JP2778681B2 - Reflector sheet and surface emitting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflector sheet used for a thin and lightweight laptop personal computer, a word processor, a backlight of a liquid crystal TV, and a surface light emitting device using the same.

[0002]

2. Description of the Related Art Conventionally, as a thin edge light type surface light emitting device used for a backlight of a liquid crystal panel or the like, an L-shaped line light source in which two straight tube portions are connected via a curved tube portion is used as a light guide plate. Are provided on two adjacent side surfaces of the light guide plate, and a light diffusion transmission portion is provided on the back surface of the light guide plate. A surface light emitting device using an L-shaped line light source requires less power consumption than a surface light emitting device in which straight I-shaped line light sources are arranged on two side surfaces of a light guide plate.

In order to efficiently use the light of the L-shaped line light source, a reflector is disposed so as to cover a portion of the L-shaped line light source that does not face the light guide plate, Light from a portion not facing the light guide plate is reflected toward the light guide plate. As such a reflector, two rectangular reflector sheets 5 are used, and one reflector sheet 5 is used.
To cover the portion of one of the straight pipe portions of the L-shaped line light source 6 which does not face the light guide plate (see FIGS. 8 and 9), and similarly curves another reflector sheet 5. In some cases, a portion of the other straight tube portion not facing the light guide plate is covered (see FIG. 10).

[0004]

However, as shown in FIG. 10, this reflector does not cover a portion of the curved tube portion of the L-shaped line light source that does not face the light guide plate, so that the light leakage 7 This causes a problem that light cannot be efficiently incident on the light guide plate.

Therefore, the present invention solves the above-mentioned problems and, by bending the cover, covers not only the straight tube portions of the L-shaped line light source or the U-shaped line light source but also the curved tube portion, It is an object of the present invention to provide a reflector sheet and a surface light-emitting device using the same, which can efficiently make light from a curved tube portion of a linear light source or a U-shaped linear light source incident on a light guide plate.

Further, the present invention provides an L-shaped line obtained by bending a reflector sheet so as to cover a curved tube portion in addition to each straight tube portion of an L-shaped line light source or a U-shaped line light source. It is an object of the present invention to provide a surface light emitting device having a reflector capable of efficiently causing light from a light source or a curved tube portion of a U-shaped line light source to enter a light guide plate.

[0007]

In order to achieve the above object, a reflector sheet according to the present invention comprises an L-shaped bottom reflecting portion, an L-shaped vertical side outer side and an L-shaped lateral side outer side of the bottom reflecting portion. Each of the band-shaped side reflectors provided continuously, the band-shaped upper surface reflector provided continuously outside each side reflector, and the other in a direction orthogonal to an extension of one of the side reflectors. The tongue piece is provided continuously from one end edge of the side reflector.

Further, in the surface light emitting device of the present invention, an L-shaped line light source having two straight pipes connected to each other via a curved pipe is disposed on two adjacent side surfaces of the light guide plate, and light is applied to the back surface of the light guide plate. In the surface light emitting device provided with the diffusion transmitting portion, the side reflection portion of the reflector sheet according to claim 1 is curved, and the bottom reflection portion and the top reflection portion of the reflector sheet sandwich the end portion of the light guide plate to reflect the side surface. The straight tube portion of the L-shaped line light source was covered with the portion, and the tongue piece was curved to cover the curved tube portion of the L-shaped line light source.

Further, in the surface light emitting device, in addition to arranging L-shaped line light sources on two adjacent side surfaces of the light guide plate, it is conceivable that U-shaped line light sources are arranged on three side surfaces of the light guide plate. Therefore, the configuration of the reflector that covers the U-shaped line light source is also configured to achieve the above object.

That is, the reflector sheet of the present invention has a flat U-shaped bottom reflecting portion, and a belt-shaped reflecting portion continuously provided on the outside of the U-shaped vertical side and the outside of the two U-shaped lateral sides of the bottom reflecting portion. In each set consisting of a side reflector, a strip-shaped upper reflector continuously provided outside each side reflector, and two vertical and horizontal side reflectors, the other in a direction orthogonal to the extension of one of the side reflectors. And a tongue piece continuously provided from one end edge of the side reflection portion.

Further, in the surface light emitting device of the present invention, a U-shaped line light source having three straight pipes connected through two curved pipes is disposed on three adjacent side surfaces of the light guide plate, and the back surface of the light guide plate is provided. 4. A surface light emitting device in which a light diffusing and transmitting part is provided in the light emitting device.
Curve the side reflection portion of the reflector sheet of the reflector sheet, sandwich the end of the light guide plate with the bottom reflection portion and the top reflection portion of the reflector sheet and cover each straight tube portion of the U-shaped line light source with the side reflection portion, The tongue was curved to cover the curved tube portion of the U-shaped line light source.

Hereinafter, a reflector sheet and a surface light emitting device according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a plan view showing an embodiment of the reflector sheet according to the present invention, FIG. 2 is a plan view showing another embodiment of the reflector sheet according to the present invention, and FIGS.
FIG. 7 is a perspective view showing a method of covering an L-shaped line light source with the reflector sheet of FIG. 2, and FIG. 7 is a perspective view showing a method of covering a U-shaped line light source with the reflector sheet of FIG. 11 and 12 are bottom reflecting portions, 21 to 25 are side reflecting portions, 31 to 3
Reference numeral 5 denotes an upper surface reflecting portion, 41 to 43 denote tongues, 5 denotes a reflector sheet, and 6 denotes an L-shaped line light source.

First, the reflector sheet 5 used to cover the L-shaped line light source 6 will be described (see FIG. 1).

The bottom reflector 11 has a flat L-shape corresponding to two adjacent side surfaces on which the L-shaped line light source 6 of the light guide plate is arranged.
The light guide plate covers the vicinity of the L-shaped line light source 6 on the front surface or the back surface.

The side reflectors 21 and 22 are disposed on the bottom reflector 11.
Of the L-shaped line light source 6 when the reflector is formed in the surface light emitting device. It is curved so as to cover a portion not facing the light guide plate.

The upper surface reflecting portions 31 and 32 are
The reflector is formed on the surface light-emitting device, and is an L-shaped line on the surface opposite to the surface covered by the bottom reflecting portion 11 of the light guide plate. The light source 6 is covered.

The tongue 41 extends from one end of the other side reflector (the side reflector 22 in FIG. 1) in a direction perpendicular to the extension of one side reflector (the side reflector 21 in FIG. 1). When the reflector is formed in the surface light emitting device, it is curved and covers the curved tube portion of the L-shaped line light source 6.

Next, the reflector sheet 5 used to cover the U-shaped line light source will be described (see FIG. 2).

The bottom reflector 12 has a flat U-shape corresponding to three adjacent sides of the light guide plate on which the U-shaped line light sources are arranged. It covers the vicinity of the U-shaped line light source on the front or back surface of the light plate.

The side reflectors 23, 24 and 25 are band-shaped and provided continuously outside the U-shaped vertical side and outside the two U-shaped lateral sides of the bottom reflector 12, respectively. Is formed so as to cover portions of the straight tube portions of the U-shaped line light source that do not face the light guide plate.

The upper reflectors 33, 34, 35 are band-shaped and provided continuously outside the side reflectors 23, 24, 25. When a reflector is formed in a surface light emitting device, a light guide plate is used. The light source covers the vicinity of the U-shaped line light source on the surface opposite to the surface covered by the bottom reflector 12 of FIG.

Each of the tongues 42 and 43 is one of two sets of side and side reflectors in FIG. 2 (two sets of the side reflectors 23 and 24 and the side reflectors 24 and 25 in FIG. 2). Is provided continuously from one edge of the other side reflection portion in a direction orthogonal to the extension of the side reflection portion, and when forming a reflector in the surface light emitting device, the curved tube portion of the U-shaped line light source is used. Are curved so as to cover portions not facing the light guide plate.

The above two types of reflector sheets 5
In this case, it is preferable that the width of the tongue pieces 41, 42, 43 is smaller than the width of the continuously provided side reflection portion, because the width is easier to bend.

Further, when the reflectors 31, 32, 33, 34, and 35 overlap at the corners of the light guide plate when the reflector is formed in the surface light emitting device, a step is formed at the corner by the thickness of the reflector sheet 5. Therefore, for example, when the light guide plate is placed in the storage case with the upper surface reflection portions 31, 32, 33, 34, and 35 being on the back side of the light guide plate, the light guide plate may be inclined. Therefore, as shown in FIG. 1 or FIG. 2, the upper surface reflection portions 31, 32, 33, 34,
It is more preferable to cut diagonally about 35.

As a material of the reflector sheet 5 covering the L-shaped line light source 6 or the U-shaped line light source, a sheet-like material having a mirror reflection surface or a light diffusion reflection surface is used. Examples of the sheet-like material having a mirror reflection surface include a metal foil such as aluminum or a film on which a metal such as aluminum or silver is deposited. Examples of the sheet having a light diffusion reflection surface include a white film, for example, a film in which a white pigment is mixed in a resin such as polyethylene terephthalate, polycarbonate, acrylonitrile butadiene styrene copolymer, and polystyrene.

Next, a description will be given of a surface light emitting device in which a reflector is formed using the reflector sheet 5 described above.

As a basic configuration of the surface light emitting device except for a reflector, an L-shaped line light source is arranged on two adjacent sides of the light guide plate, or a U-shaped line light source is arranged on three sides of the light guide plate. A light diffusion transmission portion is provided on the back surface of the light guide plate.

As the light guide plate, a rectangular plate having a thickness of about 2 to 6 mm is preferable. The material of the light guide plate is not particularly limited as long as it is a substance that allows light to pass therethrough efficiently.
A resin such as acryl, polycarbonate, polystyrene, acrylic styrene, or polyvinyl chloride, or glass can be used.

As the L-shaped line light source 6 and the U-shaped line light source, those obtained by bending a cathode ray tube such as a hot cathode ray tube or a cold cathode ray tube having a diameter of 2 to 4 mm are used. The L-shape is a shape in which two straight pipes are connected through a curved pipe, and the U-shaped is a shape in which three straight pipes are connected through two bent pipes. is there.

The light diffusing and transmitting section diffuses and reflects light guided into the light guide plate from the L-shaped line light source 6 or the U-shaped line light source,
A part thereof is directed to the surface side of the light guide plate. In addition, the light diffusion transmission portion adjusts the amount of light traveling toward the light guide plate surface by changing its area ratio. For example,
The light diffusion transmission portion is formed by dots of an arbitrary shape, and the size is changed or the number of dots is changed depending on the position. As a method of forming the light diffusion transmission portion, using a mat ink containing a particulate transparent substance such as calcium carbonate or silica having a refractive index substantially equal to or less than that of the light guide plate, gravure printing, offset printing, screen printing, etc. Is formed by a printing method or a transfer method.

When only one L-shaped line light source 6 and one U-shaped line light source are arranged, a side reflector is provided on the side surface of the light guide plate where the L-shaped line light source 6 and the U-shaped line light source are not arranged. May be formed. As the side reflection plate, (1) white polyethylene terephthalate film, (2) white painted or white printed aluminum plate, (3) metal plate or metal foil having a mirror surface, metal-deposited film or plate, (4) white An ink coating layer or printing layer, (5) a vapor deposition layer, (6) a white resin layer, or the like can be used.

Further, a back reflector may be provided on the back surface of the light guide plate. As the back reflection plate, (1) a white polyethylene terephthalate film, (2) a white painted or white printed aluminum plate, or the like can be used.

Further, it is preferable to dispose a light diffusing plate on the front side of the light guide plate so as not to be in close contact with the light diffusing plate. As a light diffusion plate,
(1) A light diffusing film in which a light diffusing substance is applied to a film, (2) a film having a diffusive property itself, (3) a milky white resin plate can be used.

In order to provide a reflector for covering the L-shaped line light source 6 in the above-described surface light emitting device, an end of the light guide plate is sandwiched between the bottom reflecting portion 11 and the top reflecting portions 31 and 32 of the reflector sheet 5. The side reflectors 21 and 2 cover the straight pipes of the L-shaped line light source 6 with the side reflectors 21 and 22.
2 is bent (see FIGS. 3 to 5), and the tongue 41 is bent so as to cover the curved tube portion of the L-shaped line light source 6 (see FIG. 6).

Further, in order to provide a reflector covering the U-shaped line light source, the bottom reflecting portion 12 and the top reflecting portions 33, 34, 35 of the reflector sheet 5 sandwich the end of the light guide plate and the side reflecting portion 23. , 24, and 25, the side reflectors 23, 24, and 25 are curved so as to cover each straight tube portion of the U-shaped line light source, and the tongue piece 42 is formed so as to cover the curved tube portion of the U-shaped line light source. 43
Is curved (see FIG. 7).

In the above-described manner of providing the reflector for covering the L-shaped line light source 6 or the U-shaped line light source, the tongue piece is provided inside the side reflection part of the tongue piece 41 which is not provided continuously in FIG. Although 41 is inserted, the present invention is not limited to this. For example, tongue pieces 41, 4
2, 43 may be overlapped.

The distance between the L-shaped line light source 6 or the U-shaped line light source and the reflector is preferably kept uniform by interposing a spacer between them. If the distance between the L-shaped line light source 6 or the U-shaped line light source and the reflector is non-uniform or the distance is zero, light is emitted at a portion of the straight line portion of the line light source that is not facing the light guide plate. The reflected light is not efficiently reflected on the light guide plate side. As a method of forming the spacer, a translucent ring is fitted to the line light source, or a convex portion is printed with transparent ink on the inside of the reflector.

Further, the bottom reflecting portions 11, 12 and the top reflecting portions 31, 32, 33, 3 of the reflector sheet 5 are provided.
The light guide plates 4 and 35 may sandwich the end of the light guide plate together with the light diffusion plate or the back reflector disposed on the front or back surface of the light guide plate, or may sandwich only the end of the light guide plate.

[0040]

The present invention has the above-described structure, and thus operates as follows.

That is, the reflector sheet has a tongue, and the reflector obtained by bending the reflector sheet covers the curved tube portion of the L-shaped line light source or the U-shaped line light source with the tongue. Therefore, light emitted to the opposite side to the light guide of the curved tube portion of the L-shaped line light source or the U-shaped line light source is reflected by the tongue, and the curved tube portion of the L-shaped line light source or the U-shaped line light source Is prevented from leaking.

[0042]

【Example】

Example 1 Using a silver vapor-deposited film (GR38W manufactured by Kimoto Co.), its shape was continuously provided on the bottom surface of the L-shaped flat reflecting portion, and outside of the L-shaped vertical side and the L-shaped lateral side of the bottom reflecting portion. Band-shaped side reflectors, a band-shaped upper surface reflector continuously provided outside each side reflector, and one edge of the other side reflector in a direction orthogonal to an extension of one side reflector. To obtain a reflector sheet.

Next, a transparent acrylic resin plate having a length of 70 mm, a width of 50 mm and a thickness of 4 mm was used as a light guide plate, and a bent cold cathode ray tube having a diameter of 3 mm and a tube luminance of 23,000 cd / m ² was formed on two adjacent sides of the light guide plate. Are arranged as an L-shaped line light source, and a light diffusion transmission portion is provided on the back surface of the light guide plate by screen printing of a large number of dots using a mat ink containing silica in an acrylic resin, and a side surface of the reflector sheet is provided. The reflecting portion is curved, and the end of the light guide plate is sandwiched between the bottom reflecting portion and the top reflecting portion of the reflector sheet.
Each straight tube portion of the L-shaped line light source was covered, and the tongue piece was curved to cover the curved tube portion of the L-shaped line light source to obtain a surface light emitting device.

As a comparative example, a rectangular silver vapor-deposited film (GR38W manufactured by Kimoto Co., Ltd.) was used as a reflector sheet, and two reflector sheets were used to bend the two straight pipe portions of the L-shaped line light source. The surface light emitting device was covered. The conditions of the light guide plate, the L-shaped line light source, and the light diffusion / transmission portion were the same as in the example.

The luminance of the surface light emitting devices of the embodiment and the comparative example was measured. As a result, the light of the curved tube portion of the L-shaped line light source was able to be incident on the light guide plate more efficiently than the comparative example. Was.

Example 2 Using a silver vapor-deposited film (GR38W manufactured by Kimoto Co., Ltd.), the shape was formed on the bottom surface reflection portion having a flat U-shape, the outside of the U-shaped vertical side of the bottom reflection portion, and the outside of the two U-shaped horizontal sides. One of the side reflectors in each set of a band-shaped side reflector provided continuously, a band-shaped upper reflector provided continuously outside each side reflector, and two vertical and horizontal side reflectors. And a tongue piece continuously provided from one end edge of the other side reflection portion in a direction orthogonal to the extension line of the above, to obtain a reflector sheet.

Next, a transparent acrylic resin plate having a length of 70 mm, a width of 45 mm and a thickness of 4 mm was used as a light guide plate, and a bent cold cathode ray tube having a diameter of 3 mm and a tube luminance of 23,000 cd / m ² was used on three sides of the light guide plate. Arranged as a character line light source, on the back of the light guide plate is provided a light diffusion transmission portion by screen printing a number of dots using a matte ink containing silica in acrylic resin, the side reflection portion of the reflector sheet While bending the end of the light guide plate between the bottom and top reflectors of the reflector sheet, covering each straight tube portion of the U-shaped line light source with the side reflectors, and bending the tongue pieces to form a U-shape. The surface light emitting device was formed by covering the curved tube portion of the linear light source.

As a comparative example, a rectangular silver vapor-deposited film (GR38W manufactured by Kimoto Co., Ltd.) was used as a reflector sheet, and three reflector sheets were used to bend the three straight pipe portions of the U-shaped line light source. The surface light emitting device was covered. Note that the conditions of the light guide plate, the U-shaped line light source, and the light diffusion / transmission portion were the same as in the example.

The luminance of the surface light emitting devices of the embodiment and the comparative example was measured. As a result, the light of the curved tube portion of the U-shaped line light source was able to be incident on the light guide plate more efficiently than the comparative example. Was.

[0050]

The reflector sheet and the surface light emitting device of the present invention have the above-described structures and functions.
The following effects are achieved.

That is, after the reflector sheet of the present invention is curved to form a reflector, the tongue prevents light leakage in the curved tube portion of the L-shaped line light source or the U-shaped line light source. The light from the curved tube portion of the linear light source or the U-shaped linear light source can be efficiently incident on the light guide plate.

Further, the surface light emitting device of the present invention has a reflector obtained by bending the above-mentioned reflector sheet, and the reflector is formed by bending a L-shaped line light source or a U-shaped line light source by a tongue. As we prevent light leak in pipe part,
The light from the curved tube portion of the L-shaped line light source or the U-shaped line light source can be efficiently incident on the light guide plate.

[Brief description of the drawings]

FIG. 1 is a plan view showing one embodiment of a reflector sheet according to the present invention.

FIG. 2 is a plan view showing another embodiment of the reflector sheet according to the present invention.

FIG. 3 is a perspective view showing a method of covering an L-shaped line light source with the reflector sheet of FIG. 1;

FIG. 4 is a perspective view showing a method of covering the L-shaped line light source with the reflector sheet of FIG. 1;

FIG. 5 is a perspective view showing a method of covering the L-shaped line light source with the reflector sheet of FIG. 1;

FIG. 6 is a perspective view showing a method of covering the L-shaped line light source with the reflector sheet of FIG. 1;

FIG. 7 is a perspective view showing a method of coating the U-shaped line light source with the reflector sheet of FIG. 2;

FIG. 8 is a perspective view showing a conventional method of coating an L-shaped line light source with a reflector sheet.

FIG. 9 is a perspective view showing a conventional method of coating an L-shaped line light source with a reflector sheet.

FIG. 10 is a perspective view showing a conventional method of coating an L-shaped line light source with a reflector sheet.

[Explanation of symbols]

 11, 12 bottom reflection part 21, 22, 23, 24, 25 side reflection part 31, 32, 33, 34, 35 top reflection part 41, 42, 43 tongue piece 5 sheet for reflector 6 L-shaped line light source 7 light leakage

Claims (4)

(57) [Claims] 1. An L-shaped planar bottom reflecting portion, a strip-shaped side reflecting portion continuously provided outside the L-shaped vertical side and the L-shaped lateral side of the bottom reflecting portion, respectively, A strip-shaped upper surface reflecting portion continuously provided on the outside, and a tongue piece continuously provided from one end edge of the other side reflecting portion in a direction orthogonal to an extension of one side reflecting portion. Characteristic reflector sheet. 2. An L-shaped linear light source, in which two straight pipes are connected via a curved pipe, is disposed on two adjacent side surfaces of a light guide plate,
In a surface light emitting device having a light diffusion transmission portion provided on a back surface of a light guide plate, a side reflection portion of the reflector sheet according to claim 1 is curved, and an end portion of the light guide plate is formed by a bottom reflection portion and a top reflection portion of the reflector sheet. A surface light-emitting device characterized in that each straight tube portion of the L-shaped line light source is covered by a side reflection portion with the tongue interposed therebetween, and the tongue is curved to cover the curved tube portion of the L-shaped line light source. 3. A flat U-shaped bottom reflecting portion, a strip-shaped side reflecting portion continuously provided outside the U-shaped vertical side and outside the two U-shaped lateral sides of the bottom reflecting portion, and each side reflecting portion. In each set consisting of a strip-shaped upper surface reflecting portion continuously provided outside the portion and two vertical and horizontal side reflecting portions, one end edge of the other side reflecting portion in a direction orthogonal to an extension of one side reflecting portion. A reflector sheet comprising a tongue piece provided continuously. 4. A U-shaped linear light source having three straight pipe portions connected to each other via two curved pipe portions is disposed on three adjacent side surfaces of the light guide plate, and a light diffusion transmission portion is provided on the back surface of the light guide plate. In the surface light emitting device, the side reflection portion of the reflector sheet according to claim 3 is curved, and an end of the light guide plate is sandwiched between the bottom reflection portion and the top reflection portion of the reflector sheet, and the U-shaped line is formed by the side reflection portion. A surface light emitting device, wherein each straight tube portion of a light source is covered, and a tongue piece is curved to cover a curved tube portion of a U-shaped line light source.