JP2011086419A - Transparent structure, light source module and lighting system using the same, liquid crystal display device, and image display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transparent structure realizing improved light extraction efficiency, a light source module and a lighting system using the same, and a liquid crystal display device and an image display apparatus. <P>SOLUTION: A transparent structure and a light source module are characterized by including a wiring substrate (3), an LED chip (2) as a light source arranged on the wiring substrate, and the transparent structure (5) formed on the wiring substrate to cover the light source, the transparent structure including a plurality of projection portions on a light extraction surface, each of the plurality of projection portions being formed of part of the radius of a circle centered at the light source and an arc or a chord of the circle in a cross-section of the transparent structure, and the curvature of each of the circles forming the plurality of projection portions getting increasingly smaller as going farther away from the light source. A lighting system, a liquid crystal display device and an image display apparatus use the transparent structure and the light source module. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a transparent structure, a light source module, and an illumination device, a liquid crystal display device, and a video display device using the same.

  Conventionally, a light source in which an LED chip is sealed with a transparent resin performs light extraction using directly emitted light from the resin and reflected light inside the resin.

  Patent Document 1 discloses the following configuration. A direct emission region that directly emits light of the light emitting element to the outside and a total reflection region that totally reflects the light of the light emitting element are formed at the front interface of the mold resin that seals the light emitting element. The direct emission region is formed in a convex lens shape. A light reflecting portion having a concave mirror shape is provided on the back surface of the mold resin. A part of the light emitted from the light emitting element is emitted forward by receiving a lens action when passing directly through the emission region. Another part of the light emitted from the light emitting element is totally reflected by the total reflection region, then reflected by the light reflecting portion, and emitted forward from the total reflection region.

JP 2002-94129 A

  An object of the present invention is to provide a transparent structure, a light source module, an illumination device, a liquid crystal display device, and an image display device using the same, which improve light extraction efficiency.

  In order to solve the above-described problems, the present invention is characterized in that it includes a wiring board, a light source disposed on the wiring board, and a transparent structure that is formed on the wiring board and covers the light source. The light extraction surface has a plurality of convex portions (uneven portions), and in the cross section of the transparent structure, each of the plurality of convex portions is a part of a radius of a circle centered on the light source and a circle arc or string. A transparent structure, a light source module, and a lighting device, a liquid crystal display device, and a video display device using the transparent structure, the light source module, and the curvature of each of the circles constituting the plurality of convex portions are reduced as the distance from the light source increases. is there.

  According to the present invention, it is possible to provide a transparent structure, a light source module, and an illumination device, a liquid crystal display device, and an image display device using the transparent structure, which can improve the light extraction efficiency. Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

It is a top view of the light source module 1 of this invention. It is a top view of the light source module 1 except the transparent structure 5 and the peripheral frame 4 in FIG. 1a. It is the sectional view on the AA line which shows the optical structure of FIG. It is sectional drawing in the BB line shown to FIG. 1b of the light source module 1. FIG. It is sectional drawing in the CC line shown in FIG. 1b of the light source module 1. FIG. It is sectional drawing which shows an optical structure with another light source module. It is sectional drawing which shows an optical structure with another light source module. It is sectional drawing which shows an optical structure with another light source module. It is sectional drawing which shows an optical structure with another light source module. It is a top view of another light source module. It is a top view of another light source module. It is a structural diagram at the time of forming the interface curved surface of a transparent structure with a flat surface. It is a top view of another light source module. It is sectional drawing which shows the optical structure of the light source module using the 1st transparent structure and 2nd transparent structure which comprise a transparent structure. It is sectional drawing of the 2nd transparent structure which comprises a transparent structure. It is sectional drawing which shows the optical structure of the light source module using the 1st structure which comprises a transparent structure. It is sectional drawing which shows the optical structure of another light source module. It is sectional drawing which shows the optical structure of another light source module. It is sectional drawing which shows the optical structure of another light source module. It is sectional drawing which shows the optical structure of another light source module. It is sectional drawing which shows the optical structure of another light source module. It is sectional drawing which shows the optical structure of another light source module. It is sectional drawing which shows the optical structure of another light source module. It is sectional drawing of the structure where two or more another light source modules were formed continuously. FIG. 15 is a top view when a plurality of second structures constituting the transparent structure of FIG. 14 are continuously formed. It is the DD sectional view taken on the line of FIG. 15a. It is a top view of the illuminating device which arranged the light source module of FIG. 14 in two or more plane form. It is the EE sectional view taken on the line of FIG. It is a top view of the optical sheet which added the release paper to the 2nd transparent structure used for FIG. 16a, FIG. 16b, and an adhesive layer. It is the FF sectional view taken on the line of FIG. FIG. 16B is a top view of the integrally formed reflecting structure used in FIGS. 16A and 16B. It is the GG sectional view taken on the line of FIG. It is sectional drawing of the liquid crystal display device using the illuminating device of FIG. 16a, FIG. 16b. It is a top view of another light source module. It is the HH sectional view taken on the line of FIG. It is a top view of the light source module which connected FIG. 17a, FIG. 17b to the wiring board with two or more heat sinks. It is the II sectional view taken on the line of FIG. It is a top view of the illuminating device which arranged the light source module of FIG. 18a, FIG. 18b in multiple numbers. It is the JJ sectional view taken on the line of FIG. It is sectional drawing of the liquid crystal display device using the illuminating device of FIG. 18c and FIG. 18d. It is a schematic plan view inside the back side of the video display apparatus using FIG. 16g or FIG. 18e. It is a top view of another light source module 225 of the present invention. It is the KK sectional view taken on the line of FIG.

Light emitted from a light source covered with a transparent resin, which is also a sealing material, or glass or the like (radiated light) enters the interface with air at a critical angle exceeding the critical angle and cannot be extracted. As a result, there is a problem that the light extraction efficiency is lowered. Another problem is that the light extraction area is restricted by the presence of the critical angle, so that the luminance uniformity and viewing angle of the light source are also lowered. Another problem is a solution that removes total reflection. However, a hemispherical or semi-cylindrical light extraction structure (such as a shell-type structure) is used for the light emitted from a point light source. It is a point to use. That is, by making the interface hemispherical with respect to the point light source, total reflection can be prevented and light extraction efficiency can be improved. On the other hand, however, there is a problem that the thickness of the convex portion of the structure is added compared to the interface of the flat surface, which is essentially disadvantageous for the thinned structure. In particular, a large structure has a problem in that it is disadvantageous in terms of weight reduction with an increase in volume.
In the present invention, since the incident angle with respect to the interface can be made zero by means of providing a thin structure having a surface in which the interface of the transparent material covering the light source is always orthogonal to the radiated light from the light source, the high refractive index material can be obtained. Even if it is used, total reflection can be removed and suppressed, and while realizing a light source module with an ultra-thin and lightweight structure, it simultaneously improves light extraction efficiency, brightness uniformity, and viewing angle expansion.

  The means to form an interface that removes and suppresses total reflection with a thin structure is to form a surface that is orthogonal to the light emitted from the light source, and to continue the interface of a transparent structure with concentric hemispherical curved surfaces with different curvatures. This is realized by a concavo-convex structure in which a plane that is parallel to the radiated light and a plane that is orthogonal to the plane are alternately formed. By miniaturizing the concavo-convex structure formed at the interface, the transparent structure can be made thinner and lighter.

Other effects of the present invention include the following points.
(1) Since the light source such as the LED chip can be covered with a high refractive index material, in addition to improving the light extraction efficiency from the material forming the transparent structure to the outside, the light source such as the LED chip is changed to the transparent material. The light extraction efficiency can be improved at the same time, and there is a synergistic effect on the overall efficiency improvement.
(2) Since total reflection can be suppressed from the entire area of the interface, light extraction efficiency can be improved without depending on the light distribution pattern of a light source such as a single color LED or white LED.
(3) In a light source module in which a reflective structure is formed at the interface on the side of the transparent structure, the reflected light (specular reflection) from the reflective structure is formed so as to be orthogonal to the interface (parallel surface) of the transparent structure. As a result, total reflection can be removed and suppressed for reflected light as well as radiated light, and the efficiency can be further improved.
(4) For the reflected light of (3) above, control by the combined structure of the surface that generates the reflected light of the reflective structure and the interface (parallel surface) position of the transparent structure that extracts the reflected light. By doing so, the luminance uniformity can be improved.
(5) By dividing the transparent structure into two parts, a sealing part that covers the light source from the functional surface and an interface forming part of the concavo-convex structure for extracting light, and the latter interface forming part is made into an optical sheet (optical film) This improves the assembly, yield, and usability of the light source module.

  FIG. 1 a is a top view of the light source module 1 according to the first embodiment. FIG. 1B is a top view of the light source module 1 with the transparent structure 5 and the peripheral frame 4 removed in FIG. 1A. 2a is a cross-sectional view taken along line AA showing the optical structure of FIG. 1a. 2b is a cross-sectional view of the light source module 1 taken along line BB shown in FIG. 1b. FIG. 2c is a cross-sectional view of the light source module 1 taken along line CC shown in FIG. 1b.

  In FIG. 1 a, the LED chip 2 as a light source is disposed at the center of the wiring board 3, and the wiring board 3 is covered with a transparent structure 5 so as to fit in a rectangular peripheral frame 4.

  In FIG. 2 a, the transparent structure 5 forms an interface 9 made of a concavo-convex structure having a plurality of concentric curvatures with the LED chip 2 positioned at the center. The interface 9 is a plane 7 (7-0, 7-1) discretely orthogonal to the emitted light 6 (6-0, 6-1, 6-2, 6-3...) From the LED chip 2. , 7-2, 7-3..., And planes 8 (8-1, 8-2, 8-3...) Parallel to each other. In the transparent structure 5, a parallel surface 8 is inserted between the orthogonal surfaces 7, and the curvature and shape are changed by a length (pitch) d10 so that the convex portions are arranged in a plane. ing. That is, the curvature of each circle constituting the convex portion decreases as the distance from the light source increases. In the cross section of the parallel surface 8, that is, in the cross section of the transparent structure 5, a part of the radius of the circle is formed with an equal length d10, so that the structural distortion generated in the groove of the concavo-convex portion formed in a ring shape in a planar shape. (Thermal expansion and contraction strain, pressure deformation strain, etc.) are uniformized and reduced throughout the transparent structure 5. Similarly, the groove depth of the concavo-convex structure may be increased at a constant rate toward the central portion where the LED chip 2 is disposed.

  In the cross section of the transparent structure 5, the surface 8 is a part of a radius of a circle centered on the LED chip 2, and the surface 7 is configured by an arc or string of a circle centered on the LED chip 2. As a result, the thickness 13 of the convex portion formed by the hemispherical orthogonal surface (the hemispherical surface having the maximum radius) 12 can be removed, and a flat thin structure can be easily realized. At this time, the radiated light 6 from the LED chip 2 disposed at the center of the transparent structure 5 is transmitted through the surface 7 orthogonal to the interface 9, so that total reflection is suppressed and the light extraction efficiency is greatly improved. ing.

  In particular, when the conditions for thinning are relaxed, the arrangement of the interfaces 9 does not have to be planar.

  Since the size of the LED chip 2 is usually about 0.1 mm square or more even at the minimum size, the entire light emitting area of the LED chip 2 is not necessarily a point light source with respect to the interface 9 of the transparent structure 5. The radiated light 6 is not orthogonal to the orthogonal surface 7 (because it deviates from the point light source), and an incident angle θi may occur with respect to the normal of the orthogonal surface 7 that is a curved surface. Even in such a case, if the incident angle θi is within the critical angle θo, total reflection is suppressed (transmitted and refracted), so that the light extraction efficiency is improved.

  The same applies to the case where the emitted light 6 is incident on the parallel surface 8 because of the geometric optical structure. The reflected light totally reflected by the parallel surface 8 (does not enter and does not occur if it is a point light source) enters the adjacent orthogonal surface 7 and has an incident angle θi substantially equal to the direct radiation light 6. . Therefore, considering the critical angle θo determined by the size of the LED chip 2 and the refractive index of the material, the light extraction efficiency is improved by allowing a variation width in the shape of the transparent structure 5 (interface 9 thereof).

  When the surface area of the interface 9 of the transparent structure 5 increases in the horizontal direction (X and Y axis directions) shown in FIG. 2a, the light can be extracted by preventing and suppressing total reflection from the entire area of the interface 9 The viewing angle is also increased at the same time that the luminance uniformity with respect to 6 is improved.

  The transparent structure 5 is formed using a silicone resin having a high light transmittance (refractive index n1 is 1.4). An acrylic resin may be used. The uneven structure of the interface 9 is collectively formed by a mold. When the silicone resin is used with respect to air (refractive index no = 1), the critical angle θo is about 45 degrees. Therefore, the condition of the incident angle θi for suppressing the total reflection with respect to the orthogonal surface 7 can basically be relaxed to 45 degrees if transmission and refraction of the radiated light 6 are allowed. By considering the critical angle θo, the formation of the interface 9 and the manufacturing process, the processing and assembly variation accuracy is eased, and cost merit such as yield improvement is added.

  Furthermore, by adding the degree of freedom of the incident angle θi (θi ≦ θo), a function can be added. For example, by shifting the inclination angle of the orthogonal surface 7, it is possible to easily realize improvement in brightness uniformity, improvement in light collection characteristics, and control with respect to transmitted light that is radiated light from the transparent structure 5. .

  The transparent structure 5 may use an inorganic material such as glass having a large refractive index n1 instead of an organic material depending on the module form. In other words, the transparent structure 5 is a module using a low melting point glass (300 ° C. or less) having a high refractive index n 1 and a ceramic substrate for the wiring substrate 3 and the peripheral frame 4. Even when the base material refractive index n2 of the LED chip 2 is large (2.0 or more), since the total reflection at the interface 9 can be prevented by using the transparent structure 5, the refractive index n1 is changed to the base material refractive index n2. Can be approached. Therefore, the light extraction efficiency from the LED chip 2 to the transparent structure 5 can be improved, and at the same time, the light extraction efficiency from the transparent structure 5 to the air (no) can be improved. When a white LED (for example, a blue LED + yellow phosphor) is used for the LED chip 2, the yellow phosphor may be mixed and kneaded with powdery low-melting glass to be collectively melted.

  On the other hand, the surfaces of the wiring board 3 and the peripheral frame 4 surrounding the transparent structure 5 in a concave shape have a high reflectivity characteristic. The peripheral frame 4 is formed on the wiring substrate 3 and on the side surface of the transparent structure 5. The inner side surface of the peripheral frame 4 forms a reflective interface 11 with the side surface of the transparent structure 5. The shape of the reflective interface 11 is such that the emitted light 6 of the LED chip 2 that is a light source is reflected by the reflective interface 11 of the transparent structure 5 (to improve the efficiency, the incident angle θi to the reflective interface 11 can be totally reflected. In some cases, the transparent structure 5 is formed so as to be taken out from the parallel surface 8. At this time, with respect to the peripheral frame 4, the reflection interface 11 is formed so as to be inclined so as to be orthogonal to the surface 8 on which the reflected light is parallel and opposite to the radiated light 6.

  In FIG. 1b, the wiring board 3 has a double-sided wiring structure, and the electrode pattern (solid line part) 15 (15-1, 15-2, 15-3) on the front surface and the electrode pattern (dashed line part) on the back surface via the Cu through hole 14. ) 16 (16-1, 16-2, 16-3) are electrically connected.

  The electrode pattern 15 includes electrodes (not shown) of the LED chip 2 and electrode patterns 15-1 and 15-2 for connection with Au wires 17-1 and 17-2, and a die for mounting the LED chip 2. It is formed with the electrode pattern 15-3 of the bonding part. In some cases, the LED chip 2 is CCB-connected using a flip chip. The central electrode pattern 15-3 has a high heat dissipation structure (low heat) connected to the electrode pattern 16-3 of the wiring board 3 through a plurality of Cu through holes 14 in order to dissipate the heat generated in the LED chip 2 to the back surface. Resistance structure).

  2b and 2c, the wiring board 3 is a glass epoxy board, and electrode patterns 15 (15-1, 15-2, 15-3) and electrode patterns 16 (16-1, 16-2) formed on both surfaces. 16-3), and a white resist layer 18 and a white resist layer 19 having high reflectivity and high reliability are formed on the surface of the wiring board 3, respectively. A flexible wiring board may be used for the wiring board 3.

The resist layer 19 on the back surface may not be a high reflectivity material when it is not directly related to optical characteristics. Opening 20 (20-1, 20-2, 20-3), opening 21 (21-1, 21-2, 21-) in which resist layer 18 and resist layer 19 are not formed on electrode pattern 15 and electrode pattern 16 3) Ni / Au plating is applied on the Cu foil pattern. The opening 20 secures an area for DB / WB of the LED chip 2 and covers the other area with the resist layer 18 to reflect the radiated light. The opening 21 on the back surface is provided to solder the light source module 1 to an external wiring board (not shown) or an external heat dissipation structure (not shown).
In the opening 20 (20-3) formed in the electrode pattern 15-3, a die made of Ag paste on the Ni / Au plating in order to improve the high reflection characteristic with respect to the radiated light from the LED chip 2 to the back surface. A bonding layer 22 is formed. The opening 20 (20-3) may be subjected to Ni / Ag plating instead of Ni / Au plating. Furthermore, instead of Ag plating, highly reliable Sn plating with high reflection characteristics (85% or more, equivalent to Ag) is used, and the white (or transparent) die bonding layer 22 with high reliability and high heat dissipation is thinned (1 to 1). (About 20 μm). For the die bonding layer 22, a silicone resin containing a white high thermal conductive filler (such as alumina particles) is used.

  As a case where the white resist layer 18 and the resist layer 19 are not used, a white ceramic (alumina) substrate may be used instead of the wiring substrate 3 as a glass epoxy substrate. The peripheral frame 4 is formed by molding a white reflective sheet (acrylic resin) with a mold. Instead of the white reflective sheet, the outer shape of the peripheral frame 4 may be directly formed with a white ceramic substrate having a high reflectance or a white resist layer formed in a laminated manner. That is, the surface of the peripheral frame 4 has reflectivity, and the peripheral frame 4 is formed with a high reflectance (90% or more) surface by a white ceramic substrate, a white resist layer, or the like. In the case of a white ceramic substrate, high reflectance and high efficiency characteristics can be obtained with high reliability by using a multilayer ceramic substrate in which the wiring substrate 3 and the peripheral frame 4 are integrated.

  FIG. 3 is a cross-sectional view showing an optical structure of the light source module 23 using the transparent structure 25 according to the second embodiment. It is a modification with respect to the transparent structure 5 of Example 1. FIG. In FIG. 3, the basic structure of the light source module 23 is such that an LED chip 24 as a light source is disposed at the center of a wiring board 32 and is covered with a transparent structure 25 so as to fit in a rectangular peripheral frame 33.

  The interface 28 for extracting light from the transparent structure 25 has an interface 27 having a flat central portion that is directly above the LED chip 24 and an interface 28 having an uneven structure. That is, a flat region is formed on the light extraction surface of the transparent structure 25. The flat region of the interface 27 is formed within a critical angle θo 31 where total reflection does not occur. The interface 28 is a plane 30 (30-1, 30-2, 30) that is parallel to a plane 29 (29-1, 29-2, 29-3,...) Orthogonal to the emitted light 26 from the LED chip 24. -3 ...). The interface 27 and the interface 28 are basically arranged in one plane in order to reduce the thickness of the transparent structure 25. When the emitted light is controlled, the thickness reduction is alleviated, but there is a case where a certain amount of width is given to the arrangement of the interfaces 28. Even in this case, thinning can be realized independently by miniaturizing the uneven structure of the interface 28.

  FIG. 4 is a cross-sectional view showing an optical structure of the light source module 35 using the transparent structure 34 according to the third embodiment. It is a modification with respect to the transparent structure 25 of Example 2. FIG.

  In FIG. 4, the basic structure of the light source module 35 is that an LED chip 36 as a light source is arranged at the center of a wiring board 37 and is covered with a transparent structure 34 so as to fit in a rectangular peripheral frame 38. .

  The interface 39 for extracting light from the transparent structure 34 is formed flat so that convex portions are arranged in a plane at a flat interface 40 and an interface 41 having a concavo-convex structure. The interface 40 is composed of two regions, and a flat interface is formed by the interface 40-1 at the center portion that is directly above the LED chip 36 and the interface 40-2 near the end of the peripheral frame 38. That is, a flat region is formed in the central part of the transparent structure 34 or the peripheral part of the transparent structure 34. The stability of the structure is secured by providing a flat interface. Furthermore, the interface 40-2 makes it easy to form the interface 41 having a concavo-convex structure at the time of molding from the arrangement relationship with the peripheral frame 38. In particular, when a continuous plane is formed, processing at the boundary region of the transparent structure 34 is facilitated.

  The flat region of the interface 40-1 is formed within a critical angle 44θo in which total reflection does not occur with respect to the emitted light 45-1 from the LED chip 36. The interfaces 41 are alternately formed with surfaces 43 that are parallel to the surfaces 42 that are orthogonal to the emitted light 45-1 from the LED chip 36. At the interface 40-2, total reflection tends to occur with respect to the radiation 45-2 from the LED chip 36. In this case, the reflective interface 47-1 of the peripheral frame 38 (the inclined surface formed by the peripheral frame 38 and the transparent structure 34), the reflective interface 47-2 of the wiring substrate 37 (the white reflective resist layer of the wiring substrate 3). (The surface formed by the transparent structure 34, which is omitted in FIG. 4 but is the same as the resist layer 18 in FIGS. 2b and 2c) and sequential reflection (multiple reflection), and light extraction from the interface 41 is repeated. Forming a structure. In the multiple reflection at the interfaces 47-1 and 47-2, the efficiency is improved by using a highly reflective member.

  FIG. 5 is a cross-sectional view showing an optical structure of the light source module 49 using the transparent structure 48 according to the fourth embodiment. It is a modification with respect to the transparent structure 5 of Example 1. FIG. In FIG. 5, the basic structure of the light source module 49 is that an LED chip 50 as a light source is arranged at the center of the wiring board 51 and is covered with a transparent structure 48 so as to fit in a rectangular peripheral frame 52.

  The interface 53 for extracting light from the transparent structure 48 is formed in a concavo-convex structure that alternately repeats a surface 56 that is parallel to a surface 55 that is orthogonal to the emitted light 54 from the LED chip 50, and has a groove depth 57. Characterized by a constant structure. That is, the thickness of the several convex part in a transparent structure is made equal. By making the groove depth 57 uniform, structural distortion generated by stress such as thermal expansion of the transparent structure 48 is equalized and reduced. Furthermore, when the uneven structure is formed with a mold, it can be easily formed.

  FIG. 6 is a cross-sectional view showing an optical structure of the light source module 59 using the transparent structure 58 according to the fifth embodiment. It is a modification with respect to the transparent structure 5 of Example 1. FIG.

  In FIG. 6, the basic structure of the light source module 59 is such that an LED chip 60 as a light source is disposed at the center of a wiring board 61 and is covered with a transparent structure 58 so as to fit in a rectangular peripheral frame 62.

  The interface (64 + 65) for extracting light from the transparent structure 58 is formed with a concavo-convex structure that alternately repeats a surface 65 that is parallel to the surface 64 orthogonal to the radiation light 63 from the LED chip 60. The structure is characterized in that the angle width 66 of the orthogonal surface 64 viewed from the chip 60 is constant. That is, the circumference angles of the arcs constituting the plurality of convex portions are made equal. By making the angular width 66 of the divided orthogonal surfaces 64 constant, the solid angle from the LED chip 60 is made equal and the luminous intensity is optimized. Furthermore, the structural distortion to the central part generated by stress such as thermal expansion of the transparent structure 58 is reduced.

  FIG. 7 a is a top view showing an optical structure of the light source module 68 using the transparent structure 67 according to the sixth embodiment. It is a modification with respect to the transparent structure 5 of Example 1. FIG.

  In FIG. 7 a, the basic structure of the light source module 68 is that an LED chip 69 as a light source is arranged at the center, and the inner region of a rectangular (elongated) peripheral frame 70 is covered with a transparent structure 67. . The interface of the transparent structure 67 (uneven surface repeated with a solid line and a broken line) is concentrically formed so as to fit inside the peripheral frame 70.

  Similarly, FIG. 7 b is a top view showing an optical structure of the light source module 72 using the transparent structure 71 according to the sixth embodiment. It is a modification with respect to the transparent structure 5 of Example 1. FIG.

  In FIG. 7 b, the basic structure of the light source module 72 is that an LED chip 73 as a light source is arranged in the center, and the inner region of a peripheral frame 74 having a circular shape (the same applies to an elliptical shape) is covered with a transparent structure 71. ing. The interface of the transparent structure 71 (uneven surface repeated with a solid line and a broken line) is concentrically formed so as to fit inside the peripheral frame 74.

  FIG. 8 is a partial structural view of a part of the light source module 76 using the transparent structure 75 according to the seventh embodiment, in which the interface curved surface structure of the transparent structure 75 is formed as a flat surface. Plane) and a top view (XY plane). It is a modification with respect to the transparent structure 5 of Example 1. FIG.

  A structure in which a three-dimensional curved surface 77 (XZ plane, YZ plane) of an orthogonal plane 7 and a parallel plane 8 constituting the interface 9 of the transparent structure 5 of FIGS. And The deviation amount (angle) of the flat surface 78 with respect to the orthogonal surface 7 and the parallel surface 8 is within the critical angle θo. Here, in the cross section of the transparent structure 75, each of the plurality of convex portions is configured by a part of a radius of a circle centering on the light source and a plurality of circular chords. By dividing the curved surface 77 into multi-parts and forming an appropriate fine flat surface structure (FIG. 8: two parts 78-1 and 78-2), the mold shape with respect to the interface 77 is simplified, the mold molding is simplified, and low Cost reduction is realized.

  FIG. 9 is a top view showing an optical structure of the light source module 80 using the transparent structure 79 according to the eighth embodiment. It is a modification with respect to the transparent structure 5 of Example 1. FIG.

  In FIG. 9, the basic structure of the light source module 80 is that an LED chip 81 as a light source is disposed at the center of the wiring board 82 and is covered with a transparent structure 79 so as to fit in a rectangular peripheral frame 83.

  The transparent structure 79 includes a concavo-convex structure 89 (a concave line 86 is a solid line circle and a convex part 87 is a broken line circle) formed by a surface 85 in which the inside of the thick broken line 88 is parallel to the orthogonal surface 84, and a region excluding it. Forms a flat surface 90. The flat surface 90 has a structure in which the surface of the concavo-convex structure 89 is equivalently filled with the same material. By controlling the arrangement of the concavo-convex structure 89 (region where total reflection does not occur) of the transparent structure 79, the thick broken line 88 can be displayed in an arbitrary shape and structure (character, pattern). By miniaturizing the concavo-convex structure 89, the surface of the transparent structure 79 can be flattened and at the same time the display resolution of characters / patterns / marks and the like can be improved.

  FIG. 10 a is a cross-sectional view of a light source module 92 using a transparent structure 91 composed of a first transparent structure 98 and a second transparent structure 93 according to the ninth embodiment. FIG. 10 b shows a cross-sectional view of the second transparent structure 93. FIG. 10 c is a cross-sectional view of the light source module 94 with the second transparent structure 93 removed from the light source module 92. It is a modification with respect to the transparent structure 5 of Example 1. FIG.

  In FIG. 10 a, the basic structure of the light source module 92 is that the first transparent structure 98 is arranged such that the LED chip 95 as a light source is disposed at the center of the wiring board 96 and the top thereof is accommodated at the height of the peripheral frame 97. (The light source module 94 is formed), and a second transparent structure 93 formed of a film or a sheet shown in FIG. 10b is formed thereon. The concave-convex structure 103 of the second transparent structure 93 formed with respect to the emitted light 102 from the LED chip 95 is the same as the optical arrangement relationship in the first embodiment described above.

The transparent structure 91 includes a first transparent structure 98 and a second transparent structure 93, and the refractive index n1a of the first transparent structure 98 and the refractive index n1b of the second transparent structure 93 are Almost equal.
That is, the ratio between the refractive index of the second transparent structure 93 and the refractive index of the first transparent structure 98 is set to 0.9 or more and 1.1. As shown in FIG. 10 c, the first transparent structure 98 is formed so as to have the flat surface-like interface 101 up to the upper height of the peripheral frame 97 by using a transparent silicone resin in advance in the light source module 94. . The second transparent structure 93 is formed in a sheet shape (film shape) with a two-layer structure of a transparent acrylic resin layer 99 having a concavo-convex structure and a transparent adhesive layer 100 as shown in FIG. The refractive indexes of are substantially equal. That is, the ratio between the refractive index of the second transparent structure and the refractive index of the pressure-sensitive adhesive layer 100 is set to 0.9 or more and 1.1.

  The light source module 92 is formed in close contact with the interface 101 of the first transparent structure 98 of the light source module 94 using the adhesive layer 100 of the second transparent structure 93. At this time, in order to prevent the interface 101 from containing voids or the like, a lattice-like air escape structure (not shown) is formed and attached to the adhesive layer 100.

  FIG. 10a shows only the basic configuration of the light source module 92, but there are cases where a plurality of light source modules 92 are used and arranged two-dimensionally in a two-dimensional manner. As shown in FIG. 10a, the second transparent structure 93 has a structure that covers the upper part of the peripheral frame 97, thereby removing the non-light-emitting portion that occurs at the boundary of the adjacent portion and simultaneously expanding the viewing angle. ing. In some cases, the upper portion of the peripheral frame 97 has an acute angle or thin line structure (not shown) to remove unevenness in the boundary of the non-light emitting portion. In addition, when the viewing angle is expanded, the structure of the light source module 92 can be brought closer to 180 degrees by geometrically thinning and large area.

  FIG. 11 a is a cross-sectional view showing a modification of the LED chip 2 that is the light source of the first embodiment in the light source module 104 according to the tenth embodiment.

The light source 105 includes a blue LED chip 106 and a transparent resin 107 in which a phosphor is dispersed. The LED chip 106 is substantially hemispherically covered with the transparent resin 107. The shape of the transparent resin 107 is formed by die molding or potting. The phosphor thickness 108 formed on the LED chip 106 is set to 5 to 50 μmt in order to transmit the excitation light. In the transparent resin 107, a YAG (Ce) phosphor using the LED chip 106 as an excitation light source is dispersed and used. Similarly, the three-wavelength phosphor may be dispersed using a UV-LED as an excitation light source.

  FIG. 11B is a cross-sectional view showing a modification of the tenth embodiment of the light source module 109 according to the eleventh embodiment.

The light source 110 includes an LED chip 111, a first transparent resin 112 that does not include a phosphor, and a second transparent resin 113 in which the phosphor is dispersed. The first transparent resin 112 covers the LED chip 111, and The second transparent resin 113 covers the first transparent resin 112. The first transparent resin 112 and the second transparent resin 113 are covered with a substantially hemispherical shape centered on the LED chip 111. The second transparent resin 113 keeps the spherical shell thickness 114 viewed from the LED chip 111 to be substantially constant (5 to 50 μmt), and transmits the excitation light uniformly. In the second transparent resin 113, a YAG (Ce) phosphor using the blue LED chip 111 as an excitation light source is dispersed and used. Similarly, the three-wavelength phosphor may be dispersed using a UV-LED as an excitation light source.

  FIG. 11C is a cross-sectional view showing a modification of the tenth embodiment of the light source module 115 according to the twelfth embodiment.

The light source 116 includes an LED chip 117 and a transparent resin 118 in which a phosphor is dispersed. The LED chip 117 partially covers only the upper surface with a transparent resin 118 having a constant thickness (5 to 50 μmt) 119. The radiated light from the LED chip 117 takes out direct excitation light from the side surface, and phosphor emission and excitation light from the upper surface.

  FIG. 12 a is a cross-sectional view illustrating a modification of the twelfth embodiment of the light source module 120 according to the thirteenth embodiment.

  The light source 121 includes an LED chip 122 and a transparent resin 123 in which a phosphor is dispersed. On the light source 121, a transparent structure 125 having an interface 124 made of an uneven structure that removes and suppresses total reflection is formed. A concave portion 126 on a spherical surface having a small radius of curvature is formed at the center of the transparent structure 125 so that total reflection does not occur. Thereby, the light emitted from directly above the light source 121 is controlled, and the light extraction intensity from the light source module 120 is made uniform.

  FIG. 12B is a cross-sectional view showing a modification of the thirteenth embodiment, which is a light source module 127 according to the fourteenth embodiment.

  An inverted conical recess 129 is formed at the center of the transparent structure 128 so as not to cause total reflection. Thereby, the light emitted from directly above the light source 130 is controlled, and the light extraction intensity from the light source module 127 is made uniform.

  FIG. 13A is a cross-sectional view showing a modification of the first embodiment in the light source module 131 according to the fifteenth embodiment.

  The light source module 131 is formed so that the LED chip 133 is disposed on the wiring substrate 132, the reflective structure 134 is disposed on the peripheral side surface thereof, and the transparent structure 135 is covered thereon. The emitted light 136 from the LED chip 133 is extracted from the interface 137 on the upper side of the transparent structure 135 by the outgoing light 138-1 that is directly extracted and the reflected light 138-2 that is reflected by the reflective structure 134 and is output. Yes.

  Outgoing light 138-1 is extracted from orthogonal surfaces 139 (139-0, 139-1, 139-2,...) That form the interface 137 with respect to the emitted light 136. The reflected light 138-2 acts as a surface orthogonal to the parallel surface 141 (141-1, 141-2, 141-3...) Constituting the interface 137 with respect to the radiated light 136. The light is taken out by being reflected (mainly specular reflection) at the interface 140 of the reflective structure 134.

  The shape of the interface 140 is determined geometrically and optically by the shape and arrangement of the LED chip 133, the reflective structure 134, and the transparent structure 135, and has a convex curved surface structure (parabolic approximate curve, elliptic approximate curve, etc.). That is, when the reflected light 138-2 is taken out orthogonally on the surface 141 parallel to the transparent structure 135 with respect to the emitted light 136 emitted from the arbitrary surface (point light source) of the LED chip 133, the interface 140 of the reflective structure 134. The shape and position are uniquely determined by the convex curved surface structure described above. The reflective structure 134 is molded using a white acrylic resin with high reflectivity and high reliability.

  Since the emitted light 136 from the LED chip 133 can extract almost all of the emitted light 138-1 and reflected light 138-2 without depending on the radiation pattern of the LED chip 133 that is a light source, the light extraction of the light source module 131 is possible. The efficiency is greatly improved.

  FIG. 13 b is a cross-sectional view showing a modification of the fifteenth embodiment, which is a light source module 142 according to the sixteenth embodiment.

  The light source module 142 is formed so that the LED chip 144 is disposed on the wiring substrate 143, the reflective structure 145 is disposed on the peripheral side surface thereof, and the transparent structure 146 is covered thereon. The emitted light 147 from the LED chip 144 is extracted as outgoing light 149-1 that is directly extracted from the interface 148 on the top of the transparent structure 146 and reflected light 149-2 that is reflected by the reflective structure 145 and is output. . A portion of the reflective structure 145 that is in contact with the transparent structure 146 has a stepped shape.

  The outgoing light 149-1 is extracted from a surface 150 (150-0, 150-1, 150-2,...) Orthogonal to the radiation light 147 that forms the interface 148. The reflected light 149-2 acts as a surface orthogonal to the parallel surface 151 (151-1, 151-2, 151-3...) Constituting the interface 148 with respect to the radiated light 147. The light is reflected (mainly specularly reflected) at the interface 152 of the reflective structure 145 and taken out.

  The interface 152 is formed by a step structure alternately with a surface 153 parallel to the radiated light 147 (a surface that does not reflect) and a surface 154 that reflects the radiated light 147. Unlike the case of the fifteenth embodiment, by adding a surface 153 parallel to the interface 152, the position and area of the interface 148 of the transparent structure 146 from which the reflected light 149-2 is extracted are expanded. As a result, the surface 151 that is parallel to the transparent structure 146 with respect to the radiated light 147 and the surface 156 that is orthogonal to the reflected light 155 at the interface 152 of the reflective structure 145 (the same surface as the surface 151 that is parallel). In the meantime, light is extracted from almost the entire area of the parallel surface 151 (orthogonal surface 156) of the transparent structure 146 to improve the luminance uniformity.

  FIG. 14 is a cross-sectional view of a plurality of light source modules 157 (157-1, 157-2...) According to the seventeenth embodiment.

  In the plurality of light source modules 157 (157-1, 157-2,...), The LED chip 158 and the reflective structure 159 are mounted on the wiring board 160, and the transparent structure 161 is formed thereon and formed integrally. . The transparent structure 161 includes a first structure 169 and a second structure 170.

  FIG. 15 a is a top view of the second structure 170 constituting the transparent structure 161.

  15b is a cross-sectional view taken along the line DD of FIG. 15a, and shows a structure in which a release separator 171 is attached to the second structure 170. FIG.

  As shown in FIG. 14, the wiring board 160 has a double-sided wiring structure, and wiring patterns 162-1 and 162-2 are formed on both sides of the Cu through hole 163 at the center of the board on which the LED chip 158 is mounted for each light source module 157. The high heat dissipation structure is formed by the AGSP substrate structure. On the surface of the wiring board 160, a white resist 164 having a high reflectivity is formed in a region excluding the Cu through hole 163. A wiring pattern 162-2 formed on the back surface of the wiring board 160 is closely attached to a heat radiating housing 165 made of a thin aluminum plate via a highly heat conductive adhesive sheet 166, and efficiently dissipates heat generated from the LED chip 158. Yes.

  A thin carbon sheet (0.1 to 1.0 mmt) with high thermal conductivity may be used as the heat radiating casing 165. The anisotropic thermal conductivity with respect to the horizontal direction in the plane is Cu level, and the heat dissipation from the heat generating part of the wiring pattern 162-2 to the peripheral part (not shown) is improved to provide a high heat dissipation structure to the outside air. Realized. At the same time, the weight has been reduced by converting the aluminum sheet into a carbon sheet.

The structure of the wiring pattern 162-2 is a shape that is one digit larger than the area of the LED chip 158 and the Cu through hole 163, and a thick copper foil (50 to 150 μmt) is used to form a heat spreading structure, to the heat radiating case 165. High heat dissipation is ensured.

  Ni / Ag plating 167 is applied to the surface of the wiring pattern 162-1 on the Cu through-hole 163 on which the LED chip 158 is mounted, and the light flux from the LED chip 158 is reflected. In order to ensure high reliability and optical characteristics, Ni / Ag / Au plating or Ni / Sn plating may be used. For the connection between the Cu through hole 163 and the LED chip 158, the back surface of the LED chip 158 is metallized and fixed (die bonding) with an Au / Au or Au / Sn junction. When the back metallization is not formed, it is directly fixed with a white silicone resin (high reflectivity member). In this case, the thickness is reduced within 1 to 20 μm in order to reduce the thermal resistance of the fixing portion. When a white alumina substrate is used for the wiring substrate 160, a transparent silicone resin (transmission) may be used for the die bonding material of the LED chip 158 and reflected by the alumina substrate.

  On the wiring substrate 160, the LED chip 158 and a reflective structure 159 surrounding the periphery thereof are arranged, and a transparent structure 161 is formed thereon. Adjacent reflection structures 159-1 and 159-2 are formed so as to integrate step structures.

  The transparent structural body 161 is formed by being divided into a first structural body 169 and a second structural body 170 at the top surface 168 of the reflective structural body 159.

  The first structure 169 has a monotonous flat surface, a concave surface approximated by a flat surface, or a convex surface, and is formed of a silicone-based transparent resin.

  As shown in FIGS. 15A and 15B, the second structure 170 is formed by a laminated structure of an acrylic transparent resin layer 173 and an adhesive layer 174 having a high transmittance made of an acrylic transparent resin. In the second structure 170 in FIG. 15B, an uneven interface 172 is formed on the surface of the acrylic transparent resin layer 173 from which light is extracted to remove and suppress total reflection.

  The first structure 169 and the second structure 170 are closely integrated with each other at the surface 168 of the highest part via the adhesive layer 174 capable of absorbing the above-described monotonous flat surface to form a transparent structure 161. Yes. The uneven interface 172 of the transparent structure 161 is formed in a structure that removes and suppresses total reflection with respect to the radiated light 175 from the LED chip 158.

  From the optical aspect, the relationship of n1a ≦ n1b is used, using 1.4 as the refractive index n1a of the first structure 169 and 1.4 to 1.7 as the refractive index n1b of the second structure 170. Is maintained. The allowable numerical range of the refractive index ni is such that the ratio of the refractive index n1a of the first structure 169 and the refractive index n1b of the second structure 170 is 0.9 or more and 1.1 due to the existence of a critical angle. By satisfying the following, total reflection inside the transparent structure 161 can be suppressed. In some cases, a difference is provided as n1a <n1b. When the emitted light is incident on the second structure from the first structure, a condensing function can be realized using the difference in refractive index.

  Furthermore, since the total reflection from the transparent structure 161 to the outside (no in the air = 1.0) can be removed and suppressed, the refractive indexes n1a and n1b are changed to the base material refractive index n2 of the LED chip 158 (in the case of a blue LED). N2 = 2.4). That is, the light extraction efficiency from the LED chip 158 to the transparent structure 161 can be greatly improved at the same time.

  By reducing the shape of the reflective structure 159 and the transparent structure 161 (169 + 170) with respect to the LED chip 158 at the same time as increasing the size, the viewing angle is increased to nearly 180 degrees.

  The luminance unevenness between the adjacent light source modules 157-1 and 157-2 has a structure in which the second structure 170 constituting the transparent structure 161 is arranged on the upper part of the reflecting structures 159-1 and 159-2. The radiated light 175 can be exchanged and relaxed and suppressed.

  Since the transparent structure 161 is divided into two parts, the second structure 170 can be assembled in a later process, and the workability and yield of the light source module 157 are improved.

Regarding the thinning of the light source module, in the case of the light source module 157 including the LED chip 158, the wiring substrate 160, the transparent structure 161 (169 + 170), and the reflection structure 159, as an example, the size of the light source module 157: 30 mm square, LED Chip 158 size: 0.3 mm square, wiring board 160 thickness: 0.5 mm, reflection structure 159 thickness: 1.0 mm
If the thickness of the second structure 170 is 0.5 mm, the thickness can be about 2.0 mm. In the case of a hemispherical transparent structure, since the height is 16 mm or more, there is a reduction effect of almost one digit. If the size of the light source module 157 can be increased, the thickness reduction effect can be further increased because the thickness does not increase basically. At the same time, since the increase in volume and weight of the second structure 170 can be suppressed, a reduction effect can be obtained at a large ratio with respect to the weight reduction of the light source module 157.

  As a result of thinning the light source module 157, it is possible to make it flexible as a base material function. Therefore, there is a degree of freedom and an effect that a curved light source module can be easily formed instead of a flat type.

  As a modified example, a phosphor layer is formed so as not to generate bubbles at the laminated interface (not shown) of the acrylic transparent resin layer 173 and the pressure-sensitive adhesive layer 174 constituting the second structure 170, thereby forming a white light source. In some cases. The light source module at this time forms a YAG (Ce) phosphor layer and a three-wavelength phosphor layer on the second structure 170 using a blue LED chip or UV-LED as an excitation light source. The phosphor layer is a thin sheet or film dispersed in an acrylic resin or a silicone resin, and the second structure 170 is formed in a three-layer structure using this. In order to remove the color tone difference due to sheet thickness dependence with respect to the radiated light from the LED chip, a distribution in which the phosphor dispersion density decreases as the distance from the LED chip that is the excitation light source is patterned on the thin sheet. Cost reduction is also realized by efficient formation of the density distribution pattern of the phosphor.

  As another modification, a thin phosphor film may be formed on the surface of the acrylic transparent resin layer 173 constituting the second structure 170 to form a white light source. The light source module at this time forms a YAG (Ce) phosphor film and a three-wavelength phosphor film on the concave-convex interface 172 using a blue LED chip or UV-LED as an excitation light source. The thickness of the phosphor film is 5 to 100 μm, and the phosphor is dispersed in an acrylic transparent resin. After forming the phosphor film into a thin film sheet, the phosphor film is mounted on the concavo-convex interface 172 of the second structure 170 and laminated and adhered during molding to be integrated. In addition, the phosphor film may be integrally formed in the acrylic transparent resin 173 at the same time as the uneven interface 172 is formed.

  As another modified example, a structure in which a thin plate, a sheet, or a film is formed with an acrylic transparent resin in which a phosphor is dispersed, and is disposed on the uneven interface 172 of the second structure 170 via an air layer is used. In some cases. The excitation light emitted from the light source module 157 forms white light by exciting, reflecting, or transmitting the phosphor dispersed in the thin plate, thin sheet, or film. At this time, since the thin phosphor has an effect of scattering the emitted light, it also functions as a diffusion plate. That is, in the case of an illuminating device in which a diffusing plate is arranged outside the light source module 157, a diffusing plate in which phosphors are dispersed is used as the diffusing plate 185 in FIG. Thus, a white illumination device can be formed.

  By separating the phosphor from the light source module 157 and adding the function to add the phosphor to the diffusion plate, it is possible to suppress and reduce the member cost and manufacturing cost of the lighting device.

  FIG. 16A shows a case where the diffuser plate 185 is removed by a direct type illumination device 181 in which a large number of light source modules 176 (176-1, 176-2, 176-3...) Related to Example 18 are arranged vertically and horizontally. And is a modification of the seventeenth embodiment. FIG. 16B is a cross-sectional view taken along line EE of the direct illumination device 181 of FIG. 16A.

  In the light source module 176 (176-1, 176-2, 176-3...), The LED chip 177 and the reflective structure 178 are mounted on the wiring board 179, and the transparent structure 180 is formed on the LED chip 177. On the other hand, it is integrally formed.

  In this embodiment, the LED chip 177 is used as the light source, but a white light source basically composed of the excitation light source and the phosphor described in Embodiments 10 to 12 may be used instead.

  Furthermore, the case where the LED chip 177 can emit white light by RGB three-color light emission (formation of two external electrode terminals by the same driving current) and does not require a phosphor is also included.

  The direct illumination device 181 includes a heat radiating housing 183, a diffusion plate 185 that emits light from the light source module 176, and a large number of light source modules 176 (a drive circuit and a power supply unit for the LED chip 177 are omitted).

  In the case of using a thin plate or sheet of acrylic transparent resin in which the phosphor described in Example 17 is dispersed instead of the diffusion plate 185 described above, the LED chip 177 of the light source module 176 is excited by blue LED or UV-LED. A white light source is formed by using the light source. This is because the phosphor of the white light source can be separated from the light source module 176, and the phosphor can be separately dispersed and formed on the diffusion plate 185 of the lighting device 181. In the light source module 176, the structure is simplified and the assembly structure and the manufacturing process are simplified at the same time as the phosphor is separated, and the yield improvement and the characteristic variation reduction can be easily realized.

  The light source module 176 is fixed to the heat radiating housing 183 via a highly heat-conductive adhesive sheet 182, and the diffusion plate 185 is disposed on the light extraction surface side of the light source module 176 via the air layer 184, and diffuses with the heat radiating housing 183. The plate 185 is configured to be incorporated in the outer frame casing 186.

  FIG. 16C is a top view of the optical sheet 188 in which a large number of second structures 187 constituting the transparent structure 180 used in the direct type illumination device 181 are arranged in a plane. 16d is a cross-sectional view taken along line FF in FIG. 16c. As in the case of Example 17, the second structure 187 has an acrylic transparent resin layer 190 and an acrylic transparent resin, which has a concavo-convex interface 189 on which the light extraction surface side suppresses total reflection. A two-layer structure of a high pressure-sensitive adhesive layer 191 is integrally formed, and a release separator 192 is attached to the pressure-sensitive adhesive layer 191 side to be used as an independent optical sheet 188.

  FIG. 16E is a top view in which a large number of reflecting structures 178 of the light source module 176 used in the direct type illumination device 181 are integrally molded. 16f is a cross-sectional view taken along line GG in FIG. 16e.

  In addition to the wiring board 179 constituting the light source module 176 and the second structure 187, the reflecting structure 178 is integrated, thereby simplifying the assembly process of the direct type lighting device 181 and improving the assemblability and yield. Improvement and further cost reduction are realized.

  FIG. 16 g is a cross-sectional view of a liquid crystal display device 193 incorporating the direct illumination device 181.

  In order to use the direct illumination device 181 as a white light source, as described above, the diffusion plate 185 is a thin plate or sheet of acrylic transparent resin in which fine particles having a different refractive index from the base resin and phosphor particles are mixed and dispersed. The film is formed effectively and functionally, and the LED chip 177 of the light source module 176 is a blue LED or UV-LED. In particular, in some cases, the diffusion plate 185 is formed using only phosphor fine particles instead of transparent fine particles having a refractive index different from that of the acrylic transparent resin.

  A styrene resin, a vinyl chloride resin, a polycarbonate resin, or the like may be used in place of the acrylic resin.

  When emitted light extracted from the LED chip 177 to the air layer 184 through the transparent structure 180 enters the diffuser plate 185, a color difference depending on the incident angle may occur due to the influence of the thickness of the phosphor layer. is there. In order to eliminate this, the amount of dispersion of the phosphor layers as seen from the direction of the LED chip 177 (point light source) which is an excitation light source is made equal. That is, a distribution in which the dispersion density decreases as the distance from the LED chip 177 increases is formed on the diffusion plate 185. As a result, the color tone of white light is made uniform with respect to the viewing angle, and at the same time, the amount of phosphor used is reduced and the cost is reduced.

  White light from the diffusion plate 185 of the direct type illumination device 181 includes a liquid crystal panel 194 having a pair of substrates and a liquid crystal layer sandwiched between the pair of substrates, a pair of deflecting plates 195a disposed on both surfaces of the liquid crystal panel 194, and It is taken out via the polarizing plate 195b.

  By arranging a plurality of thin light source modules 176 vertically and horizontally, two-dimensional area control can be performed at the same time as ultra-thin and light weight, and low power consumption is realized.

  The heat generated in the light source module 176 incorporated in the direct type illumination device 181 is evenly distributed in the basic unit of the light source module 176 because of the direct type, and has high heat dissipation from the heat radiating housing 183 directly into the air. Heat is radiated to the outside through an opening 197 on a slit provided in the external housing 196.

  FIG. 17 a is a top view of another light source module 198 according to the nineteenth embodiment, which is a modification of the first embodiment. FIG. 17B is a cross-sectional view taken along line HH of the light source module 198 of FIG. 17A.

  In the light source module 198, the LED chip 199 and the reflective structure 200 disposed in the periphery are mounted on the wiring board 201, and the transparent structure 202 is formed thereon.

  Both the wiring substrate 201 and the reflective structure 200 are formed of a white ceramic substrate having a high reflectance. The reflective structure 200 is laminated on the wiring substrate 201 and is integrally formed with a large number of pieces. The wiring pattern (not shown in the figure) of the wiring board 201 is through-hole connected by two-layer wiring as in the first embodiment. On the surface of the transparent structure 202, a concavo-convex interface 203 that suppresses total reflection is formed in a flat shape, and at the same time as the transparent structure 202 of the light source module 198 is thinned (thickness reduction 204 compared to the hemispherical shape), an LED chip. The light extraction efficiency from 199 is greatly improved. Further, the height of the uneven interface 203 is formed lower than the highest portion of the reflective structure 200 by taking advantage of the thinning effect of the transparent structure 202. When the light source module 198 is handled, damage such as scratches is not applied to the uneven interface 203.

  FIG. 18A shows a linear light source module 205 in which the light source modules 198 (198-1a, 198-1b, 198-2a, 198-2b...) According to the nineteenth embodiment are routed and arranged on the wiring board 207 in a straight line. It is a top view.

  18B shows a structure in which the heat radiation substrate 206 is attached to the linear light source module 205 using the adhesive sheet 208 having high thermal conductivity, and is a cross-sectional view taken along the line II in FIG. 16A.

  FIG. 18 c is a top view of the block illumination device 209 using the linear light source module 205 according to the nineteenth embodiment when the diffusion plate 210 is removed. 18d is a cross-sectional view taken along line JJ in FIG. 18c.

  FIG. 18E is a cross-sectional view of the liquid crystal display device 211 using the block illumination device 209 according to the nineteenth embodiment.

  FIG. 18F shows an example of the video display device 212 using the liquid crystal display device 211 according to the nineteenth embodiment, and shows a plan view of the inside on the back side of the video display device 212.

  The heat generated in the linear light source module 205 is uniformly radiated from the heat dissipation substrate 206 to the heat dissipation housing 217 of the block type lighting device 209 and is efficiently taken out into the air.

  The heat dissipating board 206 (206-1, 206-2...) Discretized for each block is formed by processing a part of the heat dissipating case 217 to form a plurality of protrusions and bending them at right angles. Yes.

  The block illumination device 209 of FIG. 18c has a function of being controlled to be lit by being divided into N × M blocks, so that brightness adjustment and the like are easy and power consumption is reduced.

  The block type illumination device 209 shown in FIG. 18c has the necessary number of linear light source modules 205 to secure the luminance of the light source modules 198 with respect to the side surface portions 214 of each block of the integrated light guide plate 213 (in this embodiment, 2). Are placed close to each other and light is made incident. The transparent structure 202 that has been difficult to be converted to a point light source with respect to the light source module is thinned (thickness reduction 204 with respect to the hemispherical shape). Is arranged close to the side surface portion 214 for each block to suppress uneven brightness. Further, a diffusion plate 210 is disposed on the integrated light guide plate 213 that emits light from the light source module 198 via an air layer 215 to reduce luminance unevenness for each block.

  Further, a white resist having a high reflectivity is formed on the routing wiring board 207, and absorption loss is caused with respect to the multiple reflection between the side surface portion 214 of each block of the integrated light guide plate 213 and the routing wiring board 207. It is decreasing.

  In this embodiment, the LED chip 199 is used as the light source, but a white light source that is basically composed of the excitation light source and the phosphor described in Embodiments 10 to 12 may be used instead.

As a modification, in the light source module 198, only the blue LED or the UV-LED is used for the LED chip 199, and the phosphor may be separated from the light source module 198.
That is, in the light source module 198, only the excitation light is efficiently extracted from the transparent structure 202, and then the phosphor formed and arranged outside the light source module 198 is excited to emit light to form white light.

  The fluorescent material may be arranged at the side surface portion 214 of each block of the integrated light guide plate 213 immediately after the excitation light emission is taken out. In this case, a thin acrylic resin sheet or film in which a phosphor is dispersed is fixed to the side surface portion 214 of each block with a transparent adhesive sheet (not shown), and white light is applied to each block of the integrated light guide plate 213. Make it incident. As a modification, the acrylic resin sheet in which the phosphor is dispersed may be integrally formed with a transparent adhesive sheet in order to disperse the phosphor fine particles while being fixed to the side surface portion.

  When a color difference occurs, in order to remove the color difference, the amount of dispersion of the phosphor as seen from the direction of the LED chip 199 (point light source) which is an excitation light source is made equal. That is, a distribution in which the dispersion density decreases as the distance from the LED chip 199 increases is formed on the side surface portion 214. Thereby, the color tone of the white light can be made uniform with respect to the light guide plate 213, and at the same time, the amount of phosphor used can be reduced and the cost can be reduced.

  As another modification, there is a case where the phosphor is formed and arranged on the diffuser plate 210 after taking out the uniform excitation light emission from the integrated light guide plate 213, that is, reducing the luminance unevenness between the N × M blocks. . The diffusing plate 210 can form white illumination by using a diffusing plate in which phosphors are dispersed instead of a conventional diffusing plate, or by dispersing only phosphors. The phosphor is separated from the light source module 198, and the phosphor is formed as diffusion fine particles on the diffusion plate 210. Thereby, the function with respect to a structural member is isolate | separated and added in the illuminating device 209. FIG. As a result, the increase in member cost and manufacturing cost of the lighting device 203 is suppressed and eliminated.

  The white light 216 from the diffusion plate 210 of the block illumination device 209 includes a liquid crystal panel 219 having a pair of substrates and a liquid crystal layer sandwiched between the pair of substrates, and a pair of deflecting plates 218a disposed on both surfaces of the liquid crystal panel 219. And the polarizing plate 218b.

  The video display device 212 includes a power supply unit 222 for supplying power to a block-type lighting device (backlight device) 209, a liquid crystal display unit, and the like in the gap 221 between the heat radiating housing 217 and the housing 220 on the back side, and a liquid crystal display. A signal processing unit 223 that performs signal processing such as contrast and frame rate on a video signal supplied to the display unit, and structures 224a and 224b such as speakers are provided. Note that the direct type illumination device (backlight device) 181 described in Embodiment 17 may be applied to the video display device of this embodiment.

  FIG. 19 is a top view of another light source module 225 according to the twentieth embodiment. 20 is a cross-sectional view of the light source module 225 of FIG. 19 taken along the line KK.

  The light source module 225 has a plurality of LED chips 226 (226-1, 226-2, 226-3...) As light sources arranged at a constant pitch p228 in the direction of the central axis 231 at the center of the wiring board 227. It is covered with a transparent structure 230 so as to fit in an elongated rectangular peripheral frame 229.

  Unlike the case where the hemispherical structure of the first embodiment is thinned, the transparent structure 230 is thinned for a semi-cylindrical structure. In the case of the hemispherical type, the emitted light from the LED chip can be taken out from the transparent structure as a point light source. However, in the case of the present embodiment, since it is a semicylindrical type, the incident angle θi with respect to the direction of the central axis 231. Therefore, total reflection can be removed and suppressed only in the direction 240 orthogonal to the central axis 231. The advantage of the semi-cylindrical type is that, as shown in FIGS. 19 and 20, a large number of LED chips 226 can be mounted at a high density while forming a thin structure, and a light source module 225 with high brightness and high output can be realized. It is. The light extraction ratio is lower than that in the case where the interface is hemispherical, but is higher than that in a flat surface regardless of the thinned structure of the transparent structure 230.

As shown in FIGS. 19 and 20, the interface 232 of the transparent structure 230 forms an uneven structure parallel to the central axis 231 in a planar shape. That is, the transparent structure 230 has a concavo-convex structure having a plurality of concentric curvatures with respect to a direction orthogonal to the central axis 231 with respect to a plurality of LED chips 226 (226-1, 226-2, 226-3...). An interface 232 made of is formed in a planar shape.
The interface 232 is a surface 235 that is parallel to the surface 234 that is discretely orthogonal to the emitted light 233 (233-0, 233-1, 233-2,...) Orthogonal to the central axis 231 from the LED chip 226. And are alternately formed. In the transparent structure 230, a parallel surface 235 is inserted between the orthogonal surfaces 234, and the curvature and shape are changed by the length (pitch) d236 so that the convex structure of the interface 232 is arranged in a plane. I have to. As a result, the thickness 238 of the convex portion formed by a semicircular orthogonal circle (a semicircle having the maximum radius with respect to the emitted light 233) 237 in a direction orthogonal to the central axis 231 can be removed, and a flat thin structure Is easily realized. The light extraction efficiency at this time is transmitted through the surface 234 orthogonal to the interface 232 with respect to the radiated light 233 from the LED chip 226 disposed in the center of the transparent structure 230. It does not occur and is improved.

  As shown in FIG. 20, the central flat portion 239 of the interface 232 is formed with a width that does not cause total reflection. That is, the incident angle 241 is less than the critical angle θo with respect to the emitted light 233 from the LED chip 226.

  The formation region of the interface 232 in the light source module 225 includes the central flat portion 239, but is sufficiently large because total reflection does not occur even when flattened according to the principle of the present invention. In addition to high luminance and high output, improvement in luminance uniformity and expansion of viewing angle (180 degrees) are obtained.

  On the other hand, with respect to the direction of the central axis 231, the LED chips 226 are arranged within a certain pitch p228 as shown in FIG. That is, the length of the pitch p228 is set to an angle θ241 that is equal to or smaller than the critical angle θo with respect to the emitted light 233, and is substantially equal to the width of the central flat portion 239 of the interface 232. This is to remove a useless area where the emitted light 233 from the LED chip 226 is totally reflected in the interface area in the direction of the central axis 231. On the contrary, by reducing the length of the multi-chip pitch p228, a thin and highly efficient module with higher luminance and higher output can be realized.

  In the light source module 225, the LED chip 226 uses only a blue LED or a UV-LED including the case of RGB single color. In order to obtain white light for a blue LED or UV-LED, the phosphor is formed and arranged separately from the light source module 225. That is, in the light source module 225, only the excitation light is efficiently extracted from the transparent structure 230, and then the diffusion plate (the direct illumination device 181 configured with the diffusion plates 185 for the multiple light source modules 176 in FIGS. 16a and 16b) is used. Corresponding), the phosphor is excited to emit white light. In addition to fine particles having different refractive indexes, fine particles of phosphor are added to the diffusion plate. In some cases, only the fine particles of the phosphor may have the function of a diffusion plate.

  When a color difference occurs, in order to eliminate this, the amount of dispersion of the phosphors taken from the direction of the LED chip 226 that is the excitation light source is made equal. That is, a distribution in which the dispersion density is decreased as the distance from the LED chip 226 is increased is formed on the diffusion plate (not shown). As a result, the color tone of the white light is made uniform with respect to the diffusion plate (not shown), and at the same time, the amount of phosphor used is reduced to reduce the cost.

  In the lighting device (not shown) with a diffuser plate (not shown) added to the light source module 225, the functions for the components are separated and added, thereby suppressing the increase in the member cost and manufacturing / assembly cost of the lighting device. , Have been removed.

  As a modification, a surface constituting the interface 232 of the concavo-convex structure, that is, a surface 235 parallel to the orthogonal surface 234 may be formed in a direction 240 orthogonal to the central axis 231 instead of the direction of the central axis 231.

  From the principle of the present invention, contrary to the above case, the length of the pitch p228 of the LED chip 226 can be made sufficiently large with respect to the direction of the central axis 231. In this case, the width is formed such that total reflection does not occur in the orthogonal direction 240. That is, the outer shape of the light source module 225 shown in FIG. 19 is elongated in the direction of the central axis 231.

  As another modified example, by arranging a plurality of elongated light source modules 225, a two-dimensional ultra-thin light source module with high brightness and high output can be formed.

  As another modification, it can be made sufficiently long with respect to the direction of the central axis 231 and can be used as an extremely thin linear light source module. In this case, the number of LED chips 226 can be set to one of the minimum units.

  As another modification, the center axis 231 can be curved to form a ring-shaped light source module. In this case, it is necessary to use a plurality of LED chips 226 and to form the concavo-convex structure interface 232 in a ring shape.

  As another modification, ring-shaped light source modules can be concentrically arranged to form a two-dimensional ultra-thin high-luminance and high-output light source module.

  As another modification, ring-shaped linear light source modules may be arranged three-dimensionally concentrically.

1,23,35,49,59,68,72,76,80,92,94,104,109,115,120,127,131,142,157,176,198,205,225 Light source module 2,24 36, 50, 60, 69, 73, 81, 95, 106, 111, 117, 122, 133, 144, 158, 177, 199, 226 LED chips 3, 32, 37, 51, 61, 82, 96, 132, 143, 160, 179, 201, 207, 227 Wiring board 4, 33, 38, 52, 62, 70, 74, 83, 97, 229 Peripheral frame 5, 25, 34, 48, 58, 67, 71, 75, 79, 91, 125, 128, 135, 146, 161, 180, 202, 230 Transparent structure 14, 163 Through hole 15, 16 Electrode pattern 17 Ears 18, 19 Resist layers 20, 21, 197 Opening 22 Die bonding layer 26 Radiation light 86 Concave portion 87 Convex portion 89, 103 Concave structure 93 Second transparent structure 98 First transparent structure 99 Resin layers 100, 174 , 191 Adhesive layer 105, 110, 116, 121, 130 Light source 107, 118, 123 Transparent resin 112 First transparent resin 113 Second transparent resin 126, 129 Recessed shape 134, 145, 159, 178, 200 Reflective structure Body 164 White resist 165, 183, 217 Radiation housing 166, 182 Adhesive sheet 169 First structure 170, 187 Second structure 171, 192 Release separator 172, 189 Uneven surface 173, 190 Transparent resin layer 181 Directly under type Lighting devices 184 and 215 Air layers 185 and 210 Diffuser 186 Outer frame housing 1 8 Optical sheets 193, 211 Liquid crystal display devices 194, 219 Liquid crystal panels 195 a, 218 a Deflection plates 195 b, 218 b Polarizing plates 196 External housing 206 Heat dissipation substrate 209 Illumination device 212 Video display device 213 Integrated light guide plate 220 Housing 221 Gap 222 Power supply unit 223 Signal processing unit 224a, 224b Structure

Claims (28)

A wiring board;
A light source disposed on the wiring board;
A transparent structure that is formed on the wiring board and covers the light source;
The transparent structure has a plurality of convex portions on the light extraction surface,
In the cross section of the transparent structure, each of the plurality of convex portions is configured by a part of a radius of a circle centered on the light source and an arc or string of the circle,
Each of the curvatures of the circles constituting the plurality of convex portions decreases as the distance from the light source decreases. The light source module according to claim 1,
The light source module, wherein the transparent structure is hemispherical or semicylindrical. The light source module according to claim 1 or 2,
In the cross section of the transparent structure, each of the plurality of convex portions includes a part of a radius of a circle centered on the light source and a plurality of chords of the circle. The light source module according to any one of claims 1 to 3,
A light source module, wherein a flat region is formed on a light extraction surface of the transparent structure. The light source module according to claim 4,
The flat region is formed in a central portion of the transparent structure or a peripheral portion of the transparent structure. The light source module according to any one of claims 1 to 3,
A light source module, wherein a concave portion is formed on a light extraction surface of the transparent structure in the vicinity of the light source. The light source module according to any one of claims 1 to 6,
The light source module characterized in that each of a part of a radius of the circle constituting the plurality of convex portions has an equal length. The light source module according to any one of claims 1 to 6,
The light source module, wherein the plurality of convex portions in the transparent structure have the same thickness. The light source module according to any one of claims 1 to 6,
The light source module, wherein each of the arcs constituting the plurality of convex portions has an equal circumferential angle. The light source module according to any one of claims 1 to 9,
The transparent structure is composed of a first transparent structure that covers the light source and a second transparent structure that forms the interface;
The light source module, wherein the second transparent structure is formed of a film or a sheet. A second transparent structure used in the light source module according to claim 10,
The ratio of the refractive index of said 2nd transparent structure and the refractive index of said 1st transparent structure is 0.9-1.1, The 2nd transparent structure characterized by the above-mentioned. A second transparent structure used in the light source module according to claim 10,
In the second transparent structure, a pressure-sensitive adhesive layer is formed on a surface on the side where the first transparent structure is present. The second transparent structure according to claim 12,
The ratio of the refractive index of said 2nd transparent structure and the refractive index of the said adhesive layer is 0.9 or more and 1.1, The 2nd transparent structure characterized by the above-mentioned. The light source module according to any one of claims 1 to 10,
The light source module, wherein the light source is disposed in a central portion of the transparent structure. The light source module according to claim 14, wherein
A peripheral frame is disposed on the wiring board and on the side surface of the transparent structure,
The light source module, wherein the emitted light from the light source is reflected by the surface of the peripheral frame. The light source module according to claim 15, wherein
The light source module according to claim 1, wherein a surface in contact with the transparent structure is inclined with respect to the peripheral frame. The light source module according to claim 15 or 16,
The light source module, wherein the peripheral frame is formed of a reflective sheet. The light source module according to claim 15 or 16,
The light source module, wherein the surface of the peripheral frame has reflectivity. The light source module according to any one of claims 15 to 18,
A portion of the peripheral frame that contacts the transparent structure is stepped. The light source module according to any one of claims 15 to 19,
The light source comprises an LED chip and a transparent resin in which a phosphor is dispersed,
The LED chip is partially covered with the transparent resin. The light source module according to any one of claims 15 to 19,
The light source comprises an LED chip, a first transparent resin that does not contain a phosphor, and a second transparent resin in which the phosphor is dispersed,
The first transparent resin covers the LED chip,
The light source module, wherein the second transparent resin covers the first transparent resin. In the illuminating device which has a light source module as described in any one of Claims 15 thru | or 21,
A linear light source module in which one or a plurality of the light source modules are arranged;
A light guide plate that emits light from the line light source module. A pair of substrates;
A liquid crystal panel having a liquid crystal layer sandwiched between a pair of substrates;
A pair of polarizing plates disposed on both sides of the liquid crystal panel;
A liquid crystal display device comprising: the illumination device according to claim 22. A liquid crystal display device according to claim 23;
A signal processing unit that performs video signal processing on the liquid crystal display device;
A power supply unit for supplying power;
A video display device having a speaker; The light source module according to any one of claims 15 to 21,
A light source module comprising a plurality of the light source modules arranged as a surface light source. A light source module according to any one of claims 14 to 21 or 25;
And a diffusing plate that emits light from the light source module. A pair of substrates;
A liquid crystal panel having a liquid crystal layer sandwiched between a pair of substrates;
A pair of polarizing plates disposed on both sides of the liquid crystal panel;
A liquid crystal display device comprising: the lighting device according to claim 26. A diffusion plate used in claim 26,
A diffusion plate characterized in that fine particles having a different refractive index from the base resin of the diffusion plate and phosphor fine particles are dispersed.

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