JP2010040236A - Lighting system, electro-optical device, and electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To uniform luminance and to reduce a feature in thickness without degrading luminance in a direct lighting system. <P>SOLUTION: The lighting system of the so-called direct type comprises light sources and a diffusion plate arranged on the light-emitting side of the light sources. Diffusion auxiliary members are arranged on top of the diffusion plate, in regions facing the light sources, and the degree of diffusion is higher in these regions than other regions. In the diffusion plate, the diffusion factor of light is larger in regions corresponding to the diffusion auxiliary members and highest in intensity of light emitted from the light sources, and the diffusion factor of light is smaller in the other regions low in intensity of light emitted from the light sources. The luminance is therefore uniformed without degrading the luminance. The feature of the lighting system can be thinned by forming a diffusion member by a screen printing method or the like. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a direct illumination device suitable for use in an electro-optical device.

  Currently, a liquid crystal device as an example of an electro-optical device is widely used to display an image in electronic devices such as a mobile phone, a portable information terminal, and a computer display.

  In such a liquid crystal device, in order to perform transmissive display by illuminating the liquid crystal display panel from the back side, a backlight device (illumination device) is provided on the back side of the liquid crystal display panel. Such illuminating devices are roughly classified into two types, an edge light type and a direct type, depending on the position of the light source with respect to the liquid crystal display panel or the like.

  The edge light system is a system in which a light guide plate that guides light is arranged on the back side of the liquid crystal display panel, and a light source is arranged on the side surface of the light guide plate, so that low power consumption and thinning can be achieved. The liquid crystal device is suitably used. On the other hand, the direct type is a method in which a light source is disposed on the back side of a liquid crystal display panel, and high luminance can be obtained. Therefore, the direct type is suitably used for medium to large liquid crystal devices.

  By the way, in the direct type, a fluorescent lamp such as a cold cathode fluorescent lamp (CCFL) that emits white light from a fluorescent tube is generally used as a light source, but CCFL encloses mercury in the fluorescent tube. As a suitable light source that can replace the CCFL, light emitting diodes (LEDs) having high luminance characteristics, low power consumption characteristics, long life characteristics, and the like have come to be used. Yes. However, in the direct type system using such a light emitting diode, there is a problem that it is difficult to achieve luminance uniformity because light emitted from the light emitting diode has directivity.

  In order to deal with such a problem, for example, Patent Documents 1 and 2 describe a direct type backlight device capable of achieving uniform luminance.

  The backlight assembly described in Patent Literature 1 includes a light emitting diode and an optical device disposed at a position facing the light emitting diode, and forms a donut-shaped group with respect to a light incident surface of the optical device. .

  The backlight described in Patent Document 2 includes a light emitting diode, a housing that supports the light emitting diode, a first diffusion plate that is disposed in the vicinity of the opening of the housing, a light emitting diode, and a first diffusion plate. And a reflector disposed on the bottom and side surfaces of the housing, and in the second diffuser plate, a position corresponding to the light emitting diode is provided from the light emitting diode. A reflecting member that reflects light is provided.

JP 2006-12763 A JP 2004-342587 A

  In the backlight assembly described in Patent Document 1 described above, the donut-shaped group restricts the incident light from the light-emitting diode from being incident on the light incident surface of the optical equipment, and is emitted to the outgoing surface of the optical equipment. The brightness uniformity of the emitted light is improved.

  However, in this backlight assembly, a group of donut shapes having a complicated shape must be produced by, for example, an injection molding method, and there is a problem that the cost of the backlight assembly increases accordingly. .

  Further, according to the backlight described in Patent Document 2 described above, the light emitted from the light emitting diode is directly diffused by the reflecting member provided at the position corresponding to the light emitting diode in the second diffusion plate. The light is reflected by the reflecting member without being incident on the plate, the reflected light is repeatedly reflected between the reflecting plate and the like, and is incident on the second diffusion plate. For this reason, light does not concentrate in the vicinity of the position corresponding to the light-emitting diode in the second diffusion plate, it becomes possible to disperse the light, luminance unevenness and color unevenness are suppressed, and uniform luminance can be obtained.

  However, in this backlight, since the reflecting member is provided at a position corresponding to the light emitting diode, the light path from the light emitting diode to the first diffusion plate becomes longer, and the backlight can be made thinner. There is a problem that can not be.

  In this backlight, as described above, the light emitted from the light emitting diode having a large frontal luminous intensity is reflected once by the reflecting member, and further reflected to reflect the light between the reflecting plate and the like. Thus, the light is incident on the second diffusion plate. By the way, considering the characteristics of a light emitting diode having a large luminous intensity in the front direction, a backlight having such a configuration has a problem that light loss is large and light use efficiency is reduced.

  In addition to these problems, in recent years, with the increase in color rendering and definition of liquid crystal display panels, it is required to improve the luminance of the backlight in order to achieve this. Further, there is a demand for thinning the liquid crystal television, and accordingly, the backlight device is demanded to be thin.

  The present invention has been made in view of the above points, and a direct-type illumination device capable of achieving uniform luminance and thinning a shape without lowering luminance, and electro-optical using the same It is an object to provide an apparatus and an electronic device.

  In one aspect of the present invention, an illumination device includes a light source and a diffusion member disposed to face the light output side of the light source, and in the diffusion member, a diffusion assisting member is provided in a region facing the light source. They are arranged so as to overlap each other, and the diffusivity in the region is higher than those in other regions.

  Said illuminating device is provided with a light source and the diffusion member arrange | positioned at the light emission side (light-emission side) of the said light source. Here, as a light source, a light emitting diode is mentioned, for example. Examples of the diffusing member include a member that diffuses light, such as a white member or a member having irregularities on the surface. Further, the diffusion assisting member is a member that diffuses and transmits a part of the light emitted from the light source to the side opposite to the light source side and reflects the remaining light to the light source side. It is preferable.

  In particular, in this illuminating device, in the diffusion member, the diffusion assisting member is disposed so as to overlap the region facing the light source, and the diffusion degree (diffusion rate) in the region is higher than that in the other regions.

  According to this configuration, in the diffusion member, the intensity (luminous intensity) of the light emitted from the light source is maximized, and the diffusion degree of the light is increased in the region where the diffusion assisting members are arranged so as to be emitted from the light source. In the other region where the light intensity is small, the light diffusion degree is small. Thereby, the light from the light source can be uniformly diffused toward the side opposite to the light source side by the diffusion member and the diffusion auxiliary member. Therefore, the luminance uniformity can be improved without reducing the luminance of the light emitted through the emission surface of the diffusing member (the surface opposite to the light source side). That is, according to this illuminating device, the uniformity of the brightness can be improved without reducing the brightness.

  In a preferred example, in order to obtain such operational effects, a plurality of the light sources are arranged in a matrix, and a plurality of the diffusion assisting members are arranged in a matrix so as to face each of the plurality of light sources. In addition, it is preferable that each of the diffusion assisting members is disposed apart from each other. In this case, it is preferable that an interval between the light source and the diffusing member is equal to an interval between the adjacent light sources or smaller than an interval between the adjacent light sources.

  Further, according to this configuration, since only such a diffusion assisting member is provided for the diffusing member, the distance (distance) between the diffusing member and the light source can be reduced, and as a result, the lighting device can be made thinner. Can be achieved.

  Moreover, according to this structure, the manufacturing cost of an illuminating device can be reduced by forming a diffusion auxiliary member with respect to a diffusion member etc. by screen printing, inkjet printing, etc., for example.

  In one aspect of the illumination device, the diffusion assisting member has a circular planar shape that overlaps the light source in a planar manner. Thereby, it is possible to increase the degree of light diffusion in the region where the intensity of light emitted from the light source is the strongest.

  In another aspect of the illumination device described above, the diffusion assisting member is configured by stacking concentric diffusion patterns having different sizes. In a preferred example, the radius of each of the diffusion patterns is larger as it gets closer to the diffusion member, and the diffusion degree of each of the diffusion patterns is all the same or smaller as it gets closer to the diffusion member.

  According to these configurations, the light diffusion degree decreases as the diffusion pattern moves away from the central axis of the light source, and as a result, the luminance of the illumination device can be made uniform.

  In another aspect of the illumination device, each of the diffusion patterns is disposed on either the light source side or the light source side of the diffusion member.

  In another aspect of the illumination device, the diffusion assisting member is disposed on the light source side or the light source side of the diffusion member.

  Among these aspects, when the diffusion assisting member is arranged on the side opposite to the light source side of the diffusion member, the light emitted from the light source is first diffused by passing through the diffusion member and then diffused. Light is further diffused by passing through the diffusion assisting member. Therefore, compared with the structure in which the diffusion assisting member is disposed on the light source side of the diffusion member, the diffusion degree of the diffusion assisting member can be reduced, so that the light utilization rate is improved and a bright illumination device is obtained.

  In another aspect of the present invention, an electro-optical panel comprising an electro-optical layer sandwiched between a pair of substrates, and any one of the illumination devices disposed on one surface side of the electro-optical panel. An optical device can be configured. Accordingly, it is possible to configure an electro-optical device that can obtain high luminance and can achieve uniform and thin luminance.

  In still another aspect of the invention, an electronic apparatus including the electro-optical device as a display unit can be configured.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

[Configuration of liquid crystal device]
First, a configuration of a liquid crystal device 100 as an example of an electro-optical device including an illumination device according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2A.

  FIG. 1 is a cross-sectional view illustrating a schematic configuration of a liquid crystal device 100 including an illumination device 51 according to the present embodiment. FIG. 2A is a plan view of the illumination device 51 that is a component of the liquid crystal device 100 from the observation side (display side) of FIG. In FIG. 2A, for convenience, some of the components of the illumination device 51 are omitted.

  The liquid crystal device 100 includes a liquid crystal display panel 50 and a direct-type illumination device 51 that is disposed on the opposite side of the observation side of the liquid crystal display panel 50 and illuminates the liquid crystal display panel 50.

  The liquid crystal display panel 50 includes a first substrate 1 and a second substrate 2 that are bonded to each other via a frame-shaped sealing material 3, and a liquid crystal as an example of an electro-optical layer in a region partitioned by the sealing material 3. The layer 4 is sandwiched. On the surface of the liquid crystal display panel 50 on the liquid crystal layer 4 side, for example, many components such as a black matrix, a color filter, an electrode, and the like are formed in a matrix (lattice) or stripes (linear). In FIG. 1, illustration of those elements is omitted. A display area for displaying an image is formed inside the sealing material 3 in the liquid crystal display panel 50. In the present invention, the liquid crystal display panel 50 is not limited to a specific configuration, and may adopt various known configurations.

  The illumination device 51 includes a support member (housing) 11, an optical unit 12, a diffusion assisting member 15, a diffusion plate (diffusion member) 18, and an optical sheet 19.

  The support member 11 includes a first support member 11a having a plate-like shape, and a second support member 11b extending in an oblique direction from the outer peripheral portion of the first support member 11a to the outside and toward the diffusion plate 18. Have. The optical unit 12 is disposed on the surface of the first support member 11a on the liquid crystal display panel 50 side. The second support member 11 b supports the diffusion plate 18 and the optical sheet 19 in a state where a constant distance d1 is formed between the diffusion plate 18 and the light source 14. In a preferred example, it is preferable that at least the second support member 11b among the elements constituting the support member 11 is formed of a reflective material such as aluminum or silver. Thereby, a part of the light L emitted from each light source 14 that is not emitted to the diffusion plate 18 side can be returned (reflected) to the diffusion plate 18, and the light utilization efficiency can be improved.

  The optical unit 12 includes a substrate 13 and a plurality of light sources 14. The substrate 13 is, for example, a printed circuit board, and has a role as a medium for supplying power to the plurality of light sources 14 and a role for holding the plurality of light sources 14. The light source 14 is, for example, a light emitting diode, and is distributed and arranged on one surface 13a of the substrate 13 on the liquid crystal display panel 50 side. The light source 14 has a directivity characteristic that radiates light L in all directions of 360 [°]. In a preferred example, the light sources 14 are arranged in a matrix with respect to one surface 13a of the substrate 13 in order to ensure luminance uniformity. Thereby, the plurality of light sources 14 can irradiate the light L toward the diffusion plate 18. The surface of the substrate 13 is preferably reflective like the first support member 11 b of the support member 11, or a reflective member (not shown) is preferably disposed on the surface of the substrate 13. Thereby, the light L reflected by one of those members and returning to the light source 14 side is reflected again, and the light L can be used effectively. Thereby, the effective utilization of the light L reflected by the diffusion assisting member 15 can be achieved.

  The diffusion assisting member 15 is a member that diffuses light, and is formed on the diffusion plate 18. The detailed structure thereof will be described later.

  The diffusion plate 18 has a role of diffusing the light L emitted from each light source 14 toward an optical sheet 19 (for example, a diffusion sheet or a prism sheet). Examples of the diffusion plate 18 include a white member and a member having irregularities formed on the surface. The diffusion plate 18 is supported on the outer peripheral portion of the second support member 11 b of the support member 11. For this reason, a space E having a constant distance d1 is formed between the diffusion plate 18 and each light source 14. Thus, the reason why the constant distance d1 is formed between the diffusion plate 18 and each light source 14 is to diffuse the light L having directivity emitted from each light source 14 toward the liquid crystal display panel 50 side. It is for doing so.

  In the present invention, the diffusion plate 18 is not limited to a plate shape, and may be a sheet shape, that is, a diffusion sheet.

  The optical sheet 19 includes, for example, a diffusion sheet and a prism sheet. At least one (two in this example) optical sheet 19 is provided according to the application, and is disposed on the liquid crystal display panel 50 side of the diffusion plate 18.

  In the present invention, among the optical sheets 19, the diffusion sheet is arranged so as to overlap the diffusion plate 18 with an air layer interposed therebetween, thereby improving the light uniformity. The prism sheet is a diffusion sheet. This is for condensing the light diffused by the plate 18 or the like in a specific direction.

  In the liquid crystal device 100 having the above configuration, the light L emitted from the plurality of light sources 14 is diffused by passing through the diffusion assisting member 15, the diffusion plate 18, and the optical sheet 19 as indicated by broken line arrows in FIG. 1. The diffused light L is irradiated toward the display area of the liquid crystal display panel 50. At this time, the orientation of the liquid crystal molecules of the liquid crystal layer 4 is controlled in the liquid crystal display panel 50, and a desired display image is visually recognized by an observer. In particular, in the liquid crystal device 100, since the diffusion assisting member 15 is provided on the diffusion plate 18 as will be described later, high luminance can be obtained, and the luminance can be made uniform and the shape can be made thin.

(Brightness uniform structure in lighting equipment)
Next, with reference to FIG. 1, FIG. 2 (b), and FIG.

  FIG. 2B is a plan view of the diffusing plate 18 as viewed from the optical unit 12 side. FIG. 3A shows a plan view of the main part of the diffusion plate 18 in FIG. 2B, and in particular shows a planar configuration of the diffusion assisting member 15 arranged so as to overlap the diffusion plate 18. FIG. 3B shows a cross-sectional view of the main part of the diffusion plate 18 taken along the cutting line A-A ′ of FIG. 3A, and particularly shows a cross-sectional configuration of the diffusion assisting member 15. In FIG. 3B, the light source 14 disposed corresponding to the diffusion assisting member 15 is also illustrated in order to facilitate understanding of the positional relationship between the diffusion assisting member 15 and the light source 14.

  In general, when the light source 14 is a light emitting diode, the luminance distribution is the largest in the front direction of the light source 14 and decreases as the angle increases with respect to the front direction of the light source 14. For this reason, if the distance between the diffuser plate 18 and the light source 14 is reduced, the diffusion degree (diffusivity) of the light L is lowered, making it difficult to obtain uniform brightness, while increasing the distance between the diffuser plate 18 and the light source 14. Then, while uniform brightness is obtained, the brightness is lowered.

  Therefore, in a general lighting device, the distance between the diffusion plate 18 and the light source 14 is optimized in order to obtain uniform brightness without reducing the brightness. However, according to this configuration, the distance between the diffusion plate 18 and the light source 14 must be increased to some extent, and as a result, there is a problem that it is difficult to reduce the thickness of the lighting device.

  Therefore, in the present embodiment, the structure of the lighting device 51 is devised in order to improve the uniformity of the luminance and reduce the thickness of the lighting device 51 without reducing the luminance.

  Specifically, in the present embodiment, in the diffusion plate 18, the diffusion assisting member 15 is disposed so as to overlap the region facing the light source 14, and the diffusion degree in the region is made higher than that in other regions. More specifically, the surface 18a of the diffusing plate 18 on the optical unit 12 side, and the regions A1 and A2 that are planarly overlapped with the respective regions La and Lb of the light L emitted radially from the respective light sources 14. On the other hand, a diffusion auxiliary member 15 configured by laminating a plurality of diffusion patterns having different sizes (areas) is disposed.

  Here, the light L emitted from the light source 14 becomes brighter stepwise or continuously as it goes outward from the central axis L1. For example, the magnitude relationship of the brightness of the light L emitted from the light source 14 in the regions La, Lb, and Lc of the light L is represented by a region La> shown by a broken line> a region Lb shown by a one-dot chain line> a two-dot chain line. It changes stepwise or continuously like a region Lc. The diffusion assisting member 15 diffuses and transmits a part of the light Lt emitted from each light source 14 to the side opposite to the optical unit 12 side (the liquid crystal display panel 50 side) and the remaining light Lt. It is formed of a member that reflects the light Lr to the optical unit 12 side. The diffusion assisting member 15 is formed by screen printing, ink jet printing, or the like. The light Lr that has returned to the optical unit 12 side is reflected by the reflecting member formed on the surface of the substrate 13 to the diffusion plate side and is effectively used again.

  In this example, the diffusion auxiliary member 15 includes a first diffusion pattern (first diffusion auxiliary member) 16 formed on the diffusion plate 18 and a second diffusion pattern formed on the first diffusion pattern 16. (Second diffusion assisting member) 17. The first diffusion pattern 16 and the second diffusion pattern 17 have circular planar shapes having different sizes. The radius R1 of the first diffusion pattern 16 is larger than the radius R2 of the second diffusion pattern 17, and the light emitted from the light source 14 and the central axis of the first diffusion auxiliary member 16 and the second diffusion auxiliary member 17 The center axis L1 of the L region La coincides. Further, the diffusion degree of the first diffusion pattern 16 is the same as that of the second diffusion pattern 17 or smaller than that of the second diffusion pattern 17. For example, in the case of printing by ink jet printing, the degree of diffusion can be adjusted by adjusting the ink density.

  According to this configuration, in the diffusion plate 18, three regions A <b> 1 to A <b> 3 having different diffusivities are formed for each of the regions La, Lb, and Lc of the light L emitted radially from each light source 14. The region A1 is a region where the diffusion plate 18, the first diffusion pattern 16 and the second diffusion pattern 17 overlap, and the region A2 is a region where the diffusion plate 18 and the first diffusion pattern 16 overlap, A <b> 3 is an area of only the diffusion plate 18. Thereby, the diffusion rate of the light L becomes region A1> region A2> region A3. In other words, according to this configuration, in the diffusion plate 18, the diffusion ratio of the light L increases as the intensity (luminance) of the light L emitted from each light source 14 becomes the largest, and the light emitted from each light source 14. The diffusivity of the light L decreases as the L intensity decreases. Thereby, the light L from each light source 14 can be uniformly diffused toward the liquid crystal display panel 50 side by the diffusion auxiliary member 15 and the diffusion plate 18. Therefore, the luminance uniformity can be improved without reducing the luminance of the light L emitted through the emission surface 18b of the diffusion plate 18. That is, according to the illumination device 51, it is possible to improve the luminance uniformity without reducing the luminance.

  In a preferred example, a plurality of light sources 14 are arranged in a matrix in order to obtain the above-described effects, and a plurality of diffusion assisting members 15 are arranged in a matrix so as to face each of the plurality of light sources 14 and diffuse. Each of the auxiliary members 15 is spaced apart from each other. In this case, the distance d1 between the diffusion plate 18 and each point light source 14 is preferably not more than the distance d2 between the adjacent point light sources 14.

  Further, according to this configuration, since only such a diffusion structure (a laminated structure of diffusion patterns) is provided for the diffusion plate 18, the distance d1 between the diffusion plate 18 and each point light source 14 can be reduced. As a result, the lighting device 51 can be thinned.

  Moreover, according to this structure, the manufacturing cost of the illuminating device 51 can be reduced by forming the diffusion auxiliary member 15 on the diffusion plate 18 by, for example, screen printing or inkjet printing.

[Modification]
The present invention is not limited to the configuration of the lighting device and the like according to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. Hereinafter, various modifications of the present invention will be described.

(Modification 1)
First, with reference to Fig.4 (a), the structure of the illuminating device 51a which concerns on the modification 1 of this invention is demonstrated. FIG. 4A shows a cross-sectional configuration cut at a position passing through the diffusion assisting member 15 in the lighting device 51a corresponding to FIG.

  The illuminating device 51a according to the modified example 1 is different from the illuminating device 51 according to the above-described embodiment in the arrangement position of the diffusion assisting member 15 in the diffusing plate 18, and is otherwise the same. Therefore, below, the same code | symbol is attached | subjected about the element same as above-described embodiment, and the description is abbreviate | omitted suitably.

  In the illuminating device 51a according to the first modification, the diffusion assisting member 15 is a surface (light exit surface) 18b on the opposite side (liquid crystal display panel 50 side) of the diffusion plate 18 to the optical unit 12 side, and each light source 14 Are arranged in correspondence with the area overlapping the area of the light L emitted radially from the plane. Specifically, among the constituent elements of the diffusion assisting member 15, the first diffusion pattern 16 is an area on the emission surface 18 b of the diffusion plate 18 and planarly overlapping the area Lb of the light L of each light source 14. In addition, the second diffusion pattern 17 is formed on the first diffusion pattern 16 and in a region overlapping the region La of the light L of each light source 14 in a plane. In the diffusing plate 18, a region that does not overlap with the diffusion assisting member 15 overlaps the region Lc of the light L of each light source 14 in a plane.

  According to this configuration, in the diffusing plate 18, the diffusivity of the light L increases as the intensity of the light L emitted from each light source 14 increases, and the intensity of the light L emitted from each light source 14 decreases. The diffusivity of the light L becomes smaller as the area becomes larger. As a result, it is possible to obtain the same effects as those of the above-described embodiment.

  Further, according to this configuration, the light L emitted from each light source 14 is first diffused by passing through the diffusion plate 18, and the diffused light is converted into the first diffusion pattern 16 and the second diffusion pattern. The light is further diffused by passing through 17 in this order. Therefore, compared with the above-described embodiment, the diffusion degree of the diffusion auxiliary member 15, that is, the diffusion degree of the first diffusion pattern 16 and the second diffusion pattern 17 can be reduced, so that the light utilization rate is improved. And a bright lighting device.

(Modification 2)
Next, with reference to FIG.4 (b), the structure of the illuminating device 51b which concerns on the modification 2 of this invention is demonstrated. FIG. 4B shows a cross-sectional configuration cut at a position passing through the diffusion assisting member 15 in the lighting device 51b, corresponding to FIG.

  The illuminating device 51b according to Modification 2 is different from the illuminating device 51 according to the above-described embodiment in the arrangement positions of the components of the diffusion assisting member 15 in the diffusing plate 18 and is otherwise the same. Therefore, below, the same code | symbol is attached | subjected about the element same as above-described embodiment, and the description is abbreviate | omitted suitably.

  In the illuminating device 51b according to the second modification, among the components of the diffusion assisting member 15, the first diffusion pattern 16 is emitted radially from each light source 14 on the emission surface 18b of the diffusion plate 18. The second diffusion pattern 17 is formed on a region overlapping the region Lb of the light L in a plane, and the second diffusion pattern 17 is on the surface 18a opposite to the emission surface 18b of the diffusion plate 18 and from each light source 14. It is formed in a region overlapping the region La of the light L emitted radially and the first diffusion pattern 16 in a plane. According to this configuration, in the diffusing plate 18, the diffusivity of the light L increases as the intensity of the light L emitted from each light source 14 increases, and the intensity of the light L emitted from each light source 14 decreases. The diffusivity of the light L becomes smaller as the area becomes larger. As a result, it is possible to obtain substantially the same effects as the above-described embodiment.

  In the present invention, the positional relationship between the first diffusion pattern 16 and the second diffusion pattern 17 may be reversed with respect to the diffusion plate 18 of the illumination device 51b according to Modification 2. That is, in the present invention, among the constituent elements of the diffusion assisting member 15, the second diffusion pattern 17 is on the emission surface 18 b of the diffusion plate 18 and the region of the light L emitted radially from each light source 14. The first diffusion pattern 16 is formed in a region overlapping with La in a plane, and is emitted from each light source 14 radially on the surface 18a opposite to the emission surface 18b of the diffusion plate 18. The light L may be formed in a region overlapping the region Lb and the second diffusion pattern 17 in plan view.

(Modification 3)
Next, with reference to Fig.5 (a), the structure of the illuminating device 51c which concerns on the modification 3 of this invention is demonstrated. Fig.5 (a) shows the cross-sectional structure cut | disconnected in the position which passes the diffusion auxiliary member 15 in the illuminating device 51c corresponding to FIG.3 (b).

  The illuminating device 51c according to the modification 3 is different from the illuminating device 51 according to the above-described embodiment in the laminated structure of the constituent elements of the diffusion assisting member 15 in the diffusing plate 18, and is otherwise the same. Therefore, below, the same code | symbol is attached | subjected about the element same as above-described embodiment, and the description is abbreviate | omitted suitably.

  In the illuminating device 51c according to the modified example 3, the first diffusion pattern 16 and the second diffusion pattern 2 among the constituent elements of the diffusion auxiliary member 15 have a laminated structure, The second diffusion pattern 2 has a region that overlaps with each other in a planar manner. Specifically, the second diffusion pattern 17 is planar on the surface La of the light L emitted radially from each light source 14 on the surface 18a opposite to the emission surface 18b side of the diffusion plate 18. The first diffusion pattern 16 is formed on the surface of the second diffusion pattern 17 on the optical unit 12 side and on the surface 18a opposite to the emission surface 18b side of the diffusion plate 18. In addition, it is formed in a region that overlaps the region Lb of the light L emitted radially from each light source 14 in a plane.

  According to this configuration, in the diffusing plate 18, the diffusivity of the light L increases as the intensity of the light L emitted from each light source 14 increases, and the intensity of the light L emitted from each light source 14 decreases. The diffusivity of the light L becomes smaller as the area becomes larger. As a result, it is possible to obtain substantially the same effects as the above-described embodiment.

  In the present invention, in the illuminating device 51c according to the modified example 3, the second diffusion pattern 17 is on the emission surface 18b of the diffusion plate 18 and the region of the light L emitted radially from each light source 14 The first diffusion pattern 16 is formed in a region overlapping with La in a plane, and the first diffusion pattern 16 is on the surface of the second diffusion pattern 17 on the optical unit 12 side and on the emission surface 18b of the diffusion plate 18, and You may form in the area | region which planarly overlaps with area | region Lb of the light L radiate | emitted radially from each light source 14. FIG.

(Modification 4)
Next, with reference to FIG.5 (b), the structure of the illuminating device 51d which concerns on the modification 3 of this invention is demonstrated. FIG.5 (b) shows the cross-sectional structure cut | disconnected in the position which passes along the spreading | diffusion auxiliary member 15 in the illuminating device 51d corresponding to FIG.3 (b).

  The illuminating device 51d according to the modified example 4 is different in size from the illuminating device 51 according to the above-described embodiment and the illuminating devices 51a, 51b, and 51c according to the modified examples 1 to 3 in the diffusion assisting member 15. The difference is that the number of laminated diffusion patterns (diffusion assisting members) is increased. The radius R of each diffusion pattern decreases as the distance from the diffusion plate 18 increases, and the diffusivity of each diffusion pattern is the same or increases as the distance from the diffusion plate 18 increases.

  According to this configuration, the magnitude relationship of the brightness of the light L emitted radially from each light source 14 is region La> region Lb> region Lc> region Ld> region Le, and the light emitted from each light source 14. The size relationship of the diffusivity of L is the area corresponding to the area La> the area corresponding to the area La> the area corresponding to the area Lb> the area corresponding to the area Lc> the area corresponding to the area Ld> the area Le. . Here, the region corresponding to the region La is a region that overlaps the diffusion pattern farthest from the diffusion plate 18 in a planar manner. Further, the region corresponding to the region Lb is a region that overlaps in plan with the diffusion pattern that is next away from the diffusion plate 18. In addition, the region corresponding to the region Lc is a region that overlaps with the diffusion pattern next to the diffusion plate 18 in plan view. In addition, the region corresponding to the region Ld is a region that overlaps with the diffusion pattern next to the diffusion plate 18 in plan view. Further, the region corresponding to the region Le is a region that overlaps the diffusion pattern closest to the diffusion plate 18 in a plan view.

  That is, in the diffusing plate 18, the region where the intensity of the light L emitted from each light source 14 is the highest becomes larger in the diffusion ratio of the light L, and the region where the intensity of the light L emitted from each light source 14 becomes smaller. The diffusion rate of L decreases stepwise. Therefore, the light L emitted from the point light source 14 can be more uniformly diffused toward the liquid crystal display panel 50 side, and the luminance can be made more uniform.

  In addition, in the present invention, the shape and number of the light source 14 and the diffusion assisting member 15 are not limited. In the present invention, the display device as an example of the electro-optical device is not limited to the liquid crystal device, and may be applied to an organic electroluminescence display device, a plasma display device, a field emission display device, and the like.

[Electronics]
Next, a lighting device 51 according to the above-described embodiment, and a liquid crystal device including any one of the lighting devices 51a, 51b, 51c, and 51d according to the first to fourth modifications (hereinafter referred to as “liquid crystal device” A specific example of an electronic device provided with “1000” will be described with reference to FIG.

  First, an example in which the liquid crystal device 1000 according to the present invention is applied to a display unit of a portable personal computer (so-called notebook personal computer) will be described. FIG. 6A is a perspective view showing the configuration of this personal computer. As shown in the figure, a personal computer 710 includes a main body 712 having a keyboard 711 and a display 713 to which the liquid crystal device 1000 according to the present invention is applied.

  Next, an example in which the liquid crystal device 1000 according to the present invention is applied to a display unit of a mobile phone will be described. FIG. 6B is a perspective view showing the configuration of this mobile phone. As shown in the figure, a cellular phone 720 includes a plurality of operation buttons 721, a reception port 722, a transmission port 723, and a display unit 724 to which the liquid crystal device 1000 according to the present invention is applied.

  Note that examples of the electronic apparatus to which the liquid crystal device 1000 according to the present invention can be applied include a liquid crystal television and a viewfinder type in addition to the personal computer shown in FIG. 6A and the mobile phone shown in FIG. Monitor direct-view video tape recorders, car navigation devices, pagers, electronic notebooks, calculators, word processors, workstations, videophones, POS terminals, digital still cameras, etc.

Sectional drawing which shows the structure of a liquid crystal device provided with the illuminating device which concerns on embodiment of this invention. The various top views which show the structure of each component of the illuminating device of this embodiment. The top view and sectional drawing which show the structure of the diffusion assistance member of the illuminating device which concerns on this embodiment. Sectional drawing which shows the structure of the diffusion assistance member of the illuminating device which concerns on the modification 1 or 2. FIG. Sectional drawing which shows the structure of the diffusion assistance member of the illuminating device which concerns on the modification 3 or 4. FIG. The perspective view of an electronic device provided with the liquid crystal device which has a lighting device of the present invention.

Explanation of symbols

  12 optical unit, 13 substrate (base material), 14 light source, 15 diffusion assisting member, 16 first diffusion pattern (first diffusion assisting member), 17 second diffusion pattern (second diffusion assisting member), 18 Diffusion plate (diffusion member), 19 Optical sheet (diffusion sheet, prism sheet), 50 Liquid crystal display panel, 51, 51a, 51b, 51c, 51d Illumination device, 100 Liquid crystal device (electro-optical device)

Claims (11)

A light source;
A diffusing member disposed opposite to the light output side of the light source,
In the diffusing member, a diffusion assisting member is disposed in an overlapping manner in a region facing the light source, and a diffusion degree in the region is higher than in other regions.   The diffusion assisting member diffuses and transmits a part of the light emitted from the light source to the side opposite to the light source side and reflects the remaining light to the light source side. The lighting device according to claim 1.   The lighting device according to claim 1, wherein the diffusion assisting member has a circular planar shape that planarly overlaps the light source.   The lighting device according to claim 1, wherein the diffusion assisting member is configured by stacking concentric diffusion patterns having different sizes. The radius of each of the diffusion patterns is larger as it approaches the diffusion member,
5. The illumination device according to claim 4, wherein the diffusivity of each of the diffusion patterns is all the same or decreases as the diffusion member is approached.   6. The lighting device according to claim 4, wherein each of the diffusion patterns is arranged on either the light source side or the opposite side of the light source side of the diffusion member.   The illumination device according to claim 1, wherein the diffusion assisting member is disposed on the light source side of the diffusion member or on the side opposite to the light source side. A plurality of the light sources are arranged in a matrix,
A plurality of the diffusion assisting members are arranged in a matrix so as to face each of the plurality of light sources, and each of the diffusion assisting members is disposed apart from each other. Item 8. The illumination device according to any one of Items 1 to 7.   The lighting device according to claim 8, wherein an interval between the light source and the diffusing member is equal to an interval between the adjacent light sources or smaller than an interval between the adjacent light sources.   An electro-optical panel having an electro-optical layer sandwiched between a pair of substrates, and the illumination device according to claim 1 disposed on one surface side of the electro-optical panel. An electro-optical device.   An electronic apparatus comprising the electro-optical device according to claim 10 as a display unit.

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