JP2007103402A - Optical source - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate an adverse influence that a fluorescence agent included in resin exerted on the light of a light emitting element except for a light emitting element used as an excitation source of fluorescence agent. <P>SOLUTION: An optical source is provided with first and second light emitting elements 8 and 9 emitting first and second colors, a fluorescence agent which is excited by a first luminescent color and emits a third color, first resin 11 comprising a fluorescence agent and covers the first light emitting element and second resin 12 covering first resin 11 and the second light emitting element 9 arranged outside the first resin 11. Light obtained by mixing first, second and third luminescent colors is used as a luminescent color. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a light source that emits light by a combination of a light emitting element and a fluorescent agent that emits light when excited by light of the light emitting element.

  In Patent Document 1, a light emitting element that emits blue light and a fluorescent agent that emits yellow light when excited by blue light are contained in a transparent resin that covers the light emitting element. A light source that emits white light is disclosed.

  In the case of white light emission with a mixed color of blue and yellow, there are few red components among red, green, and blue components, so there is a problem in color reproducibility in backlights of liquid crystal display devices and camera flashes. It was.

In order to compensate for the shortage of the red component, the addition of a red light emitting element has been studied. However, red light is unnecessarily diffused by the fluorescent agent, or the red light transmittance is reduced. In order to increase the green component, there is a similar problem even if a fluorescent material that emits blue light that emits blue light is used.
Japanese Patent Laid-Open No. 2001-196639

  An object of the present invention is to eliminate an adverse effect of a fluorescent agent contained in a resin on light of a light emitting element other than a light emitting element used as an excitation light source of the fluorescent agent. It is an object to provide a white light source with good color reproducibility.

  As described in claim 1, the light source of the present invention emits the first and second light emitting elements emitting the first and second colors, and the third color excited by the first emitted color. A fluorescent agent that emits light; a first resin that contains the fluorescent agent and covers the first light-emitting element; and a first resin and a second resin that covers the second light-emitting element disposed outside the first resin. 2 light is used, and light in which the first, second, and third emission colors are mixed is used as the emission color.

  As described in claim 2, the light source of the present invention includes a first wall surface in contact with the first resin, and a second wall surface in contact with the second resin, and the height of the second wall surface. Can be made higher than the height of the first wall surface.

  According to a light source of the present invention, as described in claim 3, the first and second resins are hemispherical having first and second heights, and the height of the second resin is set to the first height. It can be made higher than the height of one resin.

  As described in claim 4, the light source of the present invention can set the first emission color to blue, the second emission color to red, and the third emission color to green.

  In the light source of the present invention, as described in claim 5, a plurality of the hemispherical light sources can be arranged on a substrate.

  According to the light source of the present invention, as described in claim 6, a frame is provided on the substrate, a reflective surface surrounding the second resin is provided on the frame, and the space between the reflective surface and the second resin is provided. An air layer can be interposed between the two.

  It is possible to provide a light source with good color reproducibility by preventing the occurrence of diffusion and shading due to the fluorescent agent.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a perspective view showing a horizontal light-emitting type light source (first embodiment), and FIG. 2 is a cross-sectional view taken along S1-S2 in FIG. In this light source 1, a rectangular light emitting window 3 is provided at the front center of a package 2 made of a flat resin, and electrodes 4, 5, and 6 are provided on a region extending from the left and right side surfaces to the bottom surface and on the back surface.

  As shown in FIG. 2, the package 2 has a first recess 7 formed inward from the light emitting window 3, and a part of the electrodes 4, 5, 6 is exposed on the inner wall surface of the recess 7. Yes. First and second light emitting elements 8 and 9 having different emission colors are disposed in the first recess 7. The first light emitting element 8 has a blue emission color, is disposed on the electrode 5, and wire bonding wiring is applied to the electrodes 4 and 5. The second light emitting element 9 has a red light emission color, is disposed on the electrode 5, and a wire bond wiring is applied to the electrode 6.

  A second depression 10 that is slightly smaller than the first depression 7 is formed in the depression 7 so as to surround the first light emitting element 8. The second recess 10 is filled with a first resin 11 containing a fluorescent agent. The first resin 11 is made of a transparent resin, in which a fluorescent agent is dispersed and arranged. The fluorescent agent in the first resin 11 is excited by light (excitation light) emitted from the first light-emitting element 8 and emits light having a wavelength longer than that of the excitation light, in this example, green light.

  The first recess 7 is filled with the second resin 12. The second resin 12 is a transparent resin that covers both the first resin 11 and the second light emitting element 9 that is arranged separately from the first resin 11. Since the second light emitting element 9 is arranged separately from the first resin 11, the light of the second light emitting element 9 is unnecessarily diffused or shielded by the fluorescent agent in the first resin 11. Can be eliminated.

  The height of the wall surface of the package 2 in contact with the second resin 12 is set higher than the height of the wall surface of the package 2 in contact with the first resin 11. A light diffusing material can be contained in one or both of the first and second resins 11 and 12 as necessary.

  Part of the light emitted from the first light emitting element 8 passes through the first resin 11 and the second resin 12 and exits from the light emitting window 3. A part of the light emitted from the first light emitting element 8 acts as excitation light of the fluorescent agent in the first resin 11. Light emitted from the excited fluorescent agent passes through the first and second resins 11 and 12 and exits from the light emission window 3. The light of the second light emitting element 9 goes out of the light emitting window 3 through the second resin 12. These lights emitted from the light emission window 3 are recognized as combined light. In this example, blue, red, and green light are combined to obtain white combined light.

  The previous embodiment was an application example to a horizontal light emission type light source, but an application example to a vertical light emission type light source will be described with reference to FIGS.

  FIG. 3 is a perspective view showing a vertical light emitting type light source (second embodiment), and FIG. 4 is a cross-sectional view taken along S3-S4 in FIG. In this light source 1, a rectangular light emitting window 3 is provided at the center of the top surface of a package 2 made of a rectangular parallelepiped resin, and electrodes 4, 5, 6 are provided in regions extending from the left and right side surfaces to the bottom surface.

  As shown in FIG. 4, a first recess 7 is formed in the package 2 inward from the light emitting window 3, and a part of the electrodes 4, 5, 6 is exposed on the inner wall surface of the recess 7. Yes. First and second light emitting elements 8 and 9 having different emission colors are disposed in the first recess 7. The first light emitting element 8 has a blue emission color, is disposed on the electrode 5, and wire bonding wiring is applied to the electrodes 4 and 5. The second light emitting element 9 has a red emission color, is disposed on the electrode 5, and wire bonding wiring is applied to the electrodes 5 and 6.

  A second depression 10 that is slightly smaller than the depression is formed in the depression 7 so as to surround the first light emitting element. The second recess 10 is filled with a first resin 11 containing a fluorescent agent. The fluorescent agent is excited by light (excitation light) emitted from the first light emitting element 8, and emits light having a wavelength longer than that of the excitation light, in this example, green light.

  The first recess 7 is filled with the second resin 12. The second resin 12 covers both the first resin 11 and the second light emitting element 9 that is arranged separately from the first resin 11. Since the second light emitting element 9 is arranged separately from the first resin 11, the light of the second light emitting element 9 is unnecessarily diffused or shielded by the fluorescent agent in the first resin 11. Can be eliminated.

  Part of the light emitted from the first light emitting element 8 passes through the first and second resins 11 and 12 and exits from the light emitting window. Part of the light emitted from the first light emitting element 8 acts as excitation light for the fluorescent agent. Light emitted from the excited fluorescent agent passes through the first and second resins 11 and 12 and exits from the light emission window 3. The light of the second light emitting element goes out of the light emitting window 3 through the second resin. These lights emitted from the light emission window 3 are combined to obtain white light.

  Next, an embodiment in which the first and second light emitting elements 8 and 9 are molded with a hemispherical resin will be described with reference to FIGS.

  FIG. 5 is a plan view showing a vertical light source (third embodiment), and FIG. 6 is a cross-sectional view taken along S5-S6 in FIG. The light source 1 includes a package 2 in which a resin frame 14 functioning as a light emitting window 3 is disposed on a rectangular circuit board 13. Although not shown, the circuit board 13 has a circuit pattern on the front surface and is provided with electrodes in the form of through holes from the side surface to the back surface. First and second light emitting elements 8 and 9 having different emission colors are arranged at the center of the circuit board 13, and wiring (not shown) such as wire bond wiring is applied. The first light emitting element 8 is covered with a hemispherical first resin 11 containing a fluorescent agent. The second light emitting element 9 is disposed outside the first resin 11, and both the first resin 11 and the second light emitting element 9 are covered with a hemispherical transparent second resin 12. The first and second resins 11 and 12 are not arranged in the depression as in the embodiment shown in FIGS. 1-4, but are arranged in a raised state on a plane. The height of the first resin 11 (first height) and the height of the second resin 12 (second height) are set so that the second height is higher than the first height. ing.

  The shape of the resins 11 and 12 can be set to a hemispherical shape or a similar shape by adjusting the viscosity and curing conditions of the resin. In addition, as the shape of the resin 11, 12 similar to a hemisphere, a conical shape, a quadrangular pyramid shape, a polygonal pyramid shape, a columnar shape, a quadrangular columnar shape, a polygonal columnar shape, a shape in which an inverted conical recess is provided on the top surface of the column It can also be set to (cross section M shape), lid shape or the like.

  The resin frame 14 has a light emitting window 3 in the center. The light emitting window 3 includes a reflecting surface 15 that is inclined outward from the bottom of the resin frame 14 toward the top surface. The reflection surface 15 is polygonal in plan view, and in this example, is an octagonal shape, but may be other polygons or circles. Although the resin frame 14 has enhanced reflectivity as a white resin, a metal plate or a metal thin film having excellent light reflectivity may be integrally formed on the reflective surface 15. The reflecting surface 15 and the resin 12 are separated from each other, and an air layer is interposed therebetween.

  In the embodiment shown in FIGS. 5 and 6, it is possible to avoid the problem that the light emitted from the second light emitting element 9 is diffused or shielded by the fluorescent agent in the first resin 11.

  The embodiment shown in FIG. 7 shows a linear light source having a form in which the light sources shown in FIGS. Except that there is a change in the form of the substrate 13 and the resin frame 14, the configuration is substantially the same as the configuration shown in FIGS. 5 and 6 (the same parts are given the same number). Therefore, the cross-sectional view along S7-S8 is the same as the cross-sectional view shown in FIG. In addition, if the first light emitting element 8 is biased to one side (left side in this example) and the second light emitting element 9 is biased to the other side (right side in this example), color unevenness may be caused. In order to prevent color unevenness, the arrangement of the light emitting elements in the light source may be changed depending on the position of the light source. The arrangement of the light emitting elements in the light source can be arranged in a form having a rotational deviation of a predetermined angle, such as 90 degrees, 60 degrees, etc. in addition to the form rotated by 180 degrees as shown in FIG. .

  The embodiment shown in FIG. 8 shows a planar light source having a form in which the light sources shown in FIGS. 5 and 6 are arranged two-dimensionally (matrix). Except that there is a change in the form of the substrate 13 and the resin frame 14, the configuration is substantially the same as the configuration shown in FIGS. 5 and 6 (the same parts are given the same number). Similarly to the previous embodiment, if the first light emitting element 8 is arranged on one side and the second light emitting element 9 is arranged on the other side, color unevenness may be caused. Therefore, the arrangement of the light emitting elements in the light source is changed according to the position of the light source in order to prevent color unevenness. That is, a plurality of types of light sources having different relative positions of the internal light emitting elements (first and second light emitting elements in this example) are provided, and the light sources having different types are distributed and arranged.

  In the above embodiment, each of the light emitting elements 8 and 9 is not limited to one element, and may be a plurality. Moreover, although the said embodiment illustrated the fluorescent agent of blue light excitation green light emission, the combination of excitation light sources and fluorescent agents, such as blue light excitation fluorescent agent excitation of red light emission, is not limited to said example, It is set as another combination You can also.

  In the embodiment shown in FIGS. 5 to 8, the resin frame 14 can be omitted. That is, the light source part which covered the some light emitting element with the resin on the board | substrate 13 can also be used as the light source arrange | positioned by one, linear form, or two-dimensionally.

  The present invention can be applied to a light source that performs wavelength conversion using a fluorescent agent.

It is a perspective view which shows embodiment of this invention. It is sectional drawing along S1-S2 of FIG. It is a perspective view which shows another embodiment. It is sectional drawing along S3-S4 of FIG. It is a top view which shows another embodiment. FIG. 6 is a cross-sectional view taken along S5-S6 of FIG. It is a top view which shows another embodiment. It is a top view which shows another embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light source 2 Package 3 Light emission window 7 1st hollow 8 1st light emitting element 9 2nd light emitting element 10 2nd hollow 11 1st resin 12 2nd resin

Claims (6)

  First and second light emitting elements that emit first and second colors, a fluorescent agent that is excited by the first emission color and emits a third color, and contains the fluorescent agent and the first A first resin that covers one light emitting element; a first resin; and a second resin that covers the second light emitting element disposed outside the first resin, wherein the first, second, and third resins are provided. A light source characterized by using light mixed with a light emission color as a light emission color.   A first wall surface in contact with the first resin and a second wall surface in contact with the second resin are provided, and the height of the second wall surface is made higher than the height of the first wall surface. The light source according to claim 1.   The first and second resins are hemispherical having first and second heights, and the height of the second resin is higher than the height of the first resin. Item 1. The light source according to Item 1.   The light source according to claim 1, wherein the first emission color is blue, the second emission color is red, and the third emission color is green.   A light source comprising a plurality of light sources according to claim 3 arranged on a substrate.   4. A frame is provided on the substrate, a reflective surface surrounding the second resin is provided on the frame, and an air layer is interposed between the reflective surface and the second resin. Or the light source of Claim 5.

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