JP2017022035A - Light projection unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light projection unit which can improve utilization efficiency of light from a light source, and which can easily array a plurality of light projection elements at predetermined positions while performing positioning adjustment with high accuracy so as to project light to a specific range on a surface to be radiated respectively.SOLUTION: A light projection element includes a tapered light guide body, and a light projection lens continuously provided on an emission surface of the tapered light guide body. The light projection lens is partitioned in a solid manner by a lens incident surface, a lens surface of a predetermined curvature, and a lens outside surface. In the light projection lens, the lens outside surface is arranged in such a manner that a cross section in the direction orthogonal to an optical axis is larger than a cross section of a luminous flux of the light emitting from the emission surface of the tapered light guide body across the whole length in the optical axis direction of the light projection lens, and the optical axis of each light projection element is set so that each light projection element projects light to a specific region on a surface to be radiated, by the lens outside surfaces adjacent to each other of the light projection element being connected with each other.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a light projecting unit that guides light from a light emitting light source such as an LED (light emitting diode) and projects light having a uniform illuminance distribution in a specific range on an irradiated surface.

  2. Description of the Related Art Conventionally, there is known a light projecting element that projects a specific range in an irradiated surface while uniforming illuminance distribution by combining a tapered rod-shaped optical integrator and a projection lens (for example, Patent Document 1 or Patent Document 2).

WO2008-78820 JP 2004-102132 A

  The optical integrator is made of glass or light transmissive resin, and light emitted from the light source in the rod lens repeats total reflection, thereby improving the uniformity of the illuminance distribution on the irradiated surface. In particular, as shown in FIG. 8, when the shape of the optical integrator 300 is widened in a tapered shape from the light incident surface 320 toward the light exit surface 330, the exit angle of the light emitted from the light exit surface 330 is changed. Since it can be made smaller, surface illumination with a uniform illuminance distribution in a specific range on the irradiated surface can be realized.

The light projecting elements described in Patent Document 1 and Patent Document 2 emit light from the optical integrator by arranging the projection lens so that the exit end face of the optical integrator is positioned at the front focal position of such an optical integrator. The light is enlarged and projected to a specific range within the irradiated surface.

  However, in such a conventional light projecting element, part of the light emitted from the exit surface of the optical integrator is reflected by the exit surface or the projection lens surface, and it is difficult to improve the light utilization efficiency. . Further, when a light projecting unit is configured by arranging a plurality of light projecting elements in a matrix, each light projecting element is positioned and adjusted with high accuracy so as to project a specific range on the irradiated surface. There was a problem that it was not easy to arrange in the arrangement.

  An object of the present invention is to solve the above conventional problems and achieve the following objects. That is, the present invention can improve the utilization efficiency of the light from the light source, and can provide a plurality of light projecting elements with high accuracy so that each light projecting element projects a specific range on the irradiated surface. It is an object of the present invention to provide a light projecting unit that can be easily arranged in a predetermined arrangement while performing positioning adjustment.

Means for solving the above problems are as follows. In other words, the light projecting unit has a light source and a light projecting element that improves the uniformity of the illuminance distribution of light from the light source and projects a specific range on the irradiated surface, and a plurality of the light projecting elements are adjacent to each other. The light projecting element includes a tapered light guide having an exit surface area larger than an incident surface area on which light from the light source is incident, and the tapered light guide unit. A light projecting lens connected to the light emitting surface of the light body, the light projecting lens including a lens incident surface on which the light emitted from the tapered light guide is incident, and the tapered light guide on the irradiated surface. A lens surface having a predetermined curvature for projecting light emitted from the light body and an outer surface of the lens are solidly defined, and the light projecting lens extends over the entire length in the optical axis direction of the light projecting lens. The cross-sectional area in the orthogonal direction is the light flux of the light emitted from the exit surface of the tapered light guide. The lens outer surface is arranged so as to be larger than the area, and the lens outer surfaces adjacent to each other of the light projecting elements are connected to each other so that each light projecting element projects a specific range on the irradiated surface. The optical axis of each light projecting element is set so as to emit light.

In the light projecting unit of the present invention, the lens outer surface of the light projecting lens has a polygonal cross-sectional shape orthogonal to the optical axis of the light projecting lens.

In the light projecting unit of the present invention, the shape of the exit surface of the tapered light guide is rectangular.

In the light projecting unit of the present invention, the lens outer surfaces adjacent to each other of the light projecting elements are connected to each other so that each light projecting element superimposes the same region on the irradiated surface. The optical axis of each light projecting element is set.

In the light projecting unit of the present invention, the lens outer surfaces adjacent to each other of the light projecting elements are connected to each other so that each light projecting element projects a different area on the irradiated surface adjacent to each other. The optical axis of each light projecting element is set.

  According to the present invention, the light use efficiency from the light source can be improved, and a plurality of light projecting elements can be projected with high accuracy so that each light projecting element projects a specific range on the irradiated surface. It is possible to provide a light projecting unit that can be easily arranged in a predetermined arrangement while adjusting the positioning.

It is (a) top view, (b) front view, (c) right view of the light projection unit of this invention. It is a perspective view which shows the surface side external appearance of the light projection unit of this invention. It is a perspective view which shows the back surface side external appearance of the light projection unit of this invention. It is a perspective view which shows a light projection element. It is a figure which shows the light distribution characteristic of the emitted light from the light projection unit of this invention. It is a figure which shows the other light distribution characteristic of the emitted light from the light projection unit of this invention. It is a figure which shows the modification of the light projection element of this invention. It is a perspective view which shows the conventional optical integrator.

Hereinafter, the light projecting unit of the present embodiment will be described with reference to the drawings.
1A is a plan view, FIG. 1B is a front view, FIG. 2C is a right side view, FIG. 2 is a perspective view showing a front side appearance, and FIG. FIG. 4 is a perspective view showing a light projecting element.

  As shown in FIGS. 1 to 3, the light projecting unit 100 of the present embodiment includes a light source 20 and a light projecting element 10, and a plurality of light projecting elements 10 are arranged adjacent to each other in a matrix. Yes.

  As the light source 20, a light emitting light source such as an LED (light emitting diode) having a predetermined radiation characteristic is used.

  As shown in FIGS. 1 and 4, the light projecting element 10 includes a tapered light guide 30 disposed on the light source 20 side, and a light projecting lens provided continuously on the emission surface side of the tapered light guide 30. 40.

  The tapered light guide 30 has an incident surface 31 on which light emitted from the light source 20 is incident and an output surface 32 from which light propagated through the internal space is emitted. The area of the output surface 32 is larger than that of the incident surface 31. It is a solid body of a tapered shape in which becomes larger. The cross-sectional shape orthogonal to the optical axis of the tapered light guide 30 is a quadrangle.

  The light taken into the internal space of the tapered light guide 30 is guided while repeating total reflection in the internal space, and is emitted from the emission surface 32 side as a surface light source having a uniform light intensity distribution. At this time, the outgoing angle of the outgoing light emitted from the outgoing surface 32 of the tapered light guide 30 is smaller than that of the prismatic light guide having the same area of the incident surface and the outgoing surface. Light is taken in efficiently.

  The light projecting lens 40 includes a lens incident surface 41 on which light emitted from the tapered light guide 30 is incident, and a lens surface having a predetermined curvature that irradiates and radiates light emitted from the tapered light guide onto the irradiated surface. 42 and the lens outer surface 43 are solidly formed. The lens entrance surface 41 of the light projecting lens 40 and the exit surface 32 of the tapered light guide 30 are integrally connected.

  The lens outer surface 43 of the light projecting lens 40 emits a light beam of the light beam so as not to block the light beam of the light beam emitted from the emission surface 32 of the tapered light guide 30 at a predetermined emission angle and directly reaching the lens surface 42. The cross-sectional shape that is located on the outer peripheral side and orthogonal to the optical axis of the light projecting lens 40 is formed in a square shape. Further, the light projecting lens 40 has a lens incident surface 41 of the tapered light guide 30 so that all the emitted light emitted from the tapered light guide 30 at a predetermined output angle is taken into the light projecting lens 40. The rectangular shape is larger than the area of the emission surface 32, and the cross-sectional area in the direction orthogonal to the optical axis is the light emitted from the tapered light guide over the entire length L in the optical axis direction of the light projecting lens 40. It is comprised so that it may become larger than the cross-sectional area of this light beam.

Further, the lens outer surface 43 of the light projecting lens 40 has a depth that does not block the luminous flux of the light beam that is emitted from the emission surface 32 of the tapered light guide 30 at a predetermined emission angle and reaches the lens surface 42 directly. An arbitrary shape of the lightening 44 is formed. By forming such a lightening 44, the component member can be thinned when the light projecting element 10 is manufactured by injection molding or extrusion molding with a light-transmitting resin, so that it is excellent in terms of molding speed and molding time, In addition, the desired optical quality can be ensured without causing problems such as variations in shape such as warp, sink, or void, or variations in optical characteristics such as birefringence.

The lens surface 42 of the light projecting lens 40 is appropriately curved so that the focal position of the lens surface 42 is the position of the exit surface 32 of the tapered light guide 30. Therefore, for example, in the present embodiment, the output light of the rectangular pattern emitted from the tapered light guide 30 whose cross-sectional shape is a quadrangle is enlarged and projected to the same rectangular pattern at a predetermined magnification on the irradiated surface. be able to.

As shown in FIGS. 1 to 3, the light projecting unit 100 according to the present embodiment has a plurality of light projecting elements 10 adjacent to each other in the vertical direction and the horizontal direction and arranged in a matrix.

In the light projecting unit 100, the relative angular relationship between the optical axis of each light projecting element 10 and the angle of the lens outer surface 43 with respect to the optical axis connects the adjacent lens outer surfaces 43 of the light projecting elements 10 to each other. Thus, each light projecting element 10 is set to project a specific range on the irradiated surface. That is, a configuration in which the optical axis of the light projecting element 10 is tilted with respect to the lens outer surface 43 or a structure in which the lens outer surface 43 is tilted with respect to the optical axis of the light projecting element 10 may be adopted.

The light projecting unit 100 according to the present embodiment is configured so that the emitted light from each light projecting element 10 projects light by superimposing the same region on the irradiated surface and the outside of the lens. The relative relationship between the side surface 43 and the inclined surface with respect to the optical axis is set.

FIG. 5 shows the light distribution characteristics of the emitted light from the light projecting unit in which a total of 25 light projecting elements of 5 × 5 in the vertical direction and the horizontal direction are arranged, and the light source of the light projecting element located at the center of the light projecting unit. The illuminance distribution (the shading shown on the graph) according to the intensity of light on the XY plane (irradiated surface) orthogonal to the optical axis, with the position 1 m away from the position on the optical axis as the origin. FIG. As shown in FIG. 5, the light projecting unit according to the embodiment of the present invention superimposes the emitted light having a rectangular light distribution characteristic emitted from each light projecting element on the same area on the irradiated surface. By illuminating, sufficient illuminance can be secured on the irradiated surface, the light distribution characteristics are controlled in a rectangular shape, and sufficient illuminance can be secured at the four corners of the desired range from the center of the virtual plane.

Moreover, as the light projection unit 100 which concerns on another embodiment of this invention, the emitted light from each light projecting element 10 is obtained by connecting the lens outer surfaces 43 adjacent to each other of a plurality of light projecting elements. However, the optical axis of each light projecting element 10 is set so that different areas on the irradiated surface are projected adjacent to each other.

FIG. 6 shows the light distribution characteristics of the light emitted from the light projecting unit in which nine light projecting elements on the left and right are arranged in a row with respect to the center light projecting element, and the center light projecting on the optical axis. An illuminance distribution (shading shown in the graph) corresponding to the intensity of light on an XY plane (irradiated surface) orthogonal to the optical axis with the origin at a position 1 m away from the light source position of the element. FIG. As shown in FIG. 6, the light projecting unit according to another embodiment of the present invention has a rectangular light distribution characteristic emitted from each light projecting element adjacent to different regions on the irradiated surface. By projecting the light, a wide area can be projected on the irradiated surface, and the light distribution characteristics can be controlled so that the light projected area has a rectangular shape.

The light projecting unit of the present invention is manufactured by injection molding or extrusion molding using a light transmissive resin such as polycarbonate or polymethyl methacrylate (PMMA).

The light projecting unit 100 according to the present embodiment is formed as an integral light projecting unit 100 by individually molding a plurality of light projecting elements 10 and connecting adjacent lens outer surfaces 43 of the light projecting elements 10 to each other. Although manufactured, the present invention is not limited to this example, and the entire light projecting unit 100 may be molded by injection molding or the like.

Hereinafter, modifications of the light projecting unit of the present invention will be described with reference to the drawings.
FIG. 7A and FIG. 7B are diagrams showing a modification of the light projecting element of the present invention.
As shown in FIG. 7A, as the light projecting element according to the modification of the present invention, the light projecting element 11 includes a tapered light guide and a tapered light guide, as with the light projecting element 10 described above. And a light projecting lens provided continuously on the exit surface side of the body. The lens outer surface of the light projecting lens is positioned on the outer peripheral side of the light beam that is emitted from the light emitting surface of the tapered light guide at a predetermined output angle and reaches the lens surface, and the optical axis of the light projecting lens The cross-sectional shape orthogonal to each other is configured to be circular.

Furthermore, as a light projecting element according to another modification of the light projecting unit of the present invention, as shown in FIG. 7B, the light projecting element 12 is tapered in the light projecting element shown in FIG. The light guide is formed with a depth that does not block the light beam emitted from the exit surface of the light guide at a predetermined exit angle and directly reaching the lens surface.

In the light projecting element 11 or 12 according to the modified example of the light projecting unit of the present invention described above, a flat portion is provided on the lens outer surface of the light projecting element 11 or 12, and the light projecting elements 11 or 12 are adjacent to each other. It is also possible to connect flat portions provided on the lens outer surface to form a light projecting unit.

In the light projecting element 10 according to the present embodiment, the tapered light guide 30 has a quadrangular cross-sectional shape orthogonal to the optical axis, but is not limited to this example, and is desired on the irradiated surface. For example, the cross-sectional shape may be a triangle shape or a round shape depending on the light distribution characteristics to be obtained.

In the light projecting element 10 according to the present embodiment, the lens outer surface 43 of the light projecting lens 40 has a square cross section perpendicular to the optical axis of the light projecting lens 40, but is limited to this example. Rather, depending on the arrangement configuration of the light projecting unit, for example, it may be a triangle or a polygon such as a hexagon.

In the light projecting unit according to the present invention, the space between the exit surface of the tapered light guide and the lens surface of the light projecting lens is filled with the light transmissive material, so that the light emitted from the tapered light guide is It can be prevented that a part of the light is reflected by the light exit surface or the light projecting lens surface and the light use efficiency is lowered. Moreover, it becomes possible to position the optical axis of each light projecting element with high accuracy by connecting a plurality of light projecting elements to flat portions provided on the lens outer surfaces adjacent to each light projecting element. Therefore, the light projecting unit according to the present invention can be arranged in a predetermined arrangement while facilitating the setting of the light projecting range on the irradiated surface of the plurality of light projecting elements.

The light projecting unit according to the present invention is suitable for a vehicle lamp using an LED light source. It is particularly suitable for a vehicle lamp using a plurality of LED light sources having a predetermined light distribution pattern.

DESCRIPTION OF SYMBOLS 10 Projection element 20 Light source 30 Tapered light guide 40 Projection lens 41 Lens entrance surface 42 Lens surface 43 Lens outer surface 100 Projection unit

Claims (5)

A light source and a light projecting element that enhances the uniformity of the illuminance distribution of light from the light source and projects a specific range on the irradiated surface, and a plurality of the light projecting elements are arranged adjacent to each other. An optical unit,
The light projecting element includes a tapered light guide having an exit surface area larger than an entrance surface area on which light from the light source is incident;
A light projecting lens connected to the exit surface of the tapered light guide,
The light projecting lens includes a lens incident surface on which light emitted from the tapered light guide is incident, a lens surface having a predetermined curvature for projecting light emitted from the tapered light guide on an irradiated surface, and a lens. The outer side and the solid compartment,
The light projecting lens has a cross-sectional area in a direction perpendicular to the optical axis over the entire length of the light projecting lens in the optical axis direction, which is larger than the cross-sectional area of the light beam emitted from the exit surface of the tapered light guide. The lens outer surface is arranged to be large,
By connecting the lens outer surfaces adjacent to each other of the light projecting elements, the optical axis of each light projecting element is set so that each light projecting element projects a specific range on the irradiated surface. Projection unit characterized by things.   2. The light projecting unit according to claim 1, wherein the lens outer surface of the light projecting lens has a polygonal cross-sectional shape orthogonal to the optical axis of the light projecting lens.   The light projecting unit according to claim 1, wherein a shape of an emission surface of the tapered light guide is rectangular.   By connecting the lens outer surfaces adjacent to each other of the light projecting elements, the optical axis of each light projecting element is set so that each light projecting element superimposes the same region on the illuminated surface. The light projecting unit according to any one of claims 1 to 3.   By connecting the lens outer surfaces adjacent to each other of the light projecting elements, the optical axes of the light projecting elements are set so that the light projecting elements project different areas on the irradiated surface adjacent to each other. The light projecting unit according to any one of claims 1 to 3.

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