Lighting device and 3D image display device

Abstract

This lighting device comprises: a light source; a lens on which light output from the light source is incident; and a reflector having multiple first reflection regions and reflecting output light from the lens at the respective first reflection regions in a first direction intersecting with an optical axis of the incident light on the lens. The multiple first reflection regions are arranged in steps such that first reflection regions positioned closer to a light-output side of the reflector in the first direction are distanced farther from the lens in a second direction in which the optical axis extends. Light output from a first part of the lens positioned on the light-output side in the first direction with respect to the optical axis has a light distribution angle smaller than the light distribution angle of light output from a second part of the lens positioned on the opposite side from the light-output side in the first direction with respect to the optical axis.

Description

[Technical Field]

[0001] The present invention relates to a lighting device and a three-dimensional image display device. [Background technology]

[0002] Patent Document 1 discloses a device that collimates light emitted from a light source using a lens and reflects the light emitted from the lens using a reflective surface, thereby changing the traveling direction of the light emitted from the lens. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2009 / 011122 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of one embodiment of the present invention is to provide a compact lighting device and a compact three-dimensional image display device. [Means for solving the problem]

[0005] An illumination device according to one embodiment of the present invention includes a light source, a lens into which light emitted from the light source is incident, and a reflector having a plurality of first reflective areas, each of which reflects the light emitted from the lens in a first direction intersecting an optical axis of the light incident on the lens. The plurality of first reflective areas are arranged with steps between them so that the closer a first reflective area is to the light-emission side of the reflector in the first direction, the greater its distance from the lens in a second direction in which the optical axis extends. A light distribution angle of light emitted from a first portion of the lens located on the light-emission side of the optical axis in the first direction is smaller than a light distribution angle of light emitted from a second portion of the lens located on the opposite side of the optical axis from the light-emission side in the first direction.

[0006] A three-dimensional image display device according to one embodiment of the present invention includes the illumination device and a display member that is capable of displaying three-dimensional images when light emitted from the illumination device is incident on the display member. [Effects of the Invention]

[0007] According to one embodiment of the present invention, it is possible to provide a compact lighting device and a compact three-dimensional image display device. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is an exploded perspective view showing a three-dimensional image display device including an illumination device and a display member according to a first embodiment. [Figure 2] 1 is an exploded perspective view showing a part of a three-dimensional image display device according to a first embodiment. [Figure 3] 1 is a top view showing a light source, a lens, a reflector, and a display member of a three-dimensional image display device according to a first embodiment. [Figure 4] 1 is a top view showing lenses of the three-dimensional image display device according to the first embodiment. FIG. [Figure 5] 1 is a schematic diagram showing the path of light in a three-dimensional image display device according to a first embodiment. [Figure 6] FIG. 10 is a top view showing a three-dimensional image display device according to a second embodiment. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. [Figure 8] FIG. 10 is a side view showing a lens and a reflector in the lighting device according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Each embodiment will be described below with reference to the drawings. Note that the drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between parts, etc., are not necessarily the same as those in reality. Furthermore, even when the same part is shown, the dimensions and ratios may be different depending on the drawing. Furthermore, in this specification and each drawing, elements similar to those described with reference to the previous drawings are given the same reference numerals, and detailed descriptions will be omitted as appropriate.

[0010] For ease of understanding, the following description will use an XYZ Cartesian coordinate system to explain the arrangement and configuration of each part. The X, Y, and Z axes are perpendicular to one another. The direction in which the X axis extends will be referred to as the "X direction," the direction in which the Y axis extends will be referred to as the "Y direction," and the direction in which the Z axis extends will be referred to as the "Z direction." In the following description, the Z direction will also be referred to as the upward direction, and the direction opposite to the Z direction will also be referred to as the downward direction, but these directions are unrelated to the direction of gravity.

[0011] In the following description, "parallel" means parallel within a practical range that allows for errors due to manufacturing precision, assembly precision, and the like.

[0012] First Embodiment First, the first embodiment will be described. FIG. 1 is an exploded perspective view showing a three-dimensional image display device including an illumination device and a display member according to this embodiment. FIG. 2 is an exploded perspective view showing a part of the three-dimensional image display device according to this embodiment. FIG. 3 is a top view showing the light source, the lens, the reflector, and the display member of the three-dimensional image display device according to this embodiment. FIG. 4 is a top view showing the lenses of the three-dimensional image display device according to this embodiment. FIG. 5 is a schematic diagram showing the path of light in the three-dimensional image display device according to this embodiment.

[0013] 3, the lighting device 11 according to this embodiment includes a light source 110, a lens 120, and a reflector 130. Light emitted from the light source 110 is incident on the lens 120. The reflector 130 has a plurality of reflective regions 133a, and as shown in FIG. 5, each reflective region 133a reflects the light emitted from the lens 120 in a first direction D1 that intersects with an optical axis C of the light emitted from the light source 110 and incident on the lens 120. In this embodiment, the first direction D1 is the Y direction. The "optical axis C of the light incident on the lens 120" refers to a straight line that passes through a position where the illuminance of the light emitted from the light source 110 is maximized in one plane that intersects with the light incident on the lens 120 and a position away from this plane that intersects with the light incident on the lens 120 and where the illuminance of the light is maximized in another plane that is away from this plane and intersects with the light incident on the lens 120.

[0014] 3, the plurality of reflective regions 133a are arranged with steps 133b between them so that the distance d0 from the lens 120 in the second direction D2, in which the optical axis C extends, increases with the reflective region 133a located closer to the light output side +Y of the reflector 130 in the first direction D1. In this embodiment, the second direction D2 is the X direction, which is perpendicular to the first direction D1. However, the second direction D2 does not have to be perpendicular to the first direction D1.

[0015] 5, the light distribution angle θL1 of light emitted from first portion 120a of lens 120, which is located on the light emission side +Y in first direction D1 away from optical axis C, is smaller than the light distribution angle θL2 of light emitted from second portion 120b of lens 120, which is located on the opposite side -Y from the light emission side +Y in first direction D1 away from optical axis C. In other words, light distribution angle θL1<light distribution angle θL2. The light distribution angles θL1 and θL2 can be measured, for example, by a method in accordance with JIS C 8105-5:2011.

[0016] 1 , the lighting device 11 may further include a substrate 140, a housing 150, a light blocking member 160, and a support member 170 in addition to the light source 110, the lens 120, and the reflector 130 described above. The light source 110 is disposed on the substrate 140. The housing 150 houses the light source 110, the lens 120, the reflector 130, the substrate 140, and the light blocking member 160. The light blocking member 160 controls the light incident on the lens 120 from the light source 110. The support member 170 supports the substrate 140.

[0017] In this embodiment, the lighting device 11 is used in combination with a display member 12. When light emitted from the lighting device 11 is incident on the display member 12, the display member 12 displays a three-dimensional image above. Hereinafter, a device combining the lighting device 11 and the display member 12 will be referred to as a "three-dimensional image display device 10."

[0018] However, the lighting device may be used in combination with other components, rather than in combination with a display component. An example of using the lighting device in combination with other components is to emit infrared light from the lighting device, use this infrared light as a light curtain, and combine the lighting device with a detector capable of detecting the light curtain to use it as an area sensor device. The lighting device may also be used alone. An example of using the lighting device alone is to emit ultraviolet light from the lighting device and use it as a sterilizer, or to use a color-adjustable light source for wall lighting. Each component of the 3D image display device 10 will be described in detail below.

[0019] (Lighting equipment) The substrate 140 includes an insulating layer and wiring. As shown in Fig. 2, the substrate 140 has a flat plate shape. The substrate 140 has a front surface 141 that is flat and parallel to the YZ plane, and a back surface 142 that is flat and parallel to the YZ plane and is located on the opposite side of the front surface 141. The light source 110 is disposed on the front surface 141.

[0020] However, the shape of the substrate is not limited to the above. The light source may be held by a holder or the like having wiring, instead of by a substrate.

[0021] The light source 110 includes a light-emitting element and a wavelength conversion member. The light-emitting element is an LED (Light Emitting Diode) or an LD (Laser Diode), etc. The light-emitting element is electrically connected to wiring on the substrate 140. The wavelength conversion member absorbs a portion of the light emitted by the light-emitting element and emits light with a peak emission wavelength different from the peak emission wavelength emitted by the light-emitting element. The wavelength conversion member includes, for example, a phosphor.

[0022] As shown in Fig. 5, the optical axis C of the light emitted from the light source 110 extends in the X direction. In this embodiment, the light source 110 emits visible light. The light source 110 may emit mixed light of light emitted by the light emitting element and light emitted by the wavelength conversion member. Alternatively, most of the light emitted by the light emitting element may be absorbed by the wavelength conversion member, and the light source 110 may emit mainly light emitted by the wavelength conversion member.

[0023] However, the configuration of the light source is not limited to the above. For example, the light source may not be provided with a wavelength conversion member. In this case, light emitted by a light-emitting element is emitted from the light source. Furthermore, the light source may be configured to emit ultraviolet light, infrared light, or monochromatic light in the visible range depending on the application of the lighting device.

[0024] The lens 120 is disposed on the optical axis C. Light emitted by the light source 110 is incident on the lens 120. In this embodiment, as shown in FIG. 4, the lens 120 has a main body 121 and a flange 122. The lens 120 is preferably made of a resin material such as acrylic (PMMA) or polycarbonate (PC), or a light-transmitting material such as quartz glass. The refractive index of the light-transmitting material used for the lens 120 is preferably about 1.4 to 1.9. However, the refractive index of the light-transmitting material used for the lens is not limited to the above range.

[0025] In top view, main body 121 has an asymmetric shape with respect to optical axis C. Specifically, the surface of main body 121 includes light incident surface 121a, light exit surface 121b, side surface 121c, upper surface 121d, and lower surface 121e.

[0026] The upper surface 121d is a flat surface parallel to the XY plane. The lower surface 121e is located below the upper surface 121d. The lower surface 121e is a flat surface parallel to the XY plane.

[0027] The light incident surface 121a is located between the upper surface 121d and the lower surface 121e and faces the light source 110. Light emitted from the light source 110 is incident on the light incident surface 121a. In this embodiment, the light incident surface 121a is a flat surface parallel to the YZ plane. However, the light incident surface may be a curved surface.

[0028] Light exit surface 121b is located between upper surface 121d and lower surface 121e, on the opposite side of light entrance surface 121a in the X direction. Light exit surface 121b exits light that has entered main body 121. The shape of light exit surface 121b in top view is a convex curved surface.

[0029] Specifically, the light exit surface 121b is a free-form surface. A vertex 121t0 of the light exit surface 121b in the X direction is located approximately on the optical axis C. The angle θt1 formed between the X direction and a tangent TL1 of the first end 121t1 on the light exit side (+Y) of the light exit surface 121b in the Y direction is smaller than the angle θt2 formed between the X direction and a tangent TL2 of the second end 121t2 on the opposite side (−Y) of the light exit surface 121b in the Y direction. That is, the angle θt1<the angle θt2. Therefore, as shown by the solid line in FIG. 5, the refraction angle of light L1 incident from the light source 110 to the main body 121 and emitted from the first end 121t1 is larger than the refraction angle of light L2 incident from the light source 110 to the main body 121 and emitted from the second end 121t2. As a result, the angle between light L1 and the optical axis C is smaller than the angle between light L2 and the optical axis C. As a result, the light distribution angle θL1 of light emitted from first region 121s1 located on the light emission side +Y in the Y direction from optical axis C on light emission surface 121b is smaller than the light distribution angle θL2 of light emitted from second region 121s2 located on the opposite side −Y in the Y direction from optical axis C on light emission surface 121b. This makes it possible to prevent light emitted from lens 120 from spreading toward the light emission side +Y in the Y direction.

[0030] 4, the length d1 in the Y direction of the first region 121s1 is shorter than the length d2 in the Y direction of the second region 121s2. This further prevents the light emitted from the lens 120 from spreading toward the light emission side +Y in the Y direction. However, the relationship in magnitude between these lengths is not limited to the above.

[0031] The side surface 121c is connected to the second end 121t2 of the light emitting surface 121b between the upper surface 121d and the lower surface 121e, and extends toward the light incident surface 121a without reaching the light incident surface 121a. The side surface 121c is, for example, a flat surface parallel to the XZ plane. However, the side surface may also be a curved surface. Furthermore, the main body portion 121 may not have a side surface. Furthermore, the main body portion 121 may further have another side surface connected to the first end 121t1 of the light emitting surface 121b and extending toward the light incident surface 121a.

[0032] The flange 122 has a first flange 122a that protrudes from an end of the main body 121 closer to the light source 110 in the X direction toward the light emission side +Y in the Y direction, and a second flange 122b that protrudes from the end of the main body 121 closer to the light source 110 in the X direction toward the opposite side -Y in the Y direction. The first flange 122a is connected to an end of the light incident surface 121a on the light emission side +Y in the Y direction and a first end 121t1 of the light emission surface 121b, and extends toward the light emission side +Y in the Y direction. The second flange 122b is connected to an end of the light incident surface 121a on the opposite side -Y in the Y direction and an end of the side surface 121c on the light incident surface 121a side in the X direction, and extends toward the opposite side -Y in the Y direction.

[0033] However, the shape of the lens is not particularly limited to the above shape as long as the light distribution angle θL1 is smaller than the light distribution angle θL2. For example, the lens does not need to have a flange. Furthermore, the light entrance surface and the light exit surface of the lens may both be continuous curved surfaces. In such a case, for example, the surface on the light source side in the X direction may be the light entrance surface, and the surface on the reflector side in the X direction may be the light exit surface, with the boundaries being a first end point located at the +Y end of the light exit side in the Y direction of the lens and a second end point located at the -Y end on the opposite side.

[0034] It is preferable that the light emitted from the light exit surface 121b of the lens 120 is non-parallel light. In this embodiment, the light emitted from the light exit surface 121b of the lens 120 spreads in the Y direction as it approaches the reflector 130 in the X direction, as shown in FIG.

[0035] The reflector 130 is disposed on the optical axis C as shown in Fig. 3. That is, the light source 110, the lens 120, and the reflector 130 are arranged in this order on the optical axis C. The reflector 130 reflects the light emitted from the lens 120 in the Y direction. The shape of the reflector 130 is flat as shown in Fig. 1. In this embodiment, the surface of the reflector 130 includes an upper surface 131, a lower surface 132, a reflecting surface 133, and a side surface 134 as shown in Fig. 3.

[0036] The upper surface 131 is a flat surface parallel to the XY plane. The lower surface 132 is located below the upper surface 131 and is also a flat surface parallel to the XY plane.

[0037] The reflective surface 133 is located between the upper surface 131 and the lower surface 132 and faces the lens 120. The reflective surface 133 has a plurality of reflective regions 133a and a plurality of steps 133b. As described above, the plurality of reflective regions 133a are arranged in a row with steps 133b between them so that the distance d0 from the lens 120 in the X direction increases as the reflective region 133a is located closer to the light-emitting side +Y in the Y direction. This allows the length of the reflector 130 in the Y direction to be shorter than when no steps are provided on the reflector. Furthermore, adjacent reflective regions 133a partially overlap when viewed from the X direction. This allows the length of the reflector 130 in the Y direction to be even shorter. However, adjacent reflective regions do not have to overlap when viewed from the X direction.

[0038] The shape of each reflective region 133a in a top view is, for example, a portion of a circumference. However, the shape of each reflective region is not limited to the above. For example, the shape of each reflective region may be a flat surface or another curved surface. Hereinafter, among the multiple reflective regions 133a, a region on the light-emitting side +Y in the Y direction from the optical axis C in the reflective region 133a located on the optical axis C and a reflective region 133a entirely located on the light-emitting side +Y in the Y direction from the optical axis C will be referred to as a "first reflective portion 133g1." Furthermore, among the multiple reflective regions 133a, a region on the opposite side -Y in the Y direction from the optical axis C in the reflective region 133a located on the optical axis C and a reflective region 133a entirely located on the opposite side -Y in the Y direction from the optical axis C will be referred to as a "second reflective portion 133g2."

[0039] 5, the first reflecting portion 133g1 has a focal point at a first position P1 on the optical axis C. The second reflecting portion 133g2 has a focal point at a second position P2 on the optical axis C that is closer to the light source 110 than the first position P1. The light source 110 is located closer to the lens 120 than the first position P1 and the second position P2.

[0040] 5, the path of light emitted from the light source 110 and passing through the lens 120 is indicated by a solid line. Also, in FIG. 5, the path of light emitted from the light source 110 and incident on the reflector 130 is indicated by a two-dot chain line in a case where the lens 120 is not provided in the lighting device 11 and the light source 110 is disposed at the first position P1 and the second position P2, respectively. The first region 121s1 of the light emitting surface 121b of the lens 120 is shaped so that the path of light emitted from the first region 121s1 roughly matches the path of light in a case where the lens 120 is not provided and the light source 110 is disposed at the first position P1. Therefore, the light reflected by each reflection region 133a of the first reflection portion 133g1 becomes parallel light parallel to the Y direction. Similarly, the second region 121s2 of the light exit surface 121b of the lens 120 is shaped so that the path of light exiting from the second region 121s2 roughly matches the path of light when the lens 120 is not provided and the light source 110 is disposed at the second position P2. Therefore, the light reflected by each reflective region 133a of the second reflecting portion 133g2 becomes parallel light parallel to the Y direction. In this way, in this embodiment, the light exiting the lens 120 and entering each reflective region 133a is collimated by each reflective region 133a.

[0041] However, the reflector may have three or more reflecting portions with different focal positions. In this case, the light exit surface of the lens may be divided into three or more regions according to the three or more reflecting portions of the reflector, and the light exiting from each region may illuminate the corresponding reflecting portion.

[0042] The side surface 134 is located between the upper surface 131 and the lower surface 132 and constitutes the side surface of the reflector 130 other than the reflective surface 133 .

[0043] In this embodiment, the length of the reflector 130 in the Y direction is shorter than the length of the reflector 130 in the X direction. However, the relationship between these lengths is not limited to the above.

[0044] The reflector 130 may be made of a resin member and a reflective film, such as a metal film or a dielectric multilayer film, that is provided on the surface of the resin member and forms the reflective surface 133. Alternatively, the entire reflector 130 may be made of a metal material. In these cases, the reflector 130 reflects the light emitted from the lens 120 by specular reflection. In such cases, it is easy to convert the light emitted from each reflective region 133a into parallel light parallel to the Y direction. However, the reflector may also reflect the light emitted from the lens by diffuse reflection. In such cases, the light emitted from each reflective region 133a can be spread in the Z direction.

[0045] As shown in FIG. 1, the housing 150 has a housing member 151 that can house the light source 110, the lens 120, the reflector 130, and the substrate 140, and a cover member 152.

[0046] The housing member 151 has a bottom plate portion 151a, a first side plate portion 151b, a second side plate portion 151c, and a third side plate portion 151d.

[0047] As shown in Figures 1 and 2, the bottom plate portion 151a is flat and parallel to the XY plane, and has a first arrangement portion 151e in which the lens 120 and the reflector 130 are arranged, a second arrangement portion 151f adjacent to the first arrangement portion 151e in the X direction, recessed downward more than the first arrangement portion 151e, and in which the substrate 140 is arranged, and a frame portion 151g provided on a part of the periphery of the first arrangement portion 151e and protruding upward more than the first arrangement portion 151e. The frame portion 151g has a first portion 151p1 that can sandwich the first flange portion 122a between itself and the light-shielding member 160, a second portion 151p2 that can sandwich the second flange portion 122b between itself and the light-shielding member 160, and a third portion 151p3 that has a shape corresponding to the side surface 134 of the reflector 130 and faces the side surface 134 of the reflector 130.

[0048] The first side plate 151b is connected to the end of the bottom plate 151a on the light emission side +Y in the Y direction and extends upward. The first side plate 151b has a flat plate shape and is parallel to the XZ plane. The first side plate 151b has a recess 156 that is recessed downward.

[0049] The second side plate portion 151c is connected to an end portion on the opposite side -Y in the Y direction of the bottom plate portion 151a and extends in the Z direction. The second side plate portion 151c has a flat plate shape and is parallel to the XZ plane.

[0050] The third side plate portion 151d is continuous with the end portion of the bottom plate portion 151a in the X direction and extends in the Z direction. The third side plate portion 151d has a flat plate shape and is parallel to the YZ plane.

[0051] The cover member 152, when placed on the housing member 151, covers the upper opening of the housing member 151. The cover member 152 is fixed to the housing member 151 by fasteners such as screws or rivets.

[0052] The housing 150 is made of a resin material or a metal material. The inner surface of the housing 150 is preferably a dark color, and more preferably black. However, the color of the inner surface of the housing 150 is not limited to the above. Furthermore, the shape of the housing is not limited to the above, as long as it is a shape that can accommodate each component of the lighting device.

[0053] As shown in FIG. 2 , the light blocking member 160 is disposed between the light source 110 and the lens 120. The light blocking member 160 has a flat plate shape and is parallel to the YZ plane. The light blocking member 160 has an opening 161 that penetrates the light blocking member 160 in the X direction. The opening 161 is provided in a range that overlaps with the light incident surface 121 a of the lens 120 when viewed from the X direction. Of the light emitted from the light source 110, light that is directed toward the light incident surface 121 a of the lens 120 is incident on the light incident surface 121 a through the opening 161. On the other hand, of the light emitted from the light source 110, light that is directed toward the flange portion 122 and the like is blocked by the light blocking member 160.

[0054] The light blocking member 160 is fixed to the housing 150 with fasteners such as screws or rivets, with the flange 122 of the lens 120 sandwiched between the light blocking member 160 and the first portion 151p1 and the second portion 151p2 of the frame portion 151g. This fixes the lens 120 to the housing 150.

[0055] The light blocking member 160 is made of, for example, a resin material or a metal material. The surface of the light blocking member 160 is preferably dark in color, and more preferably black.

[0056] The support member 170 has a flat plate shape and is parallel to the YZ plane. The support member 170 has a front surface 171 that is parallel to the YZ plane and a back surface 172 that is located opposite the front surface 171. The substrate 140 is disposed on the front surface 171 and is fixed to the support member 170 by fasteners such as screws or rivets. The support member 170 is fixed to the housing 150 by fasteners such as screws or rivets. In this way, the light source 110 is fixed to the housing 150. The support member 170 is made of, for example, a resin material or a metal material.

[0057] (Display element) 3, the display member 12 is disposed so as to face the reflecting surface 133 of the reflector 130 in the Y direction. In this embodiment, the display member 12 contacts the +Y end of the reflector 130 on the light emission side in the Y direction. However, the display member does not have to contact the reflector.

[0058] The display member 12 is, for example, a light guide plate on which a plurality of arc-shaped markings (not shown) are provided according to the image to be displayed. The display member 12 has a flat plate shape parallel to the XY plane. The shape of the display member 12 when viewed from above is rectangular. However, the shape of the display member is not limited to the above. The end of the display member 12 on the opposite side -Y in the Y direction is disposed in a recess 156 of the housing 150, as shown in FIG. 1. The display member 12 is made of a light-transmitting material such as glass or acrylic resin.

[0059] When the lighting device 11 irradiates the display member 12 from the Y direction, a portion of the light incident on the display member 12 is emitted in a specific direction due to the arc-shaped markings. Therefore, a specific portion of the arc-shaped markings corresponding to the position of the user's eyes appears bright to the user. Because the brighter portions differ between the user's right and left eyes, when the user views the display member 12 with both eyes, a specific position above the display member 12 appears bright. Therefore, the user can see a 3D image corresponding to the multiple arc-shaped markings above the display member 12. In this way, the display member 12 displays a 3D image using an arc 3D display. Note that in FIG. 5, light incident on the display member 12 is emitted from the display member 12 in the Y direction. However, a portion of the light incident on the display member 12 may be directed in a direction other than the Y direction due to the arc-shaped markings.

[0060] However, the structure of the display member is not limited to the above as long as it can display a three-dimensional image. For example, the display member may be a hologram sheet, and may display a three-dimensional image by holography.

[0061] Next, an example of how the three-dimensional image display device 10 according to this embodiment is used will be described. When the light source 110 is turned on, most of the light emitted by the light source 110 is incident on the light incident surface 121a of the lens 120, as shown in FIG.

[0062] As described above, the angle θt1 formed between the tangent line TL1 of the first end 121t1 of the light emitting surface 121b of the lens 120 and the X direction is smaller than the angle θt2 formed between the second end 121t2 of the light emitting surface 121b and the X direction. Therefore, the refraction angle of the light L1 that enters the lens 120 and exits from the first end 121t1 is larger than the refraction angle of the light L2 that enters the lens 120 and exits from the second end 121t2. As a result, the angle formed between the light L1 and the optical axis C is smaller than the angle formed between the light L2 and the optical axis C. Therefore, the light distribution angle θL1 of the light exiting from the first region 121s1 of the light emitting surface 121b is smaller than the light distribution angle θL2 of the light exiting from the second region 121s2.

[0063] As a result, it is possible to prevent the light emitted from the lens 120 from spreading toward the light emission side +Y in the Y direction. As a result, it is possible to shorten the length of the reflector 130 in the Y direction. Furthermore, even if the reflector 130 and the display member 12 are brought closer to each other, it is possible to prevent the light emitted from the lens 120 from directly entering the display member 12 without passing through the reflector 130.

[0064] Most of the light emitted from the first region 121s1 of the lens 120 illuminates the first reflecting portion 133g1 of the reflector 130, and most of the light emitted from the second region 121s2 of the lens 120 illuminates the second reflecting portion 133g2 of the reflector 130. As described above, the first region 121s1 is shaped so that the path of the light emitted from the first region 121s1 roughly coincides with the path of the light when the lens 120 is not provided and the light source 110 is disposed at the first position P1. Therefore, the light reflected by each reflecting region 133a of the first reflecting portion 133g1 is parallel to the Y direction. Similarly, the second region 121s2 is shaped so that the path of the light emitted from the second region 121s2 roughly coincides with the path of the light when the lens 120 is not provided and the light source 110 is disposed at the second position P2. Therefore, the light reflected by each reflective region 133a of the second reflective portion 133g2 is parallel to the Y direction. Furthermore, the light emitted from the light source 110 does not directly enter the display member 12, but enters the display member 12 via the lens 120 and the reflector 130. Therefore, uneven illuminance of the light irradiated onto the display member 12 can be suppressed.

[0065] Most of the light reflected by each reflective area 133a is incident on the display member 12. As a result, a three-dimensional image is displayed above the display member 12. As described above, the light reflected by each reflective area 133a is parallel light parallel to the Y direction, and therefore the display member 12 is irradiated with parallel light from one direction. This makes it possible to clearly display a three-dimensional image on the display member 12.

[0066] Next, the effects of this embodiment will be described. In the lighting device 11 according to this embodiment, the multiple reflective areas 133a of the reflector 130 are arranged with steps 133b between them so that the distance d0 from the lens 120 increases as the reflective areas 133a are closer to the light-emitting side +Y in the Y direction. This allows the length of the reflector in the Y direction to be shortened. This allows the lighting device 11 and the 3D image display device 10 to be made smaller.

[0067] Furthermore, the light distribution angle θL1 of light emitted from the first portion 120a of the lens 120, which is located on the light emission side +Y in the Y direction relative to the optical axis C of the light incident on the lens 120, is smaller than the light distribution angle θL2 of light emitted from the second portion 120b of the lens 120, which is located on the opposite side −Y in the Y direction relative to the optical axis C. This makes it possible to prevent the light emitted from the lens 120 from spreading toward the light emission side +Y in the Y direction. This makes it possible to reduce the length of the reflector 130 in the Y direction while preventing the light emitted from the lens 120 from not being irradiated onto the reflector 130. In particular, when the illumination device 11 is applied to the 3D image display device 10, even if the reflector 130 and the display member 12 are placed close to each other, it is possible to prevent the light emitted from the lens 120 from directly entering the display member 12 without passing through the reflector 130. This makes it possible to make the 3D image displayed by the display member 12 clearer.

[0068] Furthermore, lens 120 has light exit surface 121b that is convexly curved, and the angle θt1 formed between the X direction and a tangent TL1 to a first end 121t1 of light exit surface 121b on the light exit side +Y in the Y direction is smaller than the angle θt2 formed between the X direction and a tangent TL2 to a second end 121t2 of light exit surface 121b on the opposite side -Y in the Y direction. In this way, by the simple method of adjusting the curvature of light exit surface 121b, it is possible to make light distribution angle θL1 smaller than light distribution angle θL2.

[0069] Furthermore, the adjacent reflective regions 133a partially overlap each other when viewed in the X direction, which allows the length of the reflector 130 in the Y direction to be further shortened.

[0070] Furthermore, a first reflecting portion 133g1 including some of the multiple reflecting regions 133a has a focal point at a first position P1. A second reflecting portion 133g2 including some other of the multiple reflecting regions 133a is located on the opposite side in the Y direction from the first reflecting portion 133g1 (-Y) and has a focal point at a second position P2 closer to the reflector 130 than the first position P1. Light emitted from the first portion 120a of the lens 120 illuminates the first reflecting portion 133g1, and light emitted from the second portion 120b of the lens 120 illuminates the second reflecting portion 133g2. In this way, the reflecting surface 133 of the reflector 130 is divided into two reflecting portions 133g1 and 133g2, and the first portion 120a and the second portion 120b of the lens 120 only need to be designed according to the respective focal positions P1 and P2, which simplifies the design of the lens 120.

[0071] Furthermore, light exit surface 121b of lens 120 includes a first region 121s1 located on the light exit side +Y in the Y direction from optical axis C, and a second region 121s2 located on the opposite side −Y in the Y direction from optical axis C. A length d1 in the Y direction of first region 121s1 is shorter than a length d2 in the Y direction of second region 121s2. Therefore, it is possible to prevent light exiting lens 120 from spreading toward the light exit side +Y in the Y direction.

[0072] Furthermore, the light emitted from the lens 120 and incident on each reflective area 133a is collimated by each reflective area 133a. That is, the light emitted from the lens 120 is non-parallel, and the reflector 130 collimates the light emitted from the lens 120. This makes it possible to increase the irradiation width of the light emitted from the reflector 130 while shortening the length of the reflector 130 in the Y direction.

[0073] <Second embodiment> Next, a second embodiment will be described. FIG. 6 is a top view showing the three-dimensional image display device according to this embodiment. FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. A three-dimensional image display device 20 including an illumination device 21 according to this embodiment differs from the illumination device 11 according to the first embodiment in that it further includes another lens 280 onto which light emitted from the reflector 130 is incident. In the following explanation, in principle, only the differences from the first embodiment will be explained. The matters other than those explained below are the same as those in the first embodiment. The same applies to the other embodiments described later.

[0074] The other lens 280 is positioned between the reflector 130 and the display member 12. The other lens 280 extends with the X direction as its longitudinal direction. The other lens 280 has the same cross-sectional shape perpendicular to the X direction. Here, "having the same cross-sectional shape" means that the cross-sectional shapes are the same within a practical range that allows for errors due to manufacturing precision, etc. The other lens 280 is, for example, a cylindrical lens. As shown in FIG. 7 , the other lens 280 includes an upper surface 281, a lower surface 282, a light incident surface 283, and a light exit surface 284.

[0075] The upper surface 281 is a flat surface parallel to the XY plane. The lower surface 282 is located below the upper surface 281 and is a flat surface parallel to the XY plane. The light incident surface 283 is connected to the opposite -Y end of the upper surface 281 in the Y direction and the opposite -Y end of the lower surface 282 in the Y direction, and is a flat surface parallel to the XZ plane. The light exit surface 284 is connected to the light exit side +Y end of the upper surface 281 in the Y direction and the light exit side +Y end of the lower surface 282 in the Y direction. The light exit surface 284 is part of the side surface of a cylinder. The light exit surface 284 is connected to the light exit side +Y end of the lower surface 282 in the Y direction, and is curved so that the light exit surface 284 approaches the light exit side +Y in the Y direction as it extends upward.

[0076] However, the shape of the other lens is not limited to the above. For example, the other lens may have a shape that is symmetrical with respect to a plane that passes through the center of the other lens in the Z direction and is parallel to the XY plane, i.e., a shape that is vertically symmetrical. Furthermore, for example, the light exit surface of the other lens may be a curved surface other than the side surface of a cylinder, or may be an inclined surface inclined with respect to the XZ plane.

[0077] Most of the light reflected by each reflective region 133a of the reflector 130 is incident on a light incident surface 283 of the other lens 280. Most of the light incident on the other lens 280 is emitted from a light emitting surface 284 of the other lens 280. The light emitted from the light emitting surface 284 spreads in a third direction D3 that is perpendicular to the first direction D1 and the second direction. In this embodiment, the third direction D3 corresponds to the Z direction.

[0078] Next, the effects of this embodiment will be described. The illumination device 21 according to this embodiment further includes another lens 280, which receives the light reflected by the reflector 130, extends with the X direction as its longitudinal direction, and controls the spread in the Z direction of the light emitted from the reflector 130. Therefore, the spread in the Z direction of the light emitted from the reflector 130 can be controlled by the other lens 280.

[0079] When the light emitted from each reflective region 133a is parallel light parallel to the Y direction, the other lens 280 can control the spread of the light emitted from each reflective region 133a in the Z direction while generally maintaining the state in which the light emitted from each reflective region 133a is parallel to the Y direction when viewed from above. Therefore, when the illumination device 21 is applied to the three-dimensional image display device 20, the other lens 280 can irradiate light over a wide range of the display member 12 while suppressing blurring of the three-dimensional image displayed on the display member 12. Furthermore, when the illumination device 21 is applied to a sterilization device or the like, the light can be spread in the Z direction, thereby widening the sterilization range.

[0080] <Third embodiment> Next, a third embodiment will be described. FIG. 8 is a side view showing a lens and a reflector in the lighting device according to this embodiment. The illumination device 31 according to this embodiment differs from the illumination device 11 according to the first embodiment in the configuration of the reflector 330.

[0081] The reflecting surface 333 of the reflector 330 has a plurality of first reflecting areas 333a, a plurality of steps 333b, a plurality of second reflecting areas 333c, and a plurality of steps 333d. Each of the first reflecting areas 333a and each of the second reflecting areas 333c reflects the light emitted from the lens 120 in the Y direction.

[0082] The multiple first reflection areas 333a are arranged in a row with steps 333b between them so that the closer the first reflection areas 333a are to the light output side +Y in the Y direction, the greater the distance from the lens 120 in the X direction.

[0083] Similarly, the multiple second reflection areas 333c are arranged in a row with steps 333d between them so that the second reflection areas 333c located on the light output side +Y in the Y direction are at a greater distance from the lens 120 in the X direction.

[0084] The row of first reflection regions 333a and the row of second reflection regions 333c are aligned in the Z direction. The first reflection regions 333a and the second reflection regions 333c are arranged in a staggered pattern in the Z direction. Therefore, steps 333b and 333d are arranged so that they are not adjacent to each other in the Z direction.

[0085] Next, the effects of this embodiment will be described. Most of the light emitted from the lens 120 is incident on the plurality of first reflective regions 333a and the plurality of second reflective regions 333c of the reflector 330. Due to the presence of step 333b between the plurality of first reflective regions 333a, the intervals between the light reflected by the first reflective regions 333a tend to be dark. Similarly, due to the presence of step 333d between the plurality of second reflective regions 333c, the intervals between the light reflected by the second reflective regions 333c tend to be dark. In contrast, in this embodiment, the plurality of first reflective regions 333a and the plurality of second reflective regions 333c are arranged in a staggered pattern in the Z direction. Therefore, in a top view, the position in the X direction of the optical axis of the light reflected by each second reflective region 333c is shifted from the position in the X direction of the optical axis of the light reflected by each first reflective region 333a. Therefore, it is possible to prevent the gaps between the light reflected by the first reflection areas 333a and the gaps between the light reflected by the second reflection areas 333c from being conspicuous as dark areas.

[0086] The lighting device may be configured to include at least a light source and a lens having an asymmetric light distribution with respect to the optical axis of the incident light. That is, the lighting device does not need to include a reflector having a step on the reflective surface described in the above embodiments. In this case, the effect of making the light distribution of the light exiting the lens asymmetric with respect to the optical axis can still be obtained. Such a lighting device may include a reflector having a smooth reflective surface instead of a reflector having a step on the reflective surface. Furthermore, such a lighting device may include a reflector having a smooth reflective surface and be combined with a display member for use in a 3D image display device, etc., without including either a reflector having a step on the reflective surface or a reflector having a smooth reflective surface. Furthermore, such a lighting device may be used alone for signboard illumination, etc., without including either a reflector having a step on the reflective surface or a reflector having a smooth reflective surface.

[0087] The lighting device may also be configured to include at least a light source unit including one or more light sources and a reflector having a step on its reflective surface. That is, the lighting device does not need to include a lens whose light distribution is asymmetric with respect to the optical axis of the incident light. In this case, the effect of miniaturizing the reflector in at least the first direction can be achieved. Such a lighting device may include a lens whose light distribution is symmetric with respect to the optical axis of the incident light instead of the lens whose light distribution is asymmetric. Such a lighting device may also include a lens whose light distribution is symmetric and be combined with a display member for use in a 3D image display device. Such a lighting device may not include either a lens whose light distribution is asymmetric or a lens whose light distribution is symmetric, and may be combined with a display member for use in a 3D image display device, etc. Such a lighting device may not include either a lens whose light distribution is asymmetric or a lens whose light distribution is symmetric, and may be used alone in a sterilization device, etc. If the lighting device does not include either a lens whose light distribution is asymmetric or a lens whose light distribution is symmetric, a light source may be disposed at each focus of the reflector. [Industrial Applicability]

[0088] The present invention can be used in, for example, a three-dimensional image display device, a sterilizer, a wall lighting device, or an area sensor device.

Claims

1. A light source and a lens onto which the light emitted from the light source is incident; a reflector having a plurality of first reflective areas, each of which reflects light emitted from the lens in a first direction intersecting an optical axis of the light incident on the lens; Equipped with the plurality of first reflection regions are arranged with steps therebetween such that the first reflection regions positioned closer to the light exit side of the reflector in the first direction are spaced apart from the lens in the second direction along which the optical axis extends; a distribution angle of light emitted from a first portion of the lens located on the light emission side of the optical axis in the first direction is smaller than a distribution angle of light emitted from a second portion of the lens located on an opposite side of the light emission side of the optical axis in the first direction, the lens has a light exit surface that is a convex curved surface, an angle formed by a tangent to a first end of the light exit surface on the light exit side in the first direction and the second direction is smaller than an angle formed by a tangent to a second end of the light exit surface on the opposite side in the first direction and the second direction.

2. The lighting device according to claim 1 , wherein the adjacent first reflective regions partially overlap each other when viewed in the second direction.

3. A light source and a lens onto which the light emitted from the light source is incident; a reflector having a plurality of first reflective areas, each of which reflects light emitted from the lens in a first direction intersecting an optical axis of the light incident on the lens; another lens onto which the light reflected by the reflector is incident, the lens extending with its longitudinal direction being the second direction in which the optical axis extends, and the lens controlling the spread of the light reflected by the reflector in the first direction and a third direction orthogonal to the second direction; Equipped with the plurality of first reflection regions are arranged with steps therebetween such that the first reflection regions positioned closer to the light exit side of the reflector in the first direction are spaced apart from the lens in the second direction by a greater distance, and a light distribution angle of light emitted from a first portion of the lens that is located on the light emission side of the optical axis in the first direction is smaller than a light distribution angle of light emitted from a second portion of the lens that is located on the opposite side of the light emission side of the optical axis in the first direction.

4. A light source and a lens onto which the light emitted from the light source is incident; a reflector having a plurality of first reflective areas, each of which reflects light emitted from the lens in a first direction intersecting an optical axis of the light incident on the lens; Equipped with the plurality of first reflection regions are arranged with steps therebetween such that the first reflection regions positioned closer to the light exit side of the reflector in the first direction are spaced apart from the lens in the second direction along which the optical axis extends; the reflector further includes a plurality of second reflective areas; Each of the second reflective areas reflects light emitted from the lens in the first direction, the second reflective regions are arranged with steps therebetween such that the second reflective regions positioned closer to the light exit side in the first direction are spaced farther from the lens in the second direction; the row in which the plurality of first reflective regions are arranged in a row and the row in which the plurality of second reflective regions are arranged in a row are aligned in a third direction perpendicular to the first direction and the second direction, the plurality of second reflective areas and the plurality of first reflective areas are arranged in a staggered pattern in the third direction, a light distribution angle of light emitted from a first portion of the lens that is located on the light emission side of the optical axis in the first direction is smaller than a light distribution angle of light emitted from a second portion of the lens that is located on the opposite side of the light emission side of the optical axis in the first direction.

5. A light source and a lens onto which the light emitted from the light source is incident; a reflector having a plurality of first reflective areas, each of which reflects light emitted from the lens in a first direction intersecting an optical axis of the light incident on the lens; Equipped with the plurality of first reflection regions are arranged with steps therebetween such that the first reflection regions positioned closer to the light exit side of the reflector in the first direction are spaced apart from the lens in the second direction along which the optical axis extends; a distribution angle of light emitted from a first portion of the lens located on the light emission side of the optical axis in the first direction is smaller than a distribution angle of light emitted from a second portion of the lens located on an opposite side of the light emission side of the optical axis in the first direction, a first reflecting portion including some of the plurality of first reflecting areas has a focal point at a first position; A lighting device in which a second reflective portion including some other of the plurality of first reflective regions is located on the opposite side in the first direction from the first reflective portion and has a focus at a second position closer to the reflector than the first position.

6. the light emitted from the first portion illuminates the first reflecting portion, The lighting device according to claim 5 , wherein the light emitted from the second portion illuminates the second reflecting portion.

7. A light source and a lens onto which the light emitted from the light source is incident; a reflector having a plurality of first reflective areas, each of which reflects light emitted from the lens in a first direction intersecting an optical axis of the light incident on the lens; Equipped with the plurality of first reflection regions are arranged with steps therebetween such that the first reflection regions positioned closer to the light exit side of the reflector in the first direction are spaced apart from the lens in the second direction along which the optical axis extends; a distribution angle of light emitted from a first portion of the lens located on the light emission side of the optical axis in the first direction is smaller than a distribution angle of light emitted from a second portion of the lens located on an opposite side of the light emission side of the optical axis in the first direction, the lens has a light exit surface that is a convex curved surface, the light exit surface includes a first region located on the light exit side of the optical axis in the first direction, and a second region located on the opposite side of the optical axis in the first direction, A lighting device, wherein the length of the first region in the first direction is shorter than the length of the second region in the first direction.

8. 8. The lighting device according to claim 1, wherein light emitted from the lens and incident on each of the first reflective areas is collimated by each of the first reflective areas.

9. A lighting device; a display member capable of displaying a three-dimensional image when light emitted from the lighting device is incident thereon; Equipped with The lighting device includes: A light source and a lens onto which the light emitted from the light source is incident; a reflector having a plurality of first reflective areas, each of which reflects light emitted from the lens in a first direction intersecting an optical axis of the light incident on the lens; and the plurality of first reflection regions are arranged with steps therebetween such that the first reflection regions positioned closer to the light exit side of the reflector in the first direction are spaced apart from the lens in the second direction along which the optical axis extends; A three-dimensional image display device, wherein the distribution angle of light emitted from a first portion of the lens located on the light exit side in the first direction relative to the optical axis is smaller than the distribution angle of light emitted from a second portion of the lens located on the opposite side of the light exit side in the first direction relative to the optical axis.

Images