Vehicle headlights

Abstract

To provide a light emitting device capable of forming luminance distribution while reducing design burden and cost, and a vehicle headlamp.SOLUTION: A light emitting device comprises: a light source having a light emission surface that emits light of a first wavelength; and a wavelength conversion unit that covers the entire light emission surface of the light source and is arranged in a range that extends beyond the light emission surface, transmits part of light from the light source, converts another part of the light from the light source into light of a second wavelength, and emits the light of the first wavelength and the light of the second wavelength as combined light.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a light emitting device and a vehicle headlamp. [Background technology]

[0002] A light emitting device equipped with a plurality of light emitting elements is known as a light emitting device mounted on a vehicle (for example, Patent Document 1). Patent Document 1 describes a configuration in which the luminance of each light emitting element is made different to form a luminance distribution of light emitted from the light emitting device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-3832 Summary of the Invention [Problem to be solved by the invention]

[0004] The configuration described in Patent Document 1 requires a plurality of light-emitting elements, and the luminance of each of the plurality of light-emitting elements must be set, which increases the burden in terms of design and cost.

[0005] The present invention has been made in view of the above, and has an object to provide a light-emitting device and a vehicle headlamp that are capable of forming a luminance distribution while reducing the design burden and cost. [Means for solving the problem]

[0006] The light emitting device of the present invention comprises a light source having a light emitting surface that emits light of a first wavelength, and a wavelength conversion unit that covers the entire light emitting surface of the light source and is arranged in an area extending beyond the light emitting surface, transmits a portion of the light from the light source, converts another portion of the light from the light source to light of a second wavelength, and emits the light of the first wavelength and the light of the second wavelength as combined light.

[0007] The light emitting device may further include a light guiding section disposed between the light emitting surface and the wavelength converting section, for guiding light from the light source to the wavelength converting section.

[0008] In the light emitting device, the light guiding section may be provided in a range that overlaps the entire wavelength converting section when viewed from a normal direction of the light emitting surface.

[0009] In the above-mentioned light-emitting device, the wavelength conversion unit may have a first portion that overlaps the light-emitting surface of the light source when viewed from the normal direction of the light-emitting surface, a second portion that extends beyond the light-emitting surface when viewed from the normal direction of the light-emitting surface, and a light-shielding portion that is disposed between the first portion and the second portion and blocks light traveling inside the wavelength conversion unit.

[0010] In the light emitting device, the light blocking portion may have a reflective surface that reflects light traveling inside the wavelength converting portion.

[0011] The light emitting device may further include a light leakage suppression unit that surrounds the sides of the light source and the wavelength conversion unit.

[0012] In the light emitting device, a plurality of the light sources may be provided, and the wavelength converting section may be provided across the plurality of light sources.

[0013] The vehicle headlamp according to the present invention comprises the above-described light-emitting device, a support member that supports the light-emitting device, and a projection optical system that includes at least one of a lens and a reflector that irradiates the light emitted from the light-emitting device ahead of the vehicle to form a pattern.

[0014] In the above-mentioned vehicle headlamp, the pattern may have a cutoff line, and light emitted from an edge of a region of the wavelength conversion portion of the light emitting device that overlaps with the light emitting surface may correspond to a part of the cutoff line.

[0015] The above-described vehicle headlamp may further include a shade disposed between the light emitting device and the lens, the shade blocking a portion of the light emitted from the light emitting device.

[0016] In the above-mentioned vehicle headlamp, a plurality of the light-emitting devices may be provided, and the plurality of light-emitting devices may include a light-collecting light-emitting device that forms a light-collecting pattern that is a part of the pattern, and a light-diffusing light-emitting device that forms a diffusion pattern around the light-collecting pattern. [Effects of the Invention]

[0017] According to the present invention, it is possible to provide a light emitting device and a vehicle headlamp that are capable of forming a luminance distribution while reducing the design burden and cost. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a diagram showing an example of a vehicle headlamp according to this embodiment. [Figure 2] FIG. 2 is a cross-sectional view showing an example of a light emitting device. [Figure 3] FIG. 3 is a diagram showing an example of the positional relationship between the light source, the light guide, and the wavelength conversion unit. [Figure 4] FIG. 4 is a diagram showing the light emitting state of the wavelength converting section when viewed from the normal direction of the light emitting surface. [Figure 5] FIG. 5 is a diagram showing an example of a light distribution pattern projected onto a virtual screen in front of a vehicle. [Figure 6] FIG. 6 is a diagram showing an example of a light distribution pattern projected onto a virtual screen in front of a vehicle. [Figure 7] FIG. 7 is a diagram showing the positional relationship between a light source, a light guide, and a wavelength conversion unit in a light emitting device according to a modified example. [Figure 8] FIG. 8 is a diagram schematically showing the configuration of a vehicle headlamp according to a modified example. [Figure 9] FIG. 9 is a diagram for explaining a vehicle headlamp according to a modified example. [Figure 10]FIG. 10 is a diagram for explaining a vehicle headlamp according to a modified example. [Figure 11] FIG. 11 is a diagram showing an example of a light emitting device according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. However, the present invention is not limited to the embodiment. Furthermore, the components in the following embodiment include those that are easily replaceable by a person skilled in the art, or those that are substantially the same. In the following description, the front-rear, up-down, and left-right directions refer to directions when the vehicle headlamp is attached to the vehicle, and are viewed from the driver's seat in the direction of travel of the vehicle. In this embodiment, the up-down direction is parallel to the vertical direction, and the left-right direction is horizontal.

[0020] FIG. 1 is a diagram showing an example of a vehicle headlamp 100 according to this embodiment. The vehicle headlamp 100 shown in FIG. 1 is housed in a lamp chamber formed by a lamp housing and a lamp lens (not shown). In addition to the lamp unit described above, other components such as a clearance lamp unit, a turn signal lamp unit, and a daytime running lamp unit may be disposed in the lamp chamber. An inner panel (not shown), an inner housing (not shown), an inner lens (not shown), and the like may also be disposed in the lamp chamber.

[0021] The vehicle headlamp 100 includes a light-emitting device 10, a lens (projection optical system) 20, a support member 30, and a shade 40. The vehicle headlamp 100 irradiates light emitted from the light-emitting device 10 through the lens 20 toward the front of the vehicle, forming a light distribution pattern P in front of the vehicle. In this embodiment, the light distribution pattern P is, for example, a low beam pattern. The vehicle headlamp 100 may also have another projection optical system, such as a reflector (not shown). The vehicle headlamp 100 may also be configured to have a reflector as the projection optical system instead of a lens.

[0022] The light emitting device 10 emits white light. The lens 20 has an incident surface 21 and an exit surface 22. Light from the light emitting device 10 enters the lens 20 through the incident surface 21, and the lens 20 emits the light from the exit surface 22. The support member 30 supports the light emitting device 10. The support member 30 has a base 31 and fins 32. The light emitting device 10 is fixed to the base 31. The fins 32 dissipate heat generated by the light emitting device 10. The shade 40 is disposed between the light emitting device 10 and the lens 20. The shade 40 blocks a portion of the light traveling from the light emitting device 10 toward the lens 20.

[0023] Fig. 2 is a cross-sectional view showing an example of a light emitting device 10. Fig. 2(A) shows the entire light emitting device 10, and Fig. 2(B) is an enlarged view of a main part of Fig. 2(A). As shown in Figs. 2(A) and 2(B), the light emitting device 10 includes a substrate 11, a light source 12, a light guiding section 13, a wavelength converting section 14, a light leakage suppressing section 15, and a light blocking section 16.

[0024] The substrate 11 is supported by a support member 30. On the substrate 11, wiring, circuits, etc. connected to the light source 12 are formed.

[0025] The light source 12 is mounted on the substrate 11. For example, a semiconductor light source such as an LED (Light Emitting Diode) is used as the light source 12. The light source 12 has a light-emitting surface 12a. The light-emitting surface 12a emits light having a wavelength corresponding to blue light as the first wavelength. The light-emitting surface 12a is directed, for example, toward the front of the vehicle. In this embodiment, for example, one light source 12 is provided. When there is one light source 12, the manufacturing cost of the light-emitting device 10 and the design burden of the substrate 11 can be reduced. The light source 12 is electrically connected to a terminal (not shown) of the substrate 11 via a terminal 12b, etc.

[0026] The light guiding unit 13 is disposed between the light emitting surface 12a of the light source 12 and the wavelength conversion unit 14. The light guiding unit 13 is disposed in contact with the light emitting surface 12a and the wavelength conversion unit 14. The light guiding unit 13 may be disposed such that a light-transmitting adhesive is sandwiched between the light emitting surface 12a and the wavelength conversion unit 14. The light guiding unit 13 guides light from the light source 12 to the wavelength conversion unit 14. The light guiding unit 13 is, for example, rectangular and plate-shaped. The light guiding unit 13 is formed using a colorless and transparent material that can transmit light, such as glass, a resin material, or the like.

[0027] When viewed from the normal direction R of the light-emitting surface 12a, the light-guiding section 13 is disposed at a position overlapping the entire wavelength conversion section 14. Note that the light-guiding section 13 may be disposed so as to overlap the entire first portion 14a and part of the second portion 14b (described later) of the wavelength conversion section 14 when viewed from the normal direction R. The light-guiding section 13 may be in the form of a film, for example. In this case, the light-guiding section 13 may be configured as a film formed on the surface of the wavelength conversion section 14 facing the light source 12.

[0028] The wavelength conversion unit 14 transmits a portion of the blue light from the light source and converts a portion of the blue light from the light source into yellow light of a second wavelength. The wavelength conversion unit 14 emits white light that is a combination of the blue light that transmits through the wavelength conversion unit 14 and the yellow light converted by the wavelength conversion unit 14. The wavelength conversion unit 14 is, for example, a rectangular, plate-shaped phosphor, and is disposed in an area that covers the entire light-emitting surface 12a of the light source 12 and extends beyond the light-emitting surface 12a. The wavelength conversion unit 14 has a first portion 14a that overlaps the light-emitting surface 12a when viewed from the normal direction of the light-emitting surface 12a, and a second portion 14b outside the first portion 14a.

[0029] The light leakage suppression section 15 is arranged to surround the sides of the light source 12, the light guide section 13, and the wavelength conversion section 14. The light leakage suppression section 15 is formed using a material such as a resin that can block light. The light leakage suppression section 15 suppresses light from leaking from the sides of the light source 12, the light guide section 13, and the wavelength conversion section 14. The light leakage suppression section 15 may be configured by mixing light-reflecting particles such as titanium oxide into a resin.

[0030] The light-shielding portion 16 is provided along the boundary between the first portion 14a and the second portion 14b. The light-shielding portion 16 blocks light traveling inside the wavelength conversion unit 14. That is, the light-shielding portion 16 blocks light traveling inside the first portion 14a from entering the second portion 14b. The light-shielding portion 16 also blocks light traveling inside the second portion 14b from entering the first portion 14a. The provision of the light-shielding portion 16 suppresses the entry and exit of light between the first portion 14a and the second portion 14b, thereby enabling a clear difference in luminance between the first portion 14a and the second portion 14b. Furthermore, for example, if light incident on the first portion 14a enters the second portion 14b, the light travels a longer distance through the wavelength conversion unit 14, causing the chromaticity of the light to shift toward yellow. The provision of the light-shielding portion 16 prevents the chromaticity of the light from shifting toward yellow.

[0031] The light-shielding unit 16 is formed in a film shape using a metal such as aluminum. The light-shielding unit 16 has reflective surfaces 16a and 16b. The reflective surface 16a is formed on the first portion 14a side. The reflective surface 16a formed on the first portion 14a side reflects light that reaches the reflective surface 16a from inside the first portion 14a toward the first portion 14a side. The reflective surface 16b is formed on the second portion 14b side. The reflective surface 16b formed on the second portion 14b side reflects light that reaches the reflective surface 16b from inside the second portion 14b toward the second portion 14b side. The reflective surfaces 16a and 16b can suppress attenuation of light traveling inside the wavelength conversion unit 14. The light-shielding unit 16 may be configured without the reflective surfaces 16a and 16b.

[0032] For example, the wavelength conversion section 14 can be formed into a plate shape with different members for the first portion 14a and the second portion 14b, and a metal film such as aluminum can be vapor-deposited on the side surface of the first portion 14a and the side surface of the second portion 14b, and then the first portion 14a and the second portion 14b can be joined together, thereby easily forming the wavelength conversion section 14 having the light-shielding portion 16.

[0033] 2(B), of the blue light emitted from light-emitting surface 12a of light source 12, for example, a component along the normal direction of light-emitting surface 12a (hereinafter referred to as light L1) passes through light-guiding section 13 and enters first portion 14a of wavelength conversion section 14. Furthermore, of the blue light emitted from light-emitting surface 12a of light source 12, for example, a part of a component emitted in a direction oblique to the normal direction of light-emitting surface 12a (hereinafter referred to as light L2) is guided laterally by light-guiding section 13 and enters second portion 14b of wavelength conversion section 14.

[0034] A portion of the light L1 incident on the first portion 14a of the wavelength converting unit 14 is transmitted through the first portion 14a, and another portion is converted into yellow light by the first portion 14a. The light L1 is output as combined light L3, consisting of blue light L1B transmitted through the first portion 14a and yellow light L1Y converted by the first portion 14a. The light L2 incident on the second portion 14b of the wavelength converting unit 14 is output as combined light L4, consisting of blue light L2B transmitted through the second portion 14b and yellow light L2Y converted by the second portion 14b.

[0035] More light is incident on the first portion 14a of the wavelength converter 14 than on the second portion 14b. Therefore, the combined light L3 has a greater amount of light than the combined light L4. When the wavelength converter 14 emitting the combined light L3 and L4 is viewed from the normal direction of the light-emitting surface 12a, a luminance distribution is formed. In other words, a luminance distribution is formed in which the luminance decreases from the first portion 14a side to the second portion 14b side.

[0036] Fig. 3 is a diagram showing an example of the positional relationship between the light source 12, the light guide 13, and the wavelength converter 14. Figs. 3(A) to 3(D) show the positional relationship when the light emitting device 10 is viewed from the normal direction of the light emitting surface 12a. Fig. 4 is a diagram showing the light emitting state of the wavelength converter 14 when viewed from the normal direction of the light emitting surface 12a. Figs. 4(A) to 4(D) show the light emitting state of the wavelength converter 14 when viewed from the normal direction of the light emitting surface 12a for each of the configurations shown in Figs. 3(A) to 3(D).

[0037] 3(A), in plan view, for example, the light source 12 can be disposed at the corners of the light-guiding section 13 and the wavelength converting section 14. That is, the wavelength converting section 14 has a rectangular first portion 14a that includes the upper left corner in plan view and a part of the left side and a part of the top side. The wavelength converting section 14 also has an L-shaped second portion 14b along the right side and the bottom side.

[0038] In the configuration shown in Fig. 3(A), when light is emitted from the wavelength conversion unit 14, a luminance distribution is formed in which the luminance decreases from the first portion 14a side to the second portion 14b side. That is, as shown in Fig. 4(A), a luminance distribution is formed in which the luminance gradually decreases from the upper left side to the right and lower side. Note that, in the example shown in Fig. 3(A), the light source 12 is disposed in the upper left corner of the wavelength conversion unit 14, but this is not limiting, and the light source 12 may also be disposed in the upper right, lower left, or lower right corner of the wavelength conversion unit 14.

[0039] 3(B), for example, the light source 12 can be disposed in the center of the light-guiding section 13 and the wavelength converting section 14 in a planar view. That is, the wavelength converting section 14 has a rectangular first section 14a in the center in a planar view. The wavelength converting section 14 also has second sections 14b along the four sides around the first section 14a.

[0040] In the configuration shown in Fig. 3(B), when light is emitted from the wavelength conversion unit 14, a luminance distribution is formed in which the luminance decreases from the first portion 14a to the second portion 14b. That is, as shown in Fig. 4(B), a luminance distribution is formed in which the luminance gradually decreases from the central portion to the peripheral portion.

[0041] 3(C), for example, the light source 12 can be arranged closer to one side in the vertical or horizontal direction of the light guiding section 13 and the wavelength converting section 14 in plan view. In the example shown in FIG. 3(C), the light source 12 is arranged closer to the left side of the light guiding section 13 and the wavelength converting section 14. The region of the wavelength converting section 14 that includes the left side in plan view is the first portion 14a. The region of the wavelength converting section 14 that includes the right side in plan view is the second portion 14b.

[0042] In the configuration shown in Fig. 3(C), when light is emitted from the wavelength conversion unit 14, a luminance distribution is formed in which the luminance decreases from the first portion 14a to the second portion 14b. That is, as shown in Fig. 4(C), a luminance distribution is formed in which the luminance gradually decreases from the left side to the right side.

[0043] 3(D), in plan view, for example, the light source 12 can be disposed closer to one side of the light guiding section 13 and the wavelength converting section 14 in the vertical direction and positioned in the center with both sides left and right. In the example shown in FIG. 3(D), the light source 12 is disposed closer to the upper sides of the light guiding section 13 and the wavelength converting section 14. The center of the upper side of the wavelength converting section 14 in plan view is the first portion 14a. Furthermore, the region of the wavelength converting section 14 including the left side, right side, and lower side in plan view is the second portion 14b.

[0044] In the configuration shown in Fig. 3(D), when light is emitted from the wavelength conversion unit 14, a luminance distribution is formed in which the luminance decreases from the first portion 14a side to the second portion 14b side. That is, as shown in Fig. 4(D), a luminance distribution is formed in which the luminance gradually decreases from the center of the upper side to the left side, right side, and lower side.

[0045] The light emitted from the light emitting device 10 is partially blocked by the shade 40 and is irradiated ahead of the vehicle by the lens 20. In this case, a low beam pattern is formed as a light distribution pattern P ahead of the vehicle.

[0046] Figures 5 and 6 are diagrams showing an example of a light distribution pattern projected onto a virtual screen in front of a vehicle. Figures 5 and 6 show a light distribution pattern corresponding to a vehicle driving on the left side of the road. In Figures 5 and 6, lines VV indicate vertical lines on the screen, and lines HH indicate horizontal lines on the left and right sides of the screen.

[0047] FIG. 5 shows an example of a light distribution pattern when a light emitting device 10 having the configuration shown in FIG. 3(D) is used. A light distribution pattern P1a shown in the upper part of FIG. 5 is formed from a light emitting device 10 having the configuration shown in FIG. 3(D). By removing a predetermined portion 40a of this light distribution pattern P1a using a shade 40 or the like, a light distribution pattern P1 shown in the lower part of FIG. 5 is formed. In the light distribution pattern P1, a cutoff line CL is formed along a horizontal line HH. The cutoff line CL has horizontal cutoff lines CLa and CLb and an oblique cutoff line CLc. The luminance of the light distribution pattern P1 decreases downward from the cutoff line CL, and decreases toward both the left and right of the vertical line VV.

[0048] Figure 6 shows an example of a light emitting device 10 having the configuration shown in Figure 3(C) when the left side is positioned upward. The light emitting device 10 having the configuration shown in Figure 3(C) forms a light distribution pattern P2a shown in the upper part of Figure 6. By removing a predetermined portion 40b of this light distribution pattern P2a using a shade 40 or the like, a light distribution pattern P2 shown in the lower part of Figure 6 is formed.

[0049] In the light distribution pattern P2, a cutoff line CL is formed along the horizontal line HH. The cutoff line CL has horizontal cutoff lines CLa and CLb and an oblique cutoff line CLc. In the light distribution pattern P2, the luminance decreases downward from the cutoff line CL. In the light distribution pattern P2, light emitted from the edge of the region of the wavelength conversion unit 14 of the light emitting device 10 that overlaps with the light emitting surface 12a corresponds to part of the cutoff line CL. With this configuration, the cutoff line CL can be formed efficiently.

[0050] As described above, the light emitting device 10 of this embodiment includes a light source 12 having a light emitting surface 12a that emits light of a first wavelength, and a wavelength conversion unit 14 that covers the entire light emitting surface 12a of the light source 12 and is positioned in an area extending beyond the light emitting surface 12a, transmits a portion of the light from the light source 12, converts another portion of the light from the light source 12 to light of a second wavelength, and emits the light of the first wavelength and the light of the second wavelength as combined light.

[0051] According to this configuration, by disposing a portion of the wavelength conversion unit 14 so that it extends beyond the light-emitting surface 12a, when the combined light is emitted from the wavelength conversion unit 14, a luminance distribution can be formed between the portion covering the light-emitting surface 12a and the portion extending beyond the light-emitting surface 12a. Therefore, the luminance distribution can be formed without changing the configuration of the light source 12 itself. This makes it possible to provide a light-emitting device 10 that can form a luminance distribution while reducing the design burden and cost.

[0052] The light emitting device 10 according to this embodiment further includes a light guiding section 13 that is disposed between the light emitting surface 12a and the wavelength converting section 14 and that guides light from the light source 12 to the wavelength converting section 14. This configuration allows the light emitted from the light emitting surface 12a to be efficiently incident on the wavelength converting section 14.

[0053] In the light emitting device 10 according to this embodiment, the light guiding section 13 is provided in a range that overlaps the entire wavelength converting section 14 when viewed from the normal direction of the light emitting surface 12a. This configuration allows the light emitted from the light emitting surface 12a to be efficiently incident on the entire wavelength converting section 14, including both the portion of the wavelength converting section 14 that covers the light emitting surface 12a (first portion 14a) and the portion of the wavelength converting section 14 that extends beyond the light emitting surface 12a (second portion 14b).

[0054] In the light-emitting device 10 according to this embodiment, the wavelength conversion unit 14 includes a light-shielding portion 16 between a first portion 14a corresponding to the light-emitting surface 12a and a second portion 14b outside the first portion 14a, which blocks light traveling through the wavelength conversion unit 14. For example, when light incident on the first portion 14a enters the second portion 14b, the distance it travels through the wavelength conversion unit 14 increases, resulting in a greater proportion of the light being converted to yellow. This results in a stronger yellow color in the light emitted from the second portion 14b. This configuration prevents light from entering the second portion 14b from the first portion 14a, thereby preventing strong yellow light from being emitted from the second portion 14b.

[0055] In the light-emitting device 10 according to this embodiment, the light-shielding portion 16 has reflective surfaces 16a and 16b that reflect light. With this configuration, light absorption in the light-shielding portion 16 can be suppressed by reflecting light at the reflective surfaces 16a and 16b, and therefore a decrease in light utilization efficiency can be suppressed.

[0056] The light emitting device 10 according to this embodiment further includes a light leakage suppression section 15 arranged to surround the sides of the light source 12 and the wavelength conversion section 14. This configuration can suppress light leakage from the sides of the light source 12 and the wavelength conversion section 14.

[0057] The vehicle headlamp 100 according to this embodiment includes the above-described light-emitting device 10, a support member 30 that supports the light-emitting device 10, and a lens 20 that irradiates light emitted from the light-emitting device 10 to form a light distribution pattern P ahead of the vehicle. With this configuration, the light-emitting device 10 is provided that can form a luminance distribution while reducing the design burden and cost, and therefore a brightness distribution can be formed in the light distribution pattern P without using a configuration in which multiple light sources are provided and the luminance is set for each light source. This makes it possible to provide a vehicle headlamp 100 that can reduce the design burden and cost.

[0058] In the vehicle headlamp 100 according to this embodiment, the light distribution pattern P has a cutoff line CL, and part of the cutoff line CL corresponds to light emitted from an edge of a region of the wavelength conversion unit 14 of the light emitting device 10 that overlaps with the light emitting surface 12a. With this configuration, the cutoff line CL can be formed efficiently.

[0059] The vehicle headlamp 100 according to this embodiment further includes a shade 40 that is disposed between the light emitting device 10 and the lens 20 and blocks a portion of the light emitted from the light emitting device 10. According to this configuration, the shade 40 can easily form the outer shape of the light distribution pattern P, such as the cutoff line CL.

[0060] The technical scope of the present invention is not limited to the above-described embodiment, and appropriate modifications can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, a configuration in which one light source 12 is provided is described as an example, but this is not limiting. A plurality of light sources 12 may be provided.

[0061] FIG. 7 is a diagram showing the positional relationship between the light source 12, the light guide 13, and the wavelength conversion unit 14 of a light-emitting device 10A according to a modified example. FIG. 7(A) shows the positional relationship when the light-emitting device 10 is viewed from the normal direction of the light-emitting surface 12a. FIG. 7(B) shows the light-emitting state of the wavelength conversion unit 14 when light (blue light) is emitted from the light-emitting surface 12a, as viewed from the normal direction of the light-emitting surface 12a. The light-emitting device 10A shown in FIGS. 7(A) and 7(B) is configured such that multiple light sources 12 are provided, and the light guide 13 and the wavelength conversion unit 14 are provided across the multiple light sources 12. With this configuration, the provision of multiple light sources 12 can increase the amount of light. Furthermore, because the wavelength conversion unit 14 is provided across the multiple light sources 12, manufacturing costs can be reduced compared to when a wavelength conversion unit 14 is provided separately for each light source 12.

[0062] In the above embodiment, a configuration in which one light-emitting device 10 is provided in one vehicle headlamp 100 has been described as an example, but the present invention is not limited to this. A configuration in which multiple light-emitting devices are provided in one vehicle headlamp 100 may also be used.

[0063] FIG. 8 is a diagram schematically illustrating the configuration of a vehicle headlamp 100B according to a modified example. FIG. 8(A) illustrates the positional relationship of light emitting devices 10B and 10C provided in the vehicle headlamp 100B when viewed from the normal direction of the light emitting surface 12a. As shown in FIG. 8(A), the vehicle headlamp 100B may be configured to include, for example, two light emitting devices 10B and 10C. The light emitting device 10B is configured such that the light source 12 is disposed in the upper right corner of the wavelength conversion unit 14. The light emitting device 10C is configured such that the light source 12 is disposed in the upper left corner of the wavelength conversion unit 14.

[0064] FIG. 8B is a diagram illustrating an example of a light distribution pattern projected from a vehicle headlamp 100B onto a virtual screen in front of the vehicle. As shown in FIG. 8B, a light distribution pattern P3a shown in the upper part of FIG. 8B is formed by combining light emitting devices 10B and 10C. A predetermined portion 40c of this light distribution pattern P3a is removed using a shade 40 or the like to form a light distribution pattern P3 shown in the lower part of FIG. 8B. The light distribution pattern P3 is a low beam pattern. A cutoff line CL is formed in the light distribution pattern P3 along the horizontal line HH by the shade 40. The luminance of the light distribution pattern P3 decreases downward from the cutoff line CL and decreases toward both sides of the vertical line VV in the left-right direction. In the light distribution pattern P3, light emitted from the edge (upper edge) of the region of the wavelength conversion unit 14 of the light emitting device 10B that overlaps with the light-emitting surface 12a corresponds to part of the cutoff line CL. The light distribution pattern P3 is formed using two light emitting devices 10B and 10C, and therefore the amount of light is greater than when it is formed using one light emitting device 10. Therefore, a bright light distribution pattern P3 can be obtained.

[0065] FIG. 9 is a diagram illustrating a vehicle headlamp 100C according to a modified example. FIG. 9(A) is a diagram schematically illustrating the configuration of a vehicle headlamp 100C according to a modified example. As shown in FIG. 9(A), the vehicle headlamp 100D has, for example, four light emitting devices 10D. In the light emitting devices 10D, for example, the light source 12 can be arranged closer to one side in the left-right direction of the light guiding section 13 and the wavelength converting section 14. In the example shown in FIG. 9, the light source 12 is arranged closer to the left side of the light guiding section 13 and the wavelength converting section 14.

[0066] 9(B) shows the light-emitting state of the wavelength conversion unit 14 of one light-emitting device 10D when viewed from the normal direction of the light-emitting surface 12a. As shown in FIG. 9(B), when the light-emitting device 10D emits light, a luminance distribution is formed such that the luminance gradually decreases from the left side to the right side.

[0067] 9(C) is a diagram showing an example of a light distribution pattern emitted from a vehicle headlamp 100C onto a virtual screen in front of the vehicle. As shown in FIG. 9(C), a vehicle headlamp 100D can form, for example, an ADB pattern as a light distribution pattern P4 using four light-emitting devices 10D. In the light distribution pattern P4, each individual pattern (hereinafter referred to as a unit pattern) Pu is formed so that its brightness decreases from the left side to the right side. The left side of the unit light distribution pattern Pu corresponds to the left side of the wavelength conversion unit 14.

[0068] In this way, by combining multiple light-emitting devices 10D, it is possible to form a light distribution pattern P4, which is an ADB pattern. By controlling the light emission timing of each light-emitting device 10D, it is possible to adjust the on / off state of each unit light distribution pattern Pu.

[0069] FIG. 10 is a diagram illustrating a vehicle headlamp 100E according to a modified example. FIG. 10(A) is a diagram schematically illustrating the configuration of the vehicle headlamp 100E according to the modified example. As shown in FIG. 10(A), the vehicle headlamp 100E includes, for example, a light-emitting device 10E for collecting light and a light-emitting device 10F for diffusing light. The light-emitting device 10E for collecting light can be, for example, a light-emitting device in which the luminance decreases from the center to the periphery of the wavelength conversion unit 14, such as the light-emitting device 10 shown in FIG. 3(B) above. The light-emitting device 10F for diffusing light can be, for example, a light-emitting device in which the luminance decreases from one side of the wavelength conversion unit 14 to the opposite side, such as the light-emitting device 10 shown in FIG. 3(C) above. Note that the light-emitting devices used as the light-emitting device 10E for collecting light and the light-emitting device 10F for diffusing light are not limited to those described above.

[0070] Fig. 10(B) is a diagram showing an example of a light distribution pattern emitted from a vehicle headlamp 100E onto a virtual screen in front of the vehicle. As shown in Fig. 10(B), the light distribution pattern P5 is a low beam pattern. A concentrated light distribution pattern PA, which is a part of the light distribution pattern P5, is formed by the concentrating light emitting device 10E. Furthermore, a diffused light distribution pattern PB, which is a part of the light distribution pattern P5, is formed by the diffusing light emitting device 10F. With this configuration, the light distribution pattern P5, which includes the concentrated light distribution pattern PA and the diffused light distribution pattern PB, can be formed with a sufficient amount of light.

[0071] Furthermore, in the above embodiment, the light emitting device is described with the light guide 13 provided as an example, but the present invention is not limited to this. The light guide 13 may not be provided. Fig. 11 is a diagram showing an example of a light emitting device 10G according to a modified example. The light emitting device 10G shown in Fig. 11 does not include a light guide, and the wavelength conversion unit 14 is disposed on the light emitting surface 12a of the light source 12, with a portion of the wavelength conversion unit 14 extending beyond the light emitting surface 12a.

[0072] With this configuration, light emitting device 10G is arranged so that a portion of wavelength converting unit 14 extends beyond light emitting surface 12a, and therefore a luminance distribution can be formed between the portion covering light emitting surface 12a and the portion extending beyond light emitting surface 12a when combined light is emitted from wavelength converting unit 14. Therefore, a luminance distribution can be formed without changing the configuration of light source 12 itself.

[0073] In the above embodiment, a configuration in which a light distribution pattern is formed by blocking part of the light from the light emitting device with the shade 40 has been described as an example, but the present invention is not limited to this. For example, a light blocking portion that blocks light may be disposed on the surfaces of the light source 12, the light guide portion 13, and the wavelength conversion portion 14. Furthermore, a non-light emitting portion may be formed on part of the light emitting surface 12a by designing current confinement inside the light source 12, the internal electrode arrangement, etc.

[0074] In the light-emitting device described in the above embodiment, for example, by increasing the thickness of light-guiding section 13, the amount of blue light reaching the portion extending beyond light-emitting surface 12a can be increased. In this case, the amount of blue light incident on second portion 14b of wavelength conversion section 14 increases, and the luminance of second portion 14b increases. Furthermore, by decreasing the thickness of light-guiding section 13, the amount of blue light reaching the portion extending beyond light-emitting surface 12a can be reduced. In this case, the amount of blue light incident on second portion 14b of wavelength conversion section 14 decreases, and the luminance of second portion 14b decreases. In this way, by adjusting the thickness of light-guiding section 13, the luminance distribution of combined light L3 and L4 emitted from wavelength conversion section 14 can be controlled.

[0075] In the light-emitting device described in the above embodiment, the positional relationship between the first portion 14a and the second portion 14b of the wavelength converting portion 14 can be adjusted by adjusting the arrangement of the light-shielding portion 16. This allows the luminance distribution in the wavelength converting portion 14 to be controlled. [Explanation of symbols]

[0076] CL...cutoff line, CLa, CLb...horizontal cutoff line, CLc...diagonal cutoff line, L1, L2...light, L1B, L2B...blue light, L1Y, L2Y...yellow light, L3, L4...combined light, P, P1, P2, P3, P4, P5, P1a, P2a, P3a...light distribution pattern, PA...concentrated light distribution pattern, PB...diffused light distribution pattern, Pu...unit light distribution pattern, R...normal direction, 10, 10A, 10B, 10C, 10D, 10G...light-emitting device, 10E...light-concentrating light-emitting device Optical device, 10F... diffusion light emitting device, 11... substrate, 12... light source, 12a... light emitting surface, 12b... terminal, 13... light guiding section, 14... wavelength conversion section, 14a... first section, 14b... second section, 15... light leakage suppression section, 16... light blocking section, 16a, 16b... reflective surface, 20... lens, 21... incident surface, 22... exit surface, 30... support member, 31... base, 32... fin, 40... shade, 40a, 40b, 40c... predetermined section, 100, 100B, 100C, 100D, 100E... vehicle headlamp

Claims

1. a light source having a light emitting surface that emits light of a first wavelength; a wavelength conversion unit that covers the entire light-emitting surface of the light source and is disposed in a range extending beyond the light-emitting surface, that transmits a part of the light from the light source and converts another part of the light from the light source into light with a second wavelength, and that emits light composed of the light with the first wavelength and the light with the second wavelength; a light emitting device having a support member for supporting the light emitting device; a projection optical system including at least one of a lens and a reflector that projects the light emitted from the light emitting device toward the front of the vehicle to form a pattern; Equipped with A plurality of the light emitting devices are provided, The plurality of light emitting devices include a light condensing light emitting device that forms a light condensing pattern that is a part of the pattern, and a light diffusing light emitting device that forms a diffusion pattern around the light condensing pattern. Vehicle headlights.

2. a light guide portion disposed between the light emitting surface and the wavelength converting portion, the light guide portion guiding the light from the light source to the wavelength converting portion; The vehicle headlamp according to claim 1 .

3. The light guide portion is provided in a range that overlaps the entire wavelength conversion portion when viewed from the normal direction of the light emitting surface.

3. The vehicle headlamp according to claim 2.

4. The wavelength conversion unit has a first portion that overlaps the light emitting surface of the light source when viewed from the normal direction of the light emitting surface, a second portion that protrudes from the light emitting surface when viewed from the normal direction of the light emitting surface, and a light blocking portion that is disposed between the first portion and the second portion and blocks light traveling inside the wavelength conversion unit. The vehicle headlamp according to any one of claims 1 to 3.

5. The light-blocking portion has a reflective surface that reflects light traveling inside the wavelength converting portion.

5. The vehicle headlamp according to claim 4.

6. a light leakage suppression unit that surrounds the sides of the light source and the wavelength conversion unit; The vehicle headlamp according to any one of claims 1 to 5.

7. The light source is provided in plurality, The wavelength conversion unit is provided across the plurality of light sources. The vehicle headlamp according to any one of claims 1 to 6.

8. the pattern has a cutoff line; The light emitted from the edge of the region of the wavelength conversion unit of the light emitting device that overlaps with the light emitting surface corresponds to a part of the cutoff line. The vehicle headlamp according to any one of claims 1 to 7.

9. The optical system further includes a shade disposed between the light emitting device and the lens, the shade blocking a portion of the light emitted from the light emitting device.

9. The vehicle headlamp according to claim 8.

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