JP2012048862A - Lamp assembly for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lamp assembly for vehicle that utilizes a light source including an LED element without cutting part of light therefrom and capable of forming a luminance distribution where the light with a maximum peak portion can be arranged substantially at the cutoff line.SOLUTION: In the lamp assembly for vehicle equipped with a light source including an LED element and a wavelength conversion layer, the LED element is a face-up type one equipped with a rectangular substrate, an n-type semiconductor layer laminated on one surface of the substrate, an n-electrode formed at a narrow-width region including one of the longer sides of a surface of the n-type semiconductor layer and extended in a long-side direction, a plurality of active layers laminated on the surface of the n-type semiconductor layer and extending in a longer side direction of the substrate, and partitioned by at least one groove reaching the n-type semiconductor layers, a p-type semiconductor layer laminated on a surface of each of the plurality of active layers, a transparent electrode formed on a surface of each of the p-type semiconductor layers, and a p-electrode, extended in the same direction as the n-electrode, formed at a narrow-width region including the longer side further away from the n-electrode of each of the surface of the transparent electrodes.

Description

  The present invention relates to a vehicular lamp, and more particularly to a vehicular lamp that can form a clear cut-off line.

  Conventionally, in the field of vehicular lamps, semiconductor light emitting devices in which a wavelength conversion layer having a uniform thickness is laminated on the surface of an LED element are used (see, for example, Patent Document 1 and Patent Document 2). FIG. 23 and FIG. 24 are examples of a semiconductor light emitting device in which a wavelength conversion layer Ly is stacked with a substantially uniform thickness on the surface of an LED element Cp. In the semiconductor light emitting device described in Patent Document 1 and the like, the thickness of the wavelength conversion layer is uniform, so that the luminance distribution gradually decreases as it goes to the periphery with the chip center at the maximum (see FIG. 5). This is the same principle as the surface emission Lambertian light distribution. If the in-plane luminance distribution is uniform, this can be explained as a phenomenon according to the COS function indicating the maximum value at the center.

JP 2005-322923 A JP 2008-507850 A

  However, in the field of vehicle headlamps, in order to form a clear cut-off line, it is required to distribute the maximum luminance distribution to the cut-off line. To meet this requirement, shades are used. Therefore, as shown in FIG. 7, about half of the luminance distribution must be cut, and there is a problem that the light utilization efficiency is lowered.

  The present invention has been made in view of such circumstances, and it is possible to distribute the maximum part of the luminance distribution to the cut-off line without cutting part of the light from the LED element as in the prior art. An object of the present invention is to provide a vehicular lamp using a simple light source.

  In order to achieve the above object, an invention according to claim 1 includes an LED element and a wavelength conversion layer, and includes light transmitted from the LED element and light transmitted from the LED element and light from the LED element. A light source configured to emit white light including light from the wavelength conversion layer that has been excited and emitted, and a light source image of the light source projected to the front of the vehicle, thereby facing a virtual front end of the vehicle. And a projection optical system configured to form a light distribution pattern for a headlamp on a vertical screen. The LED element includes a rectangular substrate and n stacked on one side of the substrate. Laminated on the surface of the n-type semiconductor layer, an n-electrode extending in the long-side direction formed in a narrow region including one long side of the surface of the n-type semiconductor layer, and the surface of the substrate N extending in the long side direction A plurality of active layers partitioned by at least one groove reaching the semiconductor layer; a p-type semiconductor layer stacked on each of the plurality of active layer surfaces; and a transparent electrode formed on each of the p-type semiconductor layer surfaces; Each of the transparent electrode surfaces is a face-up type LED element comprising a p-electrode formed in a narrow region including a long side far from the n-electrode and extending in the same direction as the n-electrode, The projection optical system projects a plurality of light source images of the light source toward the front of the vehicle so that an image portion corresponding to the upper p electrode of the p electrodes is positioned above, and is a virtual vertical facing the front end of the vehicle. A light distribution pattern for headlamps including a cut-off line formed by an image portion corresponding to the upper p electrode among the p electrodes of each of the plurality of light source images of the light source is formed on the screen. Characterized in that it is.

  According to the first aspect of the present invention, since the LED elements adopting the specific electrode structure are arranged in parallel, the light emitting surface of the light source has a peak on the upper p-electrode side in the longitudinal section (upper For the formation of a light distribution pattern for headlamps, a luminance distribution that gradually decreases from the upper p electrode to the n electrode is formed and a constant luminance distribution is formed in the cross section. A light source with a suitable luminance distribution can be configured.

  According to the first aspect of the present invention, a plurality of image portions corresponding to the p-electrode side (the portion where the luminance is peak) on each of the plurality of light source images of the light source are horizontally converted by the action of the projection optical system. It becomes possible to arrange densely in a direction and an oblique direction (for example, 15 degrees with respect to the horizontal). As a result, the light distribution pattern for the passing beam with excellent gradation visibility in the distance with the gradation shape in which the area near the cut-off line (horizontal cut-off line and oblique cut-off line) is brightest and the illuminance decreases from the cut-off line to the lower side. It becomes possible to form.

  According to the first aspect of the present invention, the LED element has a luminance distribution having a peak on the upper p electrode side (the p electrode side rises sharply). Without cutting the portion (see FIG. 7), it is possible to form the light distribution pattern for the passing beam by using the light emission shape of the LED element as it is. That is, the upper p-electrode side (the part where the luminance is peak) is densely arranged in the horizontal direction and the oblique direction (for example, 15 ° with respect to the horizontal) without cutting off part of the light from the LED element as in the past. Thus, the luminance gradation portion can be matched with the light distribution. For this reason, according to the first aspect of the present invention, the light utilization efficiency is improved.

  According to the first aspect of the present invention, the current (current amount or current density) supplied to the upper element part (element part composed of the active layer, the p-type semiconductor layer, and the transparent electrode) and the lower element part. ) Individually, the luminance distribution (peak position, peak width, etc.) in the longitudinal section of the LED element (light source) can be adjusted to the target luminance distribution.

  Invention of Claim 2 contains the light which permeate | transmitted the said wavelength conversion layer among the light from the said LED element including the LED element and the wavelength conversion layer arrange | positioned so that the light emission surface of the said LED element may be covered, and the said A light source configured to emit white light including light from the wavelength conversion layer that is excited by light from the LED element and emits light, and a light source image of the light source is projected to the front of the vehicle, thereby A projection optical system configured to form a light distribution pattern for a headlamp on a virtual vertical screen directly facing the unit, wherein the LED element includes a rectangular substrate, One long side of each of the plurality of n-type semiconductor layers stacked on one side and extending in the long-side direction of the substrate and defined by at least one groove reaching the substrate, and the surfaces of the plurality of n-type semiconductor layers An n-electrode extending in the long side direction formed in the narrow width region, an active layer stacked on each of the plurality of n-type semiconductor layer surfaces, a p-type semiconductor layer stacked on each of the active layer surfaces, A transparent electrode formed on each surface of the p-type semiconductor layer, and a p-electrode extending in the same direction as the n-electrode formed in a narrow region including a long side far from the n-electrode on each surface of the transparent electrode The projection optical system is configured to project a plurality of light source images of the light source so that an image portion corresponding to the upper p electrode among the p electrodes is positioned above. A head including a cut-off line that is projected forward and formed by an image portion corresponding to the upper p-electrode among the p-electrodes of each of the plurality of light source images of the light source on a virtual vertical screen that faces the front end of the vehicle. lamp Characterized in that it is configured to form a light distribution pattern.

  According to the invention described in claim 2, since the LED elements adopting the specific electrode structure are arranged in parallel, the light emitting surface of the light source has a peak on the upper p-electrode side in the longitudinal section (upper The p-electrode side rises sharply), a luminance distribution that gradually decreases from the upper p-electrode toward the lower n-electrode is formed, and a constant luminance distribution is formed in the cross section. A light source having a luminance distribution suitable for formation can be configured.

  According to the second aspect of the present invention, due to the action of the projection optical system, the plurality of image portions corresponding to the p-electrode side (the portion where the luminance is peak) on each of the plurality of light source images of the light source are horizontally It becomes possible to arrange densely in a direction and an oblique direction (for example, 15 degrees with respect to the horizontal). As a result, the light distribution pattern for the passing beam with excellent gradation visibility in the distance with the gradation shape in which the area near the cut-off line (horizontal cut-off line and oblique cut-off line) is brightest and the illuminance decreases from the cut-off line to the lower side. It becomes possible to form.

  According to the second aspect of the present invention, the LED element has a luminance distribution having a peak on the upper p-electrode side (the p-electrode side rises sharply). Without cutting the portion (see FIG. 7), it is possible to form the light distribution pattern for the passing beam by using the light emission shape of the LED element as it is. That is, the upper p-electrode side (the part where the luminance is peak) is densely arranged in the horizontal direction and the oblique direction (for example, 15 ° with respect to the horizontal) without cutting off part of the light from the LED element as in the past. Thus, the luminance gradation portion can be matched with the light distribution. For this reason, according to the invention described in claim 2, the light utilization efficiency is improved.

  According to the second aspect of the present invention, the upper element part (n-type semiconductor layer, n-electrode, active layer, p-type semiconductor layer, transparent electrode, and p-electrode) and the lower element part are supplied. By individually adjusting the current (current amount or current density), it becomes possible to adjust the luminance distribution (peak position, peak width, etc.) in the longitudinal section of the LED element (light source) to the target luminance distribution. .

  According to a third aspect of the present invention, in the first aspect of the present invention, the upper active layer among the partitioned active layers, the upper p-type semiconductor layer stacked on the surface of the upper active layer, the upper The upper transparent electrode formed on the surface of the p-type semiconductor layer and extending in the same direction as the n electrode formed in a narrow region including the long side farther from the n electrode of the upper transparent electrode surface The upper p electrode constitutes the upper element portion, and the lower active layer among the partitioned active layers, the lower p-type semiconductor layer stacked on the surface of the lower active layer, and the lower p-type The lower transparent electrode formed on the surface of the type semiconductor layer, and extending in the same direction as the n electrode formed in the narrow area including the long side far from the n electrode in the lower transparent electrode surface The lower p-electrode constitutes the lower element part, and further, the upper element part and the lower element To includes a circuit for supplying a current, the circuit is characterized by supplying the current to a current density than the element portion under the relative element portion on the increase.

  According to the third aspect of the present invention, by supplying current to the upper element portion so that the current density is larger than that of the lower element portion, the upper p in the vertical section of the light emitting surface of the light source. A luminance distribution having a peak on the electrode side (the upper p-electrode side rises steeply) and gradually decreasing from the upper p-electrode toward the n-electrode is formed, and a constant luminance distribution is formed in the cross section. It is possible to configure a light source having a luminance distribution suitable for forming a headlamp light distribution pattern.

  According to the third aspect of the present invention, the plurality of image portions corresponding to the p-electrode side (the portion where the luminance is peak) on each of the plurality of light source images of the light source are horizontally converted by the action of the projection optical system. It becomes possible to arrange densely in a direction and an oblique direction (for example, 15 degrees with respect to the horizontal). As a result, the light distribution pattern for the passing beam with excellent gradation visibility in the distance with the gradation shape in which the area near the cut-off line (horizontal cut-off line and oblique cut-off line) is brightest and the illuminance decreases from the cut-off line to the lower side. It becomes possible to form.

  Further, according to the invention described in claim 3, since the LED element has a luminance distribution having a peak on the upper p-electrode side (the p-electrode side rises steeply), the light from the LED element as in the conventional case is reduced. Without cutting the portion (see FIG. 7), it is possible to form the light distribution pattern for the passing beam by using the light emission shape of the LED element as it is. That is, the upper p-electrode side (the part where the luminance is peak) is densely arranged in the horizontal direction and the oblique direction (for example, 15 ° with respect to the horizontal) without cutting off part of the light from the LED element as in the past. Thus, the luminance gradation portion can be matched with the light distribution. For this reason, according to the invention described in claim 3, the light utilization efficiency is improved.

  According to the invention described in claim 3, the current (current amount or current density) supplied to the upper element part (element part composed of the active layer, the p-type semiconductor layer, and the transparent electrode) and the lower element part. ) Individually, the luminance distribution (peak position, peak width, etc.) in the longitudinal section of the LED element (light source) can be adjusted to the target luminance distribution.

  According to a fourth aspect of the present invention, in the second aspect of the present invention, an upper n-type semiconductor layer among the partitioned n-type semiconductor layers and one of the long sides of the upper n-type semiconductor layer surfaces are arranged. An upper n-electrode formed in a narrow-width region extending in the long side direction, an upper active layer stacked on the surface of the upper n-type semiconductor layer, and an upper p-type semiconductor stacked on the surface of the upper active layer A layer, an upper transparent electrode formed on the surface of the upper p-type semiconductor layer, and a narrow region including a long side farther from the upper n electrode of the upper transparent electrode surface, The upper p-electrode extending in the same direction as the upper n-electrode constitutes the upper element part, and the lower n-type semiconductor layer and the lower n-type semiconductor layer among the partitioned n-type semiconductor layers A lower n electrode formed in a narrow region including one long side of the surface and extending in the long side direction, the lower n-type semiconductor A lower active layer stacked on the surface of the layer, a lower p-type semiconductor layer stacked on the surface of the lower active layer, a lower transparent electrode formed on the surface of the lower p-type semiconductor layer, and the lower A lower p-electrode formed in a narrow region including a long side far from the lower n-electrode on the surface of the transparent electrode and extending in the same direction as the lower n-electrode constitutes a lower element portion. And a circuit for supplying current to the upper element part and the lower element part, and the circuit has a higher current density than the lower element part to the upper element part. An electric current is supplied to the battery.

  According to the fourth aspect of the present invention, by supplying current to the upper element portion so that the current density is larger than that of the lower element portion, the upper p in the vertical section of the light emitting surface of the light source. A luminance distribution having a peak on the electrode side (the upper p-electrode side rises steeply) and gradually decreasing from the upper p-electrode toward the n-electrode is formed, and a constant luminance distribution is formed in the cross section. It is possible to configure a light source having a luminance distribution suitable for forming a headlamp light distribution pattern.

  According to the fourth aspect of the invention, due to the action of the projection optical system, a plurality of image portions corresponding to the p-electrode side (the portion where the luminance is peak) on each of the plurality of light source images of the light source are horizontally It becomes possible to arrange densely in a direction and an oblique direction (for example, 15 degrees with respect to the horizontal). As a result, the light distribution pattern for the passing beam with excellent gradation visibility in the distance with the gradation shape in which the area near the cut-off line (horizontal cut-off line and oblique cut-off line) is brightest and the illuminance decreases from the cut-off line to the lower side. It becomes possible to form.

  According to the invention of claim 4, since the LED element has a luminance distribution having a peak on the upper p-electrode side (the p-electrode side rises steeply), one of the light from the LED element as in the conventional case. Without cutting the portion (see FIG. 7), it is possible to form the light distribution pattern for the passing beam by using the light emission shape of the LED element as it is. That is, the upper p-electrode side (the part where the luminance is peak) is densely arranged in the horizontal direction and the oblique direction (for example, 15 ° with respect to the horizontal) without cutting off part of the light from the LED element as in the past. Thus, the luminance gradation portion can be matched with the light distribution. For this reason, according to the invention of claim 4, the light utilization efficiency is improved.

  According to the invention of claim 4, the current (current amount or current density) supplied to the upper element part (element part composed of the active layer, p-type semiconductor layer, and transparent electrode) and the lower element part. ) Individually, the luminance distribution (peak position, peak width, etc.) in the longitudinal section of the LED element (light source) can be adjusted to the target luminance distribution.

  According to the present invention, there is provided a vehicular lamp using a light source capable of distributing the maximum part of the luminance distribution to the cut-off line without cutting part of the light from the LED element as in the prior art. It becomes possible.

(A) It is an external view of the vehicle lamp 10 which is one Embodiment of this invention, (b) It is a longitudinal cross-sectional view. 2 is a simplified cross-sectional view of a light source 20. FIG. (A) Front view (top view) of the LED element 21, (b) Cross-sectional view (side view) of the LED element 21, (c) LED element 21 (light emitting surface) in the AA cross section in FIG. It is an example of luminance distribution. Is an example of a luminance distribution when the current density was supplied current so that the ^{15A / cm 2, 35A / cm} 2 ( longitudinal section). It is an example of the luminance distribution of the LED element (light emission surface) of the conventional electrode structure. It is an example of the light distribution pattern for headlamps. It is a figure for demonstrating that a part of light from the said LED element was cut in the LED element of the conventional electrode structure. FIG. 11 is a front view (top view) of a modified example of the LED element 21. It is an example of the light distribution pattern for headlamps. (A) It is an external view of the vehicle lamp 10 (modification 1-1) which is one Embodiment of this invention, (b) It is a longitudinal cross-sectional view. (A) It is an external view of the vehicle lamp 10 (modification 1-2) which is one Embodiment of this invention, (b) It is a longitudinal cross-sectional view. It is a longitudinal cross-sectional view of the vehicle lamp 10 (modification 1-3) which is one Embodiment of this invention. It is a longitudinal cross-sectional view of the vehicle lamp 10 (modification 1-4) which is one Embodiment of this invention. (A) Front view (top view) of LED element 21 (Modification 2-1), (b) Cross-sectional view (side view) of LED element 21 (Modification 2-1), (c) FIG. 14 (a) It is an example of the luminance distribution of the LED element 21 (modification 2-1) in the middle BB cross section. (A) Front view (top view) of LED element 21 (Modification 2-2), (b) Cross-sectional view (side view) of LED element 21 (Modification 2-2), (c) FIG. 15 (a) It is an example of the luminance distribution of the LED element 21 (modification 2-2) in the middle CC section. (A) Front view (top view) of LED element 21 (Modification 2-3), (b) Cross-sectional view (side view) of LED element 21 (Modification 2-3), (c) FIG. It is an example of the luminance distribution of the LED element 21 (modification 2-3) in a middle DD section. (A) Front view (top view) of LED element 21 (Modification 2-4), (b) Cross-sectional view (side view) of LED element 21 (Modification 2-4), (c) FIG. 17 (a) It is an example of the luminance distribution of the LED element 21 (modification 2-4) in the middle EE cross section. (A) An example of a constant current circuit, (b) An example of another constant current circuit. It is a flowchart which shows the process example at the time of detecting disconnection and short circuits, such as the wire W in the LED element. (A) Front view (top view) of LED element 21 (Modification 2-5), (b) Cross-sectional view (side view) of LED element 21 (Modification 2-5), (c) FIG. 25 (a) It is an example of the luminance distribution of the LED element 21 (modification 2-5) in the middle FF cross section. It is a figure for demonstrating that the vertical stripe is permitted rather than the horizontal stripe when the stripe is generated in the luminance distribution of the LED element. It is a side view of the conventional semiconductor light-emitting device. It is a side view of the conventional semiconductor light-emitting device.

  Hereinafter, a vehicular lamp that is an embodiment of the present invention will be described with reference to the drawings.

  The vehicular lamp 10 of this embodiment is, for example, a vehicular headlamp, and is disposed on each of the left and right sides of the front portion of the vehicle.

  Fig.1 (a) is an external view of the vehicle lamp 10 which is one Embodiment of this invention, FIG.1 (b) is a longitudinal cross-sectional view. FIG. 2 is a simplified cross-sectional view of the light source 20.

  As shown in FIG. 1A, FIG. 1B, and FIG. 2, the vehicular lamp 10 includes an LED element 21 and a wavelength conversion layer 22 (both phosphor) disposed so as to cover the light emitting surface of the LED element 21. White light including light transmitted through the wavelength conversion layer 22 among light from the LED element 21 and light from the wavelength conversion layer 22 emitted by being excited by the light from the LED element 21. The light source 20 configured to emit light, and the light source image of the light source 20 are projected in front of the vehicle to form a headlamp light distribution pattern on a virtual vertical screen facing the front end of the vehicle. A projection optical system 30 and the like are provided.

[Structure of LED element 21]
First, the structure of the LED element 21 will be described. 3 (a) is a front view (top view) of the LED element 21, FIG. 3 (b) is a cross-sectional view (side view) of the LED element 21, and FIG. 3 (c) is a cross-sectional view taken along line AA in FIG. 3 (a). It is an example of the luminance distribution of the LED element 21 (light emitting surface).

  The LED element 21 is a face-up type (also referred to as FU type) LED element that extracts blue light from the epitaxial growth surface side, and includes a substantially rectangular light emitting surface in front view (see FIG. 3A). . While a general LED element (light emitting surface) has a size of about 300 μm in length × 500 μm in width, the LED element 21 (light emitting surface) in this embodiment has a length of H = 500 to 1200 μm and a width of about W = 4 to 5 mm. (See FIG. 3A).

  As shown in FIG. 3B, the LED element 21 has a rectangular substrate 21a, an n-type semiconductor layer 21b laminated on one surface of the substrate 21a, and a narrow width including one long side of the surface of the n-type semiconductor layer 21b. An active layer 21d and an active layer 21d stacked between a long side far from the n-electrode 21c and the n-electrode 21c on the surface of the n-electrode 21c and the n-type semiconductor layer 21b formed in the region 21b1 and extending in the long-side direction. A p-type semiconductor layer 21e laminated between one long side and the other long side of the surface, and a transparent formed between one long side and the other long side of the surface of the p-type semiconductor layer 21e The electrode 21f and the transparent electrode 21f include a p-electrode 21g formed in a narrow region 21f1 including the long side far from the n-electrode 21c and extending in the same direction as the n-electrode 21c.

  The substrate 21a is a single crystal substrate such as a sapphire substrate, for example. The n-type semiconductor layer 21b is a nitride semiconductor layer such as an n-GaN layer, for example. The n-electrode 21c is an electrode including a pad 21c1 to which a power feeding wire is connected, for example. The number of pads 21c1 can be increased or decreased according to the amount of power supply. The active layer 21d is a light emitting layer such as an InGan layer, for example. The p-type semiconductor layer 21e is, for example, a nitride semiconductor layer such as a p-GaN layer. The transparent electrode 21f is a thin electrode such as AuNi or ITO, which is a low-resistance transparent electrode. The transparent electrode 21f is laminated on substantially the entire region from one long side to the other long side of the surface of the p-type semiconductor layer 21e (see FIG. 3A). The transparent electrode 21f is used to supplement the current diffusion of the p-type semiconductor layer 21e having a higher resistivity than the n-type semiconductor layer 21b. The p electrode 21g is an electrode including, for example, a pad 21g1 to which a power feeding wire is connected. The number of pads 21g1 can be increased or decreased according to the amount of power supply.

In the use of the headlamp, the LED element 21 is supplied with a constant current (forward current: 1 to 5 A, current density: 35 A / cm ² or more to 70 A / cm ² ) controlled by a DC-DC converter or the like. A circuit (for example, a constant current circuit, not shown) is connected. For example, this circuit supplies the LED element 21 with a current having a current density such that the following current distribution is formed. When the current from this circuit flows to the n-electrode 21c through the p-electrode 21g, the transparent electrode 21f, the p-type semiconductor layer 21e, the active layer 21d, and the n-type semiconductor layer 21b, the active layer 21d emits blue light. The blue light is emitted upward from the transparent electrode 21f in FIG.

  The current supplied to the p-electrode 21g is made of a metal that is easily diffused by the p-electrode 21g. Therefore, the current is uniformly diffused in the p-electrode 21g, but in the transparent electrode 21f (longitudinal section), the resistance of the transparent electrode 21f. The current distribution does not diffuse uniformly in relation to the rate, concentrates on the p electrode 21g side (has a peak on the p electrode 21g side), and gradually decreases from the p electrode 21g toward the n electrode 21c (FIG. 3 ( c)). On the other hand, the current supplied to the p-electrode 21g is constant because the n-electrode 21c and the p-electrode 21g are arranged in parallel with each other in the transparent electrode 21f (transverse section) (see FIG. 3A). A current distribution is formed.

  The active layer 21d emits light due to the current distributed in this manner, whereby the LED element 21 (its light emitting surface) has the same luminance distribution as the current distribution, that is, the light emitting surface (longitudinal section) of the LED element 21. , A luminance distribution (see FIG. 3C) having a peak on the p-electrode 21g side and gradually decreasing from the p-electrode 21g toward the n-electrode 21c is formed on the light-emitting surface (transverse section) of the LED element 21. A constant luminance distribution is formed.

For example, the vertical H Whereas LED elements 21 of the 500 [mu] m, in case of supplying the current to the current density is ^{15A / cm 2, 35A / cm} 2 , the luminance distribution as shown in FIG. 4 (vertical surface) It is formed.

  In addition, by adjusting the thickness of the transparent electrode 21f, the area of each electrode 21c, 21f, 21g, the distance between the electrodes 21c, 21g, etc., the luminance distribution (peak position, It is possible to adjust the peak width etc. to the target luminance distribution.

[Method for Manufacturing LED Element 21]
Next, the manufacturing method (Example) of the LED element 21 is demonstrated.
A sapphire substrate 21a is prepared, and semiconductor layers (n-type semiconductor layer 21b, active layer 21d, p-type semiconductor layer 21e, etc.) are grown (epitaxially grown) by MOCVD.

The growth of the semiconductor layer will be described in order. After putting the sapphire substrate 21a into the MOCVD apparatus, thermal cleaning at 1000 ° C. is performed for 10 minutes in a hydrogen atmosphere. A buffer layer (not shown) made of a GaN layer is formed by supplying TMG (trimethylgallium) and NH ₃ . Subsequently, TMG, NH ₃ and SiH ₄ as a dopant gas are supplied to form an n-type semiconductor layer 21b made of an n-type GaN layer. Subsequently, an active layer 21d is formed on the n-type semiconductor layer 21b. In this example, a multiple quantum well structure made of InGaN / GaN was applied to the active layer 21d. That is, five cycles of growth are performed with InGaN / GaN as one cycle. Specifically, TMG, TMI (trimethylindium), and NH ₃ are supplied to form an InGaN well layer, and then TMG and NH ₃ are supplied to form a GaN barrier layer. The active layer 21d is formed by repeating this process for five cycles. Next, TMG, TMA (trimethylaluminum), NH ₃ and CP ₂ Mg (bis-cyclopentadienyl Mg) as a dopant are supplied to form a p-type AlGaN cladding layer (not shown). Subsequently, TMG, NH ₃ and CP ₂ Mg as a dopant are supplied to form a p-type semiconductor layer 21e made of a p-type GaN layer.

  Next, dry etching is performed from above the wafer so that a part of the n-type semiconductor layer 21b (n-type GaN layer) is exposed. At the time of dry etching, a resist pattern is formed by photolithography, and a portion not covered with the resist pattern is etched by reactive ion etching (RIE) using the resist pattern as a mask. Thereafter, the resist pattern is removed with a remover. After a resist pattern is newly formed by photolithography so as to cover the portion 21b1 where the n-type semiconductor layer 21b (n-type GaN layer) is exposed, ITO is used to cover the p-type semiconductor layer 21e using vapor deposition and an alloy furnace. A transparent electrode 21f made of is formed. Thereafter, the resist pattern is removed with a remover.

  A p-electrode 21g made of TiAu and an n-electrode 21c made of TiAl are formed on a partial surface of the transparent electrode 21f and an exposed surface 21b1 of the n-type semiconductor layer 21b (n-type GaN layer). When the electrodes 21g and 21c are formed, a mask is formed by photolithography except for the portions where the electrodes 21g and 21c are formed, and after the electrodes 21g and 21c are formed, the mask is removed by a remover.

  Thus, the LED element 21 is manufactured.

[Wavelength conversion layer 22]
The wavelength conversion layer 22 is disposed so as to cover the light emitting surface of the LED element 21. FIG. 2 is an example of the LED element 21 mounted on the mounting substrate C such as a ceramic substrate or a silicon substrate, and the wavelength conversion layer 22 disposed so as to cover the light emitting surface of the LED element 21. The LED element 21 and the pattern electrode on the mounting substrate C are electrically connected by a wire W.

  Thereby, white light including the blue light component transmitted through the wavelength conversion layer 22 in the blue light from the LED element 21 and the yellow light component emitted from the wavelength conversion layer 22 excited and emitted by the blue light from the LED element 21. The light source 20 (white light source) that emits (pseudo white light) can be configured. As the wavelength conversion layer 22, for example, a phosphor that emits yellow light when excited by blue light from the LED element 21 (for example, a resin layer in which phosphor particles such as YAG phosphor particles are dispersed) is used. Is possible.

  Since the luminance distribution as described above (see FIG. 3C) is formed on the LED element 21 (its light emitting surface), the light source 20 (its light emitting surface) has a luminance distribution similar to the above luminance distribution, that is, On the light emitting surface (longitudinal section) of the light source 20, a luminance distribution (see FIG. 3C) having a peak on the p-electrode 21g side and gradually decreasing from the p-electrode 21g toward the n-electrode 21c is formed. A constant luminance distribution is formed on the light source 20 (the light emitting surface thereof) (cross section).

  FIG.3 (c) is an example of the luminance distribution in the longitudinal cross-section of the LED element 21 (light emitting surface). In the LED element having the conventional electrode structure, the luminance distribution gradually decreases as the distance from the center of the chip reaches the maximum (see FIG. 5), whereas the LED element 21 has a peak on the p-electrode 21g side. It can be seen that it has a luminance distribution (the p-electrode 21g side rises sharply) (see FIG. 3C).

  FIG. 6 is an example of a light distribution pattern for headlamps. The middle horizontal line in FIG. 6 indicates a light / dark boundary, with the dark portion at the top representing the oncoming vehicle side and the light portion at the bottom representing the road surface and sidewalk side. As shown in FIG. 6, the maximum part of the illuminance (brightness) is preferably located immediately below the light / dark boundary part, and the gradation shape in which the illuminance decreases as it goes down has a far visibility and road surface. It becomes the optimal light distribution of illuminance. In the LED element of the conventional electrode structure, as shown in FIG. 7, the luminance peak is at the center of the chip. Therefore, in order to satisfy the light distribution condition, a half region must be cut and used. Was wasting light.

  In contrast, the LED element 21 of the present embodiment has a luminance distribution having a peak on the p-electrode 21g side (the p-electrode 21g side rises sharply) (see FIG. 3C). It is possible to form the light distribution pattern P suitable for the passing beam by using the light emission shape of the LED element 21 as it is without cutting a part of the light from the light. That is, the p-electrode 21g side (the portion where the luminance is peak) is arranged in the maximum illuminance portion of the light distribution without cutting a part of the light from the LED element as in the conventional case, and the luminance gradation portion is also distributed. Can be matched. For this reason, light utilization efficiency improves.

  As described above, according to the LED element 21 of the present embodiment, the electrode structure is devised to have a peak on the p-electrode 21g side in the longitudinal section of the rectangular light-emitting surface (the p-electrode 21g side is steep). 3), a luminance distribution (see FIG. 3C) that gradually decreases from the p-electrode 21g toward the n-electrode 21c is formed, and a constant luminance distribution is formed in the cross section. The light source 20 having a luminance distribution suitable for pattern formation can be configured.

  Further, since the LED element 21 is a horizontally long single LED element, a more uniform light emitting surface is formed as compared with a conventional case in which a plurality of LED elements are arranged in a row and are horizontally long (see FIG. 22). It becomes possible. As shown in FIG. 8, instead of a single LED element 21, a plurality of LED elements 21 may be arranged in a line.

  In addition, since the wavelength conversion layer 22 is a horizontally long single wavelength conversion layer, a plurality of LED elements arranged in a row as in the past are covered with a plurality of wavelength conversion layers corresponding to the LED elements (FIG. 22). Compared to the reference), the distribution of the phosphor particles is less likely to be biased, and color unevenness and brightness unevenness can be prevented.

[Vehicle lamp 10]
Next, the example which comprises the vehicle lamp 10 using the light source 20 of the said structure is demonstrated, referring drawings.

  As shown in FIGS. 1A and 1B, a vehicular lamp 10 includes a light source 20 disposed on the front side of the vehicle, and a reflecting surface 31 serving as a projection optical system of the present invention disposed on the rear side of the vehicle. Etc.

  The light source 20 has a p-electrode 21g side (a portion where the luminance is a peak) located on the front side of the vehicle, an n-electrode 21c side located on the rear side of the vehicle (that is, the reflective surface 31 side), and the irradiation direction of the light source 20 ( That is, the light emitting surface of the light source 20 is disposed so as to face downward (see FIG. 1B).

  The reflecting surface 31 is a rotating paraboloid reflecting surface whose focal point is set in the vicinity of the light source 20 (for example, a so-called multi-reflector partitioned into a plurality of small reflecting regions) so that light from the light source 20 is incident thereon. The light source 20 is disposed so as to cover a range from the side to the front of the light source 20 (that is, in front of the light source 20) (see FIGS. 1A and 1B).

  As shown in FIG. 1B, the reflecting surface 31 includes a plurality of light sources of the light source 20 (the light emitting surface thereof) such that the image portion P1 ′ corresponding to the p-electrode 21g (the portion where the luminance is peak) is positioned above. A plurality of light source images P1 of the light source 20 are projected on a virtual vertical screen (not shown) that projects an image P1 (one light source image P1 in FIG. 1B is illustrated) in front of the vehicle and faces the front end of the vehicle. A cut-off line (horizontal cut-off line) formed by densely arranging image portions P1 ′ corresponding to the respective p electrodes 21g (portions where the luminance is a peak) in the horizontal direction and in an oblique direction (for example, 15 ° with respect to the horizontal). The head lamp light distribution pattern P including CL1 and oblique cut-off line CL2 (see FIG. 9) is formed.

  According to the vehicular lamp 10 of the present embodiment, since the light source 20 is disposed in the above positional relationship with respect to the reflecting surface 31 (see FIGS. 1A and 1B), a plurality of light sources of the light source 20 are used. A plurality of image portions P1 ′ corresponding to the p-electrodes 21g (the portion where the luminance is a peak) of each image P1 can be densely arranged in the horizontal direction and the oblique direction (for example, 15 ° with respect to the horizontal). As a result, the light distribution near the cut-off line (the horizontal cut-off line CL1 and the oblique cut-off line CL2) is brightest, and the illuminance decreases as it goes downward from the cut-off line. The pattern P can be formed (see FIG. 9).

  Further, according to the vehicular lamp 10 of the present embodiment, the LED element 21 has a luminance distribution having a peak on the p-electrode 21g side (the p-electrode 21g side rises sharply) (see FIG. 3C). In this way, it is possible to form the light distribution pattern P for the passing beam by using the light emission shape of the LED element 21 as it is without cutting a part of the light from the LED element (see FIG. 7) (see FIG. 7). 9). That is, the p-electrode 21g side (the portion where the luminance is peak) is densely arranged in the horizontal direction and in the oblique direction (for example, 15 ° with respect to the horizontal) without cutting off part of the light from the LED element as in the past. Thus, the luminance gradation portion can be matched to the light distribution. For this reason, according to the vehicular lamp 10 of the present embodiment, the light utilization efficiency is improved.

[Modification 1-1]
Next, a modified example 1-1 of the vehicular lamp 10 will be described with reference to the drawings.

  Fig.10 (a) is an external view of the vehicle lamp 10 (modification 1-1) which is one Embodiment of this invention, FIG.10 (b) is a longitudinal cross-sectional view.

  As shown in FIGS. 10 (a) and 10 (b), the vehicular lamp 10 of the present modification is a light source 20 disposed on the front side of the vehicle and a projection optical system of the present invention disposed on the rear side of the vehicle. A reflection surface 32 and the like are provided.

  The light source 20 has the n-electrode 21c side positioned on the front side of the vehicle, the p-electrode 21g side (the portion where the luminance is peak) positioned on the rear side of the vehicle (that is, the reflecting surface 31 side), and the irradiation direction of the light source 20 ( That is, the light emitting surface of the light source 20 is disposed so as to face upward (see FIG. 10B).

  The reflecting surface 32 is a rotating paraboloid reflecting surface (for example, a so-called multi-reflector partitioned into a plurality of small reflecting regions) whose focal point is set in the vicinity of the light source 20 so that light from the light source 20 is incident thereon. The light source 20 is disposed so as to cover a range from the side to the front of the light source 20 (that is, in front of the light source 20) (see FIGS. 10A and 10B).

  As shown in FIG. 10B, the reflecting surface 32 is a plurality of light sources of the light source 20 (the light emitting surface thereof) such that the image portion P1 ′ corresponding to the p electrode 21g (the portion where the luminance is peak) is positioned above. A plurality of light source images P1 of the light source 20 are projected on a virtual vertical screen (not shown) facing the front end of the vehicle by projecting an image P1 (one light source image P1 in FIG. 10B is illustrated) in front of the vehicle. A cut-off line (horizontal cut-off line) formed by densely arranging image portions P1 ′ corresponding to the respective p electrodes 21g (portions where the luminance is a peak) in the horizontal direction and in an oblique direction (for example, 15 ° with respect to the horizontal). The head lamp light distribution pattern P including CL1 and oblique cut-off line CL2 (see FIG. 9) is formed.

  According to the vehicular lamp 10 of the present modification, the light source 20 is arranged in the above positional relationship with respect to the reflecting surface 32 (see FIG. 10A and FIG. 10B), and therefore, a plurality of light sources of the light source 20 A plurality of image portions P1 ′ corresponding to the p-electrodes 21g (the portion where the luminance is a peak) of each image P1 can be densely arranged in the horizontal direction and the oblique direction (for example, 15 ° with respect to the horizontal). As a result, the light distribution near the cut-off line (the horizontal cut-off line CL1 and the oblique cut-off line CL2) is brightest, and the illuminance decreases as it goes downward from the cut-off line. The pattern P can be formed (see FIG. 9).

  Further, according to the vehicle lamp 10 of the present modification, the LED element 21 has a luminance distribution having a peak on the p-electrode 21g side (the p-electrode 21g side rises sharply) (see FIG. 3C). In this way, it is possible to form the light distribution pattern P for the passing beam by using the light emission shape of the LED element 21 as it is without cutting a part of the light from the LED element (see FIG. 7) (see FIG. 7). 9). That is, the p-electrode 21g side (the portion where the luminance is peak) is densely arranged in the horizontal direction and in the oblique direction (for example, 15 ° with respect to the horizontal) without cutting off part of the light from the LED element as in the past. Thus, the luminance gradation portion can be matched to the light distribution. For this reason, according to the vehicular lamp 10 of the present modification, the light use efficiency is improved.

[Modification 1-2]
Next, a modified example 1-2 of the vehicular lamp 10 will be described with reference to the drawings.

  FIG. 11A is an external view of a vehicular lamp 10 according to an embodiment of the present invention (Modification 1-2), and FIG. 11B is a longitudinal sectional view.

  As shown in FIGS. 11 (a) and 11 (b), the vehicular lamp 10 of the present modification is a light source 20 disposed on the front side of the vehicle and a projection optical system of the present invention disposed on the rear side of the vehicle. The reflecting surface 33 is provided.

  In the light source 20, the n-electrode 21c side is positioned vertically above, the p-electrode 21g side (the portion where the luminance is peak) is positioned vertically below, and the irradiation direction of the light source 20 (that is, the light emitting surface of the light source 20) is It arrange | positions so that it may become a substantially horizontal direction (refer FIG.11 (b)).

  The reflecting surface 33 is a rotating paraboloid reflecting surface whose focal point is set in the vicinity of the light source 20 (for example, a so-called multi-reflector partitioned into a plurality of small reflecting regions) so that light from the light source 20 is incident thereon. The light source 20 is disposed in front of the light source 20 (see FIGS. 11A and 11B).

  As shown in FIG. 11B, the reflecting surface 33 is a plurality of light sources of the light source 20 (the light emitting surface thereof) such that the image portion P1 ′ corresponding to the p electrode 21g (the portion where the luminance is peak) is positioned above. A plurality of light source images P1 of the light source 20 are projected on a virtual vertical screen (not shown) facing the front end of the vehicle by projecting an image P1 (one light source image P1 in FIG. 11B is illustrated) in front of the vehicle. A cut-off line (horizontal cut-off line) formed by densely arranging image portions P1 ′ corresponding to the respective p electrodes 21g (portions where the luminance is a peak) in the horizontal direction and in an oblique direction (for example, 15 ° with respect to the horizontal). The head lamp light distribution pattern P including CL1 and oblique cut-off line CL2 (see FIG. 9) is formed.

  According to the vehicular lamp 10 of the present modification, the light source 20 is arranged in the above positional relationship with respect to the reflecting surface 33 (see FIG. 11A and FIG. 11B), and therefore, a plurality of light sources of the light source 20 A plurality of image portions P1 ′ corresponding to the p-electrodes 21g (the portion where the luminance is a peak) of each image P1 can be densely arranged in the horizontal direction and the oblique direction (for example, 15 ° with respect to the horizontal). As a result, the light distribution near the cut-off line (the horizontal cut-off line CL1 and the oblique cut-off line CL2) is brightest, and the illuminance decreases as it goes downward from the cut-off line. The pattern P can be formed (see FIG. 9).

  Further, according to the vehicle lamp 10 of the present modification, the LED element 21 has a luminance distribution having a peak on the p-electrode 21g side (the p-electrode 21g side rises sharply) (see FIG. 3C). In this way, it is possible to form the light distribution pattern P for the passing beam by using the light emission shape of the LED element 21 as it is without cutting a part of the light from the LED element (see FIG. 7) (see FIG. 7). 9). That is, the p-electrode 21g side (the portion where the luminance is peak) is densely arranged in the horizontal direction and in the oblique direction (for example, 15 ° with respect to the horizontal) without cutting off part of the light from the LED element as in the past. Thus, the luminance gradation portion can be matched to the light distribution. For this reason, according to the vehicular lamp 10 of the present modification, the light use efficiency is improved.

[Modification 1-3]
Next, a modified example 1-3 of the vehicular lamp 10 will be described with reference to the drawings.

  FIG. 12 is a longitudinal sectional view of a vehicular lamp 10 (modification 1-3) that is an embodiment of the present invention.

  As shown in FIG. 12, the vehicular lamp 10 of the present modification includes a projection lens 34a disposed on the front side of the vehicle, a light source 20 disposed on the rear side of the vehicle, and a light source so that light from the light source 20 is incident. 20 includes a reflecting surface 34b disposed so as to cover a range from the side 20 to the front (that is, in front of the light source 20), a shade 34c disposed between the projection lens 34a and the light source 20, and the like. The projection lens 34a, the reflecting surface 34b, and the shade 34c constitute the projection optical system of the present invention.

  The light source 20 has a p-electrode 21g side (a portion where the luminance is a peak) located on the front side of the vehicle, an n-electrode 21c side located on the rear side of the vehicle (that is, the reflective surface 31 side), and the irradiation direction of the light source 20 ( That is, the light emitting surface of the light source 20 is disposed so as to face upward (see FIG. 12B).

  The reflecting surface 34b is a spheroid reflecting surface in which the first focal point is set in the vicinity of the light source 20 and the second focal point is set in the vicinity of the upper end edge of the shade 34c, so that the light from the light source 20 enters. It arrange | positions so that the range from the side of the light source 20 to the front may be covered (namely, in front of the light source 20) (refer FIG. 12).

  The reflecting surface 34b projects a plurality of light source images P1 of the light source 20 (the light emitting surface thereof) to the front of the vehicle so that the image portion P1 ′ corresponding to the p-electrode 21g (the portion where the luminance is peak) is positioned above. An image portion P1 ′ corresponding to the p-electrode 21g (the portion where the luminance is peak) of each of the plurality of light source images P1 of the light source 20 is placed on a virtual vertical screen (not shown) facing the front end portion in the horizontal direction and the oblique direction. A light distribution pattern P for headlamps including a cut-off line (horizontal cut-off line CL1, oblique cut-off line CL2, see FIG. 9) formed by dense arrangement (for example, 15 ° with respect to the horizontal) is formed. It is configured.

  The shade 34c is a light shielding member for shielding a part of the reflected light from the reflective surface 34b to form a cut-off line, and the projection lens 34a and the light source with the upper end edge positioned near the focal point of the projection lens 34a. 20 is arranged.

  According to the vehicular lamp 10 of the present modification, the light source 20 is disposed in the above positional relationship (see FIG. 12), and therefore the p-electrode 21g (a portion where the luminance is a peak) for each of the plurality of light source images P1 of the light source 20. A plurality of image portions P1 ′ corresponding to can be densely arranged in the horizontal direction and the oblique direction (for example, 15 ° with respect to the horizontal). As a result, the light distribution near the cut-off line (the horizontal cut-off line CL1 and the oblique cut-off line CL2) is brightest, and the illuminance decreases as it goes downward from the cut-off line. The pattern P can be formed (see FIG. 9).

  Further, according to the vehicle lamp 10 of the present modification, the LED element 21 has a luminance distribution having a peak on the p-electrode 21g side (the p-electrode 21g side rises sharply) (see FIG. 3C). The light emitting shape of the LED element 21 can be obtained by cutting only a small part of the light from the high-luminance side end of the LED element 21 without cutting about half of the light from the LED element as shown in FIG. It is possible to form the light distribution pattern P for the passing beam using almost as it is (see FIG. 9). That is, the p-electrode 21g side (the portion where the luminance is peak) is densely arranged horizontally and obliquely (for example, 15 ° with respect to the horizontal) without cutting up to about half of the light from the LED element as in the past. Thus, the luminance gradation portion can be matched with the light distribution. For this reason, according to the vehicular lamp 10 of the present modification, the light use efficiency is improved. In addition, according to the vehicle lamp 10 of the present modification, the energy received by the shade is reduced compared to the case where the conventional LED element is used (that is, the shade is very small from the high luminance side end of the LED element 21). Since only a part of the light hits), it is possible to reduce the amount by which the shade is heated.

[Modification 1-4]
Next, modified example 1-4 of the vehicular lamp 10 will be described with reference to the drawings.

  FIG. 13 is a longitudinal sectional view of a vehicular lamp 10 (modification 1-4) according to an embodiment of the present invention.

  As shown in FIG. 13, the vehicular lamp 10 according to the present modification includes a projection lens 35a as a projection optical system of the present invention disposed on the vehicle front side, a light source 20 disposed on the vehicle rear side, and a projection lens 35a. A shade 35b disposed between the light source 20 and the like is provided. The projection lens 35a and the shade 35b constitute the projection optical system of the present invention.

  In the light source 20, the n-electrode 21c side is positioned vertically above, the p-electrode 21g side (the portion where the luminance is peak) is positioned vertically below, and the irradiation direction of the light source 20 (that is, the light emitting surface of the light source 20) is It arrange | positions so that it may face the vehicle front side (refer FIG. 13).

  The shade 35b is a light shielding member for shielding a part of the light from the light source 20 to form a cut-off line, and the projection lens 35a, the light source 20 and the light source 20 with the upper edge positioned near the focal point of the projection lens 35a. It is arranged between.

  According to the vehicular lamp 10 of the present modification, the light source 20 is arranged in the above positional relationship (see FIG. 13), and therefore the p-electrode 21g (a part where the luminance is a peak) of each of the plurality of light source images P1 of the light source 20 A plurality of image portions P1 ′ corresponding to can be arranged in the horizontal direction and the oblique direction (for example, 15 ° with respect to the horizontal). As a result, the light distribution near the cut-off line (the horizontal cut-off line CL1 and the oblique cut-off line CL2) is brightest, and the illuminance decreases as it goes downward from the cut-off line. The pattern P can be formed (see FIG. 9).

  Further, according to the vehicle lamp 10 of the present modification, the LED element 21 has a luminance distribution having a peak on the p-electrode 21g side (the p-electrode 21g side rises sharply) (see FIG. 3C). The light emitting shape of the LED element 21 can be obtained by cutting only a small part of the light from the high-luminance side end of the LED element 21 without cutting about half of the light from the LED element as shown in FIG. It is possible to form the light distribution pattern P for the passing beam using almost as it is (see FIG. 9). That is, the p-electrode 21g side (the portion where the luminance is peak) is densely arranged horizontally and obliquely (for example, 15 ° with respect to the horizontal) without cutting up to about half of the light from the LED element as in the past. Thus, the luminance gradation portion can be matched with the light distribution. For this reason, according to the vehicular lamp 10 of the present modification, the light use efficiency is improved. In addition, according to the vehicle lamp 10 of the present modification, the energy received by the shade is reduced compared to the case where the conventional LED element is used (that is, the shade is very small from the high luminance side end of the LED element 21). Since only a part of the light hits), it is possible to reduce the amount by which the shade is heated.

[Modification 2-1]
Next, the structure (Modification 2-1) of the LED element 21 will be described with reference to the drawings. 14A is a front view (top view) of the LED element 21 (modification 2-1), FIG. 14B is a cross-sectional view (side view) of the LED element 21 (modification 2-1), and FIG. (C) is an example of the luminance distribution of the LED element 21 (modification 2-1) on the BB cross section in FIG.

  In the embodiment and each modification, the transparent electrode 21f is formed in substantially the entire region from one long side to the other long side of the surface of the p-type semiconductor layer 21e (see FIG. 3A). However, the present invention is not limited to this. For example, as shown in FIGS. 14 (a) and 14 (b), the transparent electrode 21f is formed on the surface of the p-type semiconductor layer 21e from the long side far from the n-electrode 21c, and the long side and the other long side. May be formed only in a region extending to the intermediate line L extending in the long side direction.

  According to this modification, the transparent electrode 21f is not formed in the region extending from the intermediate line L to the long side closer to the n-electrode 21c on the surface of the p-type semiconductor layer 21e, and from the p-electrode 21g Since the current is less likely to be diffused, the current supplied to the p-electrode 21g is concentrated on the p-electrode 21g side (having a peak on the p-electrode 21g side) in the longitudinal section, and as it goes from the p-electrode 21g to the n-electrode 21c. A current distribution that gradually decreases and rapidly decreases in the vicinity of the intermediate line L (that is, a distribution substantially the same as that in FIG. 14C) is formed.

  The active layer 21d emits light due to the current distributed in this manner, whereby the LED element 21 (its light emitting surface) has the same luminance distribution as the current distribution, that is, the light emitting surface (longitudinal section) of the LED element 21. , A luminance distribution (see FIG. 14C) having a peak on the p-electrode 21g side, gradually decreasing toward the n-electrode 21c from the p-electrode 21g, and rapidly decreasing near the intermediate line L is formed. A constant luminance distribution is formed on the light emitting surface 21 (cross section).

  Therefore, by arranging the wavelength conversion layer 22 so as to cover the light emitting surface of the LED element 21 of the present modification, the vertical section has a peak on the p electrode 21g side, and gradually increases from the p electrode 21g toward the n electrode 21c. Suitable for formation of a light distribution pattern for headlamps in which a luminance distribution (see FIG. 14C) that decreases sharply in the vicinity of the intermediate line L is formed, and a constant luminance distribution is formed in the cross section. A light source 20 having a high luminance distribution can be configured.

  Since the light source 20 including the LED element 21 of the present modification has a luminance distribution having a peak on the p-electrode 21g side (the p-electrode 21g side rises sharply) like the light source 20 of the above-described embodiment, By using the light source 20 including the LED element 21, it is possible to configure the vehicle lamp 10 (see FIG. 1) and the vehicle lamps 10 of the modified examples 1-1 to 1-4 (see FIGS. 10 to 13). is there.

  Further, according to the present modification, the luminance distribution (peak position, peak) in the vertical cross section of the LED element 21 (light source 20) is adjusted by adjusting the vertical dimension H1 (see FIG. 14A) of the transparent electrode 21f. Can be adjusted to the target luminance distribution.

[Modification 2-2]
Next, the structure (Modification 2-2) of the LED element 21 will be described with reference to the drawings. 15A is a front view (top view) of the LED element 21 (Modification 2-2), FIG. 15B is a cross-sectional view (side view) of the LED element 21 (Modification 2-2), and FIG. (C) is an example of the luminance distribution of the LED element 21 (modification 2-2) in the CC cross section in FIG.

  In the above embodiment and each modification, the p electrode 21g has been described as being formed in the narrow region 21f1 including the long side far from the n electrode 21c on the surface of the transparent electrode 21f. It is not limited to. For example, as shown in FIGS. 15A and 15B, the p-electrode 21g may be formed in the middle between one long side and the other long side of the transparent electrode 21f.

  According to this modification, the current supplied to the p-electrode 21g is made of a metal that is easily diffused by the p-electrode 21g, so that it diffuses uniformly in the p-electrode 21g, but in the transparent electrode 21f (longitudinal section). Does not diffuse uniformly due to the resistivity of the transparent electrode 21f, but concentrates between the p electrode 21g and the n electrode 21c (having a peak between the p electrode 21g and the n electrode 21c), and p A current distribution that gradually decreases as the distance from the electrode 21g in the vertical direction (substantially the same distribution as in FIG. 15C) is formed. On the other hand, the current supplied to the p-electrode 21g is constant because the n-electrode 21c and the p-electrode 21g are arranged in parallel with each other in the transparent electrode 21f (cross section) (see FIG. 15A). A current distribution is formed.

  The active layer 21d emits light due to the current distributed in this manner, whereby the LED element 21 (its light emitting surface) has the same luminance distribution as the current distribution, that is, the light emitting surface (longitudinal section) of the LED element 21. , A luminance distribution having a peak between the p-electrode 21g and the n-electrode 21c (a steep rise between the p-electrode and the n-electrode) and gradually decreasing with increasing distance from the p-electrode 21g (FIG. 15C )) Is formed, and a constant luminance distribution is formed on the light emitting surface (transverse section) of the LED element 21.

  Therefore, by arranging the wavelength conversion layer 22 so as to cover the light emitting surface of the LED element 21 of this modification, the vertical section has a peak between the p electrode 21g and the n electrode 21c (p electrode and n electrode). A brightness distribution (see FIG. 15C) that gradually decreases as the distance from the p-electrode 21g in the vertical direction is formed, and a constant brightness distribution is formed in the transverse section. It is possible to configure the light source 20 having a luminance distribution suitable for forming a lamp light distribution pattern.

  Since the light source 20 including the LED element 21 of the present modification has a luminance distribution having a peak between the p-electrode 21g side and the n-electrode 21c, similarly to the light source 20 of the above embodiment, the LED element of the present modification It is possible to constitute the vehicular lamp 10 (see FIG. 1) and the vehicular lamp 10 (see FIGS. 10 to 13) of the modified examples 1-1 to 1-4 using the light source 20 including 21.

  For example, the portion between the p-electrode 21g side and the n-electrode 21c (the portion where the luminance is peak) is positioned on the front side of the vehicle, and the long side far from the n-electrode is positioned on the rear side of the vehicle (that is, the reflecting surface 31 side). In addition, by arranging the light source 20 so that the irradiation direction (that is, the light emitting surface) faces downward, the vehicle lamp 10 similar to that shown in FIG. 1 can be configured. The vehicular lamp 10 shown in FIGS. 10 to 13 can be similarly configured.

  Further, according to this modification, the luminance distribution (peak peak) of the LED element 21 (light source 20) is adjusted by adjusting the distance H3 (see FIG. 15A) between the n electrode 21c and the p electrode 21g. Position, peak width, etc.) can be adjusted to the desired luminance distribution.

  Here, since the light distribution pattern for headlamps has a larger diffusion in the left-right direction than in the vertical direction of the light-emitting element (LED element) light source, horizontal stripes are generated in the luminance distribution of the light-emitting element (LED element). However, the occurrence of vertical stripes has less influence on light distribution unevenness (see FIG. 21). In addition, the horizontal stripe in this application is not a luminance distribution in which the luminance decreases from the upper end to the lower end, but a luminance distribution in which peaks (peaks), valleys, peaks (peaks). 21).

  Therefore, it is preferable to adjust the area, width and thickness of the electrodes 21c, 21f and 21g, the interval between the electrodes 21c and 21g, and the like to form a luminance distribution that does not cause horizontal stripes.

[Modification 2-3]
Next, the structure (Modification 2-3) of the LED element 21 will be described with reference to the drawings. 16A is a front view (top view) of the LED element 21 (Modification 2-3), and FIG. 16B is a cross-sectional view (side view) of the LED element 21 (Modification 2-3). (C) is an example of the luminance distribution of the LED element 21 (modification 2-3) in the DD section in FIG.

  As shown in FIGS. 16A and 16B, the p-electrode 21g includes a plurality of additional electrodes 21g2 extending from the p-electrode 21g toward the n-electrode 21c, and the n-electrode 21c is the n-electrode 21c. A plurality of additional electrodes 21c2 extending from p to 21g may be included.

  According to the present modification, the current supplied to the p-electrode 21g is made of metal in which the p-electrode 21g (and the plurality of additional electrodes 21g2) easily diffuses current, and thus the p-electrode 21g (and the plurality of additional electrodes). 21g2) diffuses uniformly, but the transparent electrode 21f does not diffuse uniformly due to the resistivity of the transparent electrode 21f, and the tip of the additional electrode 21g2 of the p-electrode 21g and the additional electrode 21c2 of the n-electrode 21c Current (which has a peak between the tip of the additional electrode 21g2 of the p-electrode 21g and the tip of the additional electrode 21c2 of the n-electrode 21c) and gradually decreases as the distance from the tip increases. A distribution (substantially the same distribution as FIG. 16C) is formed. On the other hand, the current supplied to the p electrode 21g is substantially constant in the transparent electrode 21f (transverse section) because the n electrode 21c and the p electrode 21g are arranged in parallel to each other (see FIG. 16A). The current distribution is formed.

  The active layer 21d emits light due to the current distributed in this manner, whereby the LED element 21 (its light emitting surface) has the same luminance distribution as the current distribution, that is, the light emitting surface (longitudinal section) of the LED element 21. And a peak between the tip of the additional electrode 21g2 of the p electrode 21g and the tip of the additional electrode 21c2 of the n electrode 21c (the tips of the plurality of additional electrodes 21g1 of the p electrode 21g and the plurality of additional electrodes 21c1 of the n electrode 21c). A brightness distribution (see FIG. 16C) that gradually decreases as the distance from the tip increases in a vertical direction is formed between the tip and the light emitting surface (transverse section) of the LED element 21. A constant luminance distribution is formed.

  Therefore, by disposing the wavelength conversion layer 22 so as to cover the light emitting surface of the LED element 21 of this modification, in the longitudinal section, the tip of the additional electrode 21g2 of the p electrode 21g and the tip of the additional electrode 21c2 of the n electrode 21c (A steep rise between the tips of the plurality of additional electrodes 21g1 of the p electrode 21g and the tips of the plurality of additional electrodes 21c1 of the n electrode 21c), and gradually decreases from the tip in the longitudinal direction. A light source 20 having a luminance distribution suitable for forming a light distribution pattern for headlamps is formed, in which a luminance distribution (see FIG. 16C) is formed and a substantially constant luminance distribution is formed in a cross section. It becomes possible.

  In addition, the light source 20 including the LED element 21 of the present modified example has a luminance having a peak between the tip of the additional electrode 21g2 of the p-electrode 21g and the tip of the additional electrode 21c2 of the n-electrode 21c, like the light source 20 of the above-described embodiment. Because of the distribution, using the light source 20 including the LED element 21 of this modification, the vehicle lamp 10 (see FIG. 14) and the vehicle lamps 10 of the modifications 1-1 to 1-4 (FIGS. 1 and 10). To FIG. 13).

  For example, the space between the tip of the additional electrode 21g2 of the p-electrode 21g and the tip of the additional electrode 21c2 of the n-electrode 21c (the portion where the luminance is peak) is positioned on the front side of the vehicle, and the irradiation direction (that is, the light emitting surface) is downward By arranging the light source 20 so as to be, it becomes possible to configure the vehicular lamp 10 similar to that shown in FIG. The vehicular lamp 10 shown in FIGS. 10 to 13 can be similarly configured.

  Moreover, according to this modification, the LED element 21 (by adjusting the vertical overlap amount H2 (see FIG. 16A) between the additional electrode 21g2 of the p-electrode 21g and the additional electrode 21c2 of the n-electrode 21c. The luminance distribution (peak position, peak width, etc.) in the longitudinal section of the light source 20) can be adjusted to the target luminance distribution.

[Modification 2-4]
17A is a front view (top view) of the LED element 21 (Modification 2-4), and FIG. 17B is a cross-sectional view (side view) of the LED element 21 (Modification 2-4). (C) is an example of the luminance distribution of the LED element 21 (modification 2-4) in the EE cross section in FIG.

  In the above-described embodiment and each modified example, the example (see FIG. 3 and the like) using one element portion 21h including the active layer 21d, the p-type semiconductor layer 21e, and the transparent electrode 21f has been described. It is not limited to.

  For example, as shown in FIGS. 17A and 17B, a plurality of (for example, two) element portions 21h may be used. For example, the p-type semiconductor layer 21e and the like are partitioned vertically by forming at least one groove G1 extending in the same direction as the n-electrode 21c and reaching the n-type semiconductor layer 21b from the surface of the p-type semiconductor layer 21e by dry etching or the like. A transparent electrode 21f and a p-electrode 21g are formed on the upper and lower p-type semiconductor layers 21e, respectively, to form a plurality of element portions 21h arranged in parallel (FIGS. 17A and 17B). Reference).

A constant current (forward current: 1 to 5 A) controlled by a DC-DC converter or the like is respectively applied to the upper element portion 21h (one farther from the n electrode 21c) and the lower element portion 21h (one closer to the n electrode 21c). A circuit for supplying a current density (35 to 70 A / cm ² ) (for example, a constant current circuit) is connected. For example, this circuit supplies a current to the upper element portion 21h so that the current density is larger than that of the lower element portion 21h. As this circuit, for example, the circuit shown in FIG. 18A can be used.

  According to this modification, by supplying a larger current to the upper element portion 21h than the lower element portion 21h, in the longitudinal section, the upper p electrode 21g has a peak on the upper p electrode 21g side. It is possible to form a current distribution (substantially the same distribution as FIG. 17C) that gradually decreases from 1 to the n-electrode 21c. That is, the current density of the upper element part 21i is larger than the current density of the lower element part 21i.

  The upper and lower active layers 21d emit light by the current distributed in this manner, whereby the LED element 21 (its light emitting surface) has the same luminance distribution as the current distribution, that is, the light emitting surface (longitudinal section) of the LED element 21. , A luminance distribution (see FIG. 17C) having a peak on the upper p-electrode 21g side and gradually decreasing from the upper p-electrode 21g toward the n-electrode 21c is formed. In (cross section), a constant luminance distribution is formed.

  Therefore, by disposing the wavelength conversion layer 22 so as to cover the light emitting surface of the LED element 21 of this modification, the vertical cross section has a peak on the upper p electrode 21g side, and the upper p electrode 21g (n electrode 21c). A light distribution pattern for headlamps is formed in which a luminance distribution (see FIG. 17 (c)) that gradually decreases from the side far from the n electrode 21c toward the n-electrode 21c is formed, and a constant luminance distribution is formed in the cross section. The light source 20 having a luminance distribution suitable for the above can be configured.

  Further, the light source 20 including the LED element 21 of the present modification has a luminance distribution having a peak on the upper p electrode 21g side (the upper p electrode 21g side rises sharply), like the light source 20 of the above embodiment. Using the light source 20 including the LED element 21 of the present modification, the vehicle lamp 10 (see FIG. 1) and the vehicle lamp 10 of the modification 1-1 to 1-4 (see FIGS. 10 to 13) are configured. It is possible.

  For example, the peak portion on the upper p-electrode 21g side (higher brightness) is positioned on the front side of the vehicle, the n-electrode 21c is positioned on the rear side of the vehicle (that is, the reflecting surface 31 side), and the irradiation direction (that is, By disposing the light source 20 so that the light emitting surface faces downward, the vehicle lamp 10 similar to that shown in FIG. 1 can be configured. The vehicular lamp 10 shown in FIGS. 10 to 13 can be similarly configured.

  Moreover, according to this modification, the luminance distribution (peak) in the longitudinal section of the LED element 21 (light source 20) is adjusted by individually adjusting the current and current density supplied to the upper element part 21h and the lower element part 21h. , The peak width, etc.) can be adjusted to the target luminance distribution.

  Also in this case, the luminance distribution in which horizontal stripes do not occur can be formed by adjusting the area, width and thickness of the electrodes 21c, 21f and 21g, the distance between the electrodes 21c and 21g, the position and width of the groove G1, and the like. preferable.

  Further, according to the present modified example 2-4, the amount of the active layer 21d to be removed is smaller than that of the modified example 2-5 (see FIGS. 17B and 20B), so that it is brighter. The LED element 21 (light source 20) can be configured.

  In this modification, for example, a circuit (not shown) for detecting a change in the amount of current supplied to the LED element 21 is provided, and as shown in FIG. Is detected (steps S10 and S12), and when the disconnection or short circuit is detected (step S10: Yes, S12: Yes), an abnormal signal to that effect may be sent to the vehicle side device (step S14). Is possible. In this case, in the vehicle side device, a display to that effect is performed based on the abnormality signal.

[Modification 2-5]
20A is a front view (top view) of the LED element 21 (Modification 2-5), and FIG. 20B is a cross-sectional view (side view) of the LED element 21 (Modification 2-5). (C) is an example of the luminance distribution of the LED element 21 (Modification 2-5) in the FF section in FIG.

  In the embodiment and each modification, an example in which one element portion 21i including the n-type semiconductor layer 21b, the n-electrode 21c, the active layer 21d, the p-type semiconductor layer 21e, the transparent electrode 21f, and the p-electrode 21g is used ( Although described with reference to FIG. 3A, the present invention is not limited to this.

  For example, as shown in FIGS. 20A and 20B, a plurality of (for example, two) element portions 21i may be used. For example, the p-type semiconductor layer 21e and the like are partitioned vertically by forming at least one groove portion G2 extending in the same direction as the n-electrode 21c and reaching the substrate 21a from the surface of the p-type semiconductor layer 21e by dry etching or the like. By forming the n-electrode 21c, the transparent electrode 21f, and the p-electrode 21g on each of the upper and lower p-type semiconductor layers 21e, a plurality of element portions 21i (FIGS. 20A and 20B) arranged in parallel are formed. )) Can be formed. Alternatively, the plurality of element portions 21 i can be formed simply by arranging the plurality of LED elements 21 in parallel.

Circuits for supplying a constant current (forward current: 1 to 5 A, current density: 35 to 70 A / cm ² ) controlled by a DC-DC converter or the like to the upper element portion 21 i and the lower element portion 21 i, respectively. (For example, a constant current circuit) is connected. For example, this circuit supplies current to the upper element portion 21i so that the current density is larger than that of the lower element portion 21i. As this circuit, for example, the circuit shown in FIG. 18B can be used.

  According to this modification, by supplying a larger current than the lower element part 21i to the upper element part 21i (element part including the p-electrode 21g close to the long side of the LED element), Current having a peak on the upper p-electrode 21g (p-electrode 21g closest to the long side of the LED element among the p-electrodes) and gradually decreasing from the upper p-electrode 21g toward the lower n-electrode 21c A distribution (substantially the same distribution as FIG. 20C) can be formed. That is, the current density of the upper element part 21i is larger than the current density of the lower element part 21i.

  The upper and lower active layers 21d emit light by the current distributed in this manner, whereby the LED element 21 (its light emitting surface) has the same luminance distribution as the current distribution, that is, the light emitting surface (longitudinal section) of the LED element 21. , A luminance distribution (see FIG. 20C) having a peak on the upper p electrode 21g side and gradually decreasing from the upper p electrode 21g toward the lower n electrode 21c is formed. A constant luminance distribution is formed on the light emitting surface (cross section).

  Therefore, by arranging the wavelength conversion layer 22 so as to cover the light emitting surface of the LED element 21 of the present modification, the vertical cross section has a peak on the upper p electrode 21g side, and the lower n electrode from the upper p electrode 21g. A luminance distribution that gradually decreases toward the electrode 21c (see FIG. 20C) is formed, and a constant luminance distribution is formed in the cross section. The luminance distribution suitable for forming a headlamp light distribution pattern is formed. The light source 20 can be configured.

  Further, the light source 20 including the LED element 21 of the present modification has a luminance distribution having a peak on the upper p electrode 21g side (the upper p electrode 21g side rises sharply), like the light source 20 of the above embodiment. Using the light source 20 including the LED element 21 of the present modification, the vehicle lamp 10 (see FIG. 1) and the vehicle lamp 10 of the modification 1-1 to 1-4 (see FIGS. 10 to 13) are configured. It is possible.

  For example, the upper p electrode 21g side (the portion where the luminance is peak) is positioned on the front side of the vehicle, the lower n electrode is positioned on the rear side of the vehicle (that is, the reflecting surface 31 side), and the irradiation direction (that is, the light emitting surface) By disposing the light source 20 so as to face downward, a vehicle lamp 10 similar to that shown in FIG. 1 can be configured. The vehicular lamp 10 shown in FIGS. 10 to 13 can be similarly configured.

  Moreover, according to this modification, the brightness distribution (peak) in the longitudinal section of the LED element 21 (light source 20) is adjusted by individually adjusting the current and current density supplied to the upper element part 21i and the lower element part 21i. , The peak width, etc.) can be adjusted to the target luminance distribution.

  Also in this case, the luminance distribution in which no horizontal stripes are generated can be formed by adjusting the area, width and thickness of the electrodes 21c, 21f and 21g, the distance between the electrodes 21c and 21g, the position and width of the groove G2, and the like. preferable.

  In this modification, for example, a circuit (not shown) for detecting a change in the amount of current supplied to the LED element 21 is provided, and as shown in FIG. Is detected (steps S10 and S12), and when the disconnection or short circuit is detected (step S10: Yes, S12: Yes), an abnormal signal to that effect may be sent to the vehicle side device (step S14). Is possible. In this case, in the vehicle side device, a display to that effect is performed based on the abnormality signal.

  In the embodiment and each modification, the LED element 21 is an LED element that emits blue light, and the wavelength conversion layer 22 is a wavelength conversion layer that emits yellow light when excited by the blue light from the LED element 21. As described above, the present invention is not limited to this. As the LED element 21, an LED element that emits light of a wavelength other than blue light can be used, and as the wavelength conversion layer 22, a wavelength conversion layer that emits light of a wavelength other than yellow can be used. .

  The above embodiment is merely an example in all respects. The present invention is not construed as being limited to these descriptions. The present invention can be implemented in various other forms without departing from the spirit or main features thereof.

  DESCRIPTION OF SYMBOLS 10 ... Vehicle lamp, 20 ... Light source, 21 ... LED element, 21a ... Substrate (sapphire substrate), 21b ... N-type semiconductor layer, 21b1 ... Narrow region, 21c ... N electrode, 21c1 ... Pad, 21c2 ... Additional electrode, 21d ... active layer, 21e ... p-type semiconductor layer, 21f ... transparent electrode, 21f ... transparent electrode, 21f1 ... narrow region, 21g ... n electrode, 21g1 ... pad, 21g2 ... addition electrode, 21h ... element part, 21i ... element Part, 22 ... wavelength conversion layer (phosphor), 30 ... projection optical system

Claims (4)

A white color including an LED element and a wavelength conversion layer, and including light from the LED element that has passed through the wavelength conversion layer and light from the wavelength conversion layer that is excited and emitted by the light from the LED element A light source configured to emit light;
A projection optical system configured to form a light distribution pattern for headlamps on a virtual vertical screen facing the front end of the vehicle by projecting a light source image of the light source to the front of the vehicle;
In the vehicular lamp provided with
The LED element is
A rectangular substrate;
An n-type semiconductor layer laminated on one side of the substrate;
An n-electrode extending in the long side direction formed in a narrow region including one long side of the n-type semiconductor layer surface;
A plurality of active layers stacked on the surface of the n-type semiconductor layer and defined by at least one groove extending in the long side direction of the substrate and reaching the n-type semiconductor layer;
A p-type semiconductor layer stacked on each of the plurality of active layer surfaces;
A transparent electrode formed on each surface of the p-type semiconductor layer;
A p-electrode extending in the same direction as the n-electrode, formed in a narrow region including a long side far from the n-electrode on each of the transparent electrode surfaces;
Is a face-up type LED element equipped with
The projection optical system projects a plurality of light source images of the light source toward the front of the vehicle so that an image portion corresponding to the upper p electrode of the p electrodes is positioned above, and is a virtual vertical facing the front end of the vehicle. A headlamp light distribution pattern including a cut-off line formed by an image portion corresponding to the upper p electrode among the p electrodes of each of the plurality of light source images of the light source is formed on the screen. A vehicular lamp characterized by the above. An LED element and a wavelength conversion layer disposed so as to cover a light emitting surface of the LED element, and is excited by light transmitted through the wavelength conversion layer and light from the LED element among light from the LED element A light source configured to emit white light including emitted light from the wavelength conversion layer;
A projection optical system configured to form a light distribution pattern for headlamps on a virtual vertical screen facing the front end of the vehicle by projecting a light source image of the light source to the front of the vehicle;
In the vehicular lamp provided with
The LED element is
A rectangular substrate;
A plurality of n-type semiconductor layers that are stacked on one side of the substrate and that extend in the long side direction of the substrate and are partitioned by at least one groove that reaches the substrate;
An n-electrode extending in the long-side direction formed in a narrow region including one long side of each of the plurality of n-type semiconductor layer surfaces;
An active layer stacked on each of the surfaces of the plurality of n-type semiconductor layers;
A p-type semiconductor layer stacked on each of the active layer surfaces;
A transparent electrode formed on each surface of the p-type semiconductor layer;
A p-electrode extending in the same direction as the n-electrode, formed in a narrow region including a long side far from the n-electrode on each of the transparent electrode surfaces;
Is a face-up type LED element equipped with
The projection optical system projects a plurality of light source images of the light source toward the front of the vehicle so that an image portion corresponding to the upper p electrode of the p electrodes is positioned above, and is a virtual vertical facing the front end of the vehicle. A headlamp light distribution pattern including a cut-off line formed by an image portion corresponding to the upper p electrode among the p electrodes of each of the plurality of light source images of the light source is formed on the screen. A vehicular lamp characterized by the above. The upper active layer among the partitioned active layers, the upper p-type semiconductor layer stacked on the surface of the upper active layer, the upper transparent electrode formed on the surface of the upper p-type semiconductor layer, the upper The upper p electrode formed in the narrow region including the long side far from the n electrode in the transparent electrode surface and extending in the same direction as the n electrode constitutes the upper element portion,
The lower active layer among the partitioned active layers, the lower p-type semiconductor layer stacked on the lower active layer surface, the lower transparent electrode formed on the lower p-type semiconductor layer surface, and The lower p electrode formed in the narrow region including the long side far from the n electrode in the lower transparent electrode surface and extending in the same direction as the n electrode constitutes the lower element part,
And a circuit for supplying current to the upper element part and the lower element part,
2. The vehicular lamp according to claim 1, wherein the circuit supplies a current to the upper element portion so that a current density is larger than that of the lower element portion. An upper n-type semiconductor layer among the partitioned n-type semiconductor layers, an upper n-electrode extending in a long-side direction formed in a narrow region including one long side of the surface of the upper n-type semiconductor layer, An upper active layer laminated on the surface of the upper n-type semiconductor layer, an upper p-type semiconductor layer laminated on the surface of the upper active layer, and an upper transparent electrode formed on the surface of the upper p-type semiconductor layer And the upper p electrode formed in the narrow region including the long side far from the upper n electrode in the upper transparent electrode surface and extending in the same direction as the upper n electrode, It constitutes the element part,
A lower n-type semiconductor layer among the partitioned n-type semiconductor layers, a lower n-electrode extending in a long-side direction formed in a narrow region including one long side of the surface of the lower n-type semiconductor layer, Lower active layer stacked on the surface of the lower n-type semiconductor layer, lower p-type semiconductor layer stacked on the surface of the lower active layer, lower transparent electrode formed on the surface of the lower p-type semiconductor layer And a lower p-electrode formed in a narrow region including a long side far from the lower n-electrode in the lower transparent electrode surface and extending in the same direction as the lower n-electrode, It constitutes the element part,
And a circuit for supplying current to the upper element part and the lower element part,
The vehicular lamp according to claim 2, wherein the circuit supplies a current to the upper element portion so that a current density is larger than that of the lower element portion.