JP4534863B2 - Surface light source device - Google Patents

Description

  The present invention relates to a planar light source device in which a reflection sheet that reflects light from a light source has a cut portion.

  In the conventional planar light source device, the reflection sheet is attached to the inside of the casing by pasting the overlapping portion of the end of the U-shaped cross section of the reflection sheet and the end of the plate light guide with a double-sided tape. (See, for example, Patent Document 1).

JP 2000-315414 A (page 3, FIG. 1)

  In the above prior art, the light emitted from the light source is easily scattered by the double-sided tape portion, and thus there is a problem that display defects such as bright lines occur on the display surface of the planar display device.

  In addition, since double-sided tape is used, it is necessary to provide a process for lowering the quality due to the adhesion of foreign substances through the adhesive material of the double-sided tape, and further a process for attaching the double-sided tape. It was.

  The present invention has been made in view of the above problems, and without increasing the number of members and the manufacturing process, suppress the occurrence of display defects such as bright lines, and improve product quality and workability. It is aimed.

  In the planar light source device according to the present invention, the reflective sheet is disposed in the first region surrounded by the first fold line, the second fold line, and the reflection sheet end portion, and the first housing with the second fold line as an axis. It has a cut portion that is folded back so as to contact the body.

  In the present invention, the reflective sheet is folded back in the first region surrounded by the first fold, the second fold, and the end of the reflective sheet so as to be in contact with the first housing around the second fold. By having the cut portions, the occurrence of display defects such as bright lines can be suppressed without increasing the number of members and the number of manufacturing steps.

  In the following, embodiments to which the present invention can be applied will be described. The following description is for explaining embodiments of the present invention, and the present invention is not limited to the following embodiments. For the sake of clarity, the following description is omitted and simplified as appropriate. Moreover, those skilled in the art can easily change, add, and convert each element of the following embodiments within the scope of the present invention.

Embodiment 1 FIG.
FIG. 1 is a cross-sectional view for explaining a cut portion formed in the reflection sheet of the planar light source device in Embodiment 1, FIG. 2 is a plan view of the reflection sheet in Embodiment 1, and FIG. FIG. 4 is an enlarged view of a portion A in FIG. 2 in the first embodiment, FIG. 4 is a perspective view in which the reflection sheet in the first embodiment is folded at the first fold line and the second fold line, and FIG. 4 is an enlarged view of a portion B, FIG. 6 is an enlarged view of a cut portion formed so as to include an end portion of the reflection sheet in the first embodiment, and FIG. 7 is an entire surface light source device in the first embodiment. It is a perspective view which shows a structure. As shown in FIG. 1, the first housing 1 of the planar light source device has an opening 1a in the upper part.

  A reflection sheet 2 having a first fold 2a and a second fold 2b is disposed inside the first housing 1 so that light is reflected and proceeds to the opening 1a. The light source 3 is arranged in a gap formed by bending the 2a and the second fold 2b. In order to reflect light efficiently, the reflective sheet 2 is coated with alumina vapor deposition or white coat on a PET (polyethylene terephthalate) film, and the thickness is generally 0.2 mm, but this is not the only case. Not a thing.

  In addition, a light guide plate 4 that guides and diffuses light from the light source 3 to the opening 1 a is arranged inside the first housing 1 on the opening side with respect to the reflection sheet 2, and on the opening side of the light guide plate 4. A plurality of optical sheet groups 5 for effectively using light are arranged. Here, the opening side is the upper side of the drawing in FIG.

  Furthermore, it has the 2nd housing | casing 6 which makes a pair with the 1st housing | casing 1 and hold | grips from the side surface outer side of the 1st housing | casing 1. FIG.

  As shown in FIGS. 1-7, in this Embodiment 1, the reflection sheet 2 arrange | positioned so that the light from the light source 3 may be reflected and it may advance to the opening part 1a is 1st crease 2a, 2nd crease | fold. The first region 2d surrounded by 2b and the end 2c of the reflection sheet 2 has at least one notch 2e. Furthermore, it has the 2nd area | region 2f adjacent through the 1st area | region 2d and the 2nd crease | fold 2b.

  The cut portion 2e is folded back so as to be in contact with the first housing 1 with the second fold 2b as an axis. In this way, by folding back the notch 2e so as to contact the first housing 1, the first fold 2a and the second fold 2b can be folded in a U shape so as to cover the light source 3. It is possible to prevent the region 2 f of 2 from being separated from the light guide plate 4 and returning to the original state due to the restoring force applied to the reflection sheet 2.

  Furthermore, since the double-sided tape is not used, the light emitted from the light source 3 is prevented from being scattered by the double-sided tape part and causing display defects such as bright lines on the display surface of the surface display device, and the adhesive of the double-sided tape is used. It is possible to prevent adhesion of foreign matter.

  In this manner, the cutout portion 2e is formed in the first region 2d of the reflection sheet 2 by folding the cutout portion 2e so as to be in contact with the first housing 1.

  Further, by arranging the notch 2e in the vicinity of the end of the reflection sheet 2 in the first region 2d surrounded by the first fold 2a, the second fold 2b, and the end 2c of the reflection sheet 2, It is possible to improve workability when the second housing 6 is assembled from the corner where the notch portion 2e is arranged so as to be gripped from the outside of the side surface of the single housing 1.

  Furthermore, as shown in FIG. 6, the cut portion 2 e is arranged so as to include the end portion 2 c of the reflection sheet 2 in the first region 2 d, so that the cut portion 2 e comes into contact with the first housing 1 more efficiently. It is also possible to fold back like this.

  The notch 2e has a height t from the second fold 2b, a length T from the first fold 2a to the second fold 2b, and a height of the first housing 1. If h, t <h−T is preferable. By adopting such a configuration, the notch 2e does not protrude from the first housing 1 to the opening side, so that the second housing is gripped from the outside of the side surface of the first housing 1. When assembling 6 from the end, the second casing 6 does not get caught in the notch 2e, and the workability can be improved.

  The first fold line 2a and the second fold line 2b formed on the reflection sheet 2 are alternately formed with cutout portions 7 and connecting portions 8, and the length of the connecting portion 8 of the second fold line 2b is set to W [ mm], and the width of the bottom side of the cut portion 2e with the second fold 2b as the bottom side is w [mm], it is preferable that the cut portion 2e is formed in the connecting portion 8 and W> w ≧ 1. . Thus, when the width w of the bottom of the cut portion 2e is w ≧ 1, when the cut portion 2e is folded back so as to be in contact with the first housing 1 with the second fold 2b as an axis, It is easy to fold and workability can be improved.

  Moreover, since the adjacent notch part 7 does not couple | bond together via the coupling | bond part 8 by making the width w of the base of the notch part 2e into W> w, the reflection sheet 2 is made into 2nd crease | fold 2b. Even when it is bent at, a stable bent shape can be maintained.

  Further, the lower limit value 1 mm of the width w of the bottom side of the cut portion 2e described above is a value that allows the cut portion 2e to be folded back so as to contact the first housing 1 with the second fold 2b as an axis. For example, it is not limited to this.

  In particular, the width w of the bottom of the cut portion 2e is w = W / 2, and the height t [mm] with the second fold 2b of the cut portion 2e being the base is t = 1, whereby the cut portion 2e is folded back. Workability can be further improved. Furthermore, it is preferable because the bent shape of the second fold 2b can be more reliably maintained.

  The shape and the number of the notches 2e are appropriately optimized depending on the material and thickness of the reflection sheet 2 and the numbers and lengths of the notches 7 and the connecting portions 8 formed in the second fold 2b.

  For example, the specifications of the first crease 2a and the second crease 2b depend on the manufacturer, and when the length of the notch 7 is 1 mm, the length of the connecting portion 8 is 2 mm, and the notch 7 When the length of the connecting portion 8 is 1.6 mm, the length of the connecting portion 8 is 2 mm, and when the length of the cutout portion 7 is 8 mm, the length of the connecting portion 8 is 1 mm.

  As shown in FIG. 7, the light source 3 is a linear light source, and the cut portion 2 e formed in the reflection sheet 2 is formed at a position in contact with the light source holding member 9 that holds the light source 3 at the end of the light source 3. Thus, the emitted light can be reduced from the cutout portion 2g formed in the first region 2d of the reflection sheet 2, and the light can be used effectively, which is useful for improving the luminance.

  Furthermore, by forming the cut portion 2e at a position overlapping the light source holding member 9, it becomes possible to eliminate light emitted from the cut portion 2g.

  As described above, the surface light source device according to the first embodiment folds the cut portion 2e formed in the reflection sheet 2 so as to be in contact with the first housing 1, thereby increasing the number of members and the manufacturing process. In addition to preventing the reflective sheet 2 from moving away from the light guide plate 4 without increasing the display, it is possible to suppress the occurrence of display defects such as bright lines and to prevent foreign matter from adhering via the adhesive material of the double-sided tape. It becomes possible. Thereby, product quality and workability | operativity can be improved.

  In the first embodiment, the light source 3 is disposed on all three sides of the reflection sheet 2, but the present invention is not limited to this, and even when the light source is disposed on at least one side of the reflection sheet. It is possible to obtain an equivalent effect.

  In the first embodiment, a fluorescent lamp (CCFL) composed of a cold cathode tube is usually used as the light source disposed on the side surface of the light guide plate. Even when a light source using a light emitting diode (LED) having an emission color such as, B is used, the same effect can be obtained.

Sectional drawing for demonstrating the notch | incision part formed in the reflective sheet of the planar light source device in this Embodiment 1. FIG. The top view of the reflective sheet in this Embodiment 1 Enlarged view of part A in FIG. 2 in the first embodiment The perspective view which bent the reflective sheet in this Embodiment 1 by the 1st crease and the 2nd crease Part B enlarged view of FIG. 4 in the first embodiment. The enlarged view of the notch part formed so that the edge part of the reflective sheet in this Embodiment 1 may be included. The perspective view which shows the whole structure of the planar light source device in this Embodiment 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st housing | casing 1a Opening part 2 Reflective sheet 2a 1st crease 2b 2nd crease | fold 2c End part 2d of a reflective sheet 2d 1st area | region 2e Cut-in part 2f 2nd area | region 2g Cutout part 3 Light source 4 Light guide plate 5 Light source sheet group 6 Second housing 7 Notch portion 8 Connection portion 9 Light source holding member

Claims (7)

A first housing having an opening at the top;
A reflective sheet disposed inside the first housing and having a first fold line and a second fold line formed thereon;
A light source disposed in a gap formed by being bent by a first fold line and a second fold line formed in the reflection sheet in the vicinity of at least one side surface of the first housing;
A planar light source device having a second housing that forms a pair with the first housing and grips from the outside of the side surface of the first housing,
The reflection sheet is folded back so as to contact the first housing with the second fold as an axis in a first region surrounded by the first fold, the second fold, and the reflection sheet end. A planar light source device having a cut portion. The planar light source device according to claim 1, wherein the cut portion is formed in the vicinity of an end portion of the first region. The planar light source device according to claim 1, wherein the cut portion is formed so as to include an end portion of the first region. The notch has a height with respect to the second fold, t, a length from the first fold to the second fold, T, and a height of the first housing, h.
t <h−T
The planar light source device according to any one of claims 1, 2, and 3, wherein: The first fold line and the second fold line are composed of alternately provided cutout portions and connection portions, the length of the connection portion of the second fold line is W [mm], and the second fold line is When the width of the cut portion is w [mm],
Form a notch in the connecting part,
And W> w ≧ 1
5. The planar light source device according to claim 1, wherein the planar light source device satisfies the following conditions. The light source is a linear light source;
The planar light source device according to claim 1, wherein the cut portion is formed at a position in contact with a light source holding member that holds a light source at both ends of the linear light source. The light source is a linear light source;
The planar light source device according to claim 1, wherein the cut portion is formed at a position overlapping a light source holding member that holds a light source at both ends of the linear light source. .

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