JP2015159031A - Double-sided light emission type lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a double-sided light emission type lighting device capable of obtaining sufficient light volume.SOLUTION: A double-sided light emission type lighting device 1 of the invention includes: a flexible light emitting part 10 which is formed including a sheet-like light guide body; and a light source part 30 which includes a light source and is attached to a peripheral edge part of the light emitting part 10. The light emitting part 10 has an optical sheet disposed at both sides of the light guide body in a thickness direction. The light guide body includes multiple light deflection elements on a first surface in the thickness direction.

Description

  The present invention relates to a double-sided light emitting illumination device, and more particularly to an edge light type double-sided light emitting illumination device including a light guide plate.

  Conventionally, an illumination device of a system called an edge light system has been adopted for a liquid crystal television or the like. In an edge light type lighting device, a plurality of cold cathode fluorescent lamps or LEDs are arranged on an end face (incident surface) of a light-transmitting plate called a light guide plate. Usually, the light guide plate is formed with a light deflection element that efficiently guides light incident from the end surface to the exit surface. As the light deflection element, a structure in which white ink is printed in a linear or dot shape is known.

  By adjusting the light polarization element of the light guide plate, light can be emitted from both sides in the thickness direction of the light guide plate. Patent Document 1 describes such a double-sided surface emitting device.

JP 2014-22223 A

  In the surface light emitting device described in Patent Document 1, the number of components is omitted by using transmitted light that passes through the light polarization element provided on the light guide plate by printing. It is estimated that it may be difficult to obtain the light amount.

  In light of the above circumstances, an object of the present invention is to provide a double-sided light emitting illumination device capable of obtaining a sufficient amount of light.

  The present invention includes a flexible light emitting unit configured to include a sheet-like light guide, and a light source unit that includes a light source and is attached to a peripheral portion of the light emitting unit. Has optical sheets arranged on both sides in the thickness direction of the light guide, and the light guide is a double-sided illuminating device having a plurality of light deflection elements on the first surface in the thickness direction.

  According to the double-sided illumination device of the present invention, a sufficient amount of light can be obtained.

It is a perspective view which shows the double-sided light emission type illuminating device of 1st embodiment of this invention. It is a perspective view which shows the modification of the double-sided light emission type illuminating device. It is a perspective view which shows the modification of the double-sided light emission type illuminating device. It is a figure which shows typically the cross section in the II line | wire of FIG. It is a figure which shows typically the cross section corresponded in FIG. 2 about the modification of the double-sided light emission type illuminating device. It is a figure which shows typically the cross section of the double-sided light emission type illuminating device which concerns on 2nd embodiment of this invention. It is a figure which shows typically the cross section of the modification of the double-sided light emission type illuminating device. It is a figure which shows typically the cross section parallel to a X direction of the double-sided light emission type illuminating device which concerns on 3rd embodiment of this embodiment. It is a figure which shows typically the cross section parallel to a Y direction of the double-sided light emission type illuminating device which concerns on 4th embodiment of this embodiment. It is a figure which shows typically the cross section parallel to a Y direction of the double-sided light emission type illuminating device which concerns on 5th embodiment of this embodiment. It is a figure which shows typically the cross section parallel to a X direction in the modification of the double-sided light emission type illuminating device. It is a figure which shows typically the cross section parallel to a X direction in the modification of the double-sided light emission type illuminating device. It is a figure which shows typically the cross section parallel to a X direction in the modification of the double-sided light emission type illuminating device. It is a perspective view which shows the illumination set using the same double-sided light-emitting type illuminating device.

  A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing a double-sided light emitting illumination device (hereinafter simply referred to as “illumination device”) 1 of the present embodiment. The lighting device 1 includes a light emitting unit 10 having a light guide, and a light source unit 30 attached to a peripheral portion of the light emitting unit.

  The light emitting unit 10 of the present embodiment has a rectangular shape (rectangular shape) in plan view, and the light source unit 30 includes a light source such as an LED and a wiring 33 that supplies electricity to the light source, and has a long side of the light emitting unit. It is attached to one side over substantially the entire length of the long side. In the following description, the longitudinal direction of the light source unit 30 (same as the direction in which the long side of the light emitting unit 10 extends) may be referred to as “X direction”, and the direction orthogonal to the X direction may be referred to as “Y direction”.

  The arrangement of the light source unit 30 is not limited to that shown in FIG. 1 and can be changed as appropriate. In the illuminating device 1A of the modified example shown in FIG. 2, the light source unit 30 is attached to two long sides facing the light emitting unit 10 over substantially the entire long side. In the illuminating device 1B of the modification shown in FIG. 3, the two light source units 30 attached in the same manner as the illuminating device 1B are electrically connected by the wiring 33 provided along one of the short sides of the light emitting unit 10. It is connected.

FIG. 4 is a diagram schematically showing a cross section taken along the line II of FIG. In order to make the structure easy to understand, the dimensions of each part are appropriately changed.
The light emitting unit 10 includes a sheet-like light guide 11 and a diffusion sheet (optical sheet) 20 disposed on both sides in the thickness direction of the light guide 11.

  The light guide 11 is formed of a resin or the like so as to have light permeability, and has flexibility. A large number of convex microlenses (light deflection elements) 12 are discretely formed on one surface (hereinafter referred to as “first surface”) 11 a in the thickness direction of the light guide 11. The arrangement mode of the microlens 12 can be appropriately set in consideration of desired characteristics and the like required for the lighting device 1. For example, the mode described in Japanese Patent No. 5321767 can be employed. The other surface (hereinafter referred to as “second surface”) 11b in the thickness direction of the light guide 11 is flat (including substantially flat, the same applies hereinafter) 11b.

  The diffusion sheet 20 is flexible and preferably has a total light transmittance of 70% to 90% and a haze value of 80% to 93%. In general, it is known that the diffusion sheet 20 has a trade-off relationship between the total light transmittance and the haze value. A diffusion sheet having a total light transmittance of less than 70% and a haze value of greater than 93% is too diffusive and has a low transmittance. Undesirable. On the other hand, since the diffusion sheet 20 having a total light transmittance of more than 90% and a haze value of less than 80% is too low in diffusibility, the light deflection element 12 disposed on the first surface 11a of the light guide 11 is transparent. It is not desirable because it deteriorates the appearance.

The diffusion sheet 20 is preferably formed by forming a diffusion layer in which diffusion beads are coated on a transparent substrate. This is because the light emitted from the light guide 11 is deflected in the normal direction of the light emitting unit 10 by the microlens effect of the diffusion beads.
When arranging such a diffusion sheet 20 on the first surface side and the second surface side of the light guide 10, if the two diffusion sheets are in the range of the total light transmittance and haze value described above, The optical performance may be the same or different.
In the diffusion sheet 20, a coating layer that exhibits various functions may be provided on the surface facing the diffusion layer. Examples of the coating layer include a hard coating layer, an antistatic layer, and an adhesion preventing layer.

  As described above, the light emitting unit 10 has a configuration in which three sheet-like members are stacked in the thickness direction in a bonded state, and is flexible enough to be bent so as to be bent. Since the three members (the light guide 11 and the diffusion sheet 12) of the light emitting unit 10 are supported by the light source unit 30 at one end in the Y direction and the support member 15 at the other end, they are generally integrated by a bending operation or the like. Behave.

The light source unit 30 includes a cover member 32 that covers the LED 31 and supports the end of the light emitting unit 10. As the LED 31, a white LED, an RGB-LED composed of a chip that emits red, green, and blue that are the three primary colors of light can be used. Each LED 31 is arranged side by side in the X direction with the light exit surface 31 a facing the light guide 11. The light source of the light source unit is not limited to the LED, and for example, a fluorescent tube typified by CCFL (cold cathode tube), an elongated surface light source, or the like may be used.
One end of the wiring 33 is electrically connected to the LED 31 and the other end is connected to a power source (not shown). When a battery or the like is used as a power supply source for the light source, the wiring 33 is not necessarily provided.

The operation at the time of use of the illuminating device 1 of this embodiment comprised as mentioned above is demonstrated.
When electricity is supplied from the wiring 33 to the plurality of LEDs 31, each LED 31 emits light. The light of the LED enters the inside of the light guide 11 from the side surface 11c of the light guide 11, is deflected by the microlens 12, and is emitted from the first surface 11a and the second surface 11b. Light emitted from the first surface 11 a and the second surface 11 b is diffused by the diffusion sheet 20. Thus, both surfaces of the light emitting unit 10 emit light.

  According to the illuminating device 1 of this embodiment, since the diffusion sheet 20 is arrange | positioned at the thickness direction both sides of the light guide 11, the light radiate | emitted from the light guide is diffused suitably. As a result, both surfaces of the light emitting unit 10 can be made to emit light in a mode suitable for illumination, and an illumination device that can suitably illuminate both sides in the thickness direction of the light emitting unit 10 can be obtained.

  In the present embodiment, an example in which the light deflection element formed on the light guide is a convex microlens has been described, but the mode of the light deflection element is not limited thereto. For example, as in the modification shown in FIG. 5, the concave microlens 13 may be provided as the light deflection element. However, in the case of a concave microlens, a convex microlens is preferable because optical adhesion to the diffusion sheet may occur due to bending of the light emitting portion, and uneven brightness may occur. When the concave microlens 13 is used, it is preferable to provide a hard coat layer or an adhesion prevention layer on the surface of the diffusion sheet that faces the diffusion layer as described above, because optical adhesion can be suppressed. In addition, it is also possible to use a pyramid-shaped structure or dot-like printing as the light deflection element.

Further, when it is desired to make the light emission amounts different between the two exit surfaces of the illumination device of the present embodiment, the total light transmittance is changed between the optical sheet on the first surface 11a side and the optical sheet on the second surface 11b side. Also good. At this time, it is desirable to increase the total light transmittance of the optical sheet on the second surface side. In the present embodiment, light incident on the light guide 11 is emitted from the first surface 11a and the second surface 11b by the microlens 12 formed on the first surface 11a, but is emitted to the second surface side. Since the amount of light is larger, for example, a diffusion sheet having a low total light transmittance is selected as the optical sheet disposed on the first surface side, and a high total light transmittance is selected as the optical sheet disposed on the second surface side. When the diffusion sheet is selected, the light amount difference between both sides can be further increased.
In the case as described above, the total light transmittance of the optical sheet disposed on the first surface side is preferably in the range of 1% to 10%. As a result, the amount of light emitted from the second surface can be increased. In addition, since the micro lens 12 that is a light deflection element is formed on the first surface side, the visibility of the micro lens 12 is reduced by arranging an optical sheet having a low total light transmittance on the first surface side. There is also a merit that you can.

  Next, a second embodiment of the present invention will be described with reference to FIGS. The difference between the illuminating device of this embodiment and the illuminating device of 1st embodiment is the aspect of a light guide. In the following description, components that are the same as those already described are assigned the same reference numerals and redundant description is omitted.

  FIG. 6 is a diagram schematically showing a cross section of the illumination device 51 of the present embodiment, where the left side shows a cross section parallel to the Y direction and the right side shows a cross section parallel to the X direction. The cover member 32 and the support member 15 are omitted. As shown in FIG. 6, in the light guide 52 of the lighting device 51, the second surface 52b opposite to the first surface 52a on which the microlens 12 is formed has a semicircular cross-sectional shape and Y. A plurality of lenticular lenses (optical elements) 53 extending in the direction are formed side by side in the X direction.

In the illumination device 51, the light incident on the light guide 52 from the light source unit 30 travels straight along the Y direction in which the lenticular lens 53 extends. As a result, in the light emitting unit 10A, uneven luminance in the surface is suppressed, and illumination with high luminance uniformity can be performed.
In addition, since the plurality of lenticular lenses 53 extending in the Y direction perpendicular to the longitudinal direction of the light source unit 30 are formed side by side in the X direction, light hardly leaks from the end in the X direction of the light emitting unit 10A. Therefore, it is not necessary to attach a reflecting material or the like to both ends in the X direction, and the manufacturing can be simple and inexpensive.

  In this embodiment, the optical element formed on the second surface is not limited to a lenticular lens. For example, a prism lens 54 having a triangular cross section as shown in FIG. 7 may be used. However, when a prism lens is used, luminance unevenness corresponding to the arrangement of the light sources may occur near the side surface 52c of the light guide 52 on which the light from the light source unit enters. Therefore, a lenticular lens is more preferable as the optical element.

  Next, a third embodiment of the present invention will be described with reference to FIG. The difference between the illumination device 101 of the present embodiment and the illumination device of each embodiment described above is that a plurality of diffusion sheets are arranged in at least one of the light guides in the thickness direction.

  FIG. 8 is a diagram schematically showing a cross section parallel to the X direction of the lighting apparatus 101 of the present embodiment. As shown in FIG. 8, in the illumination device 101, a second diffusion sheet (second optical sheet) 62 is disposed in addition to the diffusion sheet 20 on both sides in the thickness direction of the light guide 52. The two second diffusion sheets 62 exhibit optical performance different from that of the diffusion sheet 20, and both are disposed at positions away from the diffusion sheet 20 with respect to the light guide 52.

The light emitted from the first surface 52a and the second surface 52b of the light guide 52 is emitted by being inclined with respect to the normal direction of the first surface 52a and the second surface 52b, and then diffused by the diffusion sheet 20 and Although the deflection is performed in the normal direction of the first surface 52a and the second surface 52b, the deflection may be insufficient with one diffusion sheet.
In the illumination device 101 of the present embodiment, the second diffusion sheet 62 is provided in addition to the diffusion sheet 20 and two optical sheets are arranged, so that the light emitted from the light guide 52 in the oblique direction can be efficiently emitted. It can be deflected in the normal direction of the exit surface.
In the present embodiment, the optical sheet and the second optical sheet are not limited to the diffusion sheet. For example, a lenticular lens sheet having the above-described lenticular lens or a prism sheet having the above-described prism lens may be used. Since the light incident on these sheets is also deflected in the normal direction of the exit surface, the luminance in the normal direction of the light emitting portion can be further increased by stacking two such sheets. At this time, it is desirable that a plurality of lenticular lenses and prism lenses extend in a direction (X direction) parallel to the longitudinal direction of the side surface 52c of the light guide 52 and are arranged side by side in the light source optical axis direction (Y direction). .

  In the present embodiment, the second diffusion sheet may be provided only on one side of the light guide in the thickness direction, and in this case, the second diffusion sheet may be disposed between the light guide and the diffusion sheet. Good. In particular, when the second optical sheet is a lenticular lens sheet or a prism sheet, if the second optical sheet is disposed on the outermost surface of the light emitting unit, there may be a case where the lens-specific shine or glare is visually recognized, which is not preferable. In such a case, it is preferable to arrange the second optical sheet between the light guide and the optical sheet.

Further, a third optical sheet may be arranged. Examples of the third optical sheet include a fine diffusion sheet that reduces glare of a lenticular lens sheet and a prism sheet. The fine diffusion sheet preferably has a total light transmittance of 80% to 95% and a haze value of 30% to less than 80%.
Furthermore, three or more optical sheets may be disposed in at least one of the light guides in the thickness direction.

  Next, a fourth embodiment of the present invention will be described with reference to FIG. The difference between the illumination device 151 of the present embodiment and the illumination device of each embodiment described above is that a fluorescent sheet is disposed in at least one of the light guides in the thickness direction.

  FIG. 9 is a diagram schematically showing a cross section parallel to the Y direction of the illumination device 151 of the present embodiment. The cover member 32 and the support member 15 are omitted. As shown in FIG. 9, in the lighting device 151, a fluorescent sheet 72 is disposed so as to sandwich the light guide 52 and the diffusion sheet 20 in place of the second diffusion sheet.

  Each phosphor sheet 72 contains a phosphor. This phosphor absorbs part of the light emitted from the light guide 52 and transmitted through the diffusion sheet 20, and emits excitation light. There is no restriction | limiting in particular in the fluorescent substance which the fluorescent sheet 72 contains, According to the color etc. which the illumination light emitted from the illuminating device 151 wants to have, what has a desired excitation wavelength range can be selected suitably.

  According to the illuminating device 151 of the present embodiment, since the wavelength of part of the light transmitted through the diffusion sheet 20 is converted by the fluorescent sheet 72, the color and brightness of the illumination light can be adjusted in a wider range. . Moreover, the loss of light can be suppressed compared with adjusting the color of illumination light with a simple colored sheet.

  In particular, a thin LED is suitable as a light source in order to make the light emitting portion thin enough to have flexibility as in the lighting device of the present invention, but most of the currently available thin LEDs are daylight colors. It emits blue light. Therefore, by converting the wavelength of such LED light with a fluorescent sheet, it is possible to configure an illumination device for warm illumination light such as a bulb color.

In the present embodiment, the example in which the fluorescent sheets are arranged on both sides in the thickness direction of the light guide has been described. However, the fluorescent sheets may be arranged only on one side in the thickness direction. In this way, the light wavelength is changed on one side of the light emitting unit, and the color of the light of the light source is not changed on the other side, so that the color of the illumination light is made different on both sides of the light emitting unit. Can do.
Also, if fluorescent sheets containing phosphors with different excitation wavelength ranges are arranged on both sides in the thickness direction of the light guide, the color of the illumination light can be adjusted on both sides of the light emitting unit without using the color of the light of the light source. Can be different.

  Furthermore, when it is desired to change the color of light from the light source, but to obtain illumination light having substantially the same color on both sides of the light emitting unit, a fluorescent sheet may be disposed between the light guide and the diffusion sheet. If it does in this way, a part of light by which the wavelength conversion was carried out with the fluorescent sheet will reenter a light guide, and will be radiate | emitted on the opposite side. As a result, even if the fluorescent sheet is disposed only on one side in the thickness direction, the color of the illumination light is substantially the same on both sides of the light emitting unit, and the number of parts can be reduced.

  Next, a fifth embodiment of the present invention will be described with reference to FIGS. The difference between the illuminating device 201 of this embodiment and the illuminating device of each embodiment mentioned above is a point provided with a surface protection sheet.

  FIG. 10 is a diagram schematically showing a cross section parallel to the Y direction of the illumination device 201 of the present embodiment, and the cover member 32 and the support member 15 are omitted. As shown in FIG. 10, in the lighting device 201, a surface protection sheet 82 is disposed so as to sandwich the light guide 52 and the diffusion sheet 20 instead of the second diffusion sheet and the fluorescent sheet.

As the surface protective sheet 82, a known one can be appropriately selected and used. For example, the thing which provided the hard-coat layer etc. by apply | coating the highly transparent and highly hard coating agent to the one or both surfaces of a transparent base material layer etc. is mentioned.
According to the illuminating device 201 of the present embodiment, the diffusion sheet 20 can be prevented from being damaged, and the aspect of the illumination light in the light emitting unit can be suitably held in a desired state.

FIG. 11 is a diagram schematically showing a cross section parallel to the X direction of an illuminating device 201 </ b> A which is a modification of the illuminating device 201. The diffusion sheet 20 of the lighting device 201 </ b> A includes the base material layer 21 and the diffusion particles 22 a, the diffusion layer 22 formed on one surface of the base material layer 21, and the other surface of the base material layer 21. And a hard coat layer 23A. The diffusion layer 22 faces the surface protection sheet 82, and the hard coat layer 23 </ b> A faces the light guide 52.
In the illumination device 201A, since the diffusion sheet has the hard coat layer 23A, the light deflection element and the optical element formed on the light guide are suitably protected. Further, since the diffusion layer 22 is not opposed to the light deflection element or the optical element, the diffusion performance of the diffusion sheet is also suitably maintained.

  FIG. 12 is a diagram schematically showing a cross section parallel to the X direction of an illumination device 201B which is a modification of the illumination device 201. As shown in FIG. In the lighting device 201B, the light guide 52 has a concave microlens 13 on the first surface, and the diffusion sheet 20B on the microlens 13 side has an adhesion prevention layer 23B instead of the hard coat layer 23A. . The adhesion preventing layer 23B is formed by including a small amount of particles 23b in the binder. The diffusion layer 22 faces the surface protection sheet 82, and the adhesion prevention layer 23 </ b> B faces the light guide 52. In the illumination device 201B, since the diffusion sheet 20B has the adhesion preventing layer 23B, even if the light deflection element formed on the light guide has a concave shape, optical adhesion between the diffusion sheet and the light guide can be prevented. it can. As a result, even when the user presses the surface of the light emitting unit with a finger, it is possible to prevent uneven brightness from occurring in the pressed portion.

  FIG. 13 is a diagram schematically showing a cross section parallel to the X direction of an illumination device 201C which is a modification of the illumination device 201. As shown in FIG. In the illuminating device 201C, the light guide 11A is the same as that shown in FIG. 5, has the concave microlens 13 on the first surface, and the second surface is formed flat. In addition, diffusion sheets 20B are disposed on both sides of the light guide 11A. In this modification, by providing the diffusion sheet 20B on both sides, optical adhesion between the diffusion sheet and the light guide can be prevented even on the flat first surface side. As a result, it is possible to prevent luminance unevenness due to pressing or the like.

  The embodiments and examples of the present invention have been described above. However, the technical scope of the present invention is not limited to the above-described embodiments, and combinations of components may be changed without departing from the spirit of the present invention. Various changes can be added to or deleted from each component.

  For example, when an optical element is not provided in the light guide, leakage of light incident on the light guide may be suppressed by disposing a known reflecting material at both ends in the X direction of the light guide. .

  Further, the dimension of the diffusion sheet in plan view is set to be slightly larger than the dimension of the light guide in plan view, and the light emitting unit is arranged so that the light guide is located within the range of the diffusion sheet in plan view. It may be configured. If it does in this way, the distance (floating) of a light guide and a diffusion sheet at the time of a light emission part bending can be made small, and the change of illumination light by bending etc. of a light emission part can be suppressed.

  Furthermore, the planar view shape of the light emitting part may be a square or other shapes, or the light source part may be attached to a peripheral part that is not a long side. However, it is preferable to attach the light source part to the long side of the light emitting part because there is a merit that it is easy to increase the number and size of the light sources and increase the incident light to the light guide.

FIG. 14 shows an illumination set using the illumination device of the present invention. The lighting set includes the lighting device 1 and a housing 90. The housing 90 has a rail structure, and can be attached to the lighting device 1 by sliding the short side of the light emitting unit 10 of the lighting device 1 into the rail structure of the housing 90.
A reflective layer made of metal or white ink is formed on the inner surface of the housing 90. Therefore, the illumination set including the illumination device 1 and the housing 90 can be used as a double-sided light emitting device when used alone, and when the illumination device 1 is attached to the housing 90, It can be used as a single-sided light emitting device. That is, switching between the double-sided light-emitting device and the single-sided light-emitting device can be performed.
Further, since the inner surface of the housing 90 is provided with a reflective layer, the amount of light emitted from both sides when the lighting device is used alone can be emitted from only one side, and the amount of light emitted from one side can be approximately doubled. .
In the above-described illumination set, when the illumination device is attached to the housing, it is preferable to install the illumination device so that the first surface of the light guide on which the light deflection element is formed faces the reflective layer of the housing. In other words, the second surface on which the optical element is formed is preferably the light emitting surface (upper surface). The light quantity can be increased by installing in this way.

1, 1A, 1B, 51, 151, 201, 201A, 201B, 201C Double-sided light emitting illumination device 10, 10A Light-emitting unit 11, 11A, 52, 52A Light guide 11a, 52a First surface 11b, 52b Second surface 12 , 13 Microlens (light deflection element)
20, 20A, 20B Diffusion sheet (optical sheet)
21 Base material layer 22 Diffusion layer 23A Hard coat layer 30 Light source part 31 LED (light source)
53 Lenticular lens (optical element)
54 Prism lens (optical element)
62 Second diffusion sheet (second optical sheet)
72 Fluorescent Sheet 82 Surface Protection Sheet

Claims (8)

A flexible light-emitting unit configured to include a sheet-like light guide;
A light source unit having a light source and attached to a peripheral portion of the light emitting unit;
With
The light emitting unit has optical sheets arranged on both sides in the thickness direction of the light guide,
The light guide has a plurality of light deflecting elements on a first surface in a thickness direction, and is a double-sided light emitting illumination device. The light emitting unit is formed in a rectangular shape in plan view,
The light source unit is disposed along one side of the rectangle,
The double-sided light emitting illumination device according to claim 1, wherein the light guide includes a plurality of optical elements extending in a direction orthogonal to a longitudinal direction of the light source unit on a second surface opposite to the first surface. The light emitting unit is formed in a rectangular shape in plan view,
The light source unit is disposed along two opposing sides of the rectangle.
The double-sided light emitting illumination device according to claim 1, wherein the light guide includes a plurality of optical elements extending in a direction orthogonal to a longitudinal direction of the light source unit on a second surface opposite to the first surface. The optical sheet is
A base material layer, a diffusion layer provided on one surface of the base material layer, and a coating layer provided on the other surface of the base material, etc.
The total light transmittance is set in the range of 70% to 90% and the haze value is in the range of 80% to 93%,
The coating layer is disposed to face the light guide plate,
The double-sided light emitting illumination device according to any one of claims 1 to 3. The optical sheet is
A base material layer, a diffusion layer provided on one surface of the base material layer, and a coating layer provided on the other surface of the base material, etc.
The optical sheet disposed on the first surface side has a total light transmittance set to a range of 1% to 10%,
The optical sheet disposed on the second surface side has a total light transmittance of 70% to 90% and a haze value of 80% to 93%,
Any optical sheet is disposed with the coat layer facing the light guide plate,
The double-sided light emitting illumination device according to any one of claims 1 to 3.   The double-sided light emitting illumination device according to any one of claims 1 to 5, further comprising a second optical sheet provided on at least one of the light guides in the thickness direction.   The double-sided light emitting illumination device according to any one of claims 1 to 6, further comprising a fluorescent sheet provided in at least one of the light guides in the thickness direction.   The double-sided light emitting illumination device according to any one of claims 1 to 7, wherein a surface protection sheet is disposed so as to sandwich the light guide plate and the optical sheet.

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