected to the same part, and the description is abbreviate | omitted.

In the backlight of Example 3 having the above-described configuration, since the upper edge portion 4E of the light incident end face 4 is covered with the light reflecting plate, no irradiation light is introduced from the upper edge portion 4E, so that the upper edge The occurrence of bright lines caused by the portion 4E can be suppressed.

Example 4.

8 is a partially enlarged cross-sectional view of a backlight showing the structure of a light reflector for a light source of the present invention. The light source reflector 26 has a predetermined distance from the linear light source 5 and surrounds its surroundings at the rear side, and both ends thereof are superposed on the light-emitting surface 3 side and the reflective surface 2 side of the light guide plate 10, respectively. It is fixed by the chassis 20 and the lower chassis 7. In the metal film 26a, a white PET film 26b is laid on the outer layer of the surface covering the linear light source 5 by remerizing. The end of the PET film 26b is longer than the metal film 26a, and the metal film 26a couples the end face to the light incident end surface 4 of the light guide plate 10, and the PET film 26b has an end portion of the light guide plate 10. Is superimposed on the light exit surface (3). That is, at the end of the light source reflecting plate 26 on the side overlapping the light exit surface 3, a step is formed on the surface facing the linear light source 5, and the step is the upper edge portion 4E of the light incident end surface 4. ) In addition, the shape and structure of the other member of the backlight are the same as those shown in Example 1, the same reference numerals are assigned to the same parts, and the description thereof is omitted.

In the backlight of Example 4 having the above-described configuration, since the upper edge portion 4E of the light incident end face 4 of the light guide plate 10 is covered with the light reflecting plate 26, the irradiation light is emitted from the upper edge portion 4E. Since this is not introduced, the bright line generation caused by the upper edge portion 4E can be suppressed.

Example 5

9 is a partially enlarged cross-sectional view showing a light source cover structure of a backlight of Embodiment 5 of the present invention. The light reflector 36 is a metal sheet having a thickness of about 0.1 mm, has a predetermined distance from the linear light source 5, surrounds the periphery at the rear side, and the lower end of the reflecting surface 2 of the light guide plate 10. It is superimposed on and fixed to the lower chassis 7. The upper chassis 1 is, for example, made of synthetic resin and has a substantially L-shaped cross section. The upper chassis 1 covers the linear light source 5 on the outside of the light source reflector 36 so that one side is covered by the lower chassis 7. . Ribs 1a are formed on the surface of the upper chassis 1 facing the light source reflecting plate 36 in substantially parallel to the longitudinal direction of the linear light source 5. The rib 1a is formed at the position which abuts the light incident end surface 4 of the light guide plate 10, and the height of the rib 1a is 0.05 mm-1.0 mm. The upper end of the light source reflecting plate 36 is shorter than the lower end and has a length that abuts the side surface of the rib 1a of the upper chassis 1. As shown in Fig. 9, the rib 1a covers the support portion 4E on the light incident end surface 4 of the light guide plate 10 in this embodiment. In addition, the shape and structure of the other member of a backlight are the same as that shown in Example 1, the same code | symbol is attached | subjected to the same part, and the description is abbreviate | omitted. In addition, although the rib 1a is integrally formed in the upper chassis 1 in this embodiment, it is not limited to this, For example, the rib 1a may be formed by sticking a tape made of PET.

In the backlight of the fifth embodiment having the above-described configuration, since the upper edge portion 4E of the light incident end face 4 is covered with the rib 1a of the upper chassis 1, irradiation light is introduced from the upper edge portion 4E. It is not possible to suppress the occurrence of bright lines caused by the upper edge portion 4E.

In addition, although the light guide plate 10 uses the wedge-shaped thing in Examples 1-5 mentioned above, it is not limited to this, A parallel flat plate shape may be sufficient. In addition, in Examples 1-5 mentioned above, although the thing of the type which superposed one prism sheet and a protective sheet on the light-emitting surface 3 of the light-guide plate 10 is demonstrated to an example, it is not limited to this. According to the present invention, an excellent effect can be obtained with a very thin backlight having such a degree that bright lines due to the upper edge portion 4E affect the illumination of the display device.

In addition, the dimension of each member described in 1-5 mentioned above is not limited to this, What is necessary is just a dimension which covers the upper edge part of a light incident end surface.

As mentioned above, in this invention, it shields by covering the edge part of the light-receiving end surface of a light guide plate using a light source reflector plate or a light source cover, and does not introduce the irradiation light from a light source in the said edge part. The light reflecting plate is pressed and bent by a rib provided on the light source cover or by a spacer mounted on the light reflecting plate to cover the edge portion. By this light shielding, the bright line caused by the light introduced from the edge portion is prevented, and the present invention has an excellent effect.

Claims (8)

Irradiation light from a light source arranged opposite to the light incident end face of the light guide plate having the light exit face is reflected by a light reflector for light source disposed around the light source, is introduced into the light guide plate from the light incident end face, and is provided to the backlight emitted from the light exit face. In And a light source cover which covers the light source in contact with an outer surface of the light source reflecting plate disposed around the light source, and has a rib provided on a side close to the edge portion of the light guide plate on a surface in contact with the light source reflecting plate, And the light reflecting plate for light source is disposed so as to cover the edge portion of the light incident end surface of the light guide plate on the light emitting surface side. delete Irradiation light from a light source arranged opposite to the light incident end face of the light guide plate having the light exit face is reflected by a light reflector for light source disposed around the light source, is introduced into the light guide plate from the light incident end face, and is provided to the backlight emitted from the light exit face. In And a light source cover which contacts the outer surface of the light reflector for light source disposed around the light source to cover the light source. The light source reflecting plate is provided with a spacer having a predetermined height on a side close to the edge portion of the light guide plate on a surface in contact with the light source cover. The method according to claim 1 or 3, The light source reflecting plate has a shape in which a part of the light reflecting plate is in contact with the edge portion on the light exit surface side of the light incident end surface of the light guide plate. In the backlight which is introduced into the light guide plate from the light source end face is irradiated from the light source arranged opposite to the light incident end face of the light guide plate having the light exit surface, And a light source cover provided with a rib which should be in contact with the light incident end surface of the light guide plate on a surface facing the light source, so as to cover the light source. A light source cover for a backlight for covering a light source disposed opposite to a light incident end surface of a light guide plate having a light exit surface, A light source cover, characterized in that a rib is provided on a side close to an edge portion of the light incident end surface of the light guide plate on the surface of the light guide plate toward the light source. The method according to claim 6, The rib, It has a space of 0 to 2.5 mm between the light incident end surface of the light guide plate, A light source cover comprising a height of 0.05 mm to 1.0 mm. The method according to claim 1, And the light source reflecting plate has a shape in which a part of the light reflecting plate is in contact with the light receiving end surface of the light guide plate and a part of the light exiting surface side at an edge portion where the light incident end surface of the light guide plate meets the light exit surface side.

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