WO2016080169A1

WO2016080169A1 - Surface light emitting unit

Info

Publication number: WO2016080169A1
Application number: PCT/JP2015/080511
Authority: WO
Inventors: 祐亮平尾; 孝二郎関根; 昌宏今田
Original assignee: コニカミノルタ株式会社
Priority date: 2014-11-19
Filing date: 2015-10-29
Publication date: 2016-05-26
Also published as: JPWO2016080169A1

Abstract

Provided is a surface light emitting unit which is capable of making a non-light-emitting region less noticeable than conventional surface light emitting units, while maintaining a thin thickness. A surface light emitting unit (100) is provided with: a surface light emitting panel (20) having a light emitting surface which comprises a light emitting region (RA) that emits light and a non-light-emitting region (RB) that is positioned around the light emitting region (RA) and does not emit light; a transmissive member (21) which has a front surface (21A) and a back surface (21B) and is arranged such that the back surface (21B) faces the light emitting surface; an optical control member (22) which is arranged so as to face the front surface (21A) of the transmissive member (21) for the purpose of dimming the light from the front surface (21A) of the transmissive member (21); and a diffusion member (26) which is arranged so as to face a surface of the optical control member (22), said surface being on the reverse side of the transmissive member (21)-side surface of the optical control member (22). At least a part of the optical control member (22) is provided so as to face the light emitting region (RA). The width (LA) of the optical control member (22) in a predetermined in-plane direction is smaller than the width (LC) of the light emitting region (RA) in the above-mentioned predetermined direction at least in one in-plane direction.

Description

Surface emitting unit

This disclosure relates to a surface light emitting unit including a surface light emitting panel.

In recent years, mobile phones and tablet terminals have become popular. As shown in FIGS. 15 and 16 on the front side and the back side, a general tablet terminal 50 includes a casing 51 and a plurality of display units 52 to 55. The thickness T of the tablet terminal 50 is, for example, 7 mm or less. The front side shown in FIG. 15 will be described as an example. There is a desire to reduce the width W (see FIG. 15) of the region other than the

display units

52 and 53, that is, the frame (edge) portion of the tablet terminal 50 as much as possible. The backlight and illumination built in the terminal 50 are required to be able to emit light up to a portion near the end of the casing 51.

The use of surface-emitting panels as backlights for mobile phones and tablet terminals is being studied. In the surface emitting panel, substantially the entire light emitting surface emits light. A surface light-emitting unit including a surface light-emitting panel can be applied not only to a backlight but also to the lighting field. An organic EL is known as an example of a surface emitting panel. Organic EL is expected to be a new light source because it is a thin surface emitting panel and has flexibility.

In a surface light emitting panel such as an organic EL, sealing is generally performed around the light emitting portion in order to protect the light emitting portion (such as a light emitting layer or a light emitting element) from moisture and oxygen. Since the sealing part is provided so as to cover the light emitting part, the sealing part has a larger area than the light emitting part. For this reason, not only a light emitting region that actually emits light but also a non-light emitting region that emits little or no light is formed on the surface of the surface light emitting panel that emits light (light emitting surface). When this surface emitting panel is used for the backlight of the tablet terminal as shown in FIG. 15, the area that does not emit light cannot be used for illumination of the display unit, and is the portion of the frame in FIG. 15 (ie, width W). Therefore, if the width of the non-light emitting region is large, the width W must be increased, and the display portion is relatively small. Therefore, it is required to make the width of the non-light emitting region as small as possible. In addition, it is desired to reduce the thickness of the tablet terminal and the like, and it is important that the thickness of the tablet terminal does not increase when the width of the non-light emitting area is reduced.

In the backlight system disclosed in Japanese Patent Application Laid-Open No. 2007-087900 (Patent Document 1), a side wall having an inclined shape is arranged around the light emitting surface of the flat light source, and a predetermined interval is provided from the light emitting surface. Light is guided to the backlight surface. Thereby, the backlight system enlarges the area of the light emitting region. An LED (Light Emitting Diode) illumination device disclosed in Japanese Patent Application Laid-Open No. 2013-145723 (Patent Document 2) divides a light-transmitting diffusion plate on the light projecting side of an LED light-emitting unit to separate the light from the LED. It diffuses and reduces glare. The organic EL element disclosed in Japanese Patent Application Laid-Open No. 2011-243448 (Patent Document 3) has a light reflecting layer made of a specular metal film in a portion other than the light emitting surface, so that it can be used originally. The effective use of the light that did not exist.

JP 2007-087900 A JP 2013-145723 A JP 2011-243448 A

The backlight system disclosed in Patent Document 1 needs to reflect the light emitted from the first light emitting surface by the side wall and take it out from the second light emitting surface. For this reason, a distance must be provided between the first light emitting surface and the second light emitting surface, which increases the thickness of the backlight system. Similarly, the LED illumination device disclosed in Patent Document 2 must be provided with a light transmissive diffusion plate spaced apart, which increases the thickness of the LED illumination device.

The organic EL element disclosed in Patent Document 3 has a large luminance difference between the light emitting region and the non-light emitting region, and is difficult to recognize as one surface emitting panel. Therefore, a person who sees the organic EL element recognizes the non-light emitting area.

The present disclosure has been made in order to solve the above-described problems, and an object in one aspect is to provide a surface light emitting unit capable of making a non-light emitting region less noticeable than the conventional one while keeping the thickness thin. Is to provide.

According to one embodiment, the surface light emitting unit includes a surface light emitting panel having a light emitting surface, a first transmissive member having a front surface and a back surface, and provided so that the light emitting surface and the back surface face each other, An optical adjustment member for reducing light from the surface of the first transmission member; and an optical adjustment member on a surface opposite to the first transmission member side. And a diffusing member provided to face each other. The light emitting surface of the surface light emitting panel includes a light emitting region that emits light and a non-light emitting region that is located on the outer periphery of the light emitting region and does not emit light. At least a portion of the optical adjustment member is provided to face the light emitting region. The width in the predetermined direction within the surface of the optical adjustment member is shorter than the width in the predetermined direction of the light emitting region in at least one direction within the surface.

According to the above configuration, the surface light emitting unit can make the non-light emitting region less noticeable than the conventional one while keeping the thickness thin.

It is a top view which shows the surface emitting unit according to Embodiment 1, and is equivalent to the surface emitting unit seen from the arrow I direction in FIG. FIG. 2 is a cross-sectional view taken along the line II-II in FIG. It is an arrow directional cross-sectional view of a surface emitting panel. It is a top view which shows a surface emitting panel, and is equivalent to the surface emitting panel 20 seen from the arrow IV direction in FIG. It is a top view which shows a surface emitting panel and an optical adjustment member, and is equivalent to the surface emitting unit seen from the I direction in FIG. It is a top view which shows the surface emitting panel and optical adjustment member according to a modification, and is equivalent to the surface emitting panel and optical adjustment member seen from the I direction in FIG. It is a figure which shows sectional drawing of the surface emitting unit according to Embodiment 2, and is arrow sectional drawing along the II-II line in FIG. It is a top view which shows a surface emitting panel and a reflecting member, and is equivalent to the surface emitting panel and reflecting member seen from the VIII direction in FIG. It is the figure which showed the light distribution curve of the surface emitting unit according to Embodiment 3 by the vertical in-plane light distribution. It is sectional drawing of the surface emitting unit according to a comparative example, and is arrow sectional drawing along the II-II line in FIG. 6 is a table showing the difference in configuration of surface emitting units according to a comparative example and Examples 1 to 5. 10 is a graph showing an aperture ratio and an aperture width of an optical adjustment member in Example 5. It is a figure which shows the luminance profile of the surface emitting unit according to a comparative example, and the surface emitting unit according to Example 1,2. It is a figure which shows the luminance profile of the surface emitting unit according to a comparative example, and the surface emitting unit according to Examples 3-5. It is a perspective view which shows the structure of the surface side of the tablet terminal which has a general structure. It is a perspective view which shows the structure of the back surface side of the tablet terminal which has a general structure.

Embodiments according to the present invention will be described below with reference to the drawings. In the following description, the same parts and components are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated. Each embodiment and each example described below may be combined appropriately and appropriately.

<Embodiment 1>
[Surface emitting unit 100]
With reference to FIGS. 1 to 6, surface emitting unit 100 according to the first embodiment will be described. FIG. 1 is a plan view showing the surface light emitting unit 100, and corresponds to the surface light emitting unit 100 viewed from the direction of arrow I in FIG. 2 is a cross-sectional view taken along the line II-II in FIG. As shown in FIGS. 1 and 2, the surface light emitting unit 100 includes a surface light emitting panel 20, a transmissive member 21 (first transmissive member), an optical adjustment member 22, and a transmissive member 24 (second transmissive member). And a diffusing member 26. Hereinafter, these configurations will be described in order.

[Surface emitting panel 20]
FIG. 3 is a cross-sectional view of the surface light emitting panel 20 as viewed from the direction of the arrow. FIG. 4 is a plan view showing the surface light emitting panel 20, and corresponds to the surface light emitting panel 20 viewed from the direction of arrow IV in FIG. As shown in FIGS. 3 and 4, the surface light emitting panel 20 includes an anode 12, a light emitting layer 13, a cathode 14, a sealing member 15, and an insulating layer 16.

The anode 12 is a conductive film having transparency. The anode 12 is formed, for example, by depositing ITO on the transmission member 21 (see FIG. 2). The ITO film for forming the anode 12 is divided into two regions by patterning in order to form the electrode extraction part 17 (for anode) and the electrode extraction part 18 (for cathode). The ITO film of the electrode extraction portion 18 is connected to the cathode 14.

The light emitting layer 13 generates light when supplied with electric power. The light emitting layer 13 is configured by laminating a single layer or a plurality of layers. The cathode 14 is made of aluminum (AL), for example, and is formed so as to cover the light emitting layer 13. The insulating layer 16 is provided between the cathode 14 and the anode 12. A portion of the cathode 14 opposite to the side where the insulating layer 16 is located is connected to the electrode extraction portion 18.

The sealing member 15 is made of glass, thin film glass, resin film, or the like. The sealing member 15 seals the anode 12, the light emitting layer 13, and the cathode 14 on the transmission member 21 (see FIG. 2). The

electrode extraction parts

17 and 18 are exposed from the sealing member 15 for electrical connection. The

electrode extraction portions

17 and 18 are electrically connected to an external power source through a wiring member (not shown).

The surface emitting panel 20 may be a so-called bottom emission type organic EL element or a top emission type organic EL element. Or the surface emitting panel 20 may be comprised from an inorganic EL element, and may be comprised from several light emitting diode (LED). Moreover, the surface emitting panel 20 may be a single-sided light emitting device or a double-sided light emitting device.

(Light emitting area RA and non-light emitting area RB of the surface light emitting panel 20)
With reference to FIGS. 1 to 3 again, the light emitting area RA and the non-light emitting area RB of the surface light emitting panel 20 will be described. In the surface light emitting panel 20, power is supplied to the light emitting layer 13 through a wiring member (not shown),

electrode extraction portions

17 and 18, the anode 12 (transparent electrode), and the cathode 14. Light is generated in the light emitting layer 13, and a part of the light passes through the anode 12 and the transmissive member 21 as it is, and is extracted from the light emitting surface 20 S, and the other part of the light is reflected by the cathode 14 and then the anode 12. Then, the light passes through the transmissive member 21 and is taken out from the light emitting surface 20S.

The light emitting surface 20S of the surface light emitting panel 20 includes a light emitting area RA and a non-light emitting area RB. In the example of FIG. 3, the light emitting region RA is a region on the light emitting layer 13, and the light generated in the light emitting layer 13 is emitted from the light emitting region RA (see the white arrow in FIG. 3). The non-light emitting region RB is located on the outer periphery of the light emitting region RA and emits little or no light. In the example of FIG. 3, the non-light emitting region RB is formed so as to surround the light emitting region RA by providing the sealing member 15 and the

electrode extraction portions

17 and 18 on the surface light emitting panel 20.

As shown in FIG. 1, when viewed from the viewing side of the surface light emitting unit 100, the light emitting region RA and the non-light emitting region RB are partitioned by a boundary line indicated by a one-dot chain line. The boundary line is formed in a rectangular shape having points P1, P2, Q1, and Q2 as four vertices. A rectangular light-emitting region RA is located inside the boundary line, and an annular shape is formed outside the boundary line. The non-light emitting region RB is located. As shown in FIG. 2, when the surface light emitting unit 100 is viewed in cross section, the width LA of the light emitting region RA is, for example, 3.5 mm, and the width LB of the non-light emitting region RB is, for example, 2 mm or more.

[Transparent member 21]
With reference to FIG. 2 again, the transmissive member 21 will be described. The transmission member 21 is composed of a flat plate member having a front surface 21A and a back surface 21B. The transmissive member 21 is provided so that the back surface 21 B faces the light emitting surface 20 S of the surface light emitting panel 20. Preferably, the rear surface 21B of the transmissive member 21 and the front surface 20A of the surface light emitting panel 20 are in contact with each other.

As the transmissive member 21, a material having high transmittance (for example, a total light transmittance in a visible light wavelength region measured by a method based on JIS K 7361-1: 1997 is 80% or more) and excellent in flexibility is used. It is preferable to be used. As an example, the transmissive member 21 is made of a transparent resin film such as PMMA (Polymethyl Methacrylate). The thickness of PMMA is 0.2 mm, for example.

The light emitted from the light emitting area RA enters the inside from the back surface 21B of the transmissive member 21. The incident light passes through the inside of the transmissive member 21 and is emitted as it is from the surface 21A of the transmissive member 21, or the interface between the transmissive member 21 and the optical adjustment member 22, or between the transmissive member 21 and the transmissive member 24. After being reflected at the interface between them and propagating in the in-plane direction inside the transmissive member 21, the light is emitted from the surface 21 A of the transmissive member 21.

[Optical adjustment member 22]
Referring to FIG. 2 again, the optical adjustment member 22 has a front surface 22A and a back surface 22B. The optical adjustment member 22 is provided so as to face the surface 21 A of the transmission member 21. As an example, the optical adjustment member 22 is provided on the surface 21 A of the transmission member 21 by applying white ink by inkjet onto the surface 21 A of the transmission member 21. The width LC of the optical adjustment member 22 in the surface direction (left and right direction in FIG. 2) is, for example, 3 mm. The width LC of the optical adjustment member 22 is shorter than the width LA of the light emitting region RA of the surface light emitting panel 20.

The optical adjustment member 22 has a function of dimming light from the surface 21A of the transmission member 21. More specifically, the optical adjustment member 22 transmits part of the light reaching the back surface 22B of the optical adjustment member 22 from the front surface 21A of the transmission member 21, or the optical adjustment member 22 of the optical adjustment member 22 from the front surface 21A of the transmission member 21. The other part of the light reaching the back surface 22B is reflected, or the other part of the light reaching the back surface 22B of the optical adjustment member 22 from the front surface 21A of the transmission member 21 is absorbed. As an example, the light reflectance of the optical adjustment member 22 is 47.5%. The light transmittance of the optical adjustment member 22 is 47.5%. The optical absorptivity of the optical adjustment member 22 is 5.0%. A part of the light reflected by the optical adjustment member 22 propagates again in the in-plane direction (the left-right direction in FIG. 2) inside the transmission member 21.

The optical adjustment member 22 is preferably composed of a member containing a scattering material. Specific examples of the scattering material here include inorganic fine particles such as titanium oxide, barium sulfate, magnesium sulfate, magnesium carbonate, calcium carbonate, and silica. In addition to these, organic (crosslinked) fine particles such as acrylic resin, organic silicone resin, polystyrene resin, urea resin, formaldehyde condensate, and fluorine resin are also included. In addition to these, polyolefin resins represented by polymethylpentene, polypropylene, polyethylene, alicyclic olefins dispersed in islands, polyester resins represented by polyethylene terephthalate, polyethylene-2, 6-naphthalate, etc. There may also be mentioned thermoplastic resins (including various copolymers) composed of acrylic resins typified by polymethyl methacrylate and the like. Furthermore, hollow particles or bubbles may be mentioned. As the particles, one kind may be used alone, or two or more kinds may be used in combination.

The optical adjustment member 22 may be a sheet-like member or a film-like member as long as it has a function of reducing light from the surface 21A of the transmission member 21. These members may be attached to the surface 21A of the transmissive member 21 using a transparent optical adhesive or the like, or face the surface 21A of the transmissive member 21 with a slight gap. May be provided. When the interval is provided, the back surface 22 B of the optical adjustment member 22 is preferably parallel to the surface 21 A of the transmission member 21.

[Positional relationship between optical adjustment member 22 and light emitting area RA]
With reference to FIG. 5, the positional relationship between the light emitting region RA of the surface light emitting panel 20 and the optical adjustment member 22 will be described. FIG. 5 is a plan view showing the surface light emitting panel 20 and the optical adjustment member 22 and corresponds to the surface light emitting unit 100 viewed from the I direction in FIG. In order to make the explanation easy to understand, the configuration of the surface light emitting unit 100 other than the surface light emitting panel 20 and the optical adjustment member 22 is omitted in FIG.

At least a part of the optical adjustment member 22 is provided to face the light emitting area RA of the surface light emitting panel 20. In other words, the optical adjustment member 22 is provided so as not to overlap at least a part of the light emitting region RA. Preferably, as shown in FIG. 5, the size of the optical adjustment member 22 is smaller than the size of the light emitting region RA, and the optical adjustment member 22 is provided in the plane of the light emitting region RA. In addition, the width in the predetermined direction (for example, width X1, Y1) in the plane of the optical adjustment member 22 is the width in the predetermined direction (for example, width X2, Y2) of the light emitting region RA in at least one direction in the plane. Shorter than. The “width in a predetermined direction within the surface of the optical adjustment member 22” here refers not only to the width X1 and the width Y1 corresponding to the length of the side of the optical adjustment member 22, but also to the oblique angle within the surface of the optical adjustment member 22. Including the width corresponding to the direction.

As described above, the surface light emitting panel 20 and the optical adjustment member 22 are arranged, so that light is reduced in the central portion in the light emitting area RA where the optical adjustment member 22 is covered. On the other hand, light is not dimmed at the outer peripheral portion in the light emitting area RA where the optical adjustment member 22 is not covered. Thereby, the surface emitting unit 100 can make the non-light emitting region RB located around the light emitting region RA appear bright. As a result, the surface light emitting unit 100 can reduce the luminance difference between the light emitting area RA and the non-light emitting area RB, and the non-light emitting area RB looks as if it is shining in the same way as the light emitting area RA. Can do. For this reason, the non-light emitting region RB is less noticeable.

Further, as described above, since the optical adjustment member 22 is provided by applying white ink to the surface 21A of the transmission member 21 by ink jetting, even if the optical adjustment member 22 is provided in the surface light emitting unit 100, surface light emission. The thickness of the unit 100 hardly increases.

(Modification regarding the positional relationship between the optical adjustment member 22 and the light emitting region RA)
The relationship between the surface light emitting panel 20 and the optical adjustment member 22 is not limited to the example shown in FIG. Below, with reference to FIG. 6, the modification of the surface emitting panel 20 and the optical adjustment member 22 is demonstrated. FIG. 6 is a plan view showing the surface light-emitting panel 20 and the optical adjustment member 22 according to the modification, and corresponds to the surface light-emitting panel 20 and the optical adjustment member 22 viewed from the I direction in FIG. In order to make the explanation easy to understand, the configuration of the surface light emitting unit 100 other than the surface light emitting panel 20 and the optical adjustment member 22 is omitted in FIG. 6.

The width of the optical adjustment member 22 in a predetermined direction is shorter than the width of the light emitting region RA in at least one direction, and at least a part of the optical adjustment member 22 is provided to face the light emitting region RA of the surface light emitting panel 20. As long as it is present, the positional relationship and size between the light emitting region RA and the optical adjustment member 22 are not particularly limited. For example, as shown in FIG. 6, if the width Y1 of the optical adjustment member 22 is shorter than the width Y2 of the light emitting region RA, the width X1 of the optical adjustment member 22 may be longer than the width X2 of the light emitting region RA. .

By arranging the optical adjustment member 22 with respect to the light emitting area RA as shown in FIG. 6, the surface light emitting unit 100 can reduce the luminance difference between the light emitting area RA and the non-light emitting area RB in the vertical direction of the paper in FIG. 6. Can be small. As a result, the surface light emitting unit 100 can appear as if the non-light emitting region RB is shining in the same manner as the light emitting region RA in the vertical direction of the drawing in FIG.

[Transparent member 24]
With reference to FIG. 2 again, the transmissive member 24 will be described. The transmission member 24 is composed of a flat plate member having a front surface 24A and a back surface 24B. The transmissive member 24 is provided such that the back surface 24 B faces the front surface 22 A of the optical adjustment member 22.

The transmissive member 24 is made of a material having a high transmittance (for example, a total light transmittance of 80% or more in a visible light wavelength region measured by a method according to JIS K 7361-1: 1997) and excellent flexibility. It is preferable to be used. As an example, the transmissive member 24 is made of a transparent resin film such as PMMA. The thickness of PMMA is 0.22 mm, for example.

The light from the front surface 22A of the optical adjustment member 22 enters the inside from the back surface 24B of the transmission member 24. The incident light passes through the inside of the transmissive member 24 and is emitted as it is from the surface 24 A of the transmissive member 24, or is reflected at the interface between the transmissive member 24 and the diffusing member 26 and is in-plane within the transmissive member 24. After being transmitted in the direction (left and right direction in FIG. 2), the light is emitted from the surface 24A of the transmission member 24.

[Diffusion member 26]
Referring to FIG. 2 again, the diffusion member 26 will be described. The diffusing member 26 is configured by a flat member having a front surface 26A and a back surface 26B. The diffusing member 26 is provided so as to face the surface (surface 22A) opposite to the transmitting member 21 side of the optical adjusting member 22.

In one aspect, as shown in FIG. 2, the diffusing member 26 is provided at a distance from the surface 22 A of the optical adjustment member 22, and the transmissive member 24 is provided between the transmissive member 21 and the diffusing member 26. . In this case, the diffusion member 26 is provided so that the back surface 26 B is in contact with the front surface 24 A of the transmission member 24.

In another aspect, the diffusing member 26 is provided such that its back surface 26B is in contact with the surface 22A of the optical adjusting member 22. That is, in this case, the transmission member 24 is not provided between the optical adjustment member 22 and the diffusion member 26.

The diffusing member 26 has a function of diffusing light emitted from the surface 24A of the transmitting member 24 and reaching the diffusing member 26. The diffusing member 26 is composed of, for example, a sheet-like member or a film-like member. More specifically, as the diffusing member 26, the surface of a resin member such as acrylic or polycarbonate is subjected to minute unevenness processing (that is, one using an interface reflection action), or the base material is represented by titanium oxide. A material in which a scattering material containing white scattering particles is uniformly dispersed (that is, a material using an internal scattering effect) or the like can be used. The diffusion member 26 has a Haze value of 90%, for example.

The diffusion member 26 is provided at a distance H (see FIG. 2) from the surface 20A of the surface light emitting panel 20. As a result, light emitted from a region not covered by the optical adjustment member 22 in the light emitting region RA of the surface light emitting panel 20 (hereinafter also referred to as “non-dimming region”) until reaching the diffusion member 26. To spread. Therefore, the surface emitting unit 100 can appear as if the non-light emitting region RB is shining.

Preferably, the distance H between the surface light emitting panel 20 and the diffusing member 26 is longer than the width W2 of the non-dimming region (see FIG. 2). Accordingly, the surface light emitting unit 100 can reduce the luminance difference between the area that is dimmed by the optical adjustment member 22 and the area that is not dimmed. Can be recognized as one light source.

[Brief Summary]
According to the surface light emitting unit 100 configured as described above, at least a part of the optical adjustment member 22 is provided so as to face the light emitting region RA of the surface light emitting panel 20. Further, the width in the predetermined direction in the plane of the optical adjustment member 22 is shorter than the width in the predetermined direction of the light emitting region RA in at least one direction in the plane. Thereby, light is attenuated in the central portion in the light emitting region RA where the optical adjustment member 22 is covered, and light is not attenuated in the outer peripheral portion in the light emitting region RA where the optical adjustment member 22 is not covered. As a result, the surface light emitting unit 100 can reduce the luminance difference between the light emitting area RA and the non-light emitting area RB, and the non-light emitting area RB looks as if it is shining in the same way as the light emitting area RA. Can do. For this reason, the non-light emitting region RB is less noticeable.

Further, as shown in FIG. 2, each of the surface light emitting panel 20, the transmissive member 21, the optical adjusting member 22, the transmissive member 24, and the diffusing member 26 is provided such that the interfaces thereof are in contact with each other. More specifically, the light emitting surface 20 S of the surface light emitting panel 20 is in contact with the back surface 21 B of the transmissive member 21. The front surface 21 A of the transmissive member 21 is in contact with one surface (back surface 22 B) of the optical adjustment member 22. The other surface (front surface 22A) of the optical adjustment member 22 is in contact with the back surface 24B of the transmission member 24. The front surface 24 A of the transmission member 24 is in contact with one surface (back surface 26 B) of the diffusion member 26.

With such a configuration, the loss of light at each interface is reduced, and the surface emitting unit 100 can increase the proportion of light emitted to the viewing side. Further, the light emitted from the light emitting area RA of the surface light emitting panel 20 is often inclined in the area on the non-light emitting area RB than the area on the light emitting area RA. By providing each component of the surface light emitting unit 100 in contact with each other, the surface light emitting unit 100 suppresses total reflection and Fresnel loss that occur between the interface of each component and air in the region on the non-light emitting region RB. Can do. As a result, the surface light emitting unit 100 can increase the luminance of the region corresponding to the non-light emitting region RB.

<Embodiment 2>
[Reflection member 30]
With reference to FIG. 7 and FIG. 8, surface emitting unit 100A according to the second embodiment will be described. FIG. 7 is a cross-sectional view of the surface emitting unit 100A, and is a cross-sectional view taken along the line II-II in FIG. FIG. 8 is a plan view showing the surface light emitting panel 20 and the reflecting member 30 and corresponds to the surface light emitting panel 20 and the reflecting member 30 as viewed from the VIII direction in FIG. For ease of explanation, the configuration of the surface light emitting unit 100A other than the surface light emitting panel 20 and the reflecting member 30 is omitted in FIG.

The surface light emitting unit 100A further includes a reflecting member 30 in addition to the configuration of the surface light emitting unit 100 according to the first embodiment. The reflection member 30 is provided on the non-light emitting region RB located around the light emitting region RA of the surface light emitting panel 20. The reflection member 30 may be formed on the entire non-light emitting region RB, or may be formed on a part of the non-light emitting region RB. The reflecting member 30 has a light reflecting function or a scattering function. As the reflecting member 30, for example, a specular reflecting member is used. Examples of the material used for the reflecting member 30 include polymer materials such as PET (polyethylene terephthalate), metals such as Al and Ag.

As a method for imparting the scattering function of the reflecting member 30, a method for roughening a part of the back surface 21B of the transmitting member 21, a method for roughening the surface of the reflecting member 30, and a resin binder for scattering. There is a method of providing a scattering layer mixed with particles on a smooth reflective metal film. The reflecting member 30 may be made of an organic solvent-based white ink in which scattering particles are dispersed. In this case, the scattering reflection surface by the reflection member 30 can be formed by, for example, applying white ink to the back surface 21B of the transmission member 21 by inkjet.

[Brief Summary]
The reflection member 30 reflects the light reflected at the interface between the transmission member 21 and the optical adjustment member 22 or the interface between the transmission member 21 and the transmission member 24 toward the viewing side of the surface emitting unit 100A. Thereby, the surface emitting unit 100A can radiate more light from the region on the non-light emitting region RB. As a result, the surface light emitting unit 100A can increase the luminance of the non-light emitting region RB.

<Embodiment 3>
[Light distribution curve]
With reference to FIG. 9, surface emitting unit 100B according to the third embodiment will be described. FIG. 9 is a diagram showing a light distribution curve of the surface light emitting panel 20 used in the surface light emitting unit 100B as a vertical in-plane light distribution. In surface emitting unit 100B according to the third embodiment, more light is emitted in an oblique direction in order to collect more light in non-light emitting region RB of surface emitting panel 20. Since the configuration of surface emitting unit 100B is the same as that of surface emitting unit 100 according to the first embodiment, description thereof will not be repeated.

When the surface light emitting unit 100B draws a light distribution curve in a plane perpendicular to the light emitting surface 20S (see FIG. 3) of the light emitted from the surface light emitting panel 20, the normal direction of the light emitting surface 20S (that is, FIG. 3). The luminance on the front side along the optical axis extending in the direction of the white arrow (that is, the luminance at θ = 0 ° shown in the figure) is 1, and is formed between the optical axis in the plane. When the luminance in the direction where the angle is θ (that is, the luminance in the range of −90 ° <θ <90 ° and θ ≠ 0 °) is L, the light distribution curve satisfies the condition of L> cos θ. At least.

That is, since the light distribution curve 31 shown as “Lambert light distribution” in FIG. 9 depicts L = cos θ, the condition of L> cos θ when the luminance is higher than the light distribution curve 31 at least in part. Is satisfied. For example, the light distribution curve 32 shown as “oblique light distribution” in FIG. 9 satisfies the condition of L> cos θ. The light distribution curve 32 generally satisfies the condition of L> cos θ at −80 ° ≦ θ ≦ −60 ° and 60 ° ≦ θ ≦ 80 °.

[Brief Summary]
As described above, the surface emitting unit 100B distributes light so as to satisfy the condition of L> cos θ. As a result, the surface light emitting unit 100B can guide more light to the region on the non-light emitting region RB, and can reduce the luminance difference between the light emitting region RA and the non-light emitting region RB. Thereby, the surface light emitting unit 100B can make the non-light-emitting area RB appear to shine like the light-emitting area RA, and the non-light-emitting area RB becomes inconspicuous.

<Simulation>
With reference to FIGS. 10 to 13, a simulation performed on the above-described embodiment will be described. The simulation is a comparison between Examples 1 to 5 based on the above-described embodiment and a comparative example not based on the above-described embodiment. The difference between the first to fifth embodiments and the comparative example is mainly that the optical adjusting member 22 is provided in the first to fifth embodiments, and the optical adjusting member 22 is not provided in the comparative example. Hereinafter, the configuration of the comparative example and the configurations of Examples 1 to 5 will be described in order, and then the simulation results of the comparative example and Examples 1 to 5 will be described.

(Configuration of comparative example)
With reference to FIG. 10 and FIG. 11, the structure of the surface emitting unit 200 according to a comparative example is demonstrated. 10 is a cross-sectional view of the surface light emitting unit 200, and is a cross-sectional view taken along the line II-II in FIG. FIG. 11 is a table showing the difference in configuration of the surface emitting units according to the comparative example and Examples 1 to 5.

As shown in FIG. 10, the surface light emitting unit 200 includes a surface light emitting panel 20 having a light emitting area RA and a non-light emitting area RB, a transmissive member 21, and a diffusing member 26. As shown in FIGS. 10 and 11, the surface emitting unit 200 is not provided with the optical adjustment member 22.

The width LA of the light emitting area RA of the surface light emitting panel 20 is 3.5 mm. The non-light emitting area RB of the surface light emitting panel 20 is located around the light emitting area RA, and the width LB of the non-light emitting area RB is 2 mm or more. The transmission member 21 is made of PMMA. The thickness of the transmissive member 21 is 0.42 mm. The diffusing member 26 is composed of a white scattering sheet having a light transmittance of 50%. The Haze value of the diffusing member 26 is 90%. Light distribution from the light emitting area RA is Lambert light distribution. The back surface of the light emitting region RA is a reflective electrode having a reflectance of 70%, and the back surface of the non-light emitting region RB is a metal reflecting surface having a reflectance of 60%.

(Common configuration of Examples 1 to 5)
With reference to FIG. 2 again, a configuration common to the surface emitting units according to the first to fifth embodiments will be described. Similar to the surface light emitting unit 100 according to the first embodiment, the surface light emitting unit includes a surface light emitting panel 20, a transmission member 21, an optical adjustment member 22, a transmission member 24, and a diffusion member 26.

The surface light emitting panel 20 has a light emitting area RA and a non-light emitting area RB. The width LA of the light emitting area RA is 3.5 mm. The non-light emitting region RB is located around the light emitting region RA, and the width LB of the non-light emitting region RB is 2 mm or more. The back surface of the light emitting area RA is composed of a reflective electrode having a reflectance of 70%. The back surface of the non-light emitting region RB is composed of a metal reflecting surface with a reflectance of 60%.

The transmission member 21 is made of PMMA. The thickness of the transmissive member 21 is 0.2 mm. The optical adjustment member 22 is composed of a white scattering sheet having a transmittance of 50%. The haze value of the optical adjustment member 22 is 99%. The transmission member 24 is made of PMMA. The thickness of the transmissive member 21 is 0.22 mm. The interfaces of the transmission member 21, the optical adjustment member 22, and the transmission member 24 are in contact with each other.

(Configuration of Example 1)
With reference to FIG. 11 again, a specific configuration of the surface emitting unit according to the first embodiment will be described. As shown in FIG. 11, in Example 1, the light distribution of the surface light emitting panel 20 is a Lambert light distribution (see FIG. 9). The reflectance of the optical adjustment member 22 is 47.5%. The transmittance of the optical adjustment member 22 is 47.5%. The absorptance of the optical adjustment member 22 is 5.0%. The width of the optical adjustment member 22 (width X1 or width Y1 in FIG. 5) is 3 mm.

(Configuration of Example 2)
With reference to FIG. 11 again, a specific configuration of the surface emitting unit according to the second embodiment will be described. As shown in FIG. 11, in this embodiment, the light distribution of the surface light emitting panel 20 is a Lambert light distribution (see FIG. 9). The reflectance of the optical adjustment member 22 is 47.5%. The transmittance of the optical adjustment member 22 is 47.5%. The absorptance of the optical adjustment member 22 is 5.0%. The width of the optical adjustment member 22 (width X1 or width Y1 in FIG. 5) is 0.5 mm.

(Configuration of Example 3)
Referring to FIG. 11 again, a specific configuration of the surface emitting unit according to the third embodiment will be described. As shown in FIG. 11, in this embodiment, the light distribution of the surface light emitting panel 20 is a Lambert light distribution (see FIG. 9). The reflectance of the optical adjustment member 22 is 30.0%. The transmittance of the optical adjustment member 22 is 65.0%. The absorptance of the optical adjustment member 22 is 5.0%. The width of the optical adjustment member 22 (width X1 or width Y1 in FIG. 5) is 2.75 mm.

(Configuration of Example 4)
With reference to FIG. 11 again, a specific configuration of the surface emitting unit according to the fourth embodiment will be described. As shown in FIG. 11, in this embodiment, the light distribution of the surface light emitting panel 20 is an oblique light distribution (see FIG. 9). The reflectance of the optical adjustment member 22 is 47.5%. The transmittance of the optical adjustment member 22 is 47.5%. The absorptance of the optical adjustment member 22 is 5.0%. The width of the optical adjustment member 22 (width X1 or width Y1 in FIG. 5) is 3 mm.

(Configuration of Example 5)
With reference to FIG. 11 again, a specific configuration of the surface emitting unit according to the fifth embodiment will be described. As shown in FIG. 11, in this embodiment, the light distribution of the surface light emitting panel 20 is a Lambert light distribution (see FIG. 9). The reflectance of the optical adjustment member 22 is 90%. The transmittance of the optical adjustment member 22 is 0%. The absorptance of the optical adjustment member 22 is 10%. The width of the optical adjustment member 22 (width X1 or width Y1 in FIG. 5) is 2.83 mm.

In this embodiment, the optical adjustment member 22 is provided with openings at random, and has a pattern with a predetermined opening ratio and a predetermined opening width in the longitudinal direction of the cross section (that is, the left and right direction in FIG. 2). . FIG. 12 is a graph showing the aperture ratio and the aperture width of the optical adjustment member 22 in Example 5. The horizontal axis shown in the graph of FIG. 12 indicates the position of the optical adjustment member 22 with respect to the longitudinal direction of the cross section of the optical adjustment member 22. The position “0” on the horizontal axis corresponds to the center of the optical adjustment member 22.

FIG. 12 shows two of the aperture ratio of the optical adjustment member 22 and the aperture width of the optical adjustment member 22. The “aperture ratio” here refers to the ratio of the opening width to the predetermined width. The “opening width” refers to the width of each hole provided in the predetermined width.

For example, when the aperture ratio of the width of 2 mm between the position of −1.0 mm and +1.0 mm is 10%, the optical adjustment member 22 has a total of 0.2 mm (= 2.0 mm × 0.1). An opening is provided. In this case, when the opening width is 0.01 mm, the optical adjustment member 22 has 20 pieces (= 0.2 mm / 0) having an opening width of 0.01 mm between the positions −1.0 mm to +1.0 mm. .01 mm) holes are provided.

(simulation result)
With reference to FIG. 13 and FIG. 14, simulation results comparing the normalized luminance of the surface light emitting unit 200 (see FIG. 10) according to the comparative example and the surface light emitting units according to Examples 1 to 5 will be described. FIG. 13 is a diagram illustrating luminance profiles of the surface light emitting unit 200 according to the comparative example and the surface light emitting units according to the first and second embodiments. FIG. 14 is a diagram showing luminance profiles of the surface light emitting unit 200 according to the comparative example and the surface light emitting units according to the examples 3 to 5.

The horizontal axis shown in the graphs of FIG. 13 and FIG. 14 indicates the position of the diffusing member 26 in the left-right direction in FIG. The position “0” on the horizontal axis corresponds to the center position of the diffusion member 26. The vertical axis shown in the graphs of FIGS. 13 and 14 indicates the normalized luminance with the luminance at the brightest position (that is, position 0 mm) as 1000. The normalized luminance is the luminance on the diffusing member 26.

As shown in FIGS. 13 and 14, the brightness of the region corresponding to the non-light emitting region RB (that is, the position of less than −1.75 mm and 1.75 mm or more) is higher in all of Examples 1 to 5 than in the comparative example. Is also high. That is, it can be seen that the relative luminance of the non-light-emitting area RB with respect to the light-emitting area RA is increased, and the non-light-emitting area RB is less conspicuous than the light-emitting area RA.

The surface light emitting unit described above includes a surface light emitting panel having a light emitting surface, a first transmissive member having a front surface and a back surface, and the light emitting surface and the back surface being opposed to each other; An optical adjustment member for reducing light from the surface of the first transmission member, and a surface opposite to the first transmission member side of the optical adjustment member. Provided with a diffusion member. The light emitting surface of the surface light emitting panel includes a light emitting region that emits light and a non-light emitting region that is located on the outer periphery of the light emitting region and does not emit light. At least a portion of the optical adjustment member is provided to face the light emitting region. The width in the predetermined direction within the surface of the optical adjustment member is shorter than the width in the predetermined direction of the light emitting region in at least one direction within the surface.

Preferably, the distance between the surface light-emitting panel and the diffusing member is longer than the width in a predetermined direction of the region not covered by the optical adjustment member in the light emitting region.

Preferably, the surface light emitting unit further includes a second transmission member having a front surface and a back surface and provided between the optical adjustment member and the diffusion member. The light emitting surface of the surface light emitting panel is in contact with the back surface of the first transmission member. The surface of the first transmission member is in contact with one surface of the optical adjustment member. The other surface of the optical adjustment member is in contact with the back surface of the second transmission member. The surface of the second transmission member is in contact with one surface of the diffusion member.

Preferably, a reflective member is provided on the non-light emitting area of the surface light emitting panel.
Preferably, when a light distribution curve in a plane perpendicular to the light emitting surface of light emitted from the surface emitting panel is drawn, the luminance on the front side along the optical axis extending in the normal direction of the light emitting surface is set to 1. When the luminance in the direction in which the angle formed with the optical axis in the plane is θ is L, the light distribution curve has at least a portion satisfying the condition of L> cos θ.

The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

12 anode, 13 light emitting layer, 14 cathode, 15 sealing member, 16 insulating layer, 17, 18 electrode extraction part, 20 surface light emitting panel, 20A, 21A, 22A, 24A, 26A surface, 20S light emitting surface, 21, 24 transmission Member, 21B, 22B, 24B, 26B back surface, 22 optical adjusting member, 26 diffusing member, 30 reflecting member, 31, 32 light distribution curve, 50 tablet terminal, 51 housing, 52, 53 display unit, 100, 100A, 100B, 200 Surface emitting unit, H distance, LA to LC, W, W2, X1, X2, Y1, Y2 width, P1, P2, Q1, Q2 points, RA light emitting area, RB non-light emitting area, T thickness.

Claims

A surface-emitting panel having a light-emitting surface;
A first transmissive member having a front surface and a back surface and provided so that the light emitting surface and the back surface face each other;
An optical adjustment member provided to face the surface of the first transmission member, and for dimming light from the surface of the first transmission member;
A diffusing member provided to face the surface of the optical adjustment member opposite to the first transmission member side;
The light emitting surface of the surface emitting panel includes a light emitting region that emits light, and a non-light emitting region that is located on the outer periphery of the light emitting region and does not emit light,
At least a part of the optical adjustment member is provided to face the light emitting region,
The surface emitting unit, wherein a width of the optical adjustment member in a predetermined direction is shorter than a width of the light emitting region in the predetermined direction in at least one direction of the surface.
2. The surface emitting unit according to claim 1, wherein a distance between the surface emitting panel and the diffusing member is longer than a width in the predetermined direction of a region not covered with the optical adjustment member in the light emitting region.
The surface light emitting unit further includes a second transmission member having a front surface and a back surface and provided between the optical adjustment member and the diffusion member,
The light emitting surface of the surface light emitting panel is in contact with the back surface of the first transmission member,
The surface of the first transmission member is in contact with one surface of the optical adjustment member,
The other surface of the optical adjustment member is in contact with the back surface of the second transmission member,
The surface emitting unit according to claim 1, wherein the surface of the second transmissive member is in contact with one surface of the diffusing member.
The surface emitting unit according to any one of claims 1 to 3, wherein a reflective member is provided on the non-light emitting region of the surface emitting panel.
When a light distribution curve of light emitted from the surface light emitting panel is drawn in a plane perpendicular to the light emitting surface, the luminance on the front side along the optical axis extending in the normal direction of the light emitting surface is set to 1. The light distribution curve has at least a portion satisfying the condition of L> cos θ, where L is the luminance in the direction in which the angle formed with the optical axis in the plane is θ. Item 5. The surface emitting unit according to any one of Items 1 to 4.