Patent Description:
Surface light emitting devices using LEDs (Light Emitting Diodes) are adopted in backlights of liquid crystal display devices or lighting devices (for example, refer to PTL <NUM>).

<CIT> discloses a light reflective structure for a light panel. <CIT> discloses that the light reflective structure is a continuous bowl-shaped reflective layer, and the continuous bowl-shaped reflective layer comprises a plurality of bowl-shaped reflective concaves <NUM>. <CIT> discloses an illumination device for liquid crystal panel. <CIT> discloses that the illuminating device includes straight-tube type discharge lamps <NUM> and a reflecting plate <NUM>. <CIT> discloses that the reflecting plate <NUM> has a flat rectangular plate shape and has a plurality of reflecting surfaces, each having a gutter shape. <CIT> is related to an LCD device using a backlight unit. <CIT> discloses in <FIG> that the backlight unit <NUM> includes a lower reflection plate <NUM>, a plurality of intermediate light guide panels <NUM>, and a diffusion plate <NUM>.

PTL <NUM>: <CIT>. Further of relevance is <CIT>.

For light emitting devices used as surface light sources, enhancement in luminance uniformity is desired.

It is therefore desirable to provide a light emitting device having high luminance uniformity, and a display device and a lighting device including the light emitting device.

A light emitting device according to the invention is defined in appended claim <NUM>.

A display device according to an embodiment of the technology includes, as a light emitting device that sends out illumination light toward a display panel, the light emitting device according to the embodiment of the technology as mentioned above.

A lighting device according to an embodiment of the technology includes the light emitting device according to the embodiment of the technology as mentioned above.

In the light emitting device, the display device, and the lighting device according to the embodiments of the technology, light emitted from the light emitting element directly enters the diffusion reflection sheet, or is reflected from the reflection wall and enters the diffusion reflection sheet. In the diffusion reflection sheet, the entering light is efficiently diffused by and reflected from the plurality of the particles. Light traveling from the diffusion reflection sheet toward the reflection wall is reflected from the reflection wall and enters the diffusion reflection sheet again.

According to the light emitting device, the display device, and the lighting device of the embodiments of the technology, the diffusion reflection sheet includes the plurality of the particles. This leads to efficient luminance uniformization within a region surrounded by the reflection wall. Hence, it is possible to enhance luminance uniformity. It is to be noted that the effects described here are not necessarily limited, and any effect described in the disclosure may be provided.

In the following, some examples useful for understanding the claimed invention together with an embodiment of the claimed invention and pertaining to <FIG> are described in detail with reference to the drawings.

<FIG> illustrates a cross-sectional configuration of a mid-portion of a display device (display device <NUM>) according to an example of the technology. <FIG> illustrates a cross-sectional configuration of an end portion of the display device <NUM>. The display device <NUM> includes a light emitting device <NUM> and a display panel <NUM>. A back side of the display panel is illuminated with illumination light of the light emitting device <NUM>. A rear casing <NUM> is provided on back side of the light emitting device <NUM>, with an adhesion sheet <NUM> in between. A bezel <NUM> and a holder member <NUM> are provided on a periphery of the display device <NUM>.

The light emitting device <NUM> includes, for example, a light source substrate <NUM>, a light emitting element <NUM>, a covering material <NUM>, a reflection wall <NUM>, a diffusion reflection sheet <NUM>, a first optical sheet <NUM>, a wavelength conversion sheet <NUM>, and a second optical sheet <NUM>. In the light emitting device <NUM>, the diffusion reflection sheet <NUM>, the first optical sheet <NUM>, the wavelength conversion sheet <NUM>, and the second optical sheet <NUM> are provided to face the light source substrate <NUM>. The reflection wall <NUM> is provided between the light source substrate <NUM> and the diffusion reflection sheet <NUM>, to surround the light emitting element <NUM>.

An undepicted wiring pattern is provided on the light source substrate <NUM>, to permit a light emission control for each region surrounded by the reflection wall <NUM> (segment Sg in <FIG> described later). This makes it possible to make a local light emission control (local dimming) of a plurality of the light emitting elements <NUM>. For the light source substrate <NUM>, used may be, for example, a resin-made film on which a wiring pattern is printed. Examples of the resin-made film include PET (polyethylene terephthalate), PEN (polyethylene naphthalate), and fluorine-based resin material. At an end portion of the light source substrate <NUM>, provided is, for example, a driver IC (driver IC <NUM> in <FIG> described later) that drives the light emitting element <NUM>. The driver IC may be provided on a wiring substrate separate from the light source substrate <NUM>.

The plurality of the light emitting elements <NUM> are provided on a front surface of the light source substrate <NUM>. The light emitting elements <NUM> are each an LED having, for example, a flip chip structure of a face down type, and emit light of a blue wavelength range.

<FIG> illustrates a cross-sectional configuration of the light emitting element <NUM>. The light emitting element <NUM> includes, for example, a translucent substrate <NUM> that faces the light source substrate <NUM>. A semiconductor stacked body is provided on one surface (confronted surface with the light source substrate <NUM>) of the translucent substrate <NUM>. The semiconductor stacked body includes, for example, an n type semiconductor layer <NUM>, an active layer <NUM>, and a p type semiconductor layer <NUM> in this order from side on which the translucent substrate <NUM> is disposed. A p side electrode <NUM> is provided on a surface of the p type semiconductor layer <NUM>. A shoulder is provided in a portion of the semiconductor stacked body. A portion of the n type semiconductor layer <NUM> is exposed in the shoulder. An n side electrode <NUM> is provided on an exposed surface of the n type semiconductor layer <NUM>. A reflection layer <NUM> is provided on another surface (opposite surface to the confronted surface with the light source substrate <NUM>) of the translucent substrate <NUM>. The translucent substrate <NUM> includes, for example, a sapphire substrate or silicon carbide (SiC). The n type semiconductor layer <NUM> includes, for example, an n type nitride semiconductor (e.g., n type GaN). The active layer <NUM> includes, for example, a nitride semiconductor (e.g., n type GaN) having a quantum well structure. The p type semiconductor layer <NUM> includes, for example, a p type nitride semiconductor (e.g., p type GaN). The p side electrode <NUM> and the n type electrode <NUM> include, for example, a metal material such as Al. The reflection layer <NUM> includes, for example, a silver deposition film, an aluminum deposition film, or a multi-layer reflection film. In the light emitting element <NUM>, light generated in the active layer <NUM> is reflected from the reflection layer <NUM>, the p side electrode <NUM>, and the n side electrode <NUM>, and is emitted to outside through a side surface 12A. A portion of the light generated in the active layer <NUM> may leak out to the outside through the reflection layer <NUM>.

<FIG> illustrates a light distribution characteristic of the light emitting element <NUM>. The light emitting element <NUM> is a light emitting element of a so-called side emission type, in which relatively intense light is emitted in a substantially parallel direction to a surface of the light source substrate <NUM>. The light emitting element <NUM> is, for example, an LED of a bare chip type, and is devoid of a package (package 12P in <FIG> described later) and a lens (lens <NUM> in <FIG>). Such a light emitting element <NUM> is inexpensive, and makes it possible to reduce costs incurred for the display device <NUM>. Moreover, if the light emitting element <NUM> is inexpensive, it is possible to use a large number of the light emitting elements <NUM>, and to reduce electric power to be supplied to each of the light emitting elements <NUM>. Hence, it is possible to suppress heat generation of the light emitting elements <NUM>, leading to prevention of an increase in a temperature of the light emitting device <NUM>. The light emitting element <NUM> encased inside a package may be also used.

The covering material <NUM> that covers the light emitting element <NUM> includes, for example, a resin material such as a silicone resin. The covering material <NUM> has a substantially hemispherical shape. The light emitting element <NUM> is provided inside the covering material <NUM>. The covering material <NUM> has a refractive index between a refractive index of the light emitting element <NUM> (translucent substrate <NUM>) and a refractive index of air, and has a function of enhancing efficiency of extraction of light emitted from the light emitting element <NUM>. Moreover, by the covering material <NUM>, it is possible to control a direction of light distribution of the light emitting element <NUM>.

The reflection wall <NUM> is provided for reflection of the light emitted from the light emitting element <NUM> of the side emission type, toward side on which the diffusion reflection sheet <NUM> is disposed. Although details are described later, providing the reflection wall <NUM> as mentioned above makes it possible to enhance luminance of light that enters the display panel <NUM> from the light emitting device <NUM> (enhancement in an direct upward contribution ratio). The reflection wall <NUM> includes a horizontal part <NUM> in a parallel direction, and an inclined part <NUM> in a crossing direction, with respect to, for example, the light source substrate <NUM>. The horizontal part <NUM> and the inclined part <NUM> are each provided around, for example, the single light emitting element <NUM>. The reflection wall <NUM> surrounds the light emitting element <NUM> in plan (XY plane) view. The horizontal part <NUM> is in contact with the light source substrate <NUM>. An angle of inclination of the inclined part <NUM> may be adjusted as appropriate. An upper end of the inclined part <NUM> is in contact with the diffusion reflection sheet <NUM>.

<FIG> is a perspective view of a configuration of the reflection wall <NUM> together with the rear casing <NUM> and the holder member <NUM>. <FIG> is a plan view of a configuration of the reflection wall <NUM> together with the light source substrate <NUM> and the light emitting element <NUM>. The light emitting device <NUM> includes a plurality of the segments Sg partitioned by the reflection wall <NUM>. The reflection wall <NUM> surrounds the light emission element <NUM> in, for example, a rectangular shape in plan view (a planar shape of the segment Sg is the rectangular shape). In the single segment Sg, for example, the single light emitting element <NUM> is provided. Light emission states of the light emitting elements <NUM> are controlled from the segment Sg to the segment Sg by the driver IC <NUM>, making it possible to adjust the light emission state of each of the light emitting elements <NUM> in accordance with pictures to be displayed on the display panel <NUM>. Hence, it is possible to reduce power consumption.

The reflection wall <NUM> is formed by, for example, vacuum forming or vacuum pressure forming of a resin-made shaped reflection sheet. The shaped reflection sheet is a resin sheet to a surface of which an optical element of a predetermined shape is applied. The optical element of the predetermined shape is, for example, a minute protrusion pattern. A cross-sectional shape of the protrusion pattern is, for example, a circular arc shape, an elliptical arc shape, a triangular shape, or a rectangular shape.

The diffusion reflection sheet <NUM> faces the light source substrate <NUM>, with the reflection wall <NUM> in between. The diffusion reflection sheet <NUM> permits entrance of, for example, the light emitted from the light emitting element <NUM> and the reflected light from the reflection wall <NUM>. In this embodiment, the diffusion reflection sheet <NUM> includes a plurality of particles. This causes efficient diffusion and reflection of entering light, leading to uniformization of luminance from the segment Sg to the segment Sg, although details are described later.

It is preferable that at least some of the plurality of the particles included in the diffusion reflection sheet <NUM> have a hollow structure, in view of diffusion efficiency. The plurality of the particles included in the diffusion reflection sheet <NUM> are, for example, hollow silica, titanium dioxide, and have a particle diameter of the order of, for example, nanometers.

The diffusion reflection sheet <NUM> is formed by printing on, for example, a resin sheet with an ink including the plurality of the particles in a predetermined distribution pattern from the segment Sg to the segment Sg. The ink including the plurality of the particles is printed on the resin sheet by, for example, an inkjet method.

<FIG> illustrates one example of the distribution pattern of the plurality of the particles to be printed on the diffusion reflection sheet <NUM>. The distribution pattern illustrates a distribution pattern to be printed in the single segment Sg. For example, the plurality of the particles are densified in a region directly over the light emitting element <NUM>, and are less densified in its surroundings. Luminance of the light emitted from the light emitting element <NUM> is highest directly over the light emitting element <NUM>. Accordingly, providing more particles in the region (directly over the light emitting element <NUM>) that is most intensely illuminated with the light makes it possible to cause more effective diffusion and reflection of the light.

The first optical sheet <NUM> is provided between the diffusion reflection sheet <NUM> and the wavelength conversion sheet <NUM> in parallel to them. The first optical sheet <NUM> is, for example, a POP (Prism On Prism) or PPD (Prism On Prism Diffuser). Providing the first optical sheet as mentioned above makes it possible to enhance directivity of light, leading to enhancement in front luminance. The first optical sheet <NUM> may be provided unitarily with the diffusion reflection sheet <NUM>.

The wavelength conversion sheet <NUM> is provided between the first optical sheet <NUM> and the second optical sheet <NUM> in parallel to them. The wavelength conversion sheet <NUM> includes, for example, a wavelength conversion substance such as a fluorescent substance or quantum dots. The wavelength conversion substance is excited by the light emitted from the light emitting element <NUM>, and outputs light of a different wavelength range from that of the light emitted from the light emitting element <NUM>. For example, the wavelength conversion sheet <NUM> is excited by the light of the blue wavelength range emitted from the light emitting element <NUM>, and outputs light of a red wavelength range and a green wavelength range. The wavelength conversion sheet <NUM> may be excited by the light of the blue wavelength range emitted from the light emitting element <NUM>, and output light of a yellow wavelength range. The light emitted from the light emitting element <NUM> as mentioned and the light subjected to the wavelength conversion are mixed, causing, for example, white light to enter the second optical sheet <NUM>.

The second optical sheet <NUM> is provided between the wavelength conversion sheet <NUM> and the display panel <NUM> in parallel to them. The second optical sheet <NUM> is, for example, a reflection type polarization film (DBEF: Dual Brightness Enhancement Film). For example, the second optical sheet <NUM> as mentioned separates light that has passed through the wavelength conversion sheet <NUM>, into a p wave and an s wave, and transmits the p wave while reflecting the s wave. The s wave reflected from the second optical sheet <NUM> is reflected from, for example, the light source substrate <NUM>, the reflection wall <NUM>, and the diffusion reflection sheet <NUM>, and the reflected wave is recirculated.

The display panel <NUM> is, for example, a transmissive liquid crystal display panel that displays a moving image or a still image. The display panel <NUM> is provided to face the second optical sheet <NUM>, and includes, for example, a TFT substrate <NUM>, a liquid crystal layer <NUM>, and a color filter substrate <NUM> in this order from a position close to the second optical sheet <NUM>. The display panel <NUM> may further include, for example, a polarization plate. For example, the light emitted from the light emitting device <NUM> enters the TFT substrate <NUM>, travels through the liquid crystal layer <NUM>, and is outputted on side on which the color filter substrate <NUM> is disposed.

The rear casing <NUM> is bonded to a rear surface of the light source substrate <NUM> (opposite surface to the surface on which the light emitting element <NUM> is provided), with the adhesion sheet <NUM> in between. The rear casing <NUM> includes a plate member, and maintains flatness of the light source substrate <NUM>. The rear casing <NUM> includes, for example, a metal such as Fe (iron) and Al (aluminum), glass, or a stacked body. The adhesion sheet <NUM> includes, for example, a double sided tape.

The bezel <NUM> is a frame member that covers a peripheral part of the display panel <NUM> and a peripheral part of the light emitting device <NUM>. The bezel <NUM> protects each of the peripheral part of the display panel <NUM> and the peripheral part of the light emitting device <NUM>, while enhancing aesthetic quality. The bezel <NUM> includes, for example, a metal such as Al (aluminum).

The holder member <NUM> is provided between the bezel <NUM> and an end surface of the reflection wall <NUM>. The holder member <NUM> is, for example, an attachment metal plate, and holds, for example, the bezel <NUM> and the sheets (the diffusion reflection sheet <NUM> to the second optical sheet <NUM>). The holder member <NUM> is provided on a periphery of the rear casing <NUM>, and is fixed to the rear casing <NUM> with, for example, screws. A portion of the holder member <NUM> faces the end surface of the reflection wall <NUM>. The holder member <NUM> includes, for example, a metal material such as Al (aluminum) and stainless steel.

In the display device <NUM>, upon the emission of, for example, the light of the blue wavelength range from the light emitting element <NUM> of the side emission type, the light is reflected from the reflection wall <NUM>. The reflected light enters the diffusion reflection sheet <NUM>. A portion of the light emitted from the light emitting element <NUM> directly enters the diffusion reflection sheet <NUM>. The diffusion reflection sheet <NUM> transmits a portion of the entering light. The transmitted light travels through the first optical sheet <NUM>, and enters the wavelength conversion sheet <NUM>. In the wavelength conversion sheet <NUM>, a portion of the entering light (light of the blue wavelength range) is wavelength-converted to, for example, the light of the red wavelength range and the light of the green wavelength range. The wavelength-converted light and light that has not been wavelength-converted by the wavelength conversion sheet <NUM> is synthesized to produce, for example, the white light. The white light travels through the second optical sheet <NUM> to enter the display panel <NUM>, causing picture display. Meanwhile, the light reflected from the diffusion reflection sheet <NUM> is reflected from the reflection wall <NUM>, to produce recirculated light that generates the white light as mentioned above.

Here, the diffusion reflection sheet <NUM> includes the plurality of the particles. Accordingly, the light entering the diffusion reflection sheet <NUM> is efficiently diffused by and reflected from the plurality of the particles. This causes luminance uniformization within the region surrounded by the reflection wall <NUM> (segment Sg). In the following, description about this is given with the use of a comparative example.

<FIG> illustrates a cross-sectional configuration of a display device according to a comparative example. In this display device, light emitted from a light emitting device (light emitting device <NUM>) enters the display panel <NUM>. In the light emitting device <NUM>, light emitted from the light emitting element <NUM> enters a diffusion plate <NUM>. The diffusion plate <NUM> transmits a portion of the entering light. The transmitted light enters the display panel <NUM> through an optical sheet <NUM>. Support pins <NUM> are provided between the light source substrate <NUM> and the diffusion plate <NUM>, for support of, for example, the diffusion plate <NUM>. The light emitting element <NUM> is provided inside a package 12P, and the package 12P is covered with a lens <NUM>.

In the light emitting device <NUM> as mentioned above, no reflection wall (reflection wall <NUM> in <FIG>) is provided. Accordingly, the light emitted from the light emitting element <NUM> directly enters the diffusion plate <NUM>. Within the light emitted from the light emitting element <NUM>, light that has failed to enter the diffusion plate <NUM> is not to be recirculated, causing difficulties in enhancing luminance of the light that enters the display panel <NUM> from the light emitting device <NUM>. Moreover, it is difficult for the diffusion plate <NUM> to sufficiently diffuse the entering light. Thus, luminance becomes higher in a region directly over the light emitting element <NUM>, resulting in likelihood of luminance unevenness. To suppress the occurrence of the luminance unevenness involves increasing a distance from the light emitting element <NUM> to the diffusion plate <NUM>. Magnitude of the distance from the light emitting element <NUM> to the diffusion plate <NUM> has an influence on a thickness of the display device.

In contrast, in this example, the reflection wall <NUM> is provided around the light emitting element <NUM> of the side emission type. This causes a portion of the light emitted from the light emitting element <NUM> to be reflected from the reflection wall <NUM>, and the reflected light enters the diffusion reflection sheet <NUM>. It is therefore possible to use the reflected light from the reflection wall <NUM>, in addition to the light that is emitted from the light emitting element <NUM> and directly enters the diffusion reflection sheet <NUM>. In other words, it is possible to enhance luminance of the light emitting device <NUM>. Moreover, in this embodiment, used is the diffusion reflection sheet <NUM> that includes the plurality of the particles. Thus, in the diffusion reflection sheet <NUM>, light diffusion and reflection is performed at high efficiency. This leads to efficient luminance uniformization within the segment Sg. Even in a case with reduction in a distance from the light emitting element <NUM> to the diffusion reflection sheet <NUM>, the luminance is sufficiently uniformized within the segment Sg.

Furthermore, the plurality of the particles included in the diffusion reflection sheet <NUM> have the hollow structure. This makes it possible to perform the diffusion and the reflection at higher efficiency. In addition, the plurality of the particles are densified in the region directly over the light emitting element <NUM>. Hence, it is possible to uniformize the luminance, while reducing the distance from the diffusion reflection sheet <NUM> and the light emitting element <NUM>.

Moreover, providing the diffusion reflection sheet <NUM>, instead of the diffusion plate <NUM>, leads to weight reduction. This makes unnecessary, for example, the support pins <NUM> and a middle chassis, while making it possible for the reflection wall <NUM> to support, for example, the diffusion reflection sheet <NUM>.

Moreover, the light emitting device <NUM> uses the light emitting element <NUM>, without providing the package (package 12P in <FIG>) and the lens (lens <NUM> in <FIG>). Hence, it is possible to manufacture at low costs. Furthermore, providing a number of the inexpensive light emitting elements <NUM> also makes it possible to prevent the increase in the temperature of the light emitting device <NUM>. In addition, absence of lenses makes it possible to reduce the distance from the light emitting element <NUM> to the diffusion reflection sheet <NUM>. Moreover, using the light emitting element <NUM> of the flip chip structure also makes it possible to reduce the distance from the light emitting element <NUM> to the diffusion reflection sheet <NUM>, as compared to a case with the use of a wire-bonded light emitting element.

As described, in this embodiment, the reflection wall <NUM> is provided around the light emitting element <NUM> of the side emission type. Hence, it is possible to enhance the luminance of the light emitting device <NUM>. Moreover, the diffusion reflection sheet <NUM> includes the plurality of the particles. Hence, it is possible to enhance the luminance uniformity within the segment Sg, without increasing the distance from the light emitting element <NUM> to the diffusion reflection sheet <NUM>. In other words, it is possible to provide compatibility between low profile and in-plane luminance uniformity of the light emitting device <NUM>.

Furthermore, the resin sheet such as the shaped reflection sheet that constitutes the reflection wall <NUM> efficiently reflects light of a low wavelength range, as compared to light of a high wavelength range. It is therefore preferable to use the light emitting element <NUM> that emits light of the blue wavelength range.

In addition, it is preferable to provide the wavelength conversion sheet <NUM> between the diffusion reflection sheet <NUM> and the display panel <NUM>. The wavelength conversion substance included in the wavelength conversion sheet <NUM> as mentioned above is disposed further away from the light emitting element <NUM> than a wavelength conversion substance mixed in, for example, the package (package 12P in <FIG>). This reduces influences of, for example, heat generated in the light emitting element <NUM>, leading to enhancement in wavelength conversion efficiency. Moreover, synthesizing the white light at a closer position to the display panel <NUM> reduces likelihood of color unevenness. Furthermore, an allowance range of performance of the light emitting element <NUM> is widened, making it possible to reduce costs.

Described below are modification examples of the forgoing example. In the following description, the same constituent parts to those of the forgoing example. are denoted by the same reference characters, and description thereof is omitted as appropriate.

<FIG> illustrates a plan configuration of a main part of a light emitting device (light emitting device 10A) according to a modification example <NUM> of the forgoing example. The light emitting device 10A includes a plurality of the light emitting elements <NUM> within the single segment Sg. In <FIG>, illustrated is a case where the two light emitting elements <NUM> are provided within the single segment Sg. However, the three or more light emitting elements <NUM> may be provided within the single segment Sg. Otherwise, the light emitting device 10A has similar configurations to those of the light emitting device <NUM> of the forgoing example, and has similar workings and effects as well.

<FIG> illustrates a plan configuration of a main part of a light emitting device (light emitting device 10B) according to a modification example <NUM> of the forgoing example. In the light emitting device 10B, the reflection wall <NUM> surrounds the light emitting element <NUM> in a circular shape in plan view. In other words, the light emitting device 10B includes the segment Sg having a planar shape of a circle. Otherwise, the light emitting device 10B has similar configurations to those of the light emitting device <NUM> of the forgoing embodiment, and has similar workings and effects as well.

The planar shape of the segment Sg may be any shape insofar as produces the effects of the technology. For example, a honeycomb structure illustrated in <FIG> may be also possible.

<FIG> illustrates a cross-sectional configuration of a main part of a light emitting device (light emitting device 10C) according to an embodiment. In the light emitting device 10C, a height of the reflection wall <NUM> varies within the single segment Sg. Specifically, the light emitting device 10C includes, within the single segment Sg, a low part <NUM> having a smaller height of a wall surface of the reflection wall <NUM>, and a high part <NUM> having a larger height. Otherwise, the light emitting device 10B has similar configurations to those of the light emitting device <NUM> of the forgoing example, and has similar workings and effects as well.

For example, the low part <NUM>, the high part <NUM>, and the low part <NUM> are provided in order from a close position to the light emitting element <NUM>. In <FIG>, illustrated is a case where the reflection wall <NUM> has the two different heights (in the low parts <NUM> and the high part <NUM>) within the single segment Sg. However, the reflection wall <NUM> may have three or more different heights within the single segment Sg.

Described below is an application example of the display device <NUM> as mentioned above to an electronic apparatus. Examples of the electronic apparatus include a television set, a medical monitor, a digital signage, a master monitor, a digital camera, a notebook personal computer, a mobile terminal device such as a mobile phone, and a video camera. In other words, the display device <NUM> as mentioned above is applicable to electronic apparatuses of all fields that display picture signals inputted from outside or picture signals generated inside as images or pictures.

<FIG> illustrate an external appearance of a tablet type terminal device to which the display device <NUM> of the forgoing embodiment is applied. The tablet type terminal device includes, for example, a display unit <NUM> and a non-display unit <NUM>. The display unit <NUM> includes the display device <NUM> of the forgoing embodiment.

<FIG> illustrates an external appearance of a lighting device to which the light emitting device <NUM> (or light emitting device 10A, 10B, or 10C, which is referred to as light emitting device <NUM> etc in the followings). The lighting device is a desk top lighting device including the light emitting device <NUM> etc of the forgoing embodiment. For example, a lighting unit <NUM> is attached to a post <NUM> provided on a base <NUM>. The lighting unit <NUM> includes the light emitting device <NUM> etc according to the forgoing embodiment. The lighting unit <NUM> may have any shape, e.g., a shape of a tube illustrated in <FIG> and a shape of a curved surface illustrated in <FIG>.

The light emitting device <NUM> et cetera may be applied to an interior lighting device as illustrated in <FIG>. In the lighting device, a lighting unit <NUM> includes the light emitting device <NUM> etc as mentioned above. The lighting units <NUM> in an appropriate number are arranged on a ceiling 850A of a building at appropriate intervals. It is to be noted that the lighting units <NUM> may be disposed at any locations according to their use, not only on the ceiling 850A but also a wall 850B or a floor (undepicted).

In the lighting devices, illumination is provided by light from the light emitting device <NUM> etc. Here, as described in the forgoing embodiment, the light emitting device <NUM> etc having the high in-plane luminance uniformity is provided. Hence, it is possible to produce light of uniform luminance.

Although description has been made by giving the embodiment and the modification examples as mentioned above, the contents of the technology are not limited to the above-mentioned embodiment and may be modified in a variety of ways. For example, arrangement positions, shapes, or other features of the holder member, the bezel, and the rear casing described in the forgoing example embodiments are mere examples and non- limiting, as long as they fall within the claimed device.

Moreover, sizes, size ratios, shapes, and other features of the constituent elements illustrated in the figures are mere examples, and the contents of the technology are not limited thereto.

Furthermore, in the forgoing example embodiments, described is the case where the light emitting elements <NUM> are LEDs. However, the light emitting elements <NUM> may include, for example, semiconductor lasers.

In addition, in the forgoing embodiment, description is made by giving specific examples of the configurations of, for example, the light emitting devices <NUM>, 10A, 10B, and 10C, and the display device <NUM>. However, they do not have to include all the constituent elements. Moreover, they may further include other constituent elements.

Moreover, materials and other properties of each of the constituent elements described in the forgoing embodiment are non-limiting, and other materials may be adopted.

It is to be noted that the effects described in this specification are mere examples and non-limiting, and there may be other effects.

This application claims the benefit of Japanese Priority Patent Application <CIT>.

Claim 1:
A light emitting device (10C), comprising:
a light emitting element (<NUM>) disposed on a light source substrate (<NUM>),
a reflection wall (<NUM>) disposed on the surface of the light source substrate (<NUM>) and surrounding a the light emitting element; and
a diffusion reflection sheet (<NUM>) that includes a plurality of particles and permits entrance of emitted light from the light emitting element and entrance of reflected light from the reflection wall, wherein the reflection wall (<NUM>) includes a lower wall section (<NUM>) and a higher wall section (<NUM>) having different heights, and
wherein the lower wall section (<NUM>) is located closer to the light emitting element (<NUM>), wherein the higher wall section (<NUM>) is extended in a direction perpendicular to the light source substrate (<NUM>),
wherein the light emitting device (<NUM>) includes a plurality of segments (Sg) partitioned by the reflection wall (<NUM>),
wherein each segment includes at least one light emitting element (<NUM>), and the light emitting device (<NUM>) further comprises a driver IC (<NUM>) configured to drive the light emitting elements (<NUM>), wherein light emission states of the light emitting elements (<NUM>) are controlled from a segment to a segment by the driver IC (<NUM>) to adjust the light emission state of each segment in accordance with pictures to be displayed on a display panel (<NUM>),
characterised in that
the light emitting element (<NUM>) is a side-emitting type and has a flip chip structure, in that a gap exists between a base of the lower wall section (<NUM>) and the light emitting element (<NUM>), and in that the base of the lower wall section (<NUM>) is inclined from the surface of the light source substrate (<NUM>) and configured to reflect light from the light emitting element (<NUM>) to the diffusion reflection sheet (<NUM>).