JP2006073250A - Lighting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lighting system capable of irradiating a specific irradiation area with light of uniform illuminance without being increased in size in a direction of the optical axis. <P>SOLUTION: A one-side-protruding collimation lens 22 having a light guide part 22b of predetermined thickness integrally formed on an incidence side of a lens part 22c is provided just ahead of an LED 12a in the direction of the optical axis, the light guide part 22b having an incidence plane 22d opposed to an emission plane 12a of the LED 12 with a gap 40 provided in between. This allows generally parallel light beams to be incident on a fry eye lens 25 without increasing the distance in the direction of the optical axis. Specifically, the collimation lens 22 focuses light of wide angle emitted from the LED 12 into a predetermined narrow angle at the light guide part 22b by utilizing the difference in refractivity between the light guide part 22b and an air layer formed by the gap 40, and is therefore capable of converting incident light into generally parallel light beams for emission even if the lens part 22c is disposed relatively closer to the LED 12. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an illuminating device having a surface-mounted light emitting diode as a light source and irradiating a specific irradiation region with light of uniform illuminance.

  For example, an in-vehicle illumination device such as a map lamp needs to irradiate a specific irradiation area with light of uniform illuminance. For example, as disclosed in Patent Document 1, the light emitted from the light source is converted into substantially parallel light by a collimation lens and is applied to the fly-eye lens. It can be realized by making it incident.

By the way, in recent years, a small surface-mounted light emitting diode (LED) having a relatively high output has been widely used, and it is expected that this LED is suitably used as a light source of an illumination device.
JP 2003-107124 A

  However, in general, the emission angle of the light emitted from the surface-mount type LED is extremely wide as about 160 ° to 180 °, and in order to convert the wide-angle emission light into substantially parallel light by the collimation lens, Since it is necessary to set a long distance in the optical axis direction from the LED emission plane to the collimation lens, it is difficult to reduce the size in the optical axis direction.

  This invention is made | formed in view of the said situation, and it aims at providing the illuminating device which can irradiate the light of a uniform illumination intensity to a specific irradiation area | region, without enlarging in an optical axis direction.

  According to the present invention, a surface-mounted light-emitting diode, a light guide portion having a predetermined thickness that faces an emission plane of the light-emitting diode through a gap, and a light guide portion having a predetermined thickness are integrally provided on the emission side of the light guide portion. A half-convex collimation lens having a lens portion; and a fly-eye lens having a plurality of lens portions that respectively emit light emitted from the single-convex collimation lens and superimposed on a specific irradiation region. It is characterized by that.

  According to the illuminating device of the present invention, it is possible to irradiate light having a uniform illuminance to a specific irradiation region without increasing the size in the optical axis direction.

  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 a cross-sectional view of a main part of the illumination device, FIG. 2 is an exploded perspective view of the illumination device, FIG. 3 is an explanatory view showing optical characteristics of a single convex collimation lens, and FIG. FIG. 5 is an explanatory diagram showing the relationship between the set irradiation region and the irradiation region of each lens unit.

  In FIG. 1, the code | symbol 1 shows the illuminating device suitable for a vehicle-mounted map lamp etc., for example. The illuminating device 1 includes a light source unit 10 using a surface-mounted light emitting diode (LED) 12 as a light source, and a lens optical system unit 20 provided on the light source unit 10.

  As shown in FIGS. 1 and 2, the light source unit 10 has an LED substrate 11. The LED substrate 11 holds the LED 12 by soldering or the like at a substantially central portion thereof, and further electrically connects the held LED 12 to a power source (not shown). Here, in order to improve the light emission efficiency of the LED 12, the LED substrate 11 of this embodiment is a thin aluminum substrate with good thermal conductivity, and further, the radiation fins 13 are fixed to the back surface of the LED substrate 11. is doing.

  The lens optical system unit 20 includes a lens housing 21, a one-convex collimation lens 22 accommodated and held in the lens housing 21, a light shielding plate 23, a sub-collimation lens 24, and a fly-eye lens 25.

  As shown in FIG. 2, in this embodiment, the lens housing 21 has a substantially rectangular tube shape, and an LED insertion port 30 is opened at one end in the optical axis direction. In addition, an illumination light exit 31 is opened at the other end of the lens housing 21 in the optical axis direction so as to face the LED entry port 30. As shown in FIG. 1, when the lens housing 21 is crowned on the light source unit 10, the LED 12 is exposed to the inside through the LED insertion port 30, and the emission plane 12 a of the LED 12 is opposed to the emission port 31.

  Further, the lens housing 21 has a lens insertion opening 33 opened on one side, and on the inner surfaces of the respective side walls adjacent to the lens insertion opening 33, one-convex collimation lens holding grooves 34 and a light shielding plate holding each other. A groove 35, a sub-collimation lens holding groove 36, and a fly-eye lens holding groove 37 are provided in this order from the LED insertion port 30 side.

  The single-convex collimation lens 22 has a light guide 22b for narrowing a wide-angle light emitted from the LED 12 to a predetermined narrow angle on a planar substantially rectangular lens substrate 22a inserted and supported in the single-convex collimation lens holding groove 34; The lens member is integrally formed with a lens portion 22c that converts the light narrowed down by the light guide portion 22b into a substantially parallel light and emits the light.

  More specifically, the light guide portion 22b is a substantially cylindrical member having a predetermined thickness provided with an incident plane 22d facing the emission plane 12a of the LED 12 via a predetermined gap (for example, a gap of 0.1 mm) 40. And is erected on the lens substrate 22a. Moreover, the lens part 22c is comprised by the substantially hemispherical member of the same diameter as the light guide part 22b, and is provided in a row by the output side of the light guide part 22b.

  As shown in FIG. 3, in this single convex collimation lens 22, the light guide portion 22 b converts light having a wide angle (for example, about 160 °) incident from the incident plane 22 d to a refractive index with the air layer (gap 40). Depending on the difference, the aperture is narrowed down to a predetermined narrow angle (for example, about 80 °) and guided to the lens portion 22c. And the lens part 22c converts the light guide | induced from the light guide part 22b into substantially parallel light with the curved surface, and radiate | emits it. Here, in order to efficiently narrow down the incident light in the light guide portion 22b, it is desirable that the one-convex collimation lens 22 is made of a material having a high refractive index (for example, 1.45 or more). In this case, for example, polycarbonate (refractive index of 1.585), acrylic (refractive index of 1.492), glass (refractive index of 1.500), etc. can be suitably applied.

  The light shielding plate 23 is a flat rectangular plate-like member that is inserted and supported in the light shielding plate holding groove 35, and has an opening 23 a having a slightly smaller diameter than the lens portion 22 c of the one-convex collimation lens 22 at a substantially central portion thereof. . The lens portion 22c of the one-convex collimation lens 22 is exposed to the opening 23a, whereby the light shielding plate 23 shields light emitted from the edge portion of the lens portion 22c.

  In the sub-collimation lens 24, convex lens portions 24b and 24c for correcting the angle of light emitted from the single-convex collimation lens 22 are integrated on both surfaces of a substantially rectangular lens substrate 24a inserted and supported in the sub-collimation lens holding groove 36. It is the formed biconvex lens. Then, as shown in FIG. 3, the sub-collimation lens 24 makes the light emitted from the one-convex collimation lens 22 closer to parallel light by angle correction by the convex lens portions 24b and 24c. Although the sub-collimation lens 24 is a biconvex lens, it may be a single-convex lens or a full-nel lens as long as it has a convex lens function.

  The fly-eye lens 25 is provided with a plurality of (for example, for example) an incident surface protruding downward and an output surface protruding upward on a substantially rectangular lens substrate 25a inserted and supported in the fly-eye lens holding groove 37. This is a lens member in which 2000 to 2500) fine lens portions 25b (see FIG. 4) are integrally formed in a matrix. In this embodiment, each lens unit 25b has, for example, a planar rectangular shape in which the focal position of parallel light incident from the one-convex collimation lens 22 via the sub-collimation lens 24 is set on the exit surface (see FIG. 4). It is a lens part. As shown in FIG. 5, each light beam 1 emitted from each lens portion 25b has a rectangular shape corresponding to the planar shape of the lens portion 25b, and most of them overlap with each other on the rectangular irradiation region Al. Irradiate uniformly.

  Here, reference numeral 45 in FIG. 2 denotes a side plate. The side plate 45 is formed by attaching the lenses 22, 24, 25 and the light shielding plate 23 in the lens housing 21 and then sticking them with an adhesive tape or the like, for example. The lens insertion port 33 of the body 21 is closed.

  According to such a configuration, the one-convex collimation lens 22 is integrally formed on the incident side of the lens portion 22c with the light guide portion 22b having a predetermined thickness facing the emission plane 12a of the LED 12 via the gap 40 and the incident plane 22d. By disposing the LED 12a immediately before the optical axis direction, it is possible to make the substantially parallel light incident on the fly-eye lens 25 without increasing the distance in the optical axis direction. That is, the single-convex collimation lens 22 narrows the wide-angle light emitted from the LED 12 to a predetermined narrow angle by the light guide 22b due to the difference in refractive index between the air layer formed by the gap 40 and the light guide 22b. Even when the lens portion 22c is disposed relatively close to the LED 12, the incident light can be converted into substantially parallel light and emitted. Therefore, even when the surface-mounted LED 12 is used as a light source, it is possible to irradiate light with a high degree of uniformity to a specific irradiation region with a configuration in which the length in the optical axis direction of the illumination device 1 is significantly reduced.

  At this time, a sub-collimation lens 24 is interposed between the single-convex collimation lens 22 and the fly-eye lens 25, and the sub-collimation lens 24 is used to correct the angle of light emitted from the single-convex collimation lens. Thus, parallel light can be made incident on the fly-eye lens 25, and the level of irradiation light can be further improved.

  Further, by providing the light shielding plate 23 that shields the light emitted from the edge portion of the lens portion 22c of the one-convex collimation lens 22, the light emitted without being converted into sufficient parallel light can be cut, and the irradiated light It is possible to further improve the degree of uniformity.

  In the above embodiment, an example in which the sub-collimation lens 24 is interposed between the single-convex collimation lens 22 and the fly-eye lens 25 has been described. However, good parallel light can be obtained with the single-convex collimation lens 22 alone. If this is possible, the sub-collimation lens 24 can be omitted.

Cross section of the main part of the lighting device Exploded perspective view of lighting device Explanatory drawing showing the optical characteristics of a single convex collimation lens Explanatory diagram showing optical characteristics of fly-eye lens Explanatory drawing which shows the relationship between a setting irradiation area | region and the irradiation area | region of each lens part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Illuminating device, 12 ... Surface mount type light emitting diode, 12a ... Output plane, 20 ... Lens optical system unit, 22 ... Single convex collimation lens, 22b ... Light guide part, 22c ... Lens part, 22d ... Incident plane, 23 ... Light shielding plate, 24 ... Sub collimation lens, 25 ... Fly eye lens, 40 ... Gap
Agent Patent Attorney Susumu Ito

Claims (3)

Surface mounted light emitting diodes,
A single-convex collimation lens having a light guide portion with a predetermined thickness facing the exit plane of the light-emitting diode via a gap, and a lens portion integrally provided on the exit side of the light guide portion;
A fly's eye lens having a plurality of lens portions that respectively enter the emitted light from the one-convex collimation lens and superimpose them on a specific irradiation region; and
An illumination device comprising:   The illumination according to claim 1, wherein a sub-collimation lens for correcting an angle of light emitted from the one-convex collimation lens is interposed on an optical path between the one-convex collimation lens and the fly-eye lens. apparatus.   3. The illumination device according to claim 1, further comprising a light shielding plate that shields light emitted from an edge portion of the lens portion of the lens portion of the one-convex collimation lens.

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