Lighting device

Abstract

This invention provides a lighting device that performs indirect illumination by passing light emitted from a light source through a lens having an uneven surface, thereby minimizing light loss. [Solution] The present invention provides a lighting device 1 comprising a rod-shaped lens 10, a light source 11 that irradiates light onto the lens 10, and a drive unit 12 that rotates the lens 10 so that the surface irradiated by light from the light source 11 switches between a first light intake surface 101 and a second light intake surface 103, wherein the first light intake surface 101 and the second light intake surface 103 are smooth surfaces, the first light extraction surface 102 is a surface having a first uneven pattern, and the second light extraction surface 104 is a smooth surface or a surface having a second uneven pattern, and the light extracted from the first light extraction surface 102 or the second light extraction surface 104 of the lens 10 is irradiated onto an external light-emitting surface to perform indirect illumination.

Description

Technical Field

[0001] The present invention relates to a lighting device.

Background Art

[0002] Conventionally, there has been known a lighting device that irradiates a panel with light emitted from a light source through a lens having irregularities on its surface to perform indirect lighting (see Patent Document 1). The lens of the lighting device described in Patent Document 1 is a cylindrical lens that can rotate about an axis, and has irregular wave-shaped irregularities on the entire side surface thereof.

[0003] According to the lighting device described in Patent Document 1, by rotating the lens, it is possible to change the irregularities on the surface for taking in light from the light source and the surface for emitting light, and thereby change the pattern formed by the light and shade of the light displayed on the panel.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the lighting device described in Patent Document 1, due to its structure, irregularities always exist on the entire surface for taking in light of the lens, so incident light is easily scattered and the light loss is large.

[0006] An object of the present invention is to provide a lighting device that performs indirect lighting by passing light emitted from a light source through a lens having irregularities on its surface, and in which light loss is suppressed.

Means for Solving the Problems

[0007] One aspect of the present invention provides the following lighting device in order to achieve the above object.

[0008] [1] A lighting device comprising: a rod-shaped lens having a first light-receiving surface, a second light-receiving surface, a first light-extracting surface, and a second light-extracting surface along its length; a light source that irradiates the lens with light; and a drive unit that rotates the lens so that the surface irradiated by light from the light source switches between the first light-receiving surface and the second light-receiving surface, wherein the first light-receiving surface and the second light-receiving surface are smooth surfaces, the first light-extracting surface is a surface facing the first light-receiving surface and having a first uneven pattern, and the second light-extracting surface is a smooth surface facing the second light-receiving surface and having a second uneven pattern different from the first uneven pattern, and indirect illumination is performed by irradiating an external light-irradiating surface with light extracted from the first light-extracting surface or the second light-extracting surface. [2] The lighting device according to [1] above, wherein the light source is a linear light source including a light-emitting element and a rod-shaped light guide that takes in light emitted from the light-emitting element from one end and emits it from the side toward the lens. [3] The lighting device according to [2] above, wherein the drive unit is an actuator mounted on the same substrate as the light-emitting element. [4] The lighting device according to any one of the above [1] to [3], wherein when the light-extracting surface of the lens is switched between the first light-extracting surface and the second light-extracting surface, the light emission intensity of the light source becomes less than or zero than before and after the rotation while the lens is being rotated. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a lighting device that performs indirect illumination by passing light emitted from a light source through a lens having irregularities on its surface, and which minimizes light loss. [Brief explanation of the drawing]

[0010] [Figure 1] Figures 1(a) and 1(b) are cross-sectional views of a lighting device according to an embodiment of the present invention. [Figure 2]Figures 2(a) and 2(b) are perspective views showing the external appearance of a lighting device according to an embodiment of the present invention. [Figure 3] Figures 3(a) to 3(d) are schematic diagrams, viewed from the length of the lens, illustrating the relationship between the rotation angle of the lens and the direction of light propagation extracted from the lens. [Figure 4] Figure 4 shows an example of the interior of a vehicle equipped with a lighting device according to an embodiment of the present invention. [Figure 5] Figure 5 is a cross-sectional view showing an example of the placement of a lighting device when it is mounted on the underside of the door trim upper. [Modes for carrying out the invention]

[0011] Figures 1(a) and 1(b) are cross-sectional views of a lighting device 1 according to an embodiment of the present invention. Figures 2(a) and 2(b) are perspective views showing the external appearance of the lighting device 1.

[0012] The lighting device 1 is an indirect lighting device suitable for use in the interior of a vehicle, and comprises a rod-shaped lens 10, a light source 11 that irradiates light onto the lens 10, and a drive unit 12 that rotates the lens 10.

[0013] The lens 10 has a first light intake surface 101, a first light output surface 102, a second light intake surface 103, and a second light output surface 104 along its longitudinal direction.

[0014] The first light-intake surface 101 and the second light-intake surface 103 of the lens 10 are smooth surfaces. The first light-extraction surface 102 is a surface facing the first light-intake surface 101 and has a first uneven surface pattern. The second light-extraction surface 104 is a surface facing the second light-intake surface 103 and is either a smooth surface or a surface having a second uneven surface pattern different from the first uneven surface pattern. In the examples shown in Figures 1 and 2, the second light-extraction surface 104 is a smooth surface.

[0015] The shapes of the first concavo-convex pattern and the second concavo-convex pattern are not particularly limited. For example, in order to form a more complex pattern on the light irradiation surface, it is preferably an irregular concavo-convex shape without periodicity, such as a concavo-convex shape with irregular undulations.

[0016] Note that the lens 10 is typically a substantially quadrangular prism lens having only the first light incident surface 101, the first light emitting surface 102, the second light incident surface 103, and the second light emitting surface 104 on its side surfaces, but it may have surfaces other than the first light incident surface 101, the first light emitting surface 102, the second light incident surface 103, and the second light emitting surface 104 on its side surfaces. In that case, surfaces other than the first light incident surface 101 and the second light incident surface 103 may be used as light incident surfaces, and surfaces other than the first light emitting surface 102 and the second light emitting surface 104 may be used as light emitting surfaces.

[0017] The lighting device 1 performs indirect lighting by irradiating light taken out from the first light emitting surface 102 or the second light emitting surface 104 of the lens 10 onto an external light irradiation surface. FIGS. 1(a) and 2(a) are views in a state where the first light emitting surface 102 faces the external light irradiation surface side, and FIGS. 1(b) and 2(b) are views in a state where the second light emitting surface 104 faces the external light irradiation surface side.

[0018] The lens 10 is made of a material transparent to visible light emitted from the same substrate, for example, a material such as an acrylic resin or a polycarbonate (PC) resin.

[0019] The light source 11 is a light source for irradiating light onto the side surface of the lens 10. In order to efficiently irradiate light onto the side surface of the lens 10, as shown in FIG. 1, it is preferably a linear light source in which the light emitting surface 115 extends along the length direction of the lens 10.

[0020] In the example shown in FIG. 1, the light source 11 is a linear light source including a light emitting element 111 and a light guide 112. The light guide 112 is a rod-shaped light guide that takes in light emitted from the light emitting element 111 from one end 113 and emits it toward the lens 10 from the light emitting surface 115 provided on the side surface.

[0021] The light-emitting element 111 is typically an LED (Light Emitting Diode) chip, but is not limited to this; for example, it may be an LD (Laser Diode) chip. The light-emitting color of the light-emitting element 111 is not particularly limited, and it may be an element capable of emitting multiple colors, such as a full-color LED.

[0022] The light-emitting elements 111 are mounted on a substrate 13, such as a printed circuit board. The number of light-emitting elements 111 is not particularly limited, but typically one light-emitting element 111 is positioned to face the end face of one end 113 in the longitudinal direction of the light guide 112.

[0023] The light guide 112 has irregularities 114, such as lens cuts, on its side opposite to the light emission surface 115, for reflecting light toward the light emission surface 115. Light emitted from the light-emitting element 111 enters the interior of the light guide 112 from its end 113, is reflected by the irregularities 114, etc., and is emitted from the light emission surface 115.

[0024] The shape of the light guide 112 can be a polygonal prism such as a rectangular prism or a cylinder. For example, if the light guide 112 is rectangular prism-shaped, one of the four faces that make up the side surface becomes the light-emitting surface 115, and the surface opposite to that surface is provided with irregularities 114.

[0025] The light guide 112 is made of a material that is transparent to visible light emitted from the light-emitting element 111, such as an acrylic resin or a polycarbonate resin.

[0026] The drive unit 12 can rotate the lens 10 so that the surface illuminated by light from the light source 11 switches between the first light-collecting surface 101 and the second light-collecting surface 103. Furthermore, it is preferable that the drive unit 12 can rotate the lens 10 in both directions in order to efficiently switch the surface illuminated by light from the light source 11 between the first light-collecting surface 101 and the second light-collecting surface 103.

[0027] Typically, the drive unit 12 holds one end 105 of the lens 10 in the longitudinal direction, as shown in Figure 1, and rotates the lens 10 around an axis along the longitudinal direction of the lens 10 that passes near the center of the lens 10.

[0028] In the example shown in Figure 1, the drive unit 12 is an actuator mounted on the same substrate 13 as the light-emitting element 111, which is suitable for miniaturizing the lighting device 1.

[0029] The lighting device 1 may have a cover 14 that houses and holds the lens 10 and the light source 11, as shown in Figure 1. Light extracted from the first light extraction surface 102 or the second light extraction surface 104 of the lens 10 is irradiated to the outside through the opening 141 of the cover 14.

[0030] Furthermore, the cover 14 has a hole 142 for inserting a shaft 107 that protrudes in the longitudinal direction of the lens 10 from the end 105 and the opposite end 106 of the lens 10. The portion of the cover 14 provided with the hole 142 functions as a bearing for the shaft 107, which is the axis of rotation of the lens 10.

[0031] The cover 14 is typically made of a material with low visible light transmittance, such as polypropylene (PP) or acrylonitrile-butadiene-styrene (ABS).

[0032] Figures 3(a) to 3(d) are schematic diagrams of the lens 10 as seen from the longitudinal direction, illustrating the relationship between the rotation angle of the lens 10 and the direction of light propagation extracted from the lens 10. In the examples shown in Figures 3(a) to 3(d), the second light extraction surface 104 of the lens 10 is a smooth surface.

[0033] Figure 3(b) shows the state in which the first light intake surface 101 of the lens 10 faces the light source 11 and the first light output surface 102 faces the external light-emitting surface. In this state, light emitted from the light source 11 enters the inside of the lens 10 from the first light intake surface 101 and is emitted from the first light output surface 102. At this time, the light is refracted and extracted by the surface of the first uneven pattern on the first light output surface 102, so that a pattern of light and dark corresponding to the shape of the first uneven pattern is formed on the external light-emitting surface.

[0034] Figures 3(a) and 3(c) show the lens 10 slightly rotated in both directions from the state shown in Figure 3(b). When the lens 10 rotates, the angle between the first light intake surface 101 and the first light output surface 102 with respect to the light source 11 changes, and therefore the direction of propagation of the light emitted from the first light output surface 102 changes. As a result, the pattern of light and dark formed on the external light-illuminated surface changes.

[0035] As shown in Figures 3(a) to 3(c), by changing the rotation angle of the lens 10 while keeping the light-extracting surface of the lens 10 at the first light-extracting surface 102, the pattern of light and dark formed on the external light-illuminated surface can be changed.

[0036] Furthermore, by continuously changing the rotation angle of the lens 10, it is possible to change the pattern formed by the light and dark areas of the external light-illuminated surface over time. For example, if the first uneven pattern of the lens 10 is an irregularly undulating uneven pattern, it becomes possible to create an effect where the pattern wavers like the shimmering surface of water (a wavering effect).

[0037] Figure 3(d) shows the state in which the second light intake surface 103 of the lens 10 faces the light source 11 and the second light output surface 104 faces the external light-emitting surface. In this state, light emitted from the light source 11 enters the inside of the lens 10 from the second light intake surface 103 and is emitted from the second light output surface 104. At this time, because the second light output surface 104 is a smooth surface, parallel light traveling inside the lens 10 is extracted from the second light output surface 104 while remaining almost parallel, and a uniformly emitting linear light-emitting region is formed on the external light-emitting surface.

[0038] In other words, when the second light extraction surface 104 is a smooth surface, by switching the light extraction surface of the lens 10 between the first light extraction surface 102 and the second light extraction surface 104, the light-emitting region formed on the external light-illuminating surface can be switched between a light-emitting region having a pattern corresponding to the shape of the first uneven pattern and a uniformly emitting linear light-emitting region.

[0039] Furthermore, when switching the light extraction surface between the first light extraction surface 102 and the second light extraction surface 104, the light emission intensity of the light source 11 may be reduced to less than or zero than before and after the rotation while the lens 10 is being rotated.

[0040] In other words, if the light emission intensity of the light source 11 when the light extraction surface is the first light extraction surface 102 is I1, and the light emission intensity of the light source 11 when the light extraction surface is the second light extraction surface 104 is I2, then the light emission intensity of the light source 11 during the rotation of the lens 10 to switch between the first light extraction surface 102 and the second light extraction surface 104 may be made smaller than I1 and I2, or even zero.

[0041] This makes the transition between the light-emitting region having a pattern corresponding to the shape of the first uneven pattern formed on the external light-emitting surface and the uniformly emitting linear light-emitting region less noticeable.

[0042] Furthermore, if the second light extraction surface 104 has a second uneven pattern, the light extraction surface of the lens 10 can be switched between the first light extraction surface 102 and the second light extraction surface 104, thereby switching the light-emitting region formed on the external light-illuminating surface between a light-emitting region having a pattern corresponding to the shape of the first uneven pattern and a light-emitting region having a pattern corresponding to the shape of the second uneven pattern.

[0043] In the lighting device 1, since the first light intake surface 101 and the second light intake surface 103 of the lens 10 are smooth surfaces, regardless of whether light is extracted from the first light output surface 102 or the second light output surface 104, the scattering of incident light can be reduced and light loss can be suppressed compared to the case where a lens with an uneven surface for light intake is used.

[0044] In the lighting device 1, the drive unit 12 is connected to a control unit that controls its operation, and rotates the lens 10 upon receiving an instruction signal from the control unit. The light-emitting element 111 is also connected to a control unit that controls its operation, and emits light upon receiving an instruction signal from the control unit. The control unit that controls the operation of the drive unit 12 and the control unit that controls the operation of the light-emitting element 111 may be the same.

[0045] The control unit that controls the operation of the drive unit 12 and the light-emitting element 111 is a microcomputer composed of, for example, a CPU (Central Processing Unit) that performs calculations and processing on acquired data according to a stored program, and semiconductor memories such as RAM (Random Access Memory) and ROM (Read Only Memory). The ROM stores, for example, a program for the operation of the control unit. The RAM is used, for example, as a storage area to temporarily store calculation results. The control unit may be located inside the lighting device 1, for example on the circuit board 13, or it may be located outside the lighting device 1, for example in an in-vehicle ECU (Electronic Control Unit).

[0046] The control unit can control the operation of the drive unit 12 and the light-emitting element 111 in response to instructions from the vehicle occupants via switches, etc., or to changes in the operating state of the vehicle, such as starting or unlocking the vehicle's drive system.

[0047] More specifically, the control unit can send an instruction signal to the drive unit 12 that includes the angle at which to rotate the lens 10 to rotate the lens 10, or send an instruction signal to the drive unit of the light-emitting element 111 that includes the light-emitting intensity and color to cause the light-emitting element 111 to emit light.

[0048] The control of the drive unit 12 and the light-emitting element 111 by such a control unit may be performed, for example, in response to input to a switch that specifies the pattern of indirect lighting by the lighting device 1, or automatically at predetermined timings according to a pre-prepared timetable.

[0049] Figure 4 shows an example of the interior of a vehicle 9 equipped with the lighting device 1. The lighting device 1 can provide indirect lighting by using the surfaces of interior components such as the door trim ornament surface 91 and door trim upper 92 of the doors on the driver's seat 90a and passenger seat 90b sides, the door trim ornament surface 94 and door trim upper 95 of the doors on the rear seat 93 side, the instrument panel 96, and the ceiling 97 as light-emitting surfaces.

[0050] In this way, the lighting device 1 can be used as indirect lighting to illuminate the surface of the interior components of a vehicle. In Figure 4, an example of the part used as the light-emitting surface of the lighting device 1 is shown colored gray.

[0051] The lighting device 1 can have a size and shape that corresponds to the size and shape of the space in which it is installed. Furthermore, the direction of light emitted from the lighting device 1 installed on the vehicle 9 can be freely set according to the installation location, and the lighting device 1 is installed at an angle corresponding to that direction of light emission.

[0052] Figure 5 is a cross-sectional view showing an example of the arrangement of the lighting device 1 when it is mounted on the back side of the door trim upper 92. In Figure 5, the lighting device 1 is mounted so that the length of the lens 10 is aligned with the surface of the door trim upper 92.

[0053] In this case, the lighting device 1 is positioned on the back side of the door trim upper 92, in a location not directly visible to the vehicle occupants, and the light emitted from the lighting device 1 passes through a gap in the door trim upper 92 and illuminates the surface of the door trim upper 92 in an area directly visible to the vehicle occupants.

[0054] As described above, when the lighting device 1 is used in the interior of a vehicle, the light-emitting surface of the lighting device 1 is provided on the surface of the interior component of the vehicle 9 on which the lighting device 1 is mounted. Thus, according to the embodiment of the present invention, it is also possible to provide an interior component for a vehicle that comprises a lighting device 1 and an interior component whose surface becomes the light-emitting surface of the lighting device 1.

[0055] (Effects of the embodiment) According to the lighting device 1 of the above embodiment of the present invention, patterns of light and dark corresponding to the shapes of the irregularities on the first light extraction surface 102 and the second light extraction surface 104 can be formed on the external light-illuminated surface, thereby enabling indirect lighting.

[0056] Furthermore, in the lighting device 1, since the first light intake surface 101 and the second light intake surface 103 of the lens 10 are smooth surfaces, the scattering of incident light can be reduced and light loss can be suppressed regardless of whether light is extracted from the first light extraction surface 102 or the second light extraction surface 104.

[0057] Furthermore, in the lighting device 1, if the second light extraction surface 104 is a smooth surface, the light extraction surface of the lens 10 can be switched between the first light extraction surface 102 and the second light extraction surface 104, thereby switching the light-emitting region formed on the external light-illuminating surface between a light-emitting region having a pattern corresponding to the shape of the first uneven pattern and a uniformly emitting linear light-emitting region.

[0058] Although embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the invention. Furthermore, the components of the above embodiments can be arbitrarily combined without departing from the spirit of the invention. Moreover, the above embodiments do not limit the invention as claimed. It should also be noted that not all combinations of features described in the embodiments are necessarily essential for solving the problem of the invention. [Explanation of Symbols]

[0059] 1. Lighting device 10 lenses 101 First light-receiving surface 102 First light extraction surface 103 Second light-capturing surface 104 Second light extraction surface 11 Light source 111 Light-emitting element 112 Light guide 12 Drive unit

Claims

1. A rod-shaped lens having a first light intake surface, a second light intake surface, a first light extraction surface, and a second light extraction surface along its length, A light source that illuminates the lens, A drive unit rotates the lens so that the surface onto which light from the light source is irradiated switches between the first light-collecting surface and the second light-collecting surface. Equipped with, The first light-receiving surface and the second light-receiving surface are smooth surfaces. The first light extraction surface is a surface having a first uneven pattern that faces the first light intake surface. The second light extraction surface is a smooth surface or a surface having a second uneven pattern different from the first uneven pattern, facing the second light intake surface. Indirect illumination is performed by irradiating an external light-emitting surface with light extracted from the first or second light-extraction surface. Lighting device.

2. The light source is a linear light source including a light-emitting element and a rod-shaped light guide that captures light emitted from the light-emitting element from one end and emits it from the side toward the lens. The lighting device according to claim 1.

3. The drive unit is an actuator mounted on the same substrate as the light-emitting element. The lighting device according to claim 2.

4. When the light-extracting surface of the lens is switched between the first light-extracting surface and the second light-extracting surface, the light emission intensity of the light source becomes smaller or zero during the rotation compared to before and after the rotation. A lighting device according to any one of claims 1 to 3.

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