Lighting device

Abstract

The present application provides a kind of lighting device, can make lens miniaturization.Light emitting device (100) has: light source (120) with light emitting surface (120a), reflector (130) with the reflecting surface (131) of the light reflected from light source, and the lens (140) of the light reflected by reflecting surface injection, reflecting surface is formed by the part of rotating elliptical surface (A) with first focus (F1) on light emitting surface and second focus (F2) between reflecting surface and lens.Reflecting surface intersects with the long axis (A1) of rotating elliptical surface.The value obtained by dividing the first distance (D1) of first focus and second focus by the second distance (D2) of first focus and the intersection (F0) of reflecting surface and long axis is 7 or more.In the first direction (Z) of the normal line (N) of the center (C) of light emitting surface, the maximum size of lens is 20mm or less.

Description

Technical Field

[0001] The implementation involves a lighting device. Background Technology

[0002] Previously, an illumination device was known that included: a light source, a reflector that reflects light emitted from the light source, and a lens into which light reflected by the reflector enters.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-208196 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] The purpose of this implementation is to provide an illumination device that enables the miniaturization of lenses.

[0008] Technical solutions for solving technical problems

[0009] The illumination device of this embodiment includes: a light source having a light-emitting surface, a reflector having a reflective surface that reflects light emitted from the light source, and a lens into which light reflected by the reflective surface enters. The reflective surface is formed by a portion of a rotating elliptical surface with a first focal point located on the light-emitting surface and a second focal point located between the reflective surface and the lens. The reflective surface intersects the major axis of the rotating elliptical surface. A value greater than or equal to 7 is obtained by dividing a first distance between the first and second focal points by a second distance between the first focal point and the intersection of the reflective surface and the major axis. The maximum size of the lens is 20 mm or less in a first direction extending from the normal to the center of the light-emitting surface.

[0010] The illumination device of this embodiment includes: a light source having a light-emitting surface, a reflector having a reflective surface that reflects light emitted from the light source, and a lens into which light reflected by the reflective surface enters. The reflective surface has a shape comprising portions of the outer periphery of a plurality of ellipses. A first focal point of each of the plurality of ellipses is located on the light-emitting surface. A second focal point of each of the plurality of ellipses is located between the reflective surface and the lens. The major axis of the first ellipse among the plurality of ellipses, where the distance between the first focal point and the second focal point is the smallest, intersects the reflective surface. The value obtained by dividing the first distance between the first focal point and the second focal point of the first ellipse by the second distance between the first focal point and the intersection point of the first focal point and the major axis of the reflective surface is 7 or more. In a first direction extending from the normal to the center of the light-emitting surface, the maximum size of the lens is 20 mm or less.

[0011] The effects of the invention

[0012] According to the embodiments, it is possible to provide an illumination device that enables the miniaturization of the lens. Attached Figure Description

[0013] Figure 1 This is a perspective view showing the lighting device according to the first embodiment.

[0014] Figure 2 yes Figure 1 A sectional view along line II-II.

[0015] Figure 3 This is an exploded perspective view showing the substrate and light source of the lighting device according to the first embodiment.

[0016] Figure 4 yes Figure 3 A cross-sectional view along line IV-IV.

[0017] Figure 5A It is a cross-sectional view showing the path of light emitted from the light source and reflected by the reflecting surface of the first embodiment and the reflecting surface of the reference example.

[0018] Figure 5B It is a cross-sectional view showing the path of light emitted from the light source and reflected by the reflecting surface of the first embodiment and the reflecting surface of the reference example.

[0019] Figure 6A This is a schematic diagram showing the area of ​​light illuminating the screen when the screen is set at the second focal point of the reflective surface in the reference example.

[0020] Figure 6B This is a schematic diagram showing the area of ​​light irradiated on the screen when the screen is provided with a second focal point on the reflective surface in the first embodiment.

[0021] Figure 7 This is a perspective view showing the lighting device according to the second embodiment.

[0022] Figure 8 yes Figure 7 A cross-sectional view of line VIII-VIII.

[0023] Figure 9 yes Figure 7 A cross-sectional view of the IX-IX line.

[0024] Figure 10A This is a cross-sectional view showing the shape of the reflecting surface of the first reflector in the second embodiment.

[0025] Figure 10B This is a top view showing the shape of the reflecting surface of the first reflector in the second embodiment.

[0026] Figure 11AThis is a cross-sectional view showing the shape of the reflecting surface of the second reflector in the second embodiment.

[0027] Figure 11B This is a top view showing the shape of the reflecting surface of the second reflector in the second embodiment. Detailed Implementation

[0028] <First Implementation>

[0029] First, the first embodiment will be described.

[0030] Figure 1 This is a perspective view showing the lighting device of this embodiment.

[0031] Figure 2 It means Figure 1 A sectional view along line II-II.

[0032] The lighting device 100 of this embodiment is used, for example, in vehicle lighting fixtures such as headlights. (See reference...) Figure 1 and Figure 2 In summary, the lighting device 100 includes: a substrate 110, a light source 120, a reflector 130, and a lens 140.

[0033] The following describes each part of the lighting device 100. The surface from which light is emitted on the outer surface of the light source 120 will be referred to as the "light-emitting surface 120a". Furthermore, as... Figure 2 As shown, the direction extending from the normal N at the center C of the luminous surface 120a is called the "first direction Z". The direction orthogonal to the first direction Z is called the "second direction X". The direction orthogonal to both the first direction Z and the second direction X is called the "third direction Y". For ease of explanation, the direction from the light source 120 to the reflector 130 within the first direction Z will be referred to as "upper", and its opposite direction as "lower". However, this is not intended to limit the direction of the lighting device during use; the direction of the lighting device 100 during use is arbitrary.

[0034] <Substrate>

[0035] Figure 3 This is an exploded perspective view showing the substrate and light source of the lighting device according to this embodiment.

[0036] A light source 120 is mounted on a substrate 110. The substrate 110 is, for example, a wiring substrate having an insulating layer and wiring electrically connected to the light source 120. In this embodiment, the substrate 110 is generally flat. The surface of the substrate 110 has a first surface 111 corresponding to the upper surface and a second surface 112 located opposite to the first surface 111 and corresponding to the lower surface. The first surface 111 and the second surface 112 are generally flat surfaces and are generally parallel to the second direction X and the third direction Y. However, the shape of the substrate is not limited to the above shape. For example, the substrate may also be curved.

[0037] A through-hole 110h is provided on the substrate 110. The through-hole 110h penetrates the substrate 110 in the first direction Z. For example, a heat dissipation component such as a heat sink may be disposed under the substrate 110. Alternatively, the lighting device may not have a substrate, and the light source may be held in a bracket or the like with wiring.

[0038] <Light Source>

[0039] The light source 120 emits light into the reflector 130. In this embodiment, the light source 120 is disposed within the through-hole 110h of the substrate 110. However, it is not necessary to provide a through-hole on the substrate; the light source may also be disposed on the substrate.

[0040] Figure 4 yes Figure 3 A cross-sectional view along line IV-IV.

[0041] In this embodiment, the light source 120 includes: a substrate 121, a sub-fixing member 122, a light-emitting element 123, a reflective member 124, a light-transmitting member 125, a wavelength conversion member 126, a first light-shielding member 127, and a second light-shielding member 128.

[0042] The surface of the substrate 121 has a first surface 121a, corresponding to the upper surface, and a second surface 121b, located on the opposite side of the first surface 121a and corresponding to the lower surface. In this embodiment, the first surface 121a and the second surface 121b are generally flat surfaces, and are generally parallel to the second direction X and the third direction Y. In this embodiment, a recess 121c is provided in the first surface 121a, which is recessed into the second surface 121b. A sub-fixing member 122, a light-emitting element 123, and a reflective member 124 are disposed in the recess 121c.

[0043] In addition, such as Figure 3 As shown, a plurality of wiring components 121d are provided on the substrate 121. Each wiring component 121d is electrically connected to a light-emitting element 123 and a thermistor (not shown) disposed in a recess 121c of the substrate 121. In addition, each wiring component 121d is electrically connected to the wiring of the substrate 110 via wire bonding or the like.

[0044] like Figure 4 As shown, the sub-fixing member 122 is disposed on the bottom surface of the recess 121c.

[0045] In this embodiment, the light-emitting element 123 is a laser element (LD: Laser Diode). The light-emitting element 123 is disposed on the sub-fixed member 122. The peak wavelength of the light emitted from the light-emitting element 123 is, for example, 320 nm or more and 530 nm or less. Examples of laser elements include nitride semiconductor materials such as GaN, InGaN, or AlGaN. The light-emitting element 123 emits light in a direction intersecting the first direction Z.

[0046] The reflective component 124 is disposed opposite to the light-emitting element 123 on the bottom surface of the recess 121c. The reflective component 124 reflects light upward. The surface of the reflective component 124 opposite to the light-emitting element 123 has a first reflective region 124a and a second reflective region 124b.

[0047] The first reflective region 124a is inclined relative to the first direction Z, moving upwards and further away from the light-emitting element 123. The second reflective region 124b is connected to the upper end of the first reflective region 124a. The second reflective region 124b is inclined relative to the first direction Z, moving upwards and further away from the light-emitting element 123. In this embodiment, the angle formed by the second reflective region 124b and the first direction Z is smaller than the angle formed by the first reflective region 124a and the first direction Z.

[0048] The reflective component 124 is formed primarily of glass or metal, and a reflective film such as a metal film or a dielectric multilayer film is provided in the first reflective region 124a and the second reflective region 124b.

[0049] However, the specific structure of the reflective component, such as its shape and material, is not limited to the above.

[0050] The light-transmitting component 125 is mounted on the substrate 121, covering the recess 121c of the substrate 121. The light-transmitting component 125 is formed of a light-transmitting material such as sapphire.

[0051] A wavelength conversion component 126 is disposed on the light-transmitting component 125. The wavelength conversion component 126 performs wavelength conversion on a portion of the light reflected by the reflecting component 124. The wavelength conversion component 126 may contain a phosphor, for example. Examples of phosphors used in the wavelength conversion component 126 include YAG phosphors, LAG phosphors, or α-silicon phosphors.

[0052] In this embodiment, the upper surface of the wavelength conversion component 126 corresponds to the light-emitting surface 120a. For example... Figure 3As shown, in this embodiment, the top view of the light-emitting surface 120a is that of a rectangle with the third direction Y as its length. Therefore, in this embodiment, the center C of the light-emitting surface 120a corresponds to the intersection of the diagonals of the rectangle. In this embodiment, the light-emitting surface 120a is a flat surface, approximately parallel to the second direction X and the third direction Y. However, the shape of the light-emitting surface is not limited to the above shape. For example, the light-emitting surface can also be a curved surface.

[0053] like Figure 4 As shown, the first light-shielding member 127 is disposed on the light-transmitting member 125 and around the wavelength conversion member 126. The first light-shielding member 127 is formed, for example, from aluminum oxide or aluminum nitride.

[0054] The second light-shielding member 128 is disposed around the first light-shielding member 127, covering the portion of the light-transmitting member 125 exposed from the wavelength conversion member 126 and the first light-shielding member 127. The second light-shielding member 128 is formed, for example, from a resin containing light-scattering particles such as titanium dioxide.

[0055] like Figure 3 As shown, although the maximum dimension G1 of the second direction X of the light-emitting surface 120a is not particularly limited, it is preferably 0.2 mm or more and 1.0 mm or less.

[0056] In addition, although the brightness of the light source 120 is not specifically limited, it is preferably 300 cd / mm². 2 Above, 2500cd / mm 2 The following is an example. Brightness can be measured by a luminance meter, such as the Konica Minolta CS-2000 spectroradiometer manufactured in Japan.

[0057] However, the structure of a light source is not limited to the structures described above. For example, a light source may also include multiple light-emitting elements. In this case, the peak wavelengths of the light emitted by each light-emitting element may be the same or different. Additionally, the wavelength conversion component may contain various phosphors. Furthermore, the light-emitting element may also be an LED (Light Emitting Diode).

[0058] <Reflector>

[0059] like Figure 2 As shown, the reflector 130 reflects the light emitted from the light source 120 toward the lens 140. The reflector 130 is disposed on the substrate 110. The reflector 130 is, for example, a concave mirror facing the substrate 110 and the opening of the lens 140.

[0060] like Figure 1 and Figure 2As shown, the surface of the reflector 130 includes: a reflective surface 131 opposite to the light-emitting surface 120a of the light source 120, an outer surface 132 located on the opposite side of the reflective surface 131, a first end face 133 located between the reflective surface 131 and the outer surface 132 and opposite to the substrate 110, and a second end face 134 located between the end edge of the reflective surface 131 on the lens 140 side in the second direction X and the end edge of the outer surface 132 on the lens 140 side in the second direction X.

[0061] like Figure 2 As shown, in this embodiment, the reflective surface 131 is formed from a portion of the elliptical surface A of revolution. Here, the phrase "the reflective surface 131 is formed from a portion of the elliptical surface A of revolution" means that, to a practical degree to which manufacturing errors are permissible, the reflective surface 131 is considered to be a portion of the elliptical surface A of revolution.

[0062] The elliptical surface A is a surface that causes an ellipse to rotate about its major axis A1. The major axis A1 extends in a generally second direction X. Furthermore, the elliptical surface A has two foci F1 and F2. The major axis A1 passes through the two foci F1 and F2 and is approximately orthogonal to the normal N of the center C of the luminescent surface 120a.

[0063] In this embodiment, the reflecting surface 131 is formed by a region enclosed by a first plane P1 located closer to and above the major axis A1 and parallel to the second direction X and the third direction Y within the rotating elliptical surface A, and a second plane P2 located between the two foci F1 and F2 and parallel to the first direction Z and the third direction Y. Therefore, the reflecting surface 131 intersects the major axis A1 at the intersection point F0.

[0064] However, the shape of the reflective surface is not limited to the shapes described above.

[0065] The outer surface 132 is curved in the same way as the reflective surface 131.

[0066] The first end face 133 is, for example, a flat surface, substantially parallel to the second direction X and the third direction Y. In this embodiment, the first end face 133 is positioned lower than the intersection point F0. However, the position of the first direction of the first end face can also be the same as the position of the first direction of the intersection point.

[0067] The second end face 134 is, for example, a flat surface, which is approximately parallel to the first direction Z and the third direction Y.

[0068] However, the specific shapes of the outer surface, the first end face, and the second end face are not limited to the shapes described above.

[0069] Hereinafter, the focal point F1 located inside the reflector 130 among the two focal points F1 and F2 will be referred to as the "first focal point F1". In addition, the focal point F2 located outside the reflector 130 among the two focal points F1 and F2 will be referred to as the "second focal point F2".

[0070] A reflector 130 is configured such that the position of the first focal point F1 is approximately aligned with the center C of the emitting surface 120a of the light source 120, and the second focal point F2 is located between the reflecting surface 131 and the lens 140. Therefore, light emitted from the center C of the emitting surface 120a is reflected by the reflecting surface 131, and thus, after converging at approximately the second focal point F2, enters the lens 140. However, the first focal point F1 does not necessarily have to be located at the center C, as long as it is at least located on the emitting surface 120a.

[0071] Hereinafter, the distance between the first focus F1 and the second focus F2 will be referred to as "the first distance D1". The distance between the first focus F1 and the intersection point F0 will be referred to as "the second distance D2". In this embodiment, the value obtained by dividing the first distance D1 by the second distance D2 is 7 or more. That is, D1 / D2 ≥ 7. Furthermore, while the value obtained by dividing the first distance D1 by the second distance D2 is not particularly limited, it is preferably 30 or less. That is, D1 / D2 ≤ 30 is preferred.

[0072] Furthermore, while the first distance D1 is not particularly limited, it is preferably 14 mm or more and 70 mm or less. Similarly, while the second distance D2 is not particularly limited, it is preferably 2 mm or more and 10 mm or less.

[0073] The reflector 130 is mainly formed of resin material, and a reflective film such as a metal film or a dielectric multilayer film is provided on the reflective surface 131. However, the reflector can also be formed of metal material.

[0074] <Lens>

[0075] Lens 140 is, for example, a convex lens. Lens 140 is formed of a light-transmitting material. Lens 140 is disposed spaced apart from substrate 110 in the X direction.

[0076] The surface of lens 140 has: an entrance surface 141 into which light reflected by the reflecting surface 131 enters; an exit surface 142 located on the opposite side of the entrance surface 141 and into which light entering from the entrance surface 141 exits; a first flat surface 143 located between the entrance surface 141 and the exit surface 142; and a second flat surface 144 located between the entrance surface 141 and the exit surface 142 and on the opposite side of the first flat surface 143.

[0077] The injection surface 141 is, for example, a flat surface, which is substantially parallel to the first direction Z and the third direction Y. The injection surface 142 is, for example, a convex curved surface.

[0078] The first flat surface 143 and the second flat surface 144 are, for example, substantially parallel to the second direction X and the third direction Y. The first flat surface 143 corresponds to the upper surface, and the second flat surface 144 corresponds to the lower surface. The first flat surface 143 is located closer to the upper surface than the first surface 111 of the substrate 110. The second flat surface 144 is located closer to the lower surface than the second surface 112 of the substrate 110.

[0079] However, the specific shape of the lens is not limited to the shape described above. For example, the upper and lower surfaces of the lens may not be flat surfaces, but curved surfaces. Furthermore, from the perspective of suppressing light from entering or exiting the first flat surface 143 and the second flat surface 144, the light-shielding member can cover the first flat surface 143 and the second flat surface 144. This suppresses the generation of stray light.

[0080] The maximum dimension G2 of the lens 140 in the first direction Z is 20 mm or less. This allows for miniaturization of the lens 140 in the first direction Z. When the lighting device 100 is applied to vehicle lighting fixtures such as headlights, the lens 140 is mounted on the vehicle while remaining visible from outside the vehicle. Furthermore, in the field of vehicle lighting fixtures, lenses with a first direction Z dimension of 20 mm or less offer greater design freedom in terms of both creativity and functionality due to their small size, making them preferable from the aforementioned perspective. Therefore, by using the lighting device 100 with the aforementioned lens 140 in vehicle lighting fixtures, vehicles with both high creativity and / or excellent functionality can be achieved.

[0081] In addition, although the maximum dimension G2 of the lens 140 in the first direction Z is not particularly limited, it is preferably 3 mm or more.

[0082] In this embodiment, the position of the focal point of the lens 140 is approximately the same as the position of the second focal point F2 of the reflecting surface 131. However, the position of the focal point of the lens may also deviate from the position of the second focal point of the reflecting surface.

[0083] Next, the operation of the lighting device 100 of this embodiment will be described.

[0084] Most of the light L1 emitted from the center C of the emitting surface 120a is reflected by the reflecting surface 131. Most of the light L1 reflected by the reflecting surface 131 enters the lens 140. When the lighting device 100 is used in a headlight, the light L1 emitted from the lens 140 can be used as either high beam or low beam. When the light L1 emitted from the lens 140 is used as low beam, a light-shielding member for forming a light cutoff line can be disposed between the lens 140 and the reflector 130. In this case, the light-shielding member can also be disposed on the second focal point F2.

[0085] Figure 5A It is a cross-sectional view showing the path of light emitted from the light source and reflected by the reflecting surface of this embodiment and the reflecting surface of the reference example.

[0086] exist Figure 5A In the diagram, the reflecting surface 131f and the light L2 reflected by the reflecting surface 131f are represented by a dashed line. Additionally, in... Figure 5A In the diagram, the lens 140f required for the reflecting surface 131f in the reference example is indicated by a dashed line. Additionally, in... Figure 5A In the image, the solid line represents the light L2 reflected by the reflective surface 131 of this embodiment.

[0087] The reflective surface 131f in the reference example is a reflective surface whose position of the first focal point F1 is the same as that of the first focal point F1 of the reflective surface 131 in this embodiment, and whose first distance D1 is shorter than that of this embodiment.

[0088] like Figure 5A As shown, when light L2 emitted from light source 120 and directed in one direction is reflected by the reflecting surface 131 of this embodiment, the angle θ formed by the central axis and major axis A1 of the reflected light L2 is smaller than the angle θ formed by the central axis and major axis A1 of the light L2 reflected by the reflecting surface 131f in the reference example. That is, the longer the first distance D1, the smaller the angle θ formed by the central axis and major axis A1 of the light L2 reflected by the reflecting surface 131. Furthermore, the smaller the angle θ formed by the central axis and major axis A1 of the light L2, the closer the position of the light L2 in the first direction Z is to the position of the major axis A1 in the first direction Z when it enters the lens 140. Therefore, the longer the first distance D1, the smaller the size of the lens 140 in the first direction Z can be, without changing the amount of light entering the lens 140.

[0089] Figure 5B It is a cross-sectional view showing the path of light emitted from the light source and reflected by the reflecting surface of this embodiment and the reflecting surface of the reference example.

[0090] Similarly, in Figure 5B In the diagram, the reflective surface 131g of the reference example and the light L3 reflected by the reflective surface 131g are represented by a dashed line. Additionally, in... Figure 5B In the diagram, the 140g lens required for the 131g reflecting surface of the reference example is indicated by a dashed line. Additionally, in... Figure 5B In the image, the solid line represents the light L3 reflected by the reflective surface 131 of this embodiment.

[0091] The reflective surface 131g in the reference example is a reflective surface in which the positions of the first focal point F1 and the second focal point F2 are the same as those of the first focal point F1 and the second focal point F2 of the reflective surface 131 in this embodiment, and the second distance D2 is longer than that of this embodiment.

[0092] like Figure 5B As shown, when light L3 emitted from light source 120 and directed in one direction is reflected by the reflecting surface 131 of this embodiment, the angle θ formed by the central axis and major axis A1 of the reflected light L3 is smaller than the angle θ formed by the central axis and major axis A1 of the light L3 reflected by the reflecting surface 131g in the reference example. That is, the shorter the second distance D2, the smaller the angle θ formed by the central axis and major axis A1 of the light L3 reflected by the reflecting surface 131. Furthermore, the smaller the angle θ formed by the central axis and major axis A1 of the light L3, the closer the position of the light L3 in the first direction Z is to the position of the major axis A1 in the first direction Z when it enters the lens 140. Therefore, the shorter the second distance D2, the smaller the size of the lens 140 in the first direction Z can be, without changing the amount of light entering the lens 140.

[0093] Therefore, in order to reduce the size of the lens 140 in the first direction Z, it is preferable to increase the first distance D1 and shorten the second distance D2. In this embodiment, the value obtained by dividing the first distance D1 by the second distance D2 is 7 or more. That is, D1 / D2 ≥ 7. Therefore, without changing the amount of light incident on the lens 140, the size of the lens 140 in the first direction Z can be reduced. Thus, it is possible to realize a lens 140 with a size of 20 mm or less in the first direction Z.

[0094] Figure 6A This is a schematic diagram showing the area of ​​light illuminating the screen when the screen is set at the second focal point of the reflective surface in the reference example.

[0095] Figure 6B This is a schematic diagram showing the area of ​​light illuminating the screen when the screen with the second focal point of the reflective surface is set in this embodiment.

[0096] The light source 120 is not a point light source, but has a light-emitting surface 120a. Therefore, assuming that a screen S is arranged on the second focal point F2 of the reflecting surface 131, the light emitted from the light-emitting surface 120a will not be completely focused on the second focal point F2, but will instead irradiate the screen S with an extended illumination area G in the first direction Z and the third direction Y.

[0097] And, for example Figure 5A As shown, the longer the first distance D1, the longer the distance of the light L2 reflected by the reflecting surface 131 to the screen S. Figure 6A and Figure 6BAs shown, the longer the distance from light L2 to screen S, the more extended light L2 becomes, thus increasing the area of ​​the illuminated region G on screen S. The larger the area of ​​the illuminated region G on screen S, the lower the maximum illuminance of the illuminated region G. The position of the second focal point F2 is approximately the same as the focal point of lens 140. Therefore, it is possible to consider arranging a light source with an illuminance distribution like the illuminated region G at the focal point of lens 140. Under this consideration, it can be seen that because the maximum illuminance of the illuminated region G at the second focal point F2 decreases, the maximum illuminance of the light emitted from lens 140 in the illuminated region also decreases. That is, the longer the first distance D1, the lower the maximum illuminance of the light emitted from lens 140 in the illuminated region.

[0098] In addition, for example, Figure 5B As shown, the shorter the second distance D2, the more difficult it is for the reflecting surface 131 to concentrate the light emitted from the emitting surface 120a of the light source 120. Therefore, as Figure 6A and Figure 6B As shown, the shorter the second distance D2, the larger the area of ​​the illuminated region G on the screen S. The larger the area of ​​the illuminated region G on the screen S, the lower the maximum illuminance of the illuminated region G. Therefore, the shorter the second distance D2, the lower the maximum illuminance of the light emitted from the lens 140 in the illuminated region.

[0099] Therefore, the larger the value of D1 / D2, the lower the maximum illuminance of the light emitted from lens 140 in the irradiated area. In contrast, in this embodiment, the luminance of light source 120 is 300 cd / mm². 2 Therefore, by setting the value of D1 / D2 to 7 or higher, it is possible to compensate for the reduction in maximum illuminance of the light emitted from the lens 140 in the irradiated area by increasing the brightness of the light source 120.

[0100] Furthermore, the longer the distance from the light reflected by the reflecting surface 131 and focused at the second focal point F2 to the lens 140, the more easily it expands before entering the lens 140. Therefore, the shorter the distance between the lens 140 and the second focal point F2 in the second direction X, the smaller the size of the lens 140 in the first direction Z can be. On the other hand, the shorter the focal distance of the lens 140 is made to bring the lens 140 closer to the second focal point F2, the wider the illumination area of ​​the light emitted from the lens 140, and the lower the maximum illuminance of the illumination area. Accordingly, from the perspective of miniaturizing the lens 140 in the first direction Z and suppressing the maximum illuminance of the illumination area, it is preferable that the distance between the incident surface 141 of the lens 140 and the second focal point F2 (which is the light-shielding member in the case where the lighting device 100 is provided with a light-shielding member for forming a light-dark cutoff line) in the second direction X is 10 mm or more and 25 mm or less.

[0101] Next, the effects of this embodiment will be explained.

[0102] The lighting device 100 of this embodiment includes: a light source 120 having a light-emitting surface 120a; a reflector 130 having a reflective surface 131 that reflects light emitted from the light source 120; and a lens 140 into which light reflected by the reflective surface 131 enters. The reflective surface 131 is formed from a portion of a rotating elliptical surface A, where a first focal point F1 is located on the light-emitting surface 120a and a second focal point F2 is located between the reflective surface 131 and the lens 140. The reflective surface 131 intersects the major axis A1 of the rotating elliptical surface A. The value obtained by dividing the first distance D1 between the first focal point F1 and the second focal point F2 by the second distance D2 at the intersection point F0 of the first focal point F1 and the reflective surface 131 and the major axis A1 is 7 or more. Furthermore, the maximum size of the lens 140 is 20 mm or less in the first direction Z extending from the normal N at the center of the light-emitting surface 120a. As a result, the amount of light entering the lens 140 is not changed, and a lens 140 with a reduced size in the first direction Z can be achieved. For example, when the lighting device 100 is applied to vehicle lamps such as headlights, by reducing the size of the lens 140 in the first direction Z, it is possible to achieve a vehicle with increased design freedom, creativity, and / or good functionality.

[0103] Furthermore, the first distance D1 is preferably 14 mm or more, more preferably 21 mm or more. In this embodiment, the second distance D2 is preferably 10 mm or less, more preferably 3 mm or less. By making the first distance D1 21 mm or more, or the second distance D2 3 mm or less, the value of D1 / D2 can be increased.

[0104] Furthermore, the first distance D1 is preferably 70 mm or less. This allows for the suppression of excessively low maximum illuminance of the light emitted from the lens 140 in the irradiated area.

[0105] Furthermore, the second distance D2 is preferably 2 mm or more. This allows for the suppression of excessively low maximum illuminance in the irradiated area caused by light emitted from the lens 140. Additionally, this ensures that the light source 120 is separated from the reflecting surface 131 to a degree that the reflective film constituting the reflecting surface 131 will not peel or be damaged due to heat generated at the light source 120. Furthermore, as... Figure 5B As shown, the shorter the second distance D2, the smaller the reflector 130 can be, and the higher the positional accuracy required when the relative positions of the light source 120, reflector 130, and lens 140 are combined. By making the second distance D2 2mm or more, it is possible to suppress the requirement of excessively high positional accuracy.

[0106] Furthermore, the maximum dimension G1 of the luminescent surface 120a extending in the second direction X along the major axis A1 is preferably 1.0 mm or less. This allows for a shorter first distance D1. Additionally, the maximum dimension G1 of the luminescent surface 120a in the second direction X is preferably 0.2 mm or more. This allows for a sufficiently large adjustment accuracy of the maximum dimension of the luminescent surface 120a in the second direction X compared to the position of the light source 120 in the second direction X. Therefore, even if the position of the luminescent surface 120a deviates from the designed position in the second direction X, the reduction in maximum illuminance of the light emitted from the lens 140 in the irradiated area can be suppressed.

[0107] In addition, the brightness of the light source 120 is preferably 300 cd / mm². 2 Therefore, by increasing the brightness of the light source 120, the amount by which the maximum illuminance of the light emitted from the lens 140 in the irradiated area is reduced due to the D1 / D2 value being 7 or higher can be compensated accordingly. In particular, by using a laser element as the light-emitting element 123 of the light source 120, the brightness of the light source 120 can be easily increased.

[0108] Furthermore, the lens 140 has: an entrance surface 141 into which light reflected by the reflecting surface 131 enters; an exit surface 142 located on the opposite side of the entrance surface 141 and out which light entering from the entrance surface 141 exits; a first flat surface 143 located between the entrance surface 141 and the exit surface 142; and a second flat surface 144 located on the opposite side of the first flat surface 143 in the first direction Z and located between the entrance surface 141 and the exit surface 142. Thus, because the lens 140 has the first flat surface 143 and the second flat surface 144, the size of the lens 140 in the first direction Z can be reduced compared to cases where the upper surface of the lens is convex upwards or the lower surface of the lens is convex downwards.

[0109] Furthermore, the value of D1 / D2 is preferably 30 or less. This allows for the suppression of excessively low maximum illuminance of the light emitted from the lens 140 in the irradiated area.

[0110] <Second Implementation>

[0111] Next, the second embodiment will be described.

[0112] Figure 7 This is a perspective view showing the lighting device of this embodiment.

[0113] Figure 8 yes Figure 7 A cross-sectional view of line VIII-VIII.

[0114] Figure 9 yes Figure 7 A cross-sectional view of the IX-IX line.

[0115] The lighting device 200 of this embodiment has a first unit UA and a second unit UB. For example... Figure 8 As shown, the first unit UA includes: a first substrate 210A, a first light source 220A, a first reflector 230A, a first lens 240A, a first light-shielding member 250A, and a first driving unit 260A. Figure 9 As shown, the second unit UB includes: a second substrate 210B, a second light source 220B, a second reflector 230B, a second lens 240B, a second light-shielding member 250B, and a second driving unit 260B.

[0116] The first unit UA is mainly used as a diffuser unit to emit diffuse light, and the second unit UB is mainly used as a focusing unit to emit parallel light. The following is a detailed description of each part of the lighting device 200.

[0117] <Substrate>

[0118] Since the first substrate 210A and the second substrate 210B are each constructed in the same manner as the substrate 110 of the first embodiment, detailed descriptions are omitted.

[0119] <Light Source>

[0120] Since the first light source 220A and the second light source 220B are each configured the same as the light source 120 in the first embodiment, detailed descriptions are omitted.

[0121] <Reflector>

[0122] First, let's explain the first reflector 230A.

[0123] like Figure 8 As shown, the first reflector 230A has a main body 231A that reflects light emitted from the first light source 220A to the first lens 240A, and a mounting part 232A on which the first drive part 260A is mounted.

[0124] The main body 231A is disposed on the first substrate 210A. The main body 231A is, for example, a concave mirror that opens to the first substrate 210A and the first lens 240A.

[0125] The surface of the main body 231A includes: a reflective surface 233A that is opposite to the light-emitting surface 120a of the first light source 220A and is curved into a concave shape; an outer surface 234A located on the opposite side of the reflective surface 233A; a first end surface 235A located between the reflective surface 233A and the outer surface 234A and opposite to the first substrate 210A; and a second end surface 236A located between the end edge of the reflective surface 233A on the side of the first lens 240A in the second direction X and the end edge of the outer surface 234A on the side of the first lens 240A in the second direction X.

[0126] Figure 10A This is a cross-sectional view showing the shape of the reflecting surface of the first reflector in this embodiment.

[0127] Figure 10B This is a top view showing the shape of the reflecting surface of the first reflector in this embodiment.

[0128] like Figure 10B As shown, the reflective surface 233A has a shape that is approximately symmetrical with respect to the plane PA, which is parallel to the first direction Z and the second direction X. Hereinafter, the axis that passes through the emitting surface 120a and extends in the second direction X will be referred to as "axis B".

[0129] like Figure 10A As shown, the reflecting surface 233A, in a cross-section including the plane PA, has a shape comprising portions B11, B12, B13, and B14 (hereinafter also referred to as "parts B11, B12, B13, and B14") of the outer periphery of multiple ellipses. The lengths of the major and minor axes of the ellipses constituting the multiple portions B11, B12, B13, and B14 are different from each other. The multiple portions B11, B12, B13, and B14 are arranged from the first end face 235A side to the second end face 236A side. The multiple portions B11, B12, B13, and B14 are arranged separately from the axis B in the cross-section including the plane PA as they move from the first end face 235A side to the second end face 236A side.

[0130] In this embodiment, the major axis of the ellipse forming the portion B11, which is closest to the first end face 235A, is approximately aligned with axis B. Furthermore, portion B11 reaches a position where it intersects with axis B.

[0131] Each part B11, B12, B13, and B14 has a first focus F1A and a second focus F2A. The positions of the first focus F1A of multiple parts B11, B12, B13, and B14 are approximately the same. Additionally, as... Figure 8 As shown, the position of the first focal point F1A is approximately the same as the position of the center C of the emitting surface 120a of the first light source 220A. However, the first focal point F1A does not necessarily have to be located on the center C, as long as it is located on the emitting surface 120a.

[0132] like Figure 10AAs shown, in this embodiment, although the second foci F2A of the multiple portions B11, B12, B13, and B14 are all approximately located on axis B, their positions in the second direction X are different. The lengths of the major and minor axes of the ellipse constituting portion B11 are set to be equal, so that the distance between the first foci F1A and the second foci F2A of the portion B11 closest to the first end face 235A is shorter than the distance between the first foci F1A and the second foci F2A of the other portions B12, B13, and B14. However, the position of the second foci F2A is not limited to the above-described position. For example, the positions of the multiple second foci F2A may also differ in the first direction Z.

[0133] like Figure 10B As shown, the reflective surface 233A has a shape that gradually changes with distance from the plane PA in the circumferential direction about axis B, so that the curvature of each part B11, B12, B13, and B14 satisfies the condition of an ellipse. Therefore, the reflective surface 233A has a shape of portions Bn1, Bn2, Bn3, and Bn4 that combine the outer peripheries of several other ellipses on a cross-section including axis B and closest to the first substrate 210A. Additionally, the reflective surface 233A has, for example, a shape of portions Bi1, Bi2, Bi3, and Bi4 that combine the outer peripheries of several other ellipses on a cross-section including axis B and located between portions B11 to B14 and portions Bn1 to Bn4. Furthermore, the curvature of portions Bi1 and Bn1 is different from that of portion B11. Additionally, the curvature of portions Bi2 and Bn2 is different from that of portion B12. The curvature of portions Bi3 and Bn3 is different from that of portion B13. Furthermore, the curvature of some Bi4 and Bn4 differs from that of some B14. In other words, the reflecting surface 233A has a shape that combines portions of the outer periphery of multiple ellipses in any cross-section including axis B. It should be noted that the number of portions of the outer periphery of the ellipses constituting each cross-section of the reflecting surface is not limited to four.

[0134] In this embodiment, on the reflecting surface 233A, the distance between the first focal point F1A and the second focal point F2A of the portion B11 located in plane PA and closest to the first end face 235A is shorter than the distance between the first focal point F1A and the second focal point F2A of the other portions B12-B14, Bi1-Bi4, and Bn1-Bn4. Hereinafter, the ellipse constituting the portion B11 closest to the first end face 235A will be referred to as the "first ellipse". Furthermore, the distance between the first focal point F1A and the second focal point F2A of the first ellipse, i.e., portion B11, will be referred to as the "first distance D1A". Additionally, the distance between the first focal point F1A of the first ellipse and the intersection point F0A of the major axis (axis B) of the first ellipse and the reflecting surface 233A will be referred to as the "second distance D2A".

[0135] In this embodiment, the value obtained by dividing the first distance D1A by the second distance D2A is 7 or more. That is, D1A / D2A ≥ 7. Furthermore, while not particularly limited, the value obtained by dividing the first distance D1A by the second distance D2A is 30 or less. That is, D1A / D2A ≤ 30. Additionally, while not particularly limited, the value obtained by dividing the first distance D1A by the second distance D2A is preferably 10 or less. That is, D1A / D2A ≤ 10.

[0136] Furthermore, while the first distance D1A is not particularly limited, it is preferably 14 mm or more and 70 mm or less. Similarly, while the second distance D2A is not particularly limited, it is preferably 2 mm or more and 10 mm or less.

[0137] The outer surface 234A is curved in the same way as the reflective surface 233A.

[0138] The first end face 235A is, for example, a flat surface, substantially parallel to the second direction X and the third direction Y. In this embodiment, the first end face 235A is positioned lower than the intersection point F0A. However, the position of the first end face in the first direction may also be the same as the position of the intersection point in the first direction.

[0139] like Figure 7 As shown, the second end face 236A is a curved surface on the side of the first lens 240A in the second direction X, where the two ends 236At in the third direction Y are located closer to the central portion 236Ac ​​in the second direction X than the central portion 236Ac ​​located approximately in the middle of the two ends 236At.

[0140] However, the specific shapes of the outer surface, the first end face, and the second end face are not limited to the shapes described above.

[0141] The mounting portion 232A protrudes upward from the main body portion 231A. A through hole 237A is provided in the mounting portion 232A. A first drive portion 260A is disposed within the through hole 237A.

[0142] The first reflector 230A is mainly formed of resin material, and a reflective film such as a metal film or a dielectric multilayer film is provided on the reflective surface 233A. However, the first reflector can also be formed of metal material.

[0143] Next, the second reflector 230B will be explained.

[0144] like Figure 9 As shown, the second reflector 230B has a main body 231B that reflects light emitted from the second light source 220B to the second lens 240B, and a mounting part 232B on which the second drive part 260B is mounted.

[0145] The main body 231B is disposed on the second substrate 210B. The main body 231B is, for example, a concave mirror that opens into the second substrate 210B and the second lens 240B.

[0146] The surface of the main body 231B includes: a reflective surface 233B that is opposite to the light-emitting surface 120a of the second light source 220B and is curved into a concave shape; an outer surface 234B located on the opposite side of the reflective surface 233B; a first end surface 235B located between the reflective surface 233B and the outer surface 234B and opposite to the second substrate 210B; and a second end surface 236B located between the end edge of the reflective surface 233B on the side of the second lens 240B in the second direction X and the end edge of the outer surface 234B on the side of the second lens 240B in the second direction X.

[0147] Figure 11A This is a cross-sectional view showing the shape of the reflecting surface of the second reflector in this embodiment.

[0148] Figure 11B This is a top view showing the shape of the reflecting surface of the second reflector in this embodiment.

[0149] like Figure 11B As shown, the reflective surface 233B has a shape that is approximately symmetrical with respect to the plane PB, which is parallel to the first direction Z and the second direction X. Hereinafter, the axis located in the plane PB and extending in the second direction X will be referred to as "axis E".

[0150] like Figure 11A As shown, the reflecting surface 233B is formed in a cross-section including the plane PB by a portion E1 of the outer periphery of an ellipse (hereinafter also referred to as "part E1"). The major axis of the ellipse constituting part E1 is substantially aligned with axis E. Part E1 bends in the cross-section including the plane PB as it separates from axis E from the first end face 235B side toward the second end face 236B side.

[0151] like Figure 11B As shown, the reflective surface 233B has a shape that gradually changes as it separates from the plane PB in the circumferential direction with respect to the axis E, so that the curvature of a portion E1 of the outer periphery of an ellipse satisfies the conditions of an ellipse. Therefore, the reflective surface 233B is formed on the cross-section including the axis E and closest to the second substrate 210B by a portion Em (hereinafter also referred to as "part Em") of the outer periphery of another ellipse whose curvature is different from that of the ellipse constituting part E1. In addition, the reflective surface 233B is formed on a cross-section including the axis E and located between part E1 and part Em by a portion Ek (hereinafter also referred to as "part Ek") of the outer periphery of another ellipse whose curvature is different from that of the ellipse constituting part E1. Thus, the reflective surface 233B is formed on any cross-section including the axis E by a portion of the outer periphery of an ellipse. In other words, the reflective surface 233B has a shape in the circumferential direction with respect to the axis E, which combines portions E1, Ek, and Em of the outer peripheries of multiple ellipses.

[0152] The components E1, Ek, and Em that constitute the reflecting surface 233B have a first focal point F1B and a second focal point F2B.

[0153] The positions of the first focus F1B of multiple parts E1, Ek, and Em are roughly the same. Additionally, as... Figure 9 As shown, the position of the first focal point F1B is approximately the same as the position of the center C of the emitting surface 120a of the second light source 220B. However, the first focal point F1B does not necessarily have to be located on the center C, as long as it is located on the emitting surface 120a.

[0154] In this embodiment, such as Figure 11A As shown, the positions of the second foci F2B of the multiple parts E1, Ek, and Em are close and can be considered roughly consistent. However, the positions of the second foci F2B of the multiple parts E1, Ek, and Em can also be separated from each other.

[0155] Therefore, in this embodiment, the distances between the first focus F1B and the second focus F2B of the multiple portions E1, Ek, and Em are approximately equal. Thus, when the reflecting surface 233B has a shape that combines the outer peripheries of multiple ellipses E1, Ek, and Em, the distances between the first focus F1B and the second focus F2B of the multiple ellipses can also be approximately equal. In this case, the so-called "ellipse with the smallest distance between the first focus and the second focus among the multiple ellipses" can also be any ellipse constituting the multiple portions E1, Ek, and Em. In this embodiment, for ease of understanding, the ellipse constituting portion E1 is referred to as the "first ellipse." Thus, the term "smallest distance between the first focus and the second focus" in this specification includes two cases: the case where the values ​​of multiple distances are different and the distance with the smallest value among the multiple distances is the "smallest distance," and the case where all distance values ​​are equal and the aforementioned equal distance is the "smallest distance." Furthermore, the distance between the first focus F1B and the second focus F2B will be referred to as the "first distance D1B" below.

[0156] The reflecting surface 233B intersects axis E, which is the major axis of the first ellipse. Hereinafter, the distance between the first focus F1B of the first ellipse, i.e., part E1, and the intersection point F0B of the major axis of the first ellipse and the reflecting surface 233B is called the "second distance D2B".

[0157] In this embodiment, the value obtained by dividing the first distance D1B by the second distance D2B is 7 or more. That is, D1B / D2B ≥ 7. Furthermore, while not particularly limited, the value obtained by dividing the first distance D1B by the second distance D2B is 30 or less. That is, D1B / D2B ≤ 30. Additionally, while not particularly limited, the value obtained by dividing the first distance D1B by the second distance D2B is preferably 10 or less. That is, D1B / D2B ≤ 10.

[0158] Furthermore, while the first distance D1B is not particularly limited, it is preferably 14mm or more and 70mm or less. Similarly, while the second distance D2B is not particularly limited, it is preferably 2mm or more and 10mm or less.

[0159] The outer surface 234B is curved in the same way as the reflective surface 233B.

[0160] The first end face 235B is, for example, a flat surface, substantially parallel to the second direction X and the third direction Y. In this embodiment, the first end face 235B is positioned lower than the intersection point F0B. However, the position of the first end face in the first direction may also be the same as the position of the intersection point in the first direction.

[0161] The second end face 236B is, for example, a flat surface, which is approximately parallel to the first direction Z and the third direction Y.

[0162] However, the specific shapes of the outer surface, the first end face, and the second end face are not limited to the shapes described above.

[0163] like Figure 9 As shown, the mounting portion 232B protrudes upward from the main body portion 231B. A through hole 237B is provided in the mounting portion 232B. A second drive portion 260B is disposed within the through hole 237B.

[0164] The second reflector 230B is mainly formed of resin material, and a reflective film such as a metal film or a dielectric multilayer film is provided on the reflective surface 233B. However, the second reflector can also be formed of metal material.

[0165] As described above, the reflecting surface 233A of the first reflector 230A has a shape that combines portions of the outer peripheries of multiple ellipses B11-B14, Bi1-Bi4, and Bn1-Bn4. Similarly, the reflecting surface 233B of the second reflector 230B also has a shape that combines portions of the outer peripheries of multiple ellipses E1, Ek, and Em. It should be noted that the phrase "having a shape that combines portions of the outer peripheries of multiple ellipses" means that, within the practical framework of allowing for slight deviations from the outer peripheries of each ellipse due to manufacturing errors, etc., the reflecting surface is considered to have a shape that combines portions of the outer peripheries of multiple ellipses.

[0166] <Lens>

[0167] The shapes of the first lens 240A and the second lens 240B are each substantially the same as the shape of the lens 140 in the first embodiment. However, in this embodiment, the maximum dimension of the first lens 240A in the second direction X is larger than the maximum dimension of the second lens 240B in the second direction X. Therefore, the focal distance of the first lens 240A is shorter than the focal distance of the second lens 240B. However, the relationship between the maximum dimensions of the first lens and the second lens in the second direction is not limited to the above relationship.

[0168] In this embodiment, the focal point of the first lens 240A and the second focal points F2A of the reflecting surface 233A of the first mirror 230A are located on axis B. Furthermore, the distance between the second focal point F2A of portion B11 in the second direction X and the incident surface of the first lens 240A is less than the distance between the focal point of the first lens 240A and the incident surface of the first lens 240A in the second direction X. Therefore, the other second focal points F2A of the first mirror are located closer to the first lens 240A in the second direction X than the focal point of the first lens 240A. Thus, as... Figure 8 As shown, the light L4a reflected by part B11 of the reflecting surface 233A and emitted from the first lens 240A is parallel light or diffuse light, while the light L4b reflected by other parts of the reflecting surface 233A and emitted from the first lens 240A is diffuse light. In this way, the first lens 240A can mainly emit light diffused in the first direction Z and the third direction Y.

[0169] In this embodiment, the position of the focal point of the second lens 240B is approximately the same as the position of the second focal point F2B of a portion E1 of the reflecting surface 233B of the second mirror 230B. Therefore, as Figure 9 As indicated by the middle arrow L5, parallel light is mainly emitted from the second lens 240B.

[0170] <Light-shielding components>

[0171] like Figure 8 As shown, when the first light-shielding member 250A is positioned between the reflective surface 233A of the first reflector 230A and the first lens 240A, it blocks a portion of the light from the reflective surface 233A toward the first lens 240A. When the lighting device 200 is applied to the headlights of vehicles such as motor vehicles, the first light-shielding member 250A can form a low beam light cutoff line.

[0172] Similarly, as Figure 9As shown, when the second light-shielding member 250B is positioned between the reflective surface 233B of the second reflector 230B and the second lens 240B, it blocks a portion of the light from the reflective surface 233B toward the second lens 240B. When the lighting device 200 is applied to the headlights of vehicles such as motor vehicles, the second light-shielding member 250B can form a low beam light cutoff line.

[0173] From the perspective of miniaturizing the first lens 240A in the first direction Z and suppressing the maximum illuminance of the irradiation area to a low level, the distance between the incident surface of the first lens 240A and the first light-shielding member 250A in the second direction X is preferably 10 mm or more and 25 mm or less. The same distance applies to the second lens 240B and the second light-shielding member 250B.

[0174] <Drive Department>

[0175] The first drive unit 260A switches between a first state in which the first light-shielding member 250A is positioned between the reflective surface 233A of the first mirror 230A and the first lens 240A, and a second state in which the first light-shielding member 250A is positioned offset between the reflective surface 233A of the first mirror 230A and the first lens 240A. The first drive unit 260A has an actuator such as a solenoid or a motor. The first drive unit 260A is fixed to the first mirror 230A. The first light-shielding member 250A is connected to the first drive unit 260A and rotates about a rotation axis extending in the second direction X via the first drive unit 260A.

[0176] The second drive unit 260B switches between a first state in which the second light-shielding member 250B is positioned between the reflective surface 233B of the second mirror 230B and the second lens 240B, and a second state in which the second light-shielding member 250B is positioned at an offset position between the reflective surface 233B of the second mirror 230B and the second lens 240B. The second drive unit 260B has an actuator such as a solenoid or a motor. The second drive unit 260B is fixed to the second mirror 230B. The second light-shielding member 250B is connected to the second drive unit 260B and rotates about a rotation axis extending in the second direction X via the second drive unit 260B.

[0177] The lighting device 200 may also include a control unit that controls the first light source 220A, the second light source 220B, the first drive unit 260A, and the second drive unit 260B.

[0178] Next, the operation of the lighting device 200 of this embodiment will be described.

[0179] When the lighting device 200 is applied to the headlights of vehicles such as motor vehicles, and it is desired to emit low beam from the lighting device 200, the control unit illuminates the first light source 220A and the second light source 220B, and controls the first drive unit 260A and the second drive unit 260B to switch the first unit UA and the second unit UB to a first state. This forms a low beam cutoff line in the illumination area of ​​the light emitted from the lighting device 200. Furthermore, the light emitted from the first unit UA and the light emitted from the second unit UB overlap at this time, thereby increasing the maximum illuminance of the light emitted from the lighting device 200 in the illumination area. In particular, light can be emitted from the first unit UA to an area extending in the first direction Z and the third direction Y. Additionally, since the light emitted from the second unit UB is primarily parallel light, the maximum illuminance of the light emitted from the lighting device 200 in the illumination area can be further increased.

[0180] Furthermore, when it is desired to emit high beams from the lighting device 200, the control unit illuminates the first light source 220A and the second light source 220B, and controls the first drive unit 260A and the second drive unit 260B to switch the first unit UA and the second unit UB to a second state. At this time, the light emitted from the first unit UA overlaps with the light emitted from the second unit UB, thereby increasing the maximum illuminance of the light emitted from the lighting device 200 in the illuminated area.

[0181] It should be noted that when the lighting device is used in a headlight specifically for low beams, the lighting device may not have the first drive unit and the second drive unit, making the first and second light-shielding components immovable. Furthermore, when the lighting device is used in a headlight specifically for high beams, the lighting device may not have the first light-shielding component, the second light-shielding component, the first drive unit, and the second drive unit. Additionally, the lighting device may not have either the first unit or the second unit. Furthermore, the lighting device may have three or more units.

[0182] Next, the effects of this embodiment will be explained.

[0183] The lighting device 200 of this embodiment includes: a first light source 220A having a light-emitting surface 120a; a first reflector 230A having a reflective surface 233A for reflecting light emitted from the first light source 220A; and a first lens 240A into which light reflected by the reflective surface 233A enters. The reflective surface 233A has a shape that combines portions B11 to B14, Bi1 to Bi4, and Bn1 to Bn4 of the outer periphery of a plurality of ellipses. The first focal point F1A of each of the plurality of ellipses is located on the light-emitting surface 120a. The second focal point F2A of each of the plurality of ellipses is located between the reflective surface 233A and the first lens 240A. The major axis (axis B) of the first ellipse among the plurality of ellipses, which has the smallest distance between the first focal point F1A and the second focal point F2A, intersects the reflective surface 233A. The value obtained by dividing the first distance D1A between the first focal point F1A and the second focal point F2A of the first ellipse by the second distance D2A of the intersection point F0A of the first focal point F1A of the first ellipse with the reflective surface 233A and the major axis (axis B) is 7 or more. In the first direction Z extending from the normal N of the center C of the light-emitting surface 120a, the maximum size of the first lens 240A is less than 20 mm. Therefore, without changing the amount of light incident on the first lens 240A, a first lens 240A with a small size in the first direction Z can be achieved.

[0184] Similarly, the lighting device 200 of this embodiment includes: a second light source 220B having a light-emitting surface 120a, a second reflector 230B having a reflective surface 233B that reflects light emitted from the second light source 220B, and a second lens 240B into which light reflected by the reflective surface 233B enters. The reflective surface 233B has a shape that combines a portion of the outer periphery of a plurality of ellipses E1, Ek, and Em. The first focal point F1B of each of the plurality of ellipses is located on the light-emitting surface 120a. The second focal point F2B of each of the plurality of ellipses is located between the reflective surface 233B and the second lens 240B. The major axis (axis E) of the first ellipse among the plurality of ellipses, where the distance between the first focal point F1B and the second focal point F2B is the smallest, intersects the reflective surface 233B. The value obtained by dividing the first distance D1B between the first focal point F1B and the second focal point F2B of the first ellipse by the second distance D2B of the intersection point F0B of the first focal point F1B of the first ellipse with the reflective surface 233B and the major axis (axis E) is 7 or more. In the first direction Z extending from the normal N of the center C of the light-emitting surface 120a, the maximum size of the second lens 240B is less than 20 mm. Therefore, without changing the amount of light incident on the second lens 240B, a second lens 240B with a small size in the first direction Z can be achieved.

[0185] Accordingly, for example, when the lighting device 200 is applied to vehicle lamps such as headlights, by reducing the size of the first direction Z of the first lens 240A and the second lens 240B, the design freedom can be increased, and the creativity and / or functionality of the vehicle can be improved.

[0186] <Example>

[0187] Next, the embodiments and reference examples will be described.

[0188] As shown in Table 1 below, the required size of the lens in the first direction Z and the illuminance of the luminaire were investigated in the lighting devices of the first to fourth reference examples and the lighting devices of the first and second embodiments.

[0189] It should be noted that luminous flux (lm) can be measured, for example, using an integrating sphere according to CIE 127. Additionally, luminous intensity (lx) can be measured using a lux meter (e.g., the Konica Minolta T-10A lux meter manufactured in Japan).

[0190] [Table 1]

[0191]

[0192]

[0193] The lighting devices in the first to fourth reference examples and the first and second embodiments are respectively provided with a light source, a reflector, and a lens.

[0194] In each of the first, second, and third reference examples, the light source has an LED as the light-emitting element, and a brightness of 100 cd / mm² is used. 2 A light source with a second dimension X of emitting surface of 1.0 mm, a third dimension Y of emitting surface of 3.5 mm, and a luminous flux of 1230 lm.

[0195] The mirrors in the first, second, and third reference examples use mirrors of the same shape as the second mirror 230B in the second embodiment. However, in the mirrors of the first, second, and third reference examples, mirrors with different first distances D1B are used. Specifically, the first distance D1B in the first reference example is 15 mm. The first distance D1B in the second reference example is 21 mm. The first distance D1B in the third reference example is 27 mm. The second distance D2B in the first, second, and third reference examples is 3 mm. Therefore, in the first reference example, D1B / D2B = 5. In the second reference example, D1B / D2B = 7. In the third reference example, D1B / D2B = 9.

[0196] In the light sources of the fourth reference example, the first embodiment, and the second embodiment, an LD (Light Emitting Diode) is used as the light-emitting element, and a brightness of 700 cd / mm² is employed. 2The light source has a second dimension X of 0.5 mm, a third dimension Y of 1.0 mm, and a luminous flux of 1360 lm. That is, in the light sources of the fourth reference example, the first embodiment, and the second embodiment, a light source with a luminous flux approximately the same as that of the light sources in the first reference example, the second reference example, and the third reference example, but with a smaller luminous surface size and higher brightness is used.

[0197] In the first to fourth reference examples, the first embodiment, and the second embodiment, the distance between the incident surface of the lens and the second focal point of the first ellipse of the reflector in the second direction X is 20 mm.

[0198] The mirrors in the fourth reference example, the first embodiment, and the second embodiment use mirrors with the same shape as the second mirror 230B in the second embodiment. However, in the mirrors of the fourth reference example, the first embodiment, and the second embodiment, mirrors with different first distances D1B are used. Specifically, the first distance D1B in the fourth reference example is 15 mm. The first distance D1B in the first embodiment is 21 mm. The first distance D1B in the second embodiment is 27 mm. The second distance D2B in the fourth reference example, the first embodiment, and the second embodiment is 3 mm. Therefore, in the fourth reference example, D1B / D2B = 5. In the first embodiment, D1B / D2B = 7. In the second embodiment, D1B / D2B = 9.

[0199] In each of the lighting devices constructed as described above, the required size of the lens in the first direction Z was investigated. The results are shown in the table above. Specifically, in the first reference example, the required size of the lens in the first direction Z is 70 mm. In the second reference example, the required size of the lens in the first direction Z is 60 mm. In the third reference example, the required size of the lens in the first direction Z is 50 mm. In the fourth reference example, the required size of the lens in the first direction Z is 30 mm. In the first embodiment, the required size of the lens in the first direction Z is 20 mm. In the second embodiment, the required size of the lens in the first direction Z is 10 mm.

[0200] Thus, it is known that by increasing D1B / D2B, the required size of the lens in the first direction Z tends to decrease. In particular, in the first and second embodiments where the value of D1B / D2B is 7 or higher, the required size of any lens in the first direction Z can be made less than 20 mm. That is, extremely thin lenses can be realized in the field of headlights for vehicles such as motor vehicles.

[0201] On the other hand, in the first to third reference examples, the required size of the first direction Z of any lens exceeds 20 mm. This is because the size of the second direction X of the light-emitting surface used in the first to third reference examples is larger than the size of the second direction X of the light-emitting surface used in the first and second embodiments, which correspondingly increases the required size of the first direction Z of the lens.

[0202] Furthermore, in each lighting device constructed as described above, the maximum illuminance of the area illuminated by light on the screen was investigated when a screen was placed 25m in front of the lens of each lighting device. Here, the maximum illuminance of the area illuminated by light on the screen is referred to as "luminaire illuminance". As a result, the results shown in the table above were obtained. Specifically, the luminaire illuminance in the first reference example is 32 lx. The luminaire illuminance in the second reference example is 28 lx. The luminaire illuminance in the third reference example is 23 lx. In the headlights of motor vehicles, the required luminaire illuminance is approximately 130 lx. Therefore, it is known that in the lighting devices of the first to third reference examples, the required luminaire illuminance for headlights cannot be achieved by a single unit.

[0203] Furthermore, it is known that the larger the value of D1B / D2B, the lower the illuminance of the luminaire tends to be. This is because, as described in the first embodiment, the larger the value of D1B / D2B, the more the illumination area of ​​the light at the second focal point F2B expands, and correspondingly the lower the maximum illuminance.

[0204] In contrast, the brightness of the light source in the fourth reference example, the first embodiment, and the second embodiment is seven times the brightness of the light source in the first to third reference examples. Therefore, the illuminance of the luminaire in the fourth reference example is 165 lx. The illuminance of the luminaire in the first embodiment is 150 lx. The illuminance of the luminaire in the second embodiment is 120 lx. Although the illuminance of the luminaire in the second embodiment is less than 130 lx, as described in the lighting device 200 of the second embodiment, when the first unit UA is additionally provided, the illuminance of the luminaire as a whole can be 130 lx or more. In this case, the illuminance of the luminaire in the second embodiment is sufficiently higher than that of the first to third reference examples. Therefore, it is known that the number of units required in the second embodiment to achieve an illuminance of 130 lx or more is significantly less than the number of units required in the first to third reference examples to achieve an illuminance of 130 lx or more.

[0205] Thus, in the first and second embodiments, since a light source with a brightness higher than that of the light source in the first to third reference examples is used, it is known that even if the value of D1B / D2B is increased, a lighting device with, for example, the illuminance required for a headlight can be achieved with a smaller number of units.

[0206] Industrial applicability

[0207] This invention can be used, for example, in vehicle lighting such as headlights.

[0208] Explanation of reference numerals in the attached figures

[0209] 100, 200 Illumination device; 110 Substrate; 120 Light source; 120a Emitting surface; 130 Reflector; 131 Reflecting surface; 140 Lens; 141 Entrance surface; 142 Exit surface; 143 First flat surface; 144 Second flat surface; 210A First substrate; 210B Second substrate; 220A First light source; 220B Second light source; 230A First reflector; 230B Second reflector; 233A Reflecting surface; 233B Reflecting surface; 240A First lens; 240B Second lens; 250A First light-shielding component; 250B Second light-shielding component; 260A First driving unit; 260B Second driving unit; A Rotation Elliptical surface; A1 Major axis; B, E axes; B11~B14, Bi1~Bi4, Bn1~Bn4 Part of the outer periphery of the ellipse; C Center of the luminous surface; D1, D1A, D1B First distance; D2, D2A, D2B Second distance; E1, Ek, Em Part of the outer periphery of the ellipse; F0, F0A, F0B Intersection point; F1, F1A, F1B First focus; F2, F2A, F2B Second focus; G1 Maximum dimension of the luminous surface in the second direction; G2 Maximum dimension of the lens in the first direction; PA, PB planes; UA First unit; UB Second unit; X Second direction; Y Third direction; Z First direction; θ angle.

Claims

1. A lighting device, characterized in that, have: A light source, which has a light-emitting surface; A reflector having a reflective surface that reflects light emitted from the light source; A lens into which light is reflected by the reflecting surface; The reflecting surface is formed by a portion of a rotating elliptical surface with a first focal point located on the emitting surface and a second focal point located between the reflecting surface and the lens. The reflecting surface intersects the major axis of the rotating elliptical surface. The value obtained by dividing the first distance between the first focal point and the second focal point by the second distance between the first focal point and the intersection of the reflecting surface and the major axis is 7 or greater. In a first direction extending from the normal to the center of the light-emitting surface, the maximum size of the lens is less than 20 mm.

2. A lighting device, characterized in that, have: A light source, which has a light-emitting surface; A reflector having a reflective surface that reflects light emitted from the light source; A lens into which light is reflected by the reflecting surface; The reflective surface has a shape that combines a portion of the outer periphery of multiple ellipses. The first focus of each of the plurality of ellipses is located on the light-emitting surface. The second focus of each of the plurality of ellipses is located between the reflecting surface and the lens. The major axis of the first ellipse, which has the smallest distance between its first and second foci among the plurality of ellipses, intersects the reflecting surface. The value obtained by dividing the first distance between the first focus and the second focus of the first ellipse by the second distance between the first focus of the first ellipse and the intersection of the reflecting surface and the major axis is 7 or greater. In a first direction extending from the normal to the center of the light-emitting surface, the maximum size of the lens is less than 20 mm.

3. The lighting device as described in claim 1 or 2, characterized in that, The maximum size of the light-emitting surface in the second direction extending from the long axis is 0.2 mm or more and 1.0 mm or less.

4. The lighting device as described in any one of claims 1 to 3, characterized in that, The brightness of the light source is 300 cd / mm². 2 Above, 2500cd / mm 2 the following.

5. The lighting device as described in any one of claims 1 to 4, characterized in that, The lens has: The incident surface receives light reflected from the reflecting surface. An exiting surface, located on the opposite side of the incident surface, emits light that has entered from the incident surface; A first flat surface is located between the injection surface and the injection surface; The second flat surface is located on the opposite side of the first flat surface in the first direction and is located between the injection surface and the injection surface.

6. The lighting device as described in any one of claims 1 to 5, characterized in that, In the first direction, the maximum size of the lens is 3.0 mm or more.

7. The lighting device as described in any one of claims 1 to 6, characterized in that, The light source has a laser element.

8. The lighting device as described in any one of claims 1 to 7, characterized in that, The lighting device is a vehicle lamp.

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