JP2007265688A - Collimation lens and lighting fixture using this - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a collimation lens capable of precisely converting irradiation light from a light-emitting diode into parallel light. <P>SOLUTION: In the collimation lens 22 integrating a lens part 30 with an incident face 30a directly opposed to a light-emitting part of the LED 12 and refracting light incident from the incident face 30a in a direction of an optical axis O to irradiate it from an irradiation face 30b, and a reflector part 31 with an incident face 31a surrounding the light-emitting part of the LED 12 at a periphery of the incident face 30a and reflecting the incident light from the incident face 31a with a reflecting face 31b in a direction of the optical axis O to irradiate it from an irradiation face 31c, reflected light from the reflecting face 31b is corrected for irradiation by inclining the irradiation face 31c of the reflector part 31 against a perpendicular direction of the optical axis. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a collimation lens that is integrally provided with a reflector portion around a lens portion that converts incident light into parallel light, and an illumination device using the same.

Conventionally, as a lens for converting light emitted from a light emitting diode (LED) into parallel light, a collimation lens that is integrally provided with a reflector around a lens portion that refracts incident light from the LED in the direction of the optical axis. It has been known. As a technique for improving the accuracy of the parallel light generated in this type of collimation lens, for example, Patent Document 1 discloses that the diffused light is incident on the periphery of the lens unit and the outer reflection wall (reflection surface) of the reflector unit. The technique which curved the refracting wall (incident surface) leading to) is disclosed.
JP-T-2004-516684

  By the way, in this type of collimation lens, for example, the curvature of the reflecting surface of the reflector portion is restricted depending on the demand for miniaturization and the relationship with the specifications of the lens portion formed in the center portion. There is a case. And when the shape of the reflecting surface is constrained in this way, sufficient parallel light is generated even if the incident surface of the reflector portion is curved, as in the technique disclosed in Patent Document 1 described above. There were cases where it was difficult.

  An object of this invention is to provide the collimation lens which can convert the emitted light from a light emitting diode into sufficiently high precision parallel light, and an illuminating device using the same.

  The collimation lens of the present invention has a first incident surface facing the light emitting portion of the light emitting diode, refracts incident light from the first incident surface in the optical axis direction, and emits the light from the first emission surface. A lens unit, and a second incident surface surrounding the light emitting unit of the light emitting diode at a peripheral portion of the first incident surface, and incident light from the second incident surface is reflected by the reflecting surface in the optical axis direction. A collimation lens that is integrally provided with a reflector portion that reflects and emits light from a second emission surface, wherein the second emission surface is inclined with respect to a direction perpendicular to the optical axis. .

  The illuminating device of the present invention is characterized in that the collimation lens is provided in a lens optical system that controls light emitted from a light emitting diode.

  According to the present invention, the light emitted from the light emitting diode can be converted into parallel light with sufficiently high accuracy by the collimation lens, and an illumination device having excellent optical characteristics can be realized by using such a collimation lens. Can do.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The drawings relate to an embodiment of the present invention, FIG. 1 is an exploded perspective view of the illuminating device, FIG. 2 is a cross-sectional view of the main part of the illuminating device, and FIG. 4 is a chart showing the angular intensity distribution of the light emitted from the collimation lens, FIG. 4A is a front view of the illumination unit, FIG. 4B is a sectional view taken along the line II of FIG. 6A, and FIG. It is principal part sectional drawing which shows this modification.

  The illuminating device 1 shown in FIGS. 1 and 2 includes, for example, a light source unit 10 that uses a surface-mounted light emitting diode (LED) 12 as a light source, and a lens housing 20 that is provided on the light source unit 10.

  The light source unit 10 includes, for example, an LED substrate 11 having a substantially rectangular plane shape, and an LED 12 having a single convex lens 13 fixed to an emission plane 12a is mounted by soldering or the like at a substantially central portion of the LED substrate 11. ing. Here, the LED 12 is positioned and fixed with high accuracy at the mounting position set on the LED substrate 11 by, for example, strict machine setting of the assembling apparatus. Further, the LED substrate 11 is fixed to a lid 15 that closes the base side opening of the lens housing 20.

  The lens housing 20 has a cylindrical shape extending along the optical axis O direction of the LED 12 and accommodates therein a lens optical system 21 for dimming the emitted light from the LED 12 into illumination light with uniform illuminance. In the present embodiment, the lens housing 20 has a substantially rectangular tube shape, and an inward flange 20a is projected from the tip. A step portion 20 b is provided on the inner surface of the lens housing 20.

  The lens optical system 21 includes a collimation lens 22 that converts light emitted from the LED 12 into substantially parallel light, a holder 23 that holds the collimation lens 22 between the lid body 15 in the lens housing 20, and the collimation lens 22. The fly-eye lens 24 into which the emitted light is incident and the spacer 25 interposed between the holder 23 and the fly-eye lens 24 are provided.

  The collimation lens 22 is, for example, an optical device in which a lens portion 30 disposed on the optical axis O and a reflector portion 31 disposed on the periphery of the lens portion are integrally formed of a light-transmitting resin molded product. It is composed of members.

  In the present embodiment, the lens unit 30 is constituted by, for example, a biconvex lens in which an incident surface (first incident surface) 30a and an exit surface (first exit surface) 30b are formed as spherical surfaces. The incident surface 30a of the lens unit 30 is directly opposed to the light emitting unit of the LED 12 via the one-convex lens 13, and a light beam having a small emission angle is incident on the incident surface 30a. And the lens part 30 refracts | emits the incident light from the incident surface 30a to the optical axis O direction, and radiate | emits it from the output surface 30b.

  In addition, the reflector unit 31 reflects, for example, an incident surface (second incident surface) 31a that surrounds the light emitting unit of the LED 12 around the incident surface 30a of the lens unit 30, and incident light from the incident surface 31a. It has a reflecting surface 31b and an emitting surface (second emitting surface) 31c that emits the reflected light from the reflecting surface 31b.

  For example, the incident surface 31 a is configured by a curved surface having a cylindrical shape in which the tip portion is continuous with the peripheral portion of the incident surface 30 a of the lens portion 30 and the base portion is in contact with the emission plane 12 a of the LED 12. A light beam with a large angle is incident. Further, the reflecting surface 31b is formed, for example, as a curved surface having a substantially rotating parabolic shape with the optical axis O as the center, and totally reflects incident light from the incident surface 31a in the direction of the optical axis O. In addition, the emission surface 31c is formed of, for example, an annular bank whose normal is inclined with respect to the optical axis O, and emits reflected light from the reflection surface 31b.

  Here, the emission surface 31 c is formed of a bank symmetrical to the optical axis O, thereby forming a prism on the emission side of the reflector portion 31. Thereby, the light beam reflected by the reflecting surface 31b is refracted in a direction parallel to the optical axis O when the light beam is emitted from the emitting surface 31c. That is, for example, as shown in FIG. 3, the exit surface 31 c has its normal line inclined to the acute angle side with respect to the optical axis O, so that the reflected light from the reflective surface 31 b is expanded with respect to the optical axis O. The light is refracted to the open side and emitted. Thereby, the outgoing light from the outgoing surface 31c is corrected in a direction that is more parallel to the optical axis O, and, for example, as shown by a solid line in FIG. 4, highly accurate parallel light is generated. In other words, the inclination angle of the exit surface 31c is set to an appropriate value based on the relative relationship between the entrance surface 31a and the reflection surface 31b by experiments, simulations, and the like, thereby reflecting the incident light from the entrance surface 31a. In cooperation with the surface 31b, the light is converted into more accurate parallel light along the optical axis O direction. The behavior of the emitted light when the exit surface 31c is not inclined is shown by a two-dot chain line in FIG. 3, and the angular intensity distribution is shown by a two-dot chain line in FIG.

  The holder 23 has a substantially rectangular tube shape in which the collimation lens 22 can be accommodated, and an inward flange 23 a that abuts on the collimation lens 22 protrudes from the tip of the holder 23. The holder 23 is inserted into the lens housing 20, the base side is brought into contact with the lid body 15, and the tip end side is brought into contact with the stepped part 20 b via the spacer 25, so that the collimation lens 22 is moved. It is held at a set position in the lens housing 20.

  The fly-eye lens 24 is, for example, a light-transmissive resin molding in which a plurality of lens portions 24b are integrally formed in a matrix on the inner side of a flange portion 24a that is inserted into the lens housing 20 on the tip side of the step portion 20b. It is composed of goods. The fly-eye lens 24 has a lens housing in which a distal end surface of the flange portion 24 a is in contact with the inward flange 20 a and a proximal end surface of the flange portion 24 a is in contact with a projecting piece 25 a extending from the spacer 25. 20. And each lens part 24b of the fly-eye lens 24 irradiates a specific area | region uniformly by radiate | emitting the parallel light which injects from the collimation lens 22 to the position which mutually overlaps.

  Here, for example, as shown in FIG. 5, it is possible to configure a vehicular lamp 50 such as a headlamp that requires a relatively large amount of light by combining a plurality of the lighting devices 1 described above.

  In other words, the vehicular lamp 50 includes, for example, a housing 51 in which a plurality of holding holes 51a are arranged in a matrix and open. Each lighting device 1 is placed in each holding hole 51a of the housing 51. The main part is configured as an illumination module. In this case, the specifications of the lighting device 1 incorporated in each holding hole 51a can be changed as appropriate. For example, various variations of the vehicular lamp 50 can be realized by combining the lighting devices 1 having different emission colors and light amounts. .

  According to such an embodiment, the lens unit 30 has the incident surface 30a facing the light emitting unit of the LED 12, and refracts incident light from the incident surface 30a in the direction of the optical axis O and emits the light from the output surface 30b. The reflector has an incident surface 31a surrounding the light emitting portion of the LED 12 at the periphery of the incident surface 30a, and reflects the incident light from the incident surface 31a in the direction of the optical axis O by the reflecting surface 31b and emits it from the emitting surface 31c. In the collimation lens 22 integrally provided with the portion 31, the reflected light from the reflecting surface 31b is corrected and emitted by inclining the emitting surface 31c of the reflector portion 31 with respect to the direction perpendicular to the optical axis O. Can do.

  Therefore, highly accurate parallel light can be obtained by the reflector 31 of the collimation lens 22 by setting the inclination angle of the emission surface 31c to an appropriate value based on the specifications of the reflection surface 31b.

  Further, by adopting a configuration in which the reflected light from the reflecting surface 31b is corrected by the emitting surface 31c, the degree of freedom in designing the reflecting surface 31b of the reflector portion 31 can be increased. Therefore, the lens unit 30 can be designed without being constrained by the specifications of the reflector unit 31. If the specifications of the lens unit 30 are appropriately set, the lens unit 30 can also generate highly accurate parallel light. That is, the collimation lens 22 as a whole can obtain parallel light with high accuracy.

  Then, by making the highly accurate parallel light incident on the fly-eye lens 24 in this way, illumination light with high uniformity can be emitted from the illumination device 1.

  Here, for example, as shown in FIG. 6, in addition to the configuration in which the exit surface 31c of the reflector portion 31 is inclined symmetrically with the optical axis O, the incident surface 31a is configured with a tapered surface inclined with respect to the optical axis O direction. It is also possible to do. If the inclination angles of the entrance surface 31a and the exit surface 31c, the shape of the reflection surface 31b, and the like are comprehensively set, it is possible to obtain parallel light with higher accuracy.

  Further, in the present embodiment, for example, as shown in FIG. 6, a filler made of, for example, a light-transmitting resin in a region surrounded by the incident surfaces 30 a and 31 a of the LED 12 (single convex lens 13) and the collimation lens 22. It is also possible to fill 35. If comprised in this way, the positioning precision between LED12 and the collimation lens 22 can be improved, and also highly accurate parallel light can be implement | achieved. In addition, by making the refractive index of the filler 35 coincide with the refractive index of the one-convex lens 13 or the collimation lens 22, light energy loss at the interface can be reduced.

Exploded perspective view of lighting device Cross section of the main part of the lighting device Explanatory drawing which shows the simulation result of the behavior of the light which entered the collimation lens Chart showing the angular intensity distribution of the light emitted from the collimation lens (A) is a front view of a vehicular lamp, and (b) is a cross-sectional view taken along line II of (a). Sectional drawing of the principal part showing a modification of the lighting device

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Illuminating device, 10 ... Light source unit, 11 ... LED board, 12a ... Output plane, 13 ... Single convex lens, 15 ... Lid body, 20 ... Lens housing, 20a ... Inward flange, 20b ... Step part, 21 ... Lens optics System, 22 ... Collimation lens, 23 ... Holder, 23a ... Inward flange, 24 ... Fly eye lens, 24a ... Flange part, 24b ... Lens part, 25 ... Spacer, 25a ... Projection piece, 30 ... Lens part, 30a ... Incident surface (First incident surface), 30b... Exit surface (first exit surface), 31... Reflector part, 31a... Entrance surface (second incident surface), 31b. Emission surface), 35 ... filler, 50 ... vehicle lamp, 51 ... housing, 51a ... holding hole, O ... optical axis

Claims (3)

A lens unit that has a first incident surface facing the light emitting unit of the light emitting diode, refracts incident light from the first incident surface in the optical axis direction, and emits the light from the first output surface;
A second incident surface surrounding the light emitting portion of the light emitting diode at a peripheral portion of the first incident surface; incident light from the second incident surface is reflected by the reflecting surface in the optical axis direction; A collimation lens that integrally includes a reflector portion that emits light from two exit surfaces,
A collimation lens, wherein the second emission surface is inclined with respect to a direction perpendicular to an optical axis.   2. The collimation lens according to claim 1, wherein the second incident surface is a tapered surface inclined with respect to the optical axis direction.   An illumination device comprising: a collimation lens according to claim 1 or 2 in a lens optical system that controls light emitted from a light emitting diode.

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