JP7360012B2 - Optical and illumination devices - Google Patents

Description

The present invention relates to an optical device suitable for illuminating an area of a predetermined shape such as a line shape or a rectangular shape, and an illumination device using the same.

Patent Document 1 describes providing a lighting device that can form a long linear irradiation range using a small number of light source modules. The lighting device of Patent Document 1 includes four light source units arranged in two rows. Each light source unit is composed of a pair of light source modules. The light source module converts the diverging light of the light emitting element into first output light that is emitted to the front of the substrate through the light source lens, and is refracted through the light source lens and then reflected by the second reflection plate to the front of the substrate. The light is distributed to the second emitted light. In the light source unit, the boards of two light source modules are arranged back to back to form an acute angle, and the light source unit has a line of constant width extending at an angle between the board of one light source module and the board of the other light source module. It forms a shaped illumination light. Therefore, the illumination device can provide a long linear irradiation range.

Japanese Patent Application Publication No. 2012-074278

The light emitted from the LED basically has a Lambertian light distribution pattern in which the light intensity on the optical axis is the highest (largest). Therefore, when trying to illuminate a long linear irradiation range with a small number or concentrated lighting devices, a large number of LEDs are arranged centrally, and the angles of the many optical axes are changed to disperse them along the line of the illumination target. Light distribution is achieved by applying different and complex processing to the light illuminating the ends of the line and the light illuminating the center of the line with respect to the optical axis set to intersect diagonally with the line. need to be controlled. Therefore, there is a need for an optical device that can easily convert Lambertian light distribution into a light distribution suitable for illuminating a predetermined area such as a line or a rectangle.

One aspect of the present invention is to transmit at least a portion of the first light incident along the first axis and having a light distribution characteristic having an optical axis parallel to the first axis. a first reflective surface arranged to reflect in a first substantially arc-shaped range, the first reflective surface including a plurality of reflective arc surfaces divided in a direction along the first axis; and a second reflective surface and a third reflective surface that intersect at the first axis and are arranged to sandwich the first reflective surface, and at least a portion of the light reflected by the plurality of reflective arc surfaces. An optical device having a light-transmitting output surface that refracts and outputs light around a first axis, the output surface including a cross section along the first axis having a periodic uneven shape. .

Another aspect of the present invention is an illumination device including the optical device described above and a light source that outputs first light.

In the optical device of the present invention, light (first light) incident along the first axis is reflected by the first reflecting surface arranged in an arc shape around the first axis. The light is reflected and parallelized in a direction perpendicular to the light, and the light is refracted at the exit surface and output as illumination light. Therefore, the Lambertian light distribution can be converted into a light distribution suitable for a linear or rectangular area to be illuminated, and then emitted.

FIG. 1 is a perspective view showing an example of a lighting device. The figure which shows the example which attached the lighting device to the ceiling. FIG. 3(a) shows the projection unit from the front (irradiation direction), and FIG. 3(b) shows the projection unit from the Z-axis direction. FIG. 3 is a diagram showing the projection unit divided. FIG. 3 is a cross-sectional view showing the structure of an optical element. FIG. 6(a) shows the light distribution of incident light, and FIG. 6(b) is a diagram schematically showing how the incident light is reflected by the reflective surface 31 of the optical element 11. The figure which shows the example of the light distribution of emitted light. A sectional view showing an example of a different lighting device. The figure which shows the example illuminated by the lighting device. The figure which shows the other example illuminated by the illuminating device. The figure which shows another example of the light leakage by a lighting device. A sectional view showing an example of a further different lighting device. 13(a) is a side view and FIG. 13(b) is a plan view. FIG. FIG. 3 is a diagram showing a lighting device expanded into elements. A cross-sectional view of the lighting device. The figure which shows how light is processed in a lighting device. FIG. 3 is a diagram showing the efficiency of light taken in from a light source of a lighting device. FIG. 18(a) is a plan view and FIG. 18(b) is a cross-sectional view of the optical element. 19(a) is a plan view, and FIG. 19(b) and FIG. 19(c) are diagrams showing a cross section of the optical element. 20(a) shows an optical element with a narrow light distribution, FIG. 20(b) shows an optical element with a wide light distribution, and FIG. 20(c) shows a circular light distribution. FIG. 3 is a diagram showing an example of an optical element suitable for an illumination area. 21(a) shows an optical element suitable for illuminating a U-shaped area, and FIG. 21(b) shows an optical element suitable for illuminating a V-shaped area. FIG. 21(c) is a cross-sectional view of an optical element suitable for illuminating an L-shaped area. The perspective view which shows an example of a further different lighting device. FIG. 23 is a perspective view showing the illumination device shown in FIG. 22 with the heat dissipation section removed. FIG. 24 is a diagram showing the lighting device shown in FIG. 23 in an expanded state. It is a figure which shows an example of a further different illumination device, FIG.25(a) is a side view, FIG.25(b) is a top view. FIG. 3 is a diagram showing a lighting device expanded into elements. A cross-sectional view of the lighting device. FIG. 3 is a side view showing an extracted optical element. FIG. 3 is a side view showing the optical element divided into parts. 30(a) is a view showing the optical element developed into parts, FIG. 30(a) is a view from the exit surface side, FIG. 30(b) is a view from the inner upper side, and FIG. 30(c) is a view from the inner lower side. The perspective view which shows an example of a further different lighting device. FIG. 32(a) is a side view of the lighting device, and FIG. 32(b) is a plan view of the lighting device. A cross-sectional view of the lighting device. FIG. 3 is a diagram showing a lighting device developed into parts. The perspective view which shows an example of a further different lighting device. FIG. 36(a) is a side view of the lighting device, and FIG. 36(b) is a plan view of the lighting device. A cross-sectional view of the lighting device. FIG. 3 is a diagram showing a lighting device developed into parts.

FIG. 1 shows an example of a lighting device suitable for illuminating a rectangular area. This illumination device 1 includes a projection unit 5 that projects or projects light (luminous flux) 3 controlled to illuminate a rectangular or line-shaped area 2 such as a tabletop to the front 19, and a rectangular shape that houses the projection unit 5. The housing 4 includes a housing 4 and a driver circuit 8 that drives an LED 6 that serves as a light source of the projection unit 5. The projection unit 5 has a substantially fan-shaped planar view (shape viewed on the XY plane perpendicular to the Z-axis 12), which extends in an arc shape 18 around a central axis (first axis, Z-axis) 12. an optical device (optical system) 10 including a light-transmitting optical element 11 in the shape of a columnar, rod-shaped or cylindrical lens, and an LED 6 into which source light (first light) 7 is incident from one end surface of the optical element 11; including.

As shown in FIG. 2, by being attached to a ceiling 9, the lighting device 1 can intensively illuminate a rectangular or linear elongated area 2 such as a tabletop. The illumination target is not limited to a tabletop, but may also be a wall, an indoor or outdoor signboard, a poster, etc. as long as it is a rectangular or elongated area, and the lighting device 1 can concentrate illumination on such a rectangular or elongated area 2. . The optical device 10 includes an optical element 11 that is substantially fan-shaped in plan view and extends along a first axis 12 that is the center of the fan shape, and reflective members 21 and 22 that are arranged to sandwich the optical element 11. including.

FIG. 3 shows the projection unit 5 including the optical device 10 extracted from the illumination device 1. 3(a) is a perspective view of the projection unit 5 viewed from the projection side (front) 19, and FIG. 3(b) is a perspective view of the projection unit 5 viewed from the side opposite to the projection side 19. Further, FIG. 4 shows the projection unit 5 and the optical device 10 in an expanded state.

As shown in FIG. 4, the optical device 10 has a shape (planar view) around a first axis (Z-axis) 12 serving as a central axis, as viewed in a plane (XY plane) orthogonal to the Z-axis 12. The optical element 11 is substantially fan-shaped and spread out at an angle θ (center angle θ, opening angle θ), and is made of a translucent member, such as acrylic resin or glass. The entire optical element 11 has a columnar shape extending along the Z-axis 12, and on the Z-axis 12 side (inside), one end of the Z-axis 12 (bottom side, Z-axis negative direction) is an opening 13. A cavity 14 is formed, and a surface (output surface) 15 on the opposite projection side (front, outside) 19 is approximately arcuate. Optical device 10 further includes reflective members 21 and 22 arranged to sandwich optical element 11 therebetween. Reflective members 21 and 22 include reflective surfaces 23 and 24 on the side facing optical element 11 . The reflective surface (second reflective surface) 23 and the reflective surface (third reflective surface) 24 are reflective surfaces that intersect at the Z-axis 12 and are arranged to sandwich the optical element 11 therebetween.

As shown in cross section in FIG. 5, the optical element 11 is a cylindrical lens that includes a cavity 14 formed inside along the Z-axis 12 as a whole. It includes a multi-stage inner surface (transmission/reflection surface) 16 along which transmission surfaces and reflection surfaces are alternately arranged. The inner surface 16 of the optical element 11 has a plurality of concentric arc-shaped fan-shaped transmission surfaces arranged in stages from the opposite side to the aperture 13 toward the aperture 13, that is, from the positive side to the negative side of the Z-axis 12. 32, and an arc-shaped reflective surface (first reflective surface) 31 divided into a plurality of parts by these transmission surfaces 32, which are inclined at an acute angle with respect to the XY plane along the Z axis 12. It includes an enlarged first reflective surface 31 . The inner surface 16 of the optical element 11 is arranged in order such that the inner diameter 16r gradually increases from the opposite side to the aperture 13 toward the aperture 13, that is, from the plus side to the minus side of the Z-axis 12. It includes a plurality of fan-shaped transmission surfaces 32 having concentric arc shapes. As another example, the transmitting surfaces may be arranged such that the inner diameter 16r decreases stepwise from the plus side to the minus side of the Z-axis 12, and the transmitting surfaces have the same or substantially the same shape in a concentric arc shape. It may include a plurality of fan-shaped transparent surfaces.

Specifically, in the optical element 11 of this example, the first reflective surface 31 is directed toward the aperture 13 from the opposite side (upper side, Z-axis positive direction) to the aperture 13, that is, from the positive side of the Z-axis 12. Toward the minus side, six reflective surfaces (fourth to six transparent surfaces) divided by six transparent surfaces (first to sixth transparent surfaces) 32a to 32f perpendicular to the Z-axis 12 and parallel to the XY plane. 9th reflective surface) 31a to 31f. That is, the optical element 11 has six transmission surfaces (first to sixth transmission surfaces) 32a to 32f and six reflection surfaces (first to sixth transmission surfaces) 32a to 32f, which are alternately arranged from the plus side to the minus side of the Z-axis 12. 4 to 9 reflective surfaces) 31a to 31f. The optical element 11 further includes an arc-shaped transparent surface 33 formed around the Z-axis 12 closest to the aperture 13 .

For this reason, the optical elements 11 are disposed intermittently along the first axis (Z-axis) 12, and are sequentially arranged so that the inner diameter 16r gradually increases from the opposite side to the aperture 13 toward the aperture 13. A first transmission surface 32a, a second transmission surface 32b, and a third transmission surface 32c arranged in the shape of a concentric arc, and a first transmission surface 32a, a second transmission surface 32b, and a third transmission surface 32c. A fourth reflective surface 31a, a fifth reflective surface 31b, and a sixth reflective surface 31c each having an arc shape are arranged so as to be inclined at an acute angle to the side opposite to the opening 13.

More specifically, the first transmission surface 32a furthest from the opening 13 is a fan-shaped transmission surface centered on the Z-axis 12. The fourth reflecting surface 31a furthest from the aperture 13 is arranged so as to reflect the light transmitted through the first transmitting surface 32a to a range of an arcuate angle θ of 18 around the Z-axis 12 (first range). This is the side that was made. The fourth reflective surface 31a is located on the side opposite to the opening 13 of the first transmitting surface 32a, and has a substantially fan-shaped reflective surface tilted with respect to the XY plane so as to form an inverted truncated cone about the Z-axis 12. The light 7 having an optical axis 7a parallel to the Z-axis 12 is reflected in a direction 19 perpendicular to the Z-axis 12. The fifth reflective surface 31b is located between the inner side 32b1 of the second transmitting surface 32b and the outer side 32a2 of the first transmitting surface 32a so as to reflect the light 7 transmitted through the second transmitting surface 32b. This is an arc-shaped reflective surface. The sixth reflective surface 31c is located between the inner edge 32c1 of the third transmitting surface 32c and the outer edge 32b2 of the second transmitting surface 32b so as to reflect the light 7 transmitted through the third transmitting surface 32c. This is an arc-shaped reflective surface. The seventh reflective surface 31d and the eighth reflective surface 31e are configured similarly to the fourth transparent surface 32d and the fifth transparent surface 32e.

The outer surface 15 of the optical element 11 may be a cylindrical surface, but in this example, the outer surface 15 has seven regions 15a to 15 along the Z-axis 12 corresponding to the reflective surfaces 31a to 31f and the transmitting surface 33. Divided into 15g. These regions 15a to 15g of the outer surface 15 are optimized as toric free-form surfaces so as to more evenly output the light reflected by the reflecting surfaces 31a to 31f and the light transmitted through the transmitting surface 33.

The optical device (optical system, optical system) 10 includes a second reflective surface 23 and a third reflective surface of reflective members 21 and 22 on side surfaces 17a and 17b of an optical element 11 in the shape of a cylindrical lens that is approximately fan-shaped in plan view. 24 are attached so that they are in close contact with each other.

As shown in FIGS. 3 and 4, the projection unit 5 of the illumination device 1 includes an optical device 10 and a substrate 6a attached to an aperture 13 of an optical element 11 thereof. An LED 6 is mounted on the substrate 6a, and a first reflective surface 31 provided in the interior 14 of the optical element 11 extends from the opening 13 along the Z-axis 12 and parallel to the Z-axis 12 from the LED 6. Illumination light 7 is incident towards the area. The first reflecting surface 31 composed of the divided reflecting surfaces 31a to 31f transmits illumination light (first light) 7 having a light distribution characteristic having an optical axis 7a parallel to the Z axis 12. It is arranged to reflect a first range of central angle θ of 18 about axis 12 . The optical device 10 includes a first reflective surface 31, and a second reflective surface and a third reflective surface that intersect with each other at the Z-axis 12 and are arranged to sandwich the first reflective surface 31. The second reflective surface 23 reflects the first light 7 around the Z-axis 12 in the direction of the first reflective surface 31, and the third reflective surface 24 is different from the second reflective surface 23. Reflecting the light 7 from the LED 6 in the opposite direction 18 around the Z-axis 12.

Therefore, the optical device 10 directs the light 7 emitted along the Z-axis 12 from the LED 6, which is a light source, to the second reflective surface 23 and the third reflective surface 24, which intersect at the center angle θ on the Z-axis 12. , and are mutually reflected (folded) in the direction of the first reflecting surface 31 within the range of angle θ. The optical device 10 further reflects the light in a direction perpendicular to the Z-axis 12 by the first reflecting surface 31 to a range of angle θ around the Z-axis 12 and outputs the reflected light.

The second reflective surface 23 and the third reflective surface 24 only need to be arranged so that the light 7 from the LED 6 can be folded into the range of angle θ, and only need to be arranged at least near the LED 6. These reflective surfaces 23 and 24 may be arranged so as to intersect with the first reflective surface 31, and the reflective surfaces 23 and 24 may be arranged so as to intersect with the first reflective surface 31, so that the light 7 from the LED 6 can be transmitted efficiently and without leakage. It can be folded in the direction.

In FIG. 6, light (incident light) 7 that is incident along the Z-axis 12 by the optical element 11 of the optical device 10 is reflected by the first reflecting surface 31, and is emitted in a direction 19 perpendicular to the Z-axis 12. This diagram schematically shows how this is done. As shown in FIG. 6A, the light 7 output from the LED (light source) 6 has a Lambertian light distribution centered on the optical axis 7a. A component of this light 7 around the optical axis 7a is reflected by the second reflecting surface 23 and the third reflecting surface 24 toward the fan-shaped optical element 11 having a central angle θ. In addition, as shown in FIG. 6(b), the component of the light distribution angle φ of this light 7 with respect to the optical axis 7a is determined by the component of the light distribution angle φ with respect to the optical axis 7a. The light beams 71 are divided into a plurality of groups (light beams) by the surfaces 31a to 31f, and reflected by each group, and are output in a direction 19 perpendicular to the optical axis 7a. The reflected light 71 is output as illumination light 3 via the output surface 15 on the outer surface of the optical element 11 . Further, a component of the light 7 output from the LED 6 having a large light distribution angle φ is outputted in a direction 19 perpendicular to the optical axis 7a via the transmission surface 33 near the aperture 13 of the optical element 11.

Therefore, this optical device 10 uses the first reflective surface 31, the second reflective surface 23, and the third reflective surface 24 to direct the light 7 having Lambertian light distribution in a direction perpendicular to the optical axis 7a. 19 and can be converted into illumination light 3 having a light distribution suitable for illuminating a linear or rectangular area. Furthermore, by reflecting the light 7 in a direction 19 perpendicular to the optical axis 7a by the first reflecting surface 31 and converting the light 7 into a direction perpendicular to the optical axis 7a, a light distribution angle φ is created around the optical axis 7a. It is possible to extend the portion where the luminous intensity of the Lambertian light distribution in which the luminous intensity changes is common from one end of the linear or rectangular light distribution to the other. For example, it is possible to extend the light (luminous flux) with the highest luminous intensity on the optical axis 7a from end to end of a linear or rectangular light distribution. For this reason, by controlling the curvature or inclination of the first reflective surface and controlling the luminous intensity in the width direction of the linear or rectangular shape, a linear or rectangular light distribution with a more even luminous intensity distribution can be achieved. Obtainable.

FIGS. 7A and 7B show examples of the horizontal direction (left-right direction) light distribution of the light 3 output from the projection unit 5. 7(a) is an example of the light distribution when the cross section perpendicular to the first axis of the outer surface 15 of the optical element 11 is a perfect circular arc, and FIG. This is an example of a light distribution when the cross section perpendicular to the axis is a free-form surface. By using the optical device 10, the light 7 having a Lambertian light distribution outputted from the LED 6 can be converted into light 3 having a substantially uniform luminous intensity distribution in the horizontal direction and output. By optimizing the outer surface 15 using a free-form surface, an aspheric surface, etc., it is possible to make the distribution of the light 3 output from the optical device 10 uniform.

In FIG. 8, at least a part of the first light incident along the first axis and having a light distribution characteristic having an optical axis parallel to the first axis is Another example of a lighting device that reflects light in a substantially arc-shaped first range is illustrated using a cross section. The projection unit 5a of the illumination device 1a includes a continuous first reflecting surface 31 that is approximately fan-shaped in plan view, a second reflecting surface (not shown) arranged to sandwich the first reflecting surface 31, and a second reflecting surface (not shown) arranged to sandwich the first reflecting surface 31. The optical device 10a includes three reflective surfaces 24. In this projection unit 5a as well, the optical device 10a converts the light 7 input from the LED 6 in the direction of the Z-axis 12 into a direction 19 perpendicular to the Z-axis 12, and converts it into light 3 whose luminous intensity is almost uniform in the horizontal direction. Can be converted and output.

On the other hand, in the optical device 10a of the projection unit 5a, by employing the continuous first reflective surface 31, the area occupied by the first reflective surface 31 is expanded, making it difficult to make the device compact. On the other hand, in the optical device 10 using the cylindrical optical element 11, the first reflective surface 31 is divided into a plurality of parts, and a plurality of total reflection surfaces 31a to 31f are provided inside the cylindrical lens, like a Fresnel lens. It is possible to implement as That is, the optical device 10 is divided in the direction along the Z-axis (first axis) 12, and the light (first light) 7 from the LED 6 is divided in a direction 18 around the Z-axis 12 in a direction perpendicular to the Z-axis 12. 19 includes a plurality of reflective surfaces 31a to 31f. Further, the optical device 10 includes the plurality of reflective surfaces 31a to 31f on the inside, and the inner surface 16 has a plurality of reflective surfaces 31a to 31f and a plurality of transmitting surfaces 32a to 32f corresponding to the plurality of reflective surfaces 31a to 31f, respectively. The optical element 11 includes a multi-stage optical element 11 having a fan-shaped cross section perpendicular to the Z axis (first axis) 12.

Therefore, it is possible to provide a compact optical device 10 and a compact illumination device 1 using the same. Further, the optical element 11 includes a plurality of reflective surfaces 31a to 31f and a plurality of regions (output surfaces) 15a to 15f of the outer surface 15 corresponding thereto. Therefore, it is possible to optimize each of these plurality of reflection surfaces and output surfaces for the light reflected by and the light transmitted by them, and the horizontal luminous intensity distribution becomes even more uniform. It is possible to provide an optical device 10 that converts and outputs.

Each of the plurality of output surfaces 15a to 15f provided corresponding to the plurality of reflection surfaces 31a to 31f of the optical element 11 typically has a curved cross section in the direction along the Z axis 12. It is a toric plane containing . Further, the plurality of exit surfaces 15a to 15f can be arbitrarily designed and may include a portion whose cross section perpendicular to the Z-axis 12 is non-circular.

In this way, the optical element 11 of the optical device 10 has a first light distribution characteristic having an optical axis 7a parallel to the first axis 12, in which light is incident along the first axis (Z-axis) 12. The first reflective surface 31 includes at least one first reflective surface 31 arranged to reflect at least a portion of the light 7 of one light 7 to a first range of a substantially arc-shaped angle θ about the first axis 12 . Specifically, the optical element 11 includes a plurality of reflective surfaces (reflective arc surfaces) 31a to 31f divided in the direction along the first axis 12, which function as the first reflective surface 31, and a plurality of reflective surfaces 31a to 31f, which function as the first reflective surface 31. It includes a translucent outer surface (output surface) 15 that refracts at least a portion of the light 71 reflected by the arcuate surfaces 31a to 31f and outputs it as illumination light 3 around the first axis 12. Therefore, the optical element 11 moves the traveling direction (optical axis) of the first light 7, which has an optical axis 7a parallel to the first axis 12, in a direction different from the first axis 12; a first reflecting surface 31 that converts the reflected light 71 in a direction perpendicular to the axis 12 of the illumination light 3, and a refractive surface that converts the optical axis and/or light distribution as the illumination light 3 by refracting and outputting the reflected light 71. and an exit surface 15 that functions as a lens. Therefore, compared to the optical device 1a shown in FIG. 8, which controls the light distribution of the illumination light 3 only by the reflecting surface 31, there are two Since it includes elements, it is easy to control the spread and distribution of the illumination light 3, and it is also easy to output the illumination light 3 with a more uniform light distribution.

In the optical element 11 described above, the inner surface 16 has a plurality of total internal reflections (TIR) in which a plurality of arcuate surfaces 31a to 31f constituting the first reflective surface 31 and a plurality of transmission surfaces 32a to 32f are combined, respectively. A prism is arranged, and the outer surface 15 is provided with output surfaces 15a to 15f corresponding to the arcuate surfaces 31a to 31f, so that the first reflective surface 31 and the outer surface 15 functioning as a refractive surface are integrated. In addition, corresponding to the arcuate surfaces 31a to 31f that become TIR lens surfaces, the outer surface 15 is divided into a plurality of exit surfaces 15a to 15f to form a toric surface, or a surface for controlling the light distribution around the Z axis 12 is formed. It is easy to introduce and can provide illumination light 3 with a more uniform light distribution.

Furthermore, in the optical device 10, an optical element 11 that controls the direction and spread of the illumination light 3 using the first light 7 intersects with a first axis (Z-axis) 12, and a first reflective surface. By providing the second reflective surface 23 and the third reflective surface 24 arranged to sandwich the optical element 11 including the optical element 31, the first light 7 that spreads in a 360 degree direction (all around the circumferential direction) can be optically It becomes possible to condense (fold, fold) light into a range that can be processed by the first reflective surface 31 on the element 11, and efficiently directs the light 7 output from the LED 6, which is a light source, in a desired direction and range. It can be output as

FIG. 9A shows an example in which the light 3 from the illumination device 1 including the projection unit 5 is projected onto a screen. As shown in FIG. 9(b), it was found that a plurality of light leaks 81 to 84 occurred above and below the rectangular illumination area 2. According to experiments conducted by the inventors, it was found that the arcuate light leaks 81 to 83 are caused by stray light caused by surface reflection at the transmitting surface 33 and the exit surface 15g of the lowermost layer of the optical element 11. The optical element 11 includes a surface that transmits a part of the light 7 in a direction 19 perpendicular to the Z-axis 12 at the lowest stage on the incident side of the multi-stage inner surface 16, and transmits a part of the light 7 in the Lambertian light distribution. A component with a large light distribution angle φ can be output in a direction 19 perpendicular to the Z-axis 12. Therefore, by providing an antireflection layer on at least one of the lowermost inner surface 33 and outer surface (output surface) 15g of the light-transmitting optical element 11, or applying a diffusion process, such as a texture process, the arc-shaped light can be Leakage 81 to 83 can be suppressed.

According to experiments conducted by the inventors, it was found that the angular light leakage 84 is caused by internal reflection on the side surfaces 17a and 17b of the optical element 11. Therefore, the light leakage 84 can be prevented by subjecting the end surfaces 17a and 17b, which are disposed on both sides of the optical element 11 in the direction surrounding the Z-axis 12, to anti-transmission or diffusion processing. Specifically, light leakage 84 can be prevented by painting the end surfaces 17a and 17b black or providing textured surfaces.

FIG. 10 shows an example in which the light 3 from the illumination device 1 using the optical element 11 that takes these measures is projected onto a screen. Almost no light leakage was observed, indicating that light leakage was suppressed by the above measures.

FIG. 11A shows an example of stray light 85 that may appear around the lighting device 1, for example, on the ceiling 9. This stray light 85 is thought to be caused by light reflected from the reflective surface 31 and the transmitting surface 32 of the inner surface 16 of the optical element 11.

FIG. 12 shows an example of a different lighting device 1b. In this illumination device 1b, a plurality of louvers (shielding plates) are arranged in front 19 of the outer surface (output surface) 15 of the optical element 11 of the illumination device 1 described above, at the boundaries of each layer (region) 15a to 15g. )90 included. The louver 90 is a plate-shaped member that extends from the outer surface 15 of the optical element 11 to the front 19 in parallel to the emission direction, that is, parallel to the XY plane. As shown in FIG. 11(b), in the lighting device 1b provided with the louver 90, almost no stray light 85 was observed.

The louver 90 can further make the illumination light 3 output from the outer surface 15 of the optical element 11 parallel, and can suppress the influence of diverging light generated by stray light inside the optical element 11. In the lighting device 1b, the plurality of louvers 90 are arranged in units of layers 15a to 15g in a distributed manner in the Z-axis direction, but they may be arranged in units of a plurality of layers, and there is no relationship between the layers and the louvers 90 are arranged in the Z-axis direction. They may be arranged at predetermined intervals in the direction. The spacing between the plurality of louvers 90 and the amount of protrusion (length) from the outer surface 15 of the optical element 11 are determined by the parallelism of the illumination light 3 required to illuminate the illumination area 2 and the outer surface 15 of the optical element 11 that causes stray light. It can be determined by the intensity and spread (angle) of the divergent light from the source. An example of the length of the louver 90 is to make it approximately the same as the radius (distance from the optical axis to the outer surface) of the optical element 11. If the spacing between the louvers 90 is too narrow, it is likely to cause uneven brightness at the illumination destination, and if the spacing between the louvers 90 is too wide, for example, if the louvers 90 are installed only on the top and bottom, the effects of stray light may be prevented. Hateful. Therefore, it is a preferable example to provide louvers 90 at intervals of each layer 15a to 15g.

As described above, the illumination device 1 includes a rotating lens (refractor, transparent member, optical element) 11, and the optical element 11 is a cylinder that opens in a fan shape (a cylinder with a part of the angle missing). A space 14 surrounded by a surface parallel to the side surfaces 17a and 17b of the optical element 11 and an entrance surface (aperture) 13 of the optical element 11 has a reflective surface 23 on a surface parallel to the side surfaces 17a and 17b. and has 24. An LED 6 serving as a light source is arranged inside the intersection (Z-axis) 12 of these surfaces 23 and 24. Therefore, the light source LED 6 is placed inside the cylindrical optical element 11 at a position eccentric from the rotation axis (center axis, Z axis) 12, but the light 7 from the LED 6 is reflected by the reflective surfaces 23 and 24. The light 3 is convolved and output from the optical element 11 such that the light source is on the Z-axis 12.

The optical element 11 includes arcuate exit surfaces 15a to 15g. The optical element 11 also includes a transmitting part (curved inner wall) 33 on the bottom side (the side of the aperture 13) of the interior (inner surface) 16, and a total reflection surface on the top side (in the optical axis direction, opposite to the aperture 13). 31a to 31f. The total reflection surfaces 31a to 31f are inclined inner walls (Total Internal Reflectins), and emit illumination light 3 aligned in a direction perpendicular to the Z axis 12 and the optical axis 7a to a direction 18 around the Z axis 12. Output surfaces 15a to 15g of the arc portion of the optical element 11 have curved surfaces with a lens function. Therefore, in a cross section taken along the optical axis direction 7a of the optical element 11, the total reflection surfaces 31a to 31f of the reflecting portion have straight or curved surfaces, and the output surfaces 15a to 15g also have straight or curved surfaces.

Therefore, the optical device 10 efficiently and more uniformly converts the light 7 from the light source (LED) 6 into a linear or rectangular light distribution. Therefore, by using the optical device 10, it is possible to provide the illumination device 1 that can more uniformly and brightly illuminate a linear or rectangular region.

FIG. 13(a) shows a side view of a still different lighting device 1c, and FIG. 13(b) shows a top view of the lighting device 1c. Further, FIG. 14 shows the expanded state of the elements constituting the lighting device 1c, and FIG. 15 shows the schematic configuration of the lighting device 1c, taken along the cross section XV-XV along the center of the device 1c (see FIG. 13(b)). This is shown using a cross-sectional view taken at . Furthermore, FIG. 16 shows an outline of how the illumination light 3 is output in this illumination device 1c. The illumination device 1c includes an optical device 10 that converts light (first light) 7 from an LED 6 serving as a light source into illumination light 3 and outputs it, and a substrate 6a on which the LED 6 that outputs the first light 7 is mounted. have The optical device 10 receives at least a portion of the first light 7 that is incident along the first axis (Z-axis) 12 and has a light distribution characteristic having an optical axis 7a parallel to the first axis 12. A first reflective surface 31 arranged to reflect in a first range of a substantially circular arc shape at an angle θ around the first axis 12; The second reflective surface 23 and the third reflective surface 24 are arranged to sandwich the light 71, and at least a part of the light 71 reflected by the first reflective surface 31 is refracted around the first axis 12. It includes a light-transmitting output surface 15 for outputting light.

More specifically, in the optical device 10, a first reflecting member 21 having a second reflecting surface 23 and a second reflecting member 22 having a third reflecting surface 24 are arranged along the first axis. 12 and a translucent optical element 11 having a first reflective surface 31 on its inner surface 16 and an output surface 15 on its outer surface. The first reflective surface 31 includes a plurality of reflective arc surfaces 31a to 31d divided in the direction along the first axis 12, and at least one of the light 71 reflected by the plurality of reflective arc surfaces 31a to 31d. The light-transmitting output surface 15 that refracts the light beam and outputs the light around the first axis 12 includes a periodic uneven shape 40 in a cross section along the first axis 12 . The optical element 11 further includes a transmitting surface 33 that transmits the first light 7 on the inner surface 16 on the incident side (lowermost stage) of the first light 7, and the transmitting surface 33 has a wide-angle ( peripheral components) are refracted and guided to the exit surface 15. The exit surface 15 is a portion that outputs light 72 whose direction has changed with respect to the first axis 12 due to refraction (in this example, light in a direction substantially perpendicular to the first axis 12) as illumination light 3. Periodic unevenness 40 is formed in the direction along the Z-axis 12 over the entire emission surface 15 including (region).

The periodic uneven shape 40 in the direction along the first axis (Z-axis) 12 includes a shape in which concave shapes 41 and convex shapes 42 are repeated at a predetermined pitch in the Z-axis direction, and has a sine wave shape. It may be a zigzag shape in which a straight line is bent many times in a Z shape, or it may be a shape in which a straight line and a curved line are combined, and the concave shape 41 and the convex shape 42 may be repeated mutually Shows the shape that appears. The periodic uneven shape 40 may have an amplitude, which is the distance (width) between the peak and valley of the unevenness, and a repetition pitch (period) that is constant in the direction of the Z-axis 12. It may also change according to a predetermined function. In the periodic uneven shape 40, the amplitude and period of the unevenness may be constant in the direction around the Z-axis 12 (circumferential direction, θ direction), or may vary in the θ direction according to a predetermined function. Good too. The output surface 15 may have a periodic uneven shape in the circumferential direction.

The light-transmitting exit surface 15 may include a plurality of inflection points 45 provided at predetermined intervals in a cross section along the first axis 12 . Each of the plurality of inflection points 45 is a point at which the convex shape 42 changes to the concave shape 41 or from the concave shape 41 to the convex shape 42, a point at which the curve changes from a straight line, or from a straight line to a curved line, and a point where the direction of the slope of the straight line changes. It may be at least one of the points that change.

The output surface 15 including a periodic uneven shape 40 and/or a plurality of inflection points 45 provided at predetermined intervals acts on the output illumination light 3 and changes the vertical intensity distribution (luminous intensity) of the illumination light 3. This includes the effect of making the distribution more uniform. The period of the periodic uneven shape 40 or the interval between the inflection points 45 may or may not correspond to the plurality of reflective surfaces 31a to 31d and the transmitting surface 33 of the optical element 11. In order to easily obtain the effect of making the intensity distribution constant, the ranges 15a to 15d of the outer circumferential surface (output surface) 15 facing each of the plurality of reflection arc surfaces 31a to 31d, and the range 15g corresponding to the transmission surface 33. may include at least one periodic uneven shape 40. The periodic uneven shape 40 may include a plurality of concave shapes 41 or convex shapes 42 in ranges 15a to 15d and 15g facing each of the reflective arc surfaces 31a to 31d and the transmitting surface 33. The light 71 reflected by each of the reflecting surfaces 31a to 31d enters an exit surface on the outer surface 15, which is provided with two or more concave portions 41 and/or convex portions . The number of projections and depressions corresponding to each of the reflecting surfaces 31a to 31d can be set arbitrarily. By setting the period (pitch) so that at least one combination of a concave shape 41 and a convex shape 42 is arranged corresponding to each of the reflective surfaces 31a to 31d, the output surface 15, which is the outer surface of the optical element 11, It becomes possible to proceed with the design separately from the number (number of stages) of the reflective surfaces 31 that are the inner surface 16, and the degree of freedom in designing the optical element 11 is improved.

Similarly, the cross section of the exit surface 15 in the direction along the first axis 12 may include at least two inflection points 45 in ranges 15a to 15d facing each of the plurality of reflective arc surfaces 31a to 31d. . The same applies to the range 15g corresponding to the transmission surface 33. By including at least two inflection points 45 in each of the ranges 15a to 15d and 15g of the outer circumferential surface 15, shapes that change from concave to convex, from convex to concave, from convex to concave, and from concave to convex can be changed in each range. included at least. Therefore, the light 71 reaching the outer surface 15 instead of being collimated at the outer surface 15 in the direction along the first axis 12 undergoes alternating convergence and divergence, and when reaching the illumination area 2 A certain portion of the illumination area 2 is illuminated by the illumination light 3 output through various areas 15a to 15d and 15g of the exit surface 15, and the intensity distribution (brightness distribution) of the illumination is averaged.

FIG. 16 schematically shows typical behavior of light rays in the optical element 11 in which, for example, a sinusoidal wave shape is formed along the Z-axis 12 as the periodic uneven shape 40. The concave shape 41 of the concavo-convex shape 40 functions as a concave lens to diverge light, and the convex shape 42 functions as a convex lens to converge light. Therefore, the light reflected by the plurality of reflective surfaces 31a to 31d and emitted from the outer surface 15 alternately shows areas of convergence and divergence. Since the light reflected by one reflective surface and directed toward the output surface follows different optical paths of convergence and divergence, the quality of illumination unevenness can be improved.

The exit surface 15 is a part that controls the light distribution around the first axis 12 of the illumination light 3 outputted through the exit surface 15, that is, the period, amplitude, and inflection of periodic irregularities around the Z axis. It may also include a portion where the position, interval, etc. of points change. In order to better control the light distribution in the Z-axis direction (vertical direction) at each position in the horizontal direction (XY plane) perpendicular to the Z-axis 12, optical elements are adjusted at each position of the angle θ around the Z-axis. The shape of the outer surface 15 of 11 may be set. As shown in FIGS. 13(b) and 14, in this illumination device 1c, the optical element 11 has an opening angle from the center θ0 in a plan view on a plane (XY plane) perpendicular to the Z-axis 12. At positions where θ1 is 0 degrees, 15 degrees, 30 degrees, and 45 degrees, periodic concavo-convex shapes 40 designed to make the light distribution uniform in the vertical direction (Z-axis direction) are mounted. Therefore, at the positions of the optical element 11 where the aperture angle θ1 is 0 degrees, 15 degrees, 30 degrees, and 45 degrees, portions (regions) 15 You may be prepared. The shape of the exit surface 15 between these angles can be designed so as to form a seamless surface by interpolating the uneven shapes 40 of adjacent cross sections.

Furthermore, the design of the exit surface 15 of the optical element 11 can be designed basically independently of the shape of the inner surface 16 provided with the TIR prism 39. Therefore, even if the design of the inner surface 16 is the same, the design of the output surface 15, which is the outer surface, can be changed. For this reason, an optical system that appropriately controls the light distribution in the vertical direction depending on the distance to the area 2 to be illuminated, and makes the luminance distribution in the longitudinal direction (horizontal direction) in the illumination area 2 more uniform. An element 11 can be provided. The exit surface 15 may be designed symmetrically in the horizontal direction (opening angle θ1) with respect to the center θ0, or may be designed asymmetrically due to the illumination area 2.

In this optical element 11, a plurality of reflection arc surfaces 31a to 31d are arranged on the inner surface 16, each of which includes a concentric arc-shaped reflection surface (total reflection surface) centered on the first axis 12, and It includes transparent surfaces 32a to 32d corresponding to surfaces 31a to 31d. Therefore, in the optical element 11, a multistage TIR (total internal reflection) prism 39 is formed on the inner surface 16.

The optical device 10 further includes a control member 79 that prevents the component of the first light 7 on the optical axis 7a from being directly input to the first reflective surface 31. This control member may be a control member that blocks (absorbs) light, or may be a control member that reflects or diffuses light. In this example, the optical device 10 includes, at the top of the folding mirror 20 along the first axis 12, a light-blocking or non-reflective control member 79 that projects from the first axis 12 in a fan shape. The control member 79 absorbs a portion of the first light 7 from the LED 6 around the optical axis 7a, for example, a component at an elevation angle φ1, and prevents it from being input to the optical element 11. The control member 79 may be a mirror surface or a scattering surface such as an inverted cone extending along the first axis 12, or may be capable of appropriately supplying the component of the elevation angle φ0 to the optical element 11.

FIG. 17 is a graph showing the capture efficiency of light incident on the reflective surface 31 along the Z-axis (first axis) 12 with respect to the elevation angle φ. When the elevation angle φ is 80°, there is a capture efficiency of 97%, and even if the elevation angle φ is 80° to 90°, that is, even if you discard the light at the elevation angle φ1 that is emitted directly above from the LED 6, the amount of light loss is about 3%. I understand that there is something.

On the other hand, as shown by the broken line in FIG. 16, a reflecting surface 31x is formed that includes light having an elevation angle of 80° to 90° and reflects it at another angle with respect to the Z-axis 12, for example, in a direction perpendicular to the Z-axis 12. The volume required for this corresponds to approximately 15% of the total volume of the optical element 11. As shown in FIG. 16, the optical element 11 of this example has a surface that reflects light with an elevation angle φ1 omitted, instead of a reflective surface 31x that includes a surface that reflects light with an elevation angle φ of 80° to 90° (elevation angle φ1). By adopting 31a, the thickness is reduced and the size is reduced. Therefore, by employing this optical element 11, it is possible to provide a compact optical device 10 and lighting device 1c in which the efficiency of converting the light from the LED 6 into the illumination light 3 hardly decreases.

In this way, the optical element 11 directs the first light 7 having a Lambertian light distribution output from the LED 6 at a different angle from the optical axis 7a of the first light 7, typically in a direction perpendicular to the optical axis 7a of the first light 7. The first reflecting surface 31 that controls the intensity distribution of light by reflecting it in a predetermined range (first range) of the angle θ around the optical axis 7a and this reflecting surface 31 can be designed independently, It includes a cylindrical or arcuate exit surface 15 that refracts and outputs the reflected light 71 to output illumination light 3 having a shape and intensity distribution matching the area 2 of the object to be illuminated. ing. Furthermore, by providing periodic uneven shapes 40 in the longitudinal direction (vertical direction) of the cylindrical or arcuate exit surface 15, it is possible to control the spread and intensity distribution of the illumination light 3 in the vertical direction (Z direction). By adjusting the circumferential shape of the emission surface 15, the circumferential spread (horizontal direction, XY direction) and intensity distribution can be controlled. Therefore, the optical device 10 and illumination device 1 equipped with this optical element 11 can output illumination light 3 that can more uniformly illuminate the entire area 2 of various areas, shapes, or configurations. .

18 to 21 show several examples of optical elements 11 for illumination devices suitable for regions 2 of different shapes or configurations. The optical element 11 shown in FIG. 18 is an optical element 11 that outputs illumination light 3 having a standard spread in the horizontal direction and having a so-called medium distribution. As shown in FIG. 18(a), the outer surface (output surface) 15 of the optical element 11 has an arc shape that spreads around the first axis 12 at the center. As shown in cross section in FIG. 18(b), the output surface 15 of the optical element 11 has a periodic uneven shape 40 that controls the spread of the illumination light 3 in the vertical direction along the first axis 12. We are prepared.

The optical element 11 shown in FIG. 19 is an example of an optical element 11 that outputs illumination light 3 that has a medium spread in the horizontal direction but has a large spread in the vertical direction along the first axis 12. As shown in FIG. 19(a), the outer surface (output surface) 15 of the optical element 11 is in the shape of an arc expanding around the first axis 12 at the center. As shown in cross section in FIG. 19(b), the amplitude of the periodic uneven shape 40 provided on the output surface 15 of the optical element 11 (for example, the amplitude between the peak of the convex shape 42 and the bottom of the concave shape 41) (distance, height, sag amount) may be larger than the amplitude of the uneven shape 40 shown in FIG. 18(b). The periodic uneven shape 40 may be a collection of curved surfaces like a sine wave shape, as shown in FIG. 19(b), or a zigzag shape as shown in FIG. 19(c). It may also be a collection of straight lines (slopes) with different angles.

The optical element 11 shown in FIG. 20(a) is an example suitable for illuminating a narrow region 2 in the horizontal direction. The output surface 15 of the optical element 11 has a shape suitable for outputting the illumination light 3 with a narrow light distribution, for example, a surface with a large curvature (a small radius of curvature). The optical element 11 shown in FIG. 20(b) is an example suitable for illuminating a wide (long) region 2 in the horizontal direction. An example of widening the light distribution angle is to arrange one or more uneven shapes also in the circumferential direction. As shown in FIG. 20(b), in a cross section perpendicular to the first axis 12 (horizontal cross section, plan view), the exit surface 15 has a concave shape at a position where the opening angle is 0 degrees, and both sides It can be designed to have a convex shape. The optical element 11 having an output surface 15 having a double-lobed or uneven cross section in the horizontal direction is suitable for outputting illumination light 3 with a wide light distribution for illuminating a horizontally long area 2. The optical element 11 shown in FIG. 20(c) is an example suitable for illuminating a line-shaped region 2 extending in the circumferential direction on the inner surface of a cylinder.

The optical element 11 shown in FIG. 21A is an example suitable for illuminating a three-dimensional surface (region) 2 in which a plurality of linear surfaces are combined in a U-shape. The cross section of the exit surface 15 of this optical element 11 in the direction perpendicular to the first axis 12 is straight or convex or concave with a large radius of curvature at a position facing the center of the U-shape and having an opening angle of 0 degrees. It is a curved portion 15y, and a convex portion 15z corresponding to the vertically bent position of the U-shape. By adopting such a shape of the output surface 15, the inner wall of the U-shape can be uniformly lined. An optical element 11 suitable for illumination can be provided.

The optical element 11 shown in FIG. 21(b) is an example suitable for illuminating a three-dimensional surface (region) 2 in which a plurality of linear surfaces are combined in a V-shape. A cross section of the exit surface 15 of this optical element 11 in a direction perpendicular to the first axis 12 has a convex shape 15z toward a location corresponding to a position where the surfaces intersect in a V shape. By adopting this shape, it is possible to provide an optical element 11 suitable for uniformly illuminating a V-shaped inner wall in a line.

The optical element 11 shown in FIG. 21(c) is an example suitable for illuminating a three-dimensional surface (region) 2 in which a plurality of linear surfaces are asymmetrically combined in an L-shape. A cross section of the exit surface 15 of this optical element 11 in a direction perpendicular to the first axis 12 has a convex shape 15z toward a location corresponding to a position where the surfaces intersect in an L-shape, around the first axis 12. By adopting the asymmetrical shape of the output surface 15, it is possible to provide an optical element 11 suitable for uniformly illuminating the L-shaped inner wall in a line.

As described above, by controlling the shape of the exit surface (outer surface) 15 in the cross section in the direction along the first axis 12 and the shape of the exit surface 15 in the cross section in the direction perpendicular to the first axis 12. , it is possible to output illumination light 3 having different light distribution characteristics. Therefore, if the illumination device 1 includes the optical element 11 provided with the output surface 15, it is possible to provide the illumination device 1 that can more uniformly illuminate the linear regions 2 of various configurations to be irradiated.

FIG. 22 shows different examples of the lighting device 1d. FIG. 23 shows a state in which the radiation fin 59 to which the lighting device 1d was attached has been removed, and FIG. 24 shows a state in which the lighting device 1 is expanded into its constituent elements. This lighting device 1d is an example of a module lighting device, and includes a light-shielding mask 51 that covers the periphery of the output surface 15 on the front surface (outer surface) of the optical element 11. A light-shielding mask 51 that covers the periphery of the exit surface 15 on the outside of the exit surface 15 has a function as a countermeasure against glare and stray light. The illumination device 1 includes an optical element 11 having a first reflective surface 31 on an inner surface 16, a second reflective surface 23, and a third reflective surface 24, and is installed to sandwich the inner surface 16 of the optical element 11. a folding mirror (sheet metal mirror) 24; a rectangular trumpet-shaped light-shielding mask 51 that covers the periphery of the exit surface 15 of the optical element 11; and a resin casing for assembling the optical element 11, the sheet metal mirror 20, and the mask 51. 52, 53, and 54, a board 6a on which an LED 6 serving as a light source is mounted, and a sheet metal heat spreader 58 that supports the board 6a and releases heat from the LED 6 to a heat radiation fin 59.

FIG. 25(a) shows a side view of a still different lighting device 1e, and FIG. 25(b) shows a top view of the lighting device 1e. Further, FIG. 26 shows a state in which the elements constituting the lighting device 1e are expanded, and FIG. 27 shows a schematic configuration of the lighting device 1e in a cross section XXVII-XXVII along the center of the device 1e (see FIG. 25(b)). This is shown using a cross-sectional view taken at . The illumination device 1e includes an optical device 10 that converts light (first light) 7 from an LED 6 serving as a light source into illumination light 3 and outputs it, and a substrate 6a on which the LED 6 that outputs the first light 7 is mounted. have The optical device 10 receives at least a portion of the first light 7 having a Lambertian light distribution, which is incident along a first axis (Z-axis) 12 and has an optical axis 7a parallel to the first axis 12. , the light is almost collimated in a direction perpendicular to the optical axis 7a (first axis (Z-axis) 12) in a first range having a substantially circular arc shape at an angle θ around the first axis 12. A first reflecting surface 31 arranged to reflect as 71, a second reflecting surface 23 and a third reflecting surface intersecting at the first axis 12 and arranged so as to sandwich the first reflecting surface 31. a light-transmitting output surface 15 that refracts at least a portion of the light 71 reflected by the first reflective surface 31 and outputs the light 71 around the first axis 12; and a light-shielding louver 90.

The configuration of the optical device 10 is almost the same as the example shown above except for including the louver 90, and includes a bending mirror 20 having a second reflective surface 23 and a third reflective surface 24, and an inner surface 16. The light-transmitting optical element 11 includes a first reflective surface 31 and a light-transmitting optical element 11 whose outer surface is an output surface 15 . The optical element 11 has a multi-stage inner surface 16 including a plurality of reflecting arc surfaces 31a to 31d and a plurality of transmitting surfaces 32a to 32d corresponding to the plurality of reflecting arc surfaces 31a to 31d, respectively. is provided with an exit surface 15 including a periodic uneven shape 40 and/or a plurality of inflection points 45, and a cross section perpendicular to the first axis 12 has an angle θ around the first axis 12 of 180 degrees or less. It is a translucent member that has a substantially sector-shaped shape of approximately 100 mm or less. The plurality of reflection arc surfaces 31a to 31d and the plurality of transmission surfaces 32a to 32d corresponding to the plurality of reflection arc surfaces 31a to 31d each constitute a total internal reflection (TIR) prism 39, and the optical element 11 The inner surface 16 has a configuration in which multi-stage TIR prisms 39 are arranged along the first axis 12.

FIG. 28 shows the optical element 11 extracted. Further, FIG. 29 shows a side view of the optical element 11 developed into a plurality of light-transmitting members (light-transmitting members, parts) 111a to 111e, and FIG. 30 shows a perspective view. There is. 30(a) shows the unfolded state of the optical element 11 viewed from the exit surface (outer surface) 15 side, and FIG. 30(b) shows the upper side of the inner surface 16, that is, the first light 7 It is shown from the side opposite to the incident side of the first axis (Z-axis) 12, and FIG. 30(c) is shown from the lower side of the inner surface 16, that is, from the incident side of the first axis 12.

Each of the translucent members (parts) 111a to 111e includes an end surface 115 perpendicular to the first axis (Z-axis) 12, and the optical element 11 is such that these parts 111a to 111e includes an assembly 110 stacked along the . Each of the parts 111a to 111e divides the optical element 11 into an XY plane at each position of a plurality of concentric arc-shaped fan-shaped transmission surfaces 32a to 32d arranged in stages along the Z-axis 12. As shown in FIG. 39 (TIR prism single unit), four parts 111a to 111d that are approximately fan-shaped in plan view, and one part 111e that is approximately fan-shaped in plan view and has a transmitting portion 33 without a reflective surface on the inner surface 16. . Each of the parts 111a to 111d is a part of the periodic uneven structure 40 that constitutes the outer surface 15 of the optical element 11, and has parts corresponding to the reflective surfaces 31a to 31d and the transmitting portion 33 of the inner surface 16, respectively. Contains the configuration of

Each of the translucent parts 111a to 111d has at least one combination of one of the plurality of reflective curved surfaces 31a to 31d that functions as the first reflective surface 31 and one of the plurality of transparent surfaces 32a to 32d. , that is, it includes at least one TIR prism 39 . Each part 111a-111d may be configured to include a plurality of TIR prisms 39. Each part 111a-111d includes one of the plurality of reflective curved surfaces 31a-31d and one of the plurality of transmission surfaces 32a-32d, and may be configured to include a single TIR prism 39. The TIR prism 39 has a shape protruding toward the inner surface, and in the case of the arc-shaped optical element 11, a plurality of TIR prisms 39 can be formed. On the other hand, in the case of a cylindrical or ring-shaped optical element as explained in the example below, it is difficult to create a plurality of TIR prisms 39 on the inner surface. By disassembling the optical elements in different directions, it is possible to easily manufacture an optical element having a plurality of TIR prisms 39 therein.

Furthermore, the plurality of TIR prisms 39 provided on the inner surface 16 of the optical element 11 have the function of collimating the light 7 from the LED 6 input along the Z-axis 12 in a direction perpendicular to the Z-axis 12; If the optical element 11 is optically seamless, there is a possibility that stray light may occur inside the optical element 11 . When stray light is output from the output surface 15 of the optical element 11 and recognized from the outside, it may illuminate unnecessary areas or cause glare if it enters the eyes. By disassembling and assembling the optical element 11 in the direction of the Z-axis 12 in units of TIR prisms 39, there is an advantage that generation of stray light can be suppressed in units of TIR prisms 39.

In order to prevent stray light generated in each of the parts 111a to 111e from being outputted through the other parts 111a to 111e, a light-shielding member is inserted between at least a portion of the parts 111a to 111e. A solid 110 may also be configured. Furthermore, at least a portion of the end faces 115 perpendicular to the Z-axis 12 of the parts 111a to 111e may be made light-shielding, or these may be combined.

In this example, the assembly 110 constituting the optical element 11 includes a louver 90, which is a light-shielding member that is at least partially disposed (sandwiched) between each of the translucent parts 111a to 111e. include. The louver 90 extends (protrudes) from the output surface 15 of the optical element 11 and is sandwiched between a portion 91 that prevents stray light output from the output surface 15 and each of the parts 111a to 111e, and prevents stray light between the parts. and a portion 92 that prevents.

Furthermore, the assembly 110 includes parts 111a to 111e that include a light-blocking region 117 on at least a portion of the end surface 115. The light-shielding region (portion) 117 may be formed when the parts 111a to 111e are molded using a technique such as two-color molding, or after the parts 111a to 111e are molded, desired areas are processed to have light-shielding properties. You may.

Each of the parts 111a to 111e is provided with a joint at the end of the outer surface 15 for stacking. Specifically, the uppermost part 111a has a concave structure 119 on the lower end surface, and the middle parts 111b to 111d have a convex structure 118 on the upper end surface 115 and a concave structure 119 on the lower end surface. A convex structure 118 is provided on the upper end surface 115 of the lowermost part 111e. By fitting these convex structures 118 and concave structures 119 through through holes 98 provided in the sandwiched louvers, an assembly 110 including these parts 111a to 111e can be constructed. The method of configuring the assembly 110 from the parts 111a to 111e is not limited to this, but the upper and lower structures may be reversed, adhesive may be used, or the parts 111a to 111e may be surrounded by a frame etc. It may be integrated as a whole.

The optical element 11 that does not use a louver may be configured by the assembly 110. When the optical element 11 is formed from one member, the region near the Z-axis 12 has a molded member from the top to the bottom, resulting in a thick part, which increases the solidification time during molding and reduces mass productivity. do. By dividing and manufacturing a plurality of parts each having an end face 115 on the XY plane, thick parts are eliminated and mass productivity is improved. In addition, by sandwiching a light shielding plate between the joint surfaces of each part, stray light can be shielded similarly to the above-mentioned louver. Each part may be provided with a recess corresponding to the thickness of the light shielding plate on the joint surface (end surface) 115 of each part.

FIG. 31 shows a further different lighting device 1f. FIG. 32(a) shows a side view of the lighting device 1f, and FIG. 32(b) shows a top view of the lighting device 1r. Further, FIG. 33 shows a schematic configuration of the illumination device 1f using a cross-sectional view taken along the cross section XXXIII-XXXIII (see FIG. 32(a)) along the center of the device 1f. Furthermore, FIG. 34 shows a state in which the lighting device 1f is expanded into parts. The illumination device 1f includes an optical device 10 that converts light (first light) 7 from an LED 6 serving as a light source into illumination light 3 and outputs it, and a substrate 6a on which the LED 6 that outputs the first light 7 is mounted. have The optical device 10 receives at least a portion of the first light 7 having a Lambertian light distribution, which is incident along a first axis (Z-axis) 12 and has an optical axis 7a parallel to the first axis 12. , in a circular (cylindrical) first range around the first axis 12, the light 71 is almost collimated in a direction perpendicular to the optical axis 7a (first axis (Z-axis) 12). a first reflective surface 31 arranged to reflect the light 71; and at least a part of the light 71 reflected by the first reflective surface 31 is refracted and output around the first axis (Z-axis) 12. and a light-transmitting exit surface 15.

The illumination device 1f further includes a part (on-axis light processing member) 120 for processing light along the Z-axis 12. This part 120 may be a light-shielding or reflective member so as to have the same function as the control member 79 described above. Furthermore, the part 120 may have a function that adds optical performance as a lighting device, such as a lens function or a light diffusion function, and can be used not only to illuminate a linear area but also to illuminate the axial circumference of a cylindrical optical element. It is also possible to provide a lighting device that can illuminate a wide range of areas. The shape of the part 120 may be disc-shaped, cylindrical, spherical, rectangular, etc., and may be an object such as a person, an animal, a plant, or a building made of a translucent or diffusive material. good.

The optical device 10 includes a plurality of reflective curved surfaces 31a to 31e provided concentrically around the first axis 12 along the first axis 12, and a plurality of reflective curved surfaces 31a to 31e respectively corresponding to the plurality of reflective curved surfaces 31a to 31e. The optical element 11 has a multistage inner surface 16 including a plurality of TIR prisms 39 each having transmission surfaces 32a to 32e, and an outer surface 15 having a cylindrical exit surface. The output surface (outer surface) 15 of the optical element 11 in this example is a cylindrical surface, but may be a prismatic cylindrical surface with a polygonal cross section in plan view (a surface perpendicular to the first axis 12). , it may be a surface having a cross section with a continuous contour of a plurality of concavities and convexities. Further, the cross section of the exit surface 15 in the direction along the first axis 12 may be a straight line, or may be a surface having periodic irregularities 40 as described above, and may have a plurality of inflection points. 45 may be used.

The optical element 11 is an assembly of a plurality of translucent members (parts) 111a to 111f including an end surface 115 perpendicular to the first axis 12, similar to the optical element with the arcuate exit surface 15 described above. 110 included. Each of the parts 111a to 111f is ring-shaped and includes a ring-shaped TIR prism 39 on the inner surface 16, and has a ring-shaped output surface 15 on the outer surface. A light-shielding portion 117 may be provided on a part or all of the end surface 115 of each of the parts 111a to 111f, and a louver 90, which is a light-shielding member, is sandwiched between these parts 111a to 111f to form the assembly 110. may be configured.

The illumination device 1f equipped with this cylindrical optical element 11 is suitable for illuminating a linear region of a cylindrical surface (inner surface). In this illumination device 1f as well, by changing the shape of the outer surface 15 of the optical element 11, as explained with reference to FIGS. We can provide lighting equipment suitable for The optical element 11 described above has a cylindrical shape or a partially cut-out shape of a cylindrical shape, and has a configuration suitable for illuminating an elongated linear or rectangular area 2, but a trapezoidal area It may be a conical shape or a shape cut out from a part of a conical shape suitable for illuminating a rectangular or linear area 2 from an angle, such as an egg shape, a drum shape, or a part thereof. It may be a shape cut out. By disassembling the optical element 11 into a plurality of parts along the central axis (Z-axis) 12, manufacturing them, and assembling them, optical elements 11 of various shapes can be produced from the LED 6 incident along the central axis 12. It is possible to provide an optical element 11 that collimates the light 7 in a direction perpendicular to the central axis 12 using a reflective surface 31 and outputs it as illumination light 3 suitable for the shape of the region 2 to be illuminated using a refractive surface on the outer surface.

FIG. 35 shows a still different lighting device 1g. FIG. 36(a) shows a side view of the lighting device 1g, and FIG. 36(b) shows a top view of the lighting device 1g. Further, FIG. 37 shows a schematic configuration of the illumination device 1g using a cross-sectional view taken along the cross section XXXVII-XXXVII (see FIG. 36(a)) along the center of the device 1g. Furthermore, FIG. 37 shows the lighting device 1g developed into parts. The illumination device 1g includes an optical device 10 that converts light (first light) 7 from an LED 6 serving as a light source into illumination light 3 and outputs it, and a substrate 6a on which the LED 6 that outputs the first light 7 is mounted. have The optical device 10 receives at least a portion of the first light 7 having a Lambertian light distribution, which is incident along a first axis (Z-axis) 12 and has an optical axis 7a parallel to the first axis 12. , in a circular (cylindrical) first range around the first axis 12, the light 71 is almost collimated in a direction perpendicular to the optical axis 7a (first axis (Z-axis) 12). a first reflective surface 31 arranged to reflect the light 71; and at least a part of the light 71 reflected by the first reflective surface 31 is refracted and output around the first axis (Z-axis) 12. It includes a light-transmitting exit surface 15, a plurality of light-shielding louvers 90 protruding from the exit surface 15, and a member 120 for processing on-axis light.

The optical device 10 includes an optical element 11 including a multistage inner surface 16 including a plurality of TIR prisms 39, an outer surface 15 having a cylindrical exit surface, and a louver 90. Optical element 11 includes an assembly 110 that includes a plurality of translucent members (parts) 111a to 111f, each including an end surface 115 perpendicular to first axis 12 in common with the above example. Assembly 110 further includes a plurality of louvers 90 arranged to be sandwiched between respective parts 111a to 111f. Each louver 90 has a hollow disc shape and is sandwiched between a portion 91 that controls stray light output from the outer output surface 15 and each of the parts 111a to 111f, thereby preventing stray light between each of the parts 111a to 111f. 92. Each of the light-transmitting members 111a to 111f may include a light-blocking portion 117 on the end surface 115, which works in cooperation with the louver 90 or alone to prevent stray light between the light-transmitting members 111a to 111f. Good too.

The illumination device 1g equipped with this cylindrical louvered optical element 11 is suitable, for example, for illuminating a linear region of a cylindrical surface (inner surface). The illumination device 1g may include a circular cover that covers the top and bottom of the emission surface 15, as described with reference to FIGS. 22 to 24. The illumination light 3 can be controlled by the louver 90 as well as the refraction of the output surface 15 on the outer surface of the optical element 11, and the illumination light 3 can be output in accordance with the shape of the area to be illuminated.

In the above description, the optical element 11 is explained as an example in which the first reflective surface 31 is divided into 5 or 6 parts and arranged on the inner surface 16, but the first reflective surface 31 is divided into 4 parts or less. It may be arranged as follows, or it may be arranged so as to be divided into seven or more parts. Although the fan-shaped optical element 11 is shown as having a central angle (opening angle) θ of 90 degrees, the central angle θ may be 90 degrees or less or 90 degrees or more. Further, the number of LEDs 6 arranged as a light source is not limited to one, and a plurality of multicolored LEDs may be arranged as a light source. Furthermore, the illumination device 1 may include a plurality of optical devices 10 including a plurality of optical elements 11 or a plurality of projection units 5 arranged so that the Z-axes 12 are parallel or common. good.

1 illumination device, 5 projection unit 10 optical device (optical system), 11 optical element (transparent member)
23 second reflective surface, 24 third reflective surface 31, 31a to 31f first reflective surface

Claims (15)

At least a portion of the first light incident along the first axis and having a light distribution characteristic having an optical axis parallel to the first axis is transmitted in a substantially arc shape around the first axis. a first reflective surface arranged to reflect in a first range, the first reflective surface including a plurality of reflective arc surfaces divided in a direction along the first axis;
a second reflective surface and a third reflective surface that intersect at the first axis and are arranged to sandwich the first reflective surface;
a translucent exit surface that refracts at least a portion of the light reflected by the plurality of reflective arc surfaces and outputs it around the first axis, the cross section being taken in the direction along the first axis; an output surface including a periodic uneven shape. In claim 1,
The cross section of the exit surface in the direction along the first axis includes at least one of the periodic uneven shapes in a range facing each of the plurality of reflective arc surfaces. In claim 1 or 2,
The cross section of the exit surface in the direction along the first axis includes a plurality of concave or convex portions in a range facing each of the plurality of reflective arc surfaces. At least a portion of the first light incident along the first axis and having a light distribution characteristic having an optical axis parallel to the first axis is transmitted in a substantially arc shape around the first axis. a first reflective surface arranged to reflect in a first range, the first reflective surface including a plurality of reflective arc surfaces divided in a direction along the first axis;
a second reflective surface and a third reflective surface that intersect at the first axis and are arranged to sandwich the first reflective surface;
a light-transmitting exit surface that refracts the light reflected by the plurality of reflective arc surfaces and outputs it around the first axis, the cross section in the direction along the first axis having a predetermined cross section; An optical device comprising: an exit surface including a plurality of spaced inflection points. In claim 4,
Each of the plurality of inflection points is at least one of a point where the shape changes from a convex shape to a concave shape, a point where the shape changes from a concave shape to a convex shape, a point where the shape changes from a curved line to a straight line, a point where the straight line changes to a curved line, and a point where the direction of the slope of the straight line changes. Any optical device. In claim 4 or 5,
The optical device, wherein the cross section of the exit surface in the direction along the first axis includes at least two of the inflection points in a range facing each of the plurality of reflective arc surfaces. In any one of claims 1 to 6,
The optical device, wherein the plurality of reflective arc surfaces include concentric arc-shaped reflective surfaces centered on the first axis. In any one of claims 1 to 7,
The optical device further includes a control member that prevents a component of the first light on the optical axis from being directly input to the first reflective surface. In any one of claims 1 to 8,
The output surface includes a portion that controls light distribution around the first axis of light output through the output surface. In any one of claims 1 to 9,
A multi-stage inner surface including the plurality of reflection arc surfaces and a plurality of transmission surfaces respectively corresponding to the plurality of reflection arc surfaces on the inside, the output surface on the outside, and perpendicular to the first axis. An optical device further comprising a translucent optical element having a substantially fan-shaped cross section. In claim 10,
An optical device, wherein the optical element includes an assembly of a plurality of translucent members including end faces perpendicular to the first axis. In claim 11,
The assembly is an optical device including the plurality of light-transmitting members, at least a portion of which includes the end surface having a light-blocking property. In claim 11,
The assembly includes a light-blocking member, at least a portion of which is disposed between the plurality of light-transmitting members. In any one of claims 1 to 13,
The optical device further includes a light-blocking mask that covers the periphery of the output surface. The optical device according to any one of claims 1 to 14,
and a light source that outputs the first light.

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