JP2008078043A - Lens array, illumination device, and illumination system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens array capable of creating illumination light without a sense of incongruity as a whole, without generating drastic changes of illuminance values even in the case a plurality of kinds of illumination light are superposed on one another. <P>SOLUTION: The illumination system 1 constitutes an optical distribution pattern as illumination light as a whole, by combining each irradiation region A1 to A3 by each of three kinds of lens arrays 26 to 28. In that case, each lens array 26 to 28 is provided with a plurality of lens curved surfaces 26b, 28b taking a spherical shape formed in alignment in a matrix at incident sides of lens substrates 26a to 28a, and optical faces 26c to 28c consisting of cylindrical lens faces formed at irradiation sides of the lens substrates 26a to 28a in opposition to each lens curved surface 26b to 28b. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a lens array, an illuminating device, and an illuminating system that irradiate a preset irradiation area with a predetermined light distribution.

Generally, a light emitting diode (LED) has an advantage of low power consumption and long life. Thus, in recent years, many lighting devices using LEDs as light sources have been proposed. For example, Patent Document 1 proposes an illumination device in which a fly-eye lens (lens array) in which a plurality of lens cells are arranged in a matrix is arranged to face an LED. According to such a technique, by controlling the emitted light from the LED to be substantially parallel light having a directivity angle of less than 30 degrees and entering each lens cell, a specific irradiation region similar to the planar view shape of the lens cell is obtained. Irradiation with uniform illuminance is possible.
JP 2005-190954 A

  By the way, in recent years, it is expected that the LED is applied as a light source even in a vehicular lamp that requires a large amount of light such as an in-vehicle headlight or a fog lamp as the output of the LED increases. In this case, for example, an illumination system is configured by combining a plurality of the above-described illumination devices having fly-eye lenses having different cell dimensions, lens thicknesses, and curvatures, and the illumination light with different light distributions is superposed to regulate the distribution. It is conceivable to realize a vehicular lamp that satisfies the light standard.

  However, the fly-eye lens used in the above-described illumination device is generally based on the principle of connecting and projecting the image of the entrance surface with the exit surface, so that the illuminance value changes abruptly at the boundary of different illumination light overlapping, There is a risk of visual discomfort.

  The present invention provides a lens array, an illuminating device, and an illumination system that can generate illumination light that does not cause a sense of incongruity as a whole without causing a sudden change in illuminance value even when a plurality of illumination lights are superimposed. The purpose is to provide.

  The lens array of the present invention includes a plurality of lens curved surfaces formed in a matrix on one surface of a lens substrate, and formed on the other surface of the lens substrate so as to face each lens curved surface. An optical surface having a curvature in a direction set to be smaller than a curvature in the same direction of the lens curved surfaces facing each other.

  Moreover, the illuminating device of this invention was equipped with the light source and the said lens array.

  In addition, the illumination system of the present invention includes a light source and at least two or more types of the lens arrays, and at least a part of the irradiation area of the illumination light emitted from the lens arrays is made to coincide with each other. It is characterized by that.

  According to the present invention, it is possible to generate illumination light with no sense of incongruity as a whole without causing a sudden change in illuminance value even when a plurality of illumination lights are superimposed.

  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 illumination system, FIG. 2 is a plan view of the illumination system as viewed from the exit side, FIG. 3 is a cross-sectional view taken along line II in FIG. 4A is a plan view of the first lens array, FIG. 4B is a sectional view taken along line bb in FIG. 4A, and FIG. 4C is a sectional view taken along line cc in FIG. 5A is a plan view of the second lens array, FIG. 5B is a cross-sectional view taken along line bb in FIG. 5A, and FIG. 5C is c in FIG. 5A. FIG. 6A is a plan view of the third lens array, FIG. 6B is a bb sectional view of FIG. 6A, and FIG. 6C is FIG. FIG. 7 is a cross-sectional view taken along line cc of FIG. 7a, and FIG. 7 is a diagram illustrating the relationship between the light distribution standard of fog lamps used in the current light distribution test for automotive lamps and the irradiation area of each lens array when this standard is used. Fig. 8 shows the lighting system Is an explanatory view showing an illuminance characteristic due.

  1-3, the code | symbol 1 shows the illumination system with which the some illuminating device was comprised integrally, and shows the vehicle-mounted fog lamp in this embodiment. The illumination system 1 includes, for example, a light source unit 10 using a plurality of (for example, seven) surface-mounted light-emitting diodes (LEDs) 12 each having a single-projection lens fixed on the emission surface 12a, and the light source unit 10 And a lens optical system unit 20 mounted on the head.

  The light source unit 10 has an LED substrate 11. The LED substrate 11 is formed of, for example, a substantially disk-shaped substrate, holds each LED 12 by soldering or the like, and further electrically connects each held LED 12 to a power supply circuit (not shown). Here, in the present embodiment, the LEDs 12 are arranged on the LED substrate 11 at equal intervals. Specifically, each LED 12 has, for example, one LED 12 arranged at the center of the LED substrate 11 and other LEDs 12 arranged concentrically at equal intervals. Moreover, in order to improve the light emission efficiency of each LED12, the radiation fin 13 is adhering to the back surface of the LED board 11 (refer FIG. 3).

  The lens optical system unit 20 includes a lens housing 21, a collimation lens holding plate 22 that holds a plurality of (for example, seven) collimation lenses 23 on the lens housing 21, and a plurality of types (for example, three types). A lens array holding plate 25 that holds (for example, seven) lens arrays (first to third lens arrays 26 to 28 described later) on the lens housing 21 is provided.

  In the present embodiment, the lens housing 21 is configured by a substantially cylindrical member that is open at both ends. A step portion 21a is formed on the inner periphery of the lens housing 21, and the step portion 21a sets the inner diameter on the base side of the lens housing 21 to be larger than the inner diameter on the distal end side (see FIG. 3). Here, the inner diameter of the base side of the lens housing 21 is set to substantially match the outer diameter of the LED substrate 11.

  The collimation lens holding plate 22 is configured by a substantially disk-shaped member whose outer diameter substantially matches the inner diameter of the base side of the lens housing 21. In the collimation lens holding plate 22, lens holding holes 22 a penetrating in the optical axis direction are opened at positions facing the respective LEDs 12 on the LED substrate 11. The collimation lens holding plate 22 constitutes a collimation lens unit by fitting and holding each collimation lens 23 in each lens holding hole 22a.

  As shown in FIG. 3, the collimation lens holding plate 22 holding each collimation lens 23 is inserted into the lens housing 21 from the base side, and is positioned in the lens housing 21 by contact with the stepped portion 21a. Is done. Further, in the lens housing 21, a ring-shaped spacer 24 is disposed on the base side of the collimation lens holding plate 22, and the collimation lens is held when the lens optical system unit 20 is crowned on the light source unit 10. The plate 22 faces the LED substrate 11 with the spacer 24 interposed therebetween. Then, when the optical axis distance between each LED 12 and each collimation lens 23 is regulated to an appropriate value by the spacer 24, each collimation lens 23 converts incident light from the corresponding LED 12 into substantially parallel light. Exit.

  The lens array holding plate 25 is configured by a substantially disk-shaped member that is crowned at the tip of the lens housing 21. In the lens array holding plate 25, lens holding holes 25a penetrating in the optical axis direction are opened at positions facing the collimation lenses 23 on the collimation lens holding plate 22, respectively. The lens array holding plate 25 constitutes a lens array unit by fitting and holding the first to third lens arrays 26 to 28 in the lens holding holes 25a.

  More specifically, in the present embodiment, the lens array holding plate 25 holds one first lens array 26 by each lens holding hole 25a and two second lens arrays. 27 and four third lens arrays 28 are held.

  As shown in FIG. 4, the first lens array 26 is formed in a matrix on the incident surface (one surface) side of a substantially disc-shaped lens substrate 26a fitted and held in the lens holding hole 25a. And a plurality of lens curved surfaces 26b having the same shape. In the present embodiment, each lens curved surface 26b has a spherical shape, and is arranged in a matrix along the vehicle width direction (X-axis direction) and the vertical direction (Y-axis direction) of the vehicle, for example.

  An optical surface 26c is formed on the exit surface side of the lens substrate 26a so as to face each lens curved surface 26b. Each optical surface 26c is configured by a surface that passes through the imaging position of the corresponding lens curved surface 26b, and at least one direction of curvature is set smaller than the curvature of the opposite lens curved surface 26b in the same direction. Specifically, in the present embodiment, each optical surface 26c has, for example, a curvature in the vertical direction (Y-axis direction) set to be the same as that of the lens curved surface 26b, and in the vehicle width direction (X-axis direction). It is composed of a cylindrical lens curved surface whose curvature is set to “zero”. In the present embodiment, the optical surfaces 26c are integrally formed in the same row in the vehicle width direction (X-axis direction).

  And the 1st lens array 26 irradiates specific irradiation area | region A1 (refer FIG. 7) with uniform illumination intensity by making each light which injects into each lens curved surface 26b from the collimation lens 23 mutually overlap. At this time, since the curvature in the vehicle width direction (X-axis direction) of the optical surface 26c on the emission side is set to “zero”, the emitted light from each optical surface 26c diverges in a predetermined manner.

  Similarly, as shown in FIG. 5, the second lens array 27 is arranged in a matrix on the incident surface (one surface) side of the substantially disk-shaped lens substrate 27a fitted and held in the lens holding hole 25a. And a plurality of lens curved surfaces 27b having the same shape. In the present embodiment, the lens curved surfaces 27b each have a spherical shape, and are arranged in a matrix along the vehicle width direction (X-axis direction) and the vertical direction (Y-axis direction) of the vehicle, for example.

  An optical surface 27c is formed on the exit surface side of the lens substrate 27a so as to face each lens curved surface 27b. Each optical surface 27c is constituted by a surface passing through the imaging position of the corresponding lens curved surface 27b, and the curvature in at least one direction is set smaller than the curvature in the same direction of the opposing lens curved surface 27b. Specifically, in the present embodiment, each optical surface 27c has, for example, a curvature in the vertical direction (Y-axis direction) set to be the same as that of the lens curved surface 27b, and in the vehicle width direction (X-axis direction). It is composed of a cylindrical lens curved surface whose curvature is set to “zero”. In the present embodiment, the optical surfaces 27c are integrally formed in the same row in the vehicle width direction (X-axis direction).

  And the 2nd lens array 27 irradiates specific irradiation area | region A2 (refer FIG. 7) with uniform illumination intensity by making each light which injects into each lens curved-surface 27b from the collimation lens 23 mutually overlap. At this time, since the curvature in the vehicle width direction (X-axis direction) of the optical surface 27c on the emission side is set to “zero”, the emitted light from each optical surface 27c diverges in a predetermined manner.

  Similarly, as shown in FIG. 6, the third lens array 28 is arranged in a matrix on the incident surface (one surface) side of the substantially disk-shaped lens substrate 28a fitted and held in the lens holding hole 25a. A plurality of lens curved surfaces 28b having the same shape and formed in the same manner. In the present embodiment, the lens curved surfaces 28b each have a spherical shape, and are arranged in a matrix along the vehicle width direction (X-axis direction) and the vertical direction (Y-axis direction) of the vehicle, for example.

  An optical surface 28c is formed on the exit surface side of the lens substrate 28a so as to face each lens curved surface 28b. Each optical surface 28c is configured by a surface passing through the imaging position of the corresponding lens curved surface 28b, and the curvature in at least one direction is set smaller than the curvature in the same direction of the opposing lens curved surface 28b. Specifically, in the present embodiment, each optical surface 28c has, for example, a curvature in the vertical direction (Y-axis direction) set to be the same as that of the lens curved surface 28b, and in the vehicle width direction (X-axis direction). It is composed of a cylindrical lens curved surface whose curvature is set to “zero”. In the present embodiment, the optical surfaces 28c are integrally formed in the same row in the vehicle width direction (X-axis direction).

  And the 3rd lens array 28 irradiates specific irradiation area | region A3 (refer FIG. 7) with uniform illumination intensity by making each light which injects into each lens curved surface 28b from the collimation lens 23 mutually overlap. At this time, since the curvature in the vehicle width direction (X-axis direction) of the optical surface 28c on the emission side is set to “zero”, the emitted light from each optical surface 28c diverges in a predetermined manner.

  By the way, when using the illumination system 1 as a fog lamp, as shown in FIG. 7, it is requested | required that the maximum luminous intensity in the front position C1 of the illumination system 1 is 10000 cd or less in the point of irradiation distance 10m. In addition, at the left and right positions of C1, the luminous intensity at the position C2 is required to be 1000 cd or more, the luminous intensity at the position C3 is 750 cd or more, and the luminous intensity at the position C4 is required to be 300 cd or more. Furthermore, in a region above horizontal, the luminous intensity at the position C5 is required to be 650 cd or less, and the luminous intensity at the position C6 is required to be 300 cd or less.

  For this reason, in this embodiment, the aspect ratio when the lens curved surfaces 26b of the first lens array 26 are viewed in plan is set to 2.2: 2.28, for example. Then, by setting the curvature, apex distance, and the like of each lens curved surface 26b and optical surface 26c to appropriate values using experiments, simulations, and the like, as an irradiation region A1 of the first lens array 26, for example, FIG. As shown, a rectangular region of about −6.5 ° to 6.5 ° in the width direction and about −10 ° to −1 ° in the height direction, that is, a region including the points C1 and C2 is defined. .

  In addition, the aspect ratio when the lens curved surfaces 27b of the second lens array 27 are viewed in plan is set to, for example, 1.9: 4.36. Then, by setting the curvature, apex distance, and the like of each lens curved surface 27b and optical surface 27c to appropriate values using experiments, simulations, etc., as an irradiation region A2 of the second lens array 27, for example, FIG. As shown, a rectangular region of about −15 ° to 15 ° in the width direction and about −10 ° to −1 ° in the height direction, that is, a region including the points C1, C2, and C3 is defined. Here, in the present embodiment, each second lens array 27 is set such that the center of the irradiation area A1 and the center of the irradiation area A2 coincide with each other by adjusting the optical axis thereof. Further, the irradiation area A2 is set so as to encompass the entire area of the irradiation area A1.

  In addition, the aspect ratio when the lens curved surfaces 28b of the third lens array 28 are viewed in plan is set to 1.5: 4.52, for example. Then, by setting the curvature, apex distance, and the like of each lens curved surface 28b and optical surface 28c to appropriate values using experiments, simulations, etc., as an irradiation region A3 of the third lens array 28, for example, FIG. As shown, a rectangular region of about −22 ° to 22 ° in the width direction and about −10 ° to −1 ° in the height direction, that is, a region including the points C1, C2, C3, and C4 is defined. . Here, in the present embodiment, each third lens array 28 is set so that the centers of the irradiation areas A1 and A2 and the center of the irradiation area A3 coincide with each other by adjusting the optical axis thereof. Furthermore, the irradiation area A3 is set so as to encompass the entire area of the irradiation areas A1 and A2.

  With each of these settings, in the illumination system 1 of the present embodiment, the luminous intensity of the area where the irradiation areas A1 to A3 are superimposed is the highest, and then the luminous intensity of the area where the irradiation areas A2 and A3 are superimposed is high, and the irradiation area A3 alone A light distribution pattern in which the luminous intensity of the region is the lowest is realized. And it becomes possible to satisfy the light distribution standard requested | required of a fog lamp by adjusting the output of each LED12 to an appropriate value.

  Here, the illuminance characteristic line based on the simulation result of the illumination light obtained by the illumination system 1 described above is shown in FIG. 8A, and the illuminance distribution of the entire illumination light is shown in FIG. Further, as a comparative example, when the optical surfaces 26c to 28c of the first to third lens arrays 26 to 28 are formed in a spherical shape having the same shape as the lens curved surfaces 26b to 28b (that is, the first to first lenses). The illumination characteristic line based on the simulation result of the illumination light obtained by the illumination system (when the lens array of 3 is entered and the fly-eye lens is formed on both sides on the exit side) is shown in FIG. The illuminance distribution is shown in FIG. 8A and 8C, the characteristic line indicated by a solid line is a characteristic line along the line L1 in FIG. 7, and the characteristic line indicated by a broken line in FIGS. 8A and 8C is a figure. 7 is a characteristic line along the line L2 in FIG. As is apparent from these comparisons, in the illumination system 1 of the present embodiment, the vehicle width direction (X-axis) is also particularly obtained when the irradiation areas A1 to A3 by the three types of lens arrays 26 to 28 are combined. Illuminance in the direction) can be changed gently, and illumination light with no sense of incongruity can be generated as a whole. That is, the optical surfaces 26c to 28c of the lens arrays 26 to 28 are formed by cylindrical lens curved surfaces having a curvature in the vehicle width direction (X-axis direction) of zero, so that they are condensed on the lens curved surfaces 26b to 28b and are optical surfaces. Among the light emitted from 26c to 28c, a part of the light having the emission angle in the vehicle width direction (X-axis direction) can be scattered in a predetermined manner, and the illuminance at the boundary of the irradiation area in the direction is gently changed. be able to.

  Moreover, according to such an illumination system 1, by configuring the light distribution pattern as the entire illumination light by combining the irradiation areas A1 to A3 with the three types of lens arrays 26 to 28, the configuration is simple. A desired light distribution pattern can be configured without reducing the light use efficiency. That is, by combining the irradiation areas A1 to A3 formed by the various lens arrays 26 to 28 to form a desired light distribution pattern without using a reflector or the like, the structure can be simplified. The dimension in the optical axis direction of the system 1 can be dramatically shortened. Furthermore, since energy loss due to reflection does not occur, the light emitted from each LED 12 can be used effectively.

  Here, in the above description, an example in which the curvatures of the optical surfaces 26c to 28c of the lens arrays 26 to 28 are set to be smaller in one direction than the corresponding lens curved surfaces 26b to 28b has been described. In at least any one of the arrays 26 to 28, the curvature in all directions of the optical surfaces 26c to 28c may be set smaller than the curvature of the corresponding lens curved surfaces 26b to 28b.

  For example, it is possible to set the curvatures in all directions of the optical surfaces 26c to 28c of the first to third lens arrays 26 to 28 to “zero” and to form the optical surfaces 26c to 28c as flat surfaces. FIG. 9 shows the first lens array 26 when the optical surface 26c is formed in a plane parallel to the lens substrate 26a. Further, the illuminance based on the simulation result of the irradiation light obtained by the illumination system 1 using the first to third lens arrays 26 to 28 in which the optical surfaces 26c to 28c are formed in a plane parallel to the lens substrates 26a to 28a. The characteristic lines and the illuminance distribution are shown in FIGS. As is clear from FIG. 10, even when the irradiation areas A1 to A3 by the lens arrays 26 to 28 having such a configuration are combined, the illuminance can be changed gently, and the overall illumination is not uncomfortable. Light can be generated.

  Furthermore, in at least any one of the first to third lens arrays 26 to 28, the optical surfaces 26c to 28c may be formed as a plane and inclined with respect to the lens substrates 26a to 28a. FIG. 11 shows the first lens array 26 when the optical surface 26c is formed on a plane inclined with respect to the lens substrate 26a. With this configuration, the illuminance at the boundary of the irradiation region can be changed gently, and the illuminance within the irradiation region can also be given a gradient.

  In the above-described embodiment, an example in which the illumination system 1 is configured using three different types of lens arrays 26 to 28 has been described. However, the present invention is not limited to this, and two or four types are possible. Of course, an illumination system may be configured using more than one type of lens array. Needless to say, various lens arrays having different optical surface forms may be used in appropriate combination.

Exploded perspective view of lighting system Plan view of the illumination system as seen from the exit side II sectional view of FIG. (A) is a top view of a 1st lens array, (b) is bb sectional drawing of (a), (c) is cc sectional drawing of (a). (A) is a top view of a 2nd lens array, (b) is bb sectional drawing of (a), (c) is cc sectional drawing of (a). (A) is a top view of a 3rd lens array, (b) is bb sectional drawing of (a), (c) is cc sectional drawing of (a). Explanatory drawing which shows the relationship between the light distribution standard of the fog lamp used for the test of the current automotive lamps light distribution, and the irradiation area of each lens array when this standard is used Explanatory diagram showing illuminance characteristics (A) is a top view which shows the modification of a 1st lens array, (b) is bb sectional drawing of (a), (c) is cc sectional drawing of (a). Explanatory diagram showing illuminance characteristics by lighting system (A) is a top view which shows the modification of a 1st lens array, (b) is bb sectional drawing of (a), (c) is cc sectional drawing of (a).

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Illumination system, 10 ... Light source unit, 12 ... Light emitting diode (light source), 20 ... Lens optical system unit, 26 ... 1st lens array, 26a ... Lens substrate, 26b ... Lens curved surface, 26c ... Optical surface, 27 ... Second lens array, 27a ... lens substrate, 27b ... lens curved surface, 27c ... optical surface, 28 ... third lens array, 28a ... lens substrate, 28b ... lens curved surface, 28c ... optical surface

Claims (5)

A plurality of lens curved surfaces formed in a matrix on one surface of the lens substrate;
An optical surface that is formed on the other surface of the lens substrate so as to face each of the lens curved surfaces, and has a curvature in at least one direction that is set to be smaller than the curvature of the lens curved surface in the same direction. Characteristic lens array.   The lens array according to claim 1, wherein the optical surface is a cylindrical lens curved surface.   The lens array according to claim 1, wherein the optical surface is a flat surface inclined with respect to the optical axis of the curved surface of the lens. A light source;
An illumination device comprising: the lens array according to any one of claims 1 to 3. A light source;
A plurality of lens arrays of at least two types according to any one of claims 1 to 3, and
An illumination system, wherein at least a part of an illumination area of illumination light emitted from each lens array is made to coincide with each other.

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