Vehicle luminaire and vehicle lighting tool

A vehicle luminaire according to an exemplary embodiment includes: a socket; and a light-emitting module that is provided in on one end side of the socket, and includes only three light-emitting elements. When viewing the vehicle luminaire from a direction along a central axis, light-emitting surfaces of the three light-emitting elements have an approximately rectangular shape or an approximately square shape. At the inside of an approximately rectangular luminous region with the central axis set as the center, the three light-emitting elements are provided in parallel in a row in a direction in which short sides of the luminous region face each other.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2020-070419, filed on Apr. 9, 2020; the entire contents of which are incorporated herein by reference.

FIELD

Exemplary embodiment described herein relate generally to a vehicle luminaire and a vehicle lighting tool.

BACKGROUND

From the viewpoints of energy saving and a long operation lifespan, a vehicle luminaire equipped with a light-emitting diode are becoming widespread instead of a vehicle luminaire equipped with a filament.

Here, for example, in the case of a vehicle luminaire provided in automobiles, a luminous region that is short in an upper and lower direction and is long in a right and left direction may be required. Accordingly, a technology of arranging a plurality of light-emitting diodes in a row was suggested. However, when simply arranging the plurality of light-emitting diodes in a row, unevenness in luminance occurs in a rectangular luminous region that is long in the right and left direction. When unevenness in luminance occurs, there is a concern that luminous intensity distribution standards determined from the viewpoint of safety may not be satisfied.

Here, it is desired to develop a technology capable of suppressing occurrence of unevenness in luminance in the rectangular luminous region.

DETAILED DESCRIPTION

A vehicle luminaire according to an exemplary embodiment includes: a socket; and a light-emitting module that is provided on one end side of the socket and includes only three light-emitting elements. When viewing the vehicle luminaire from a direction along a central axis, light-emitting surfaces of the three light-emitting elements have an approximately rectangular shape or an approximately square shape. At the inside of an approximately rectangular luminous region with the central axis set as the center, the three light-emitting elements are provided in parallel in a row in a direction in which short sides of the luminous region face each other.

Hereinafter, an exemplary embodiment will be described with reference to the accompanying drawings. Note that, in the drawings, the same reference numeral will be given to the same constituent element, and detailed description thereof will be appropriately omitted.

A vehicle luminaire1according to this embodiment can be provided, for example, in an automobile. Examples of the vehicle luminaire1include vehicle luminaires which can be used in a front combination light (for example, an appropriate combination of a daytime running lamp (DRL), a position lamp, a turn signal lamp, and the like), a rear combination light (for example, an appropriate combination of a stop lamp, a tail lamp, a turn signal lamp, a back lamp, a fog lamp, and the like), and the like. However, the use of the vehicle luminaire1is not limited to the examples.

FIG. 1is a schematic perspective view illustrating the vehicle luminaire1according to this embodiment.

Note that, inFIG. 9, when mounting the vehicle luminaire1to a housing101of a vehicle lighting tool100, a direction that is a forward side of the vehicle lighting tool100is set as a front side, a direction that is a rearward side is set as a rear side, a direction that is an upward side is set as an upper side, a direction that is a downward side is set as a lower side, a direction that is a rightward side is set as a right side, and a direction that is a leftward side is set as a left side. In this case, a right and left direction can be set as a horizontal direction. An upper and lower direction can be set as an approximately vertical direction.

FIG. 2is a cross-sectional view of the vehicle luminaire1inFIG. 1in a direction of line A-A.

As illustrated inFIG. 1andFIG. 2, a socket10, a light-emitting module20, a power-supply part30, and a heat transfer part40can be provided in the vehicle luminaire1.

The socket10can include a mounting part11, a bayonet12, a flange13, and a thermal radiation fin14.

The mounting part11can be provided on a surface of the flange13which is opposite to a surface on which the thermal radiation fin14is provided. An external shape of the mounting part11can be set as a columnar shape. For example, the external shape of the mounting part11is a circular column shape. The mounting part11can include a concave part11athat is opened to an end on a side opposite to the flange13side.

At least one slit11b(shown inFIG. 1) can be provided in the mounting part11. A corner portion of a board21can be provided inside the slit11b. A dimension (width) of the slit11bin a peripheral direction of the mounting part11can be set to be slightly larger than a dimension of the corner portion of the board21. In this case, positioning of the board21can be carried out by inserting the corner portion of the board21into the slit11b.

In addition, when the slit11bis provided, planar dimensions of the board21can be enlarged. According to this, the number of elements mounted on the board21can be increased. Alternatively, since the external size of the mounting part11can be reduced, a reduction in size of the mounting part11, and a reduction in size of the vehicle luminaire1can be realized.

The bayonet12can be provided on an outer surface of the mounting part11. For example, the bayonet12protrudes toward an outer side of the vehicle luminaire1. The bayonet12can be set to face the flange13. A plurality of the bayonets12can be provided. The bayonet12can be used when mounting the vehicle luminaire1to the housing101of the vehicle lighting tool100. The bayonet12can be used for twist lock.

The flange13can be set to have a plate shape. For example, the flange13can be set to have a disk shape. An outer surface of the flange13can be located on an outer side of the vehicle luminaire1in comparison to an outer surface of the bayonet12.

The thermal radiation fin14can be provided on a side of the flange13which is opposite to the mounting part11side. As the thermal radiation fin14, at least one piece can be provided. For example, a plurality of the thermal radiation fins14are provided in the socket10illustrated inFIG. 1. The plurality of thermal radiation fins14can be provided in parallel in a predetermined direction. The thermal radiation fins14can be set to have a plate shape.

As illustrated inFIG. 2, a hole10aand a hole10bthat communicates with the hole10acan be provided in the socket10. A support part32can be provided inside the hole10a. Ends of a plurality of power-supply terminals31are exposed to the inside of the hole10b. A connector105(shown inFIG. 9) including a sealing member105ais inserted into the hole10b, and the connector105can be fitted to the ends of the plurality of power-supply terminals31.

The socket10can have a function of holding the light-emitting module20and the power-supply part30, and a function of transferring heat generated in the light-emitting module20to the outside. Accordingly, it is preferable that the socket10is formed from a material such as a metal having high heat conductivity.

In addition, recently, it is desired for the socket10to efficiently thermally radiate heat generated in the light-emitting module20, and to be light in weight. Accordingly, it is more preferable that the socket10is formed from a highly heat conductive resin. For example, the highly heat conductive resin includes a resin and a filler using an inorganic material. For example, the highly heat conductive resin can be set as a material obtained by mixing a filler using carbon or aluminum oxide in a resin such as polyethylene terephthalate (PET) and nylon.

In the case of the socket10which contains the highly heat conductive resin, and in which the mounting part11, the bayonet12, the flange13, and the thermal radiation fin14are integrally formed, heat generated in the light-emitting module20can be efficiently thermally radiated. In addition, the weight of the socket10can be reduced. In this case, the mounting part11, the bayonet12, the flange13, and the thermal radiation fin14can be integrally formed by using an injection molding method or the like. In addition, the socket10and the power-supply part30can also be integrally formed by using an insert molding method or the like.

The power-supply part30can include a plurality of the power-supply terminals31and the support part32.

The plurality of power-supply terminals31can be set as a pin-shaped body. Ends of the plurality of power-supply terminals31on the light-emitting module20side can be soldered to an output terminal and an input terminal of a wiring pattern21a. Ends of the plurality of power-supply terminals31on the thermal radiation fin14side can be exposed to the inside of the hole10b. For example, the power-supply terminals31can be formed from a metal such as a copper alloy. Note that, the number, the shape, the arrangement, the material, and the like of the power-supply terminals31are not limited to the example, and can be appropriately changed.

As described above, it is preferable that socket10is formed from a material with high heat conductivity. By the way, the material with high heat conductivity may have electrical conductivity. For example, the highly heat conductive resin or the like which uses a filler containing carbon may have electrical conductivity. According to this, the support part32can be provided for insulation between the power-supply terminals31and the socket10having electrical conductivity. In addition, the support part32can also have a function of holding the plurality of power-supply terminals31. Note that, when the socket10is formed from the highly heat conductive resin (for example, a highly heat conductive resin containing a filler using aluminum oxide, or the like) having insulation properties, the support part32can be omitted. In this case, the socket10can hold the plurality of power-supply terminals31.

The support part32can be formed from a resin having insulation properties. For example, the support part32can be pressed into the hole10aprovided in the socket10, or can be bonded to an inner wall of the hole10a.

The heat transfer part40can be provided between the socket10and the light-emitting module20. It is preferable that the heat transfer part40is formed from a material with high heat conductivity. For example, the heat transfer part40can be formed from a metal such as aluminum, an aluminum alloy, copper, and a copper alloy. The heat transfer part40can be bonded to a bottom surface11a1of the concave part11a. In this case, it is preferable to use adhesive with high heat conductivity as adhesive. For example, the adhesive can be set as adhesive in which a filler using an inorganic material is mixed. In addition, the heat transfer part40can also be attached to the bottom surface11a1of the concave part11athrough a layer including heat conductive grease (thermal radiation grease). As the heat conductive grease, for example, grease obtained by mixing a filler using an inorganic material in modified silicone can be used. In addition, the heat transfer part40can also be inserted into the bottom surface11a1of the concave part11aby using an insert molding method or the like.

Note that, when heat generated in the light-emitting module20is less, the heat transfer part40can also be omitted. When the heat transfer part40is omitted, for example, the light-emitting module20can be bonded to the bottom surface11a1of the concave part11a.

The light-emitting module20can be provided on one end side of the socket10.

As illustrated inFIG. 1andFIG. 2, the light-emitting module20can include the board21, a light-emitting element22, a diode23, and a resistor24.

The board21has a plate shape. For example, a planar shape of the board21can be set as an rectangular shape. For example, the board21can be bonded to a surface40aof the heat transfer part40on a side opposite to the bottom surface11a1side of the concave part11a. As adhesive for bonding the board21to the heat transfer part40, the same adhesive for bonding the heat transfer part40to the bottom surface11a1of the concave part11acan be used. For example, the board21can be formed from an inorganic material such as ceramics (for example, aluminum oxide, aluminum nitride, and the like), an organic material such as paper phenol and glass epoxy, or the like. In addition, the board21may be a member obtained by coating a surface of a metal plate with an insulating material. When the amount of heat generation in the light-emitting element22is large, from the viewpoint of thermal radiation, it is preferable that the board21is formed by using a material with high heat conductivity. Examples of the material with high heat conductivity include ceramics such as aluminum oxide and aluminum nitride, a highly heat conductive resin, a member obtained by coating a surface of a metal plate with an insulating material, and the like. In addition, the board21may have a single-layer structure, or a multi-layer structure.

In addition, the wiring pattern21acan be provided on the surface of the board21. For example, the wiring pattern21acan be formed from a material containing silver as a main component, a material containing copper as a main component, or the like.

For example, the light-emitting element22can be set as a light-emitting diode, an organic light-emitting diode, a laser diode, or the like. For example, the light-emitting element22can be set as a surface mounting type light-emitting element. When viewing the vehicle luminaire1from a direction along a central axis1a, a planar shape of a light-emitting surface22a(upper surface) of the light-emitting element22can be set as an approximately rectangular shape.

As the light-emitting element22, three pieces can be provided. The three light-emitting elements22can be provided on a side of the board21which is opposite to the heat transfer part40side. The three light-emitting elements22can be electrically connected to the wiring pattern21a. The three light-emitting elements22can be connected in series.

The three light-emitting elements22can be provided in parallel in a row in the right and left direction. In this case, the three light-emitting elements22can be aligned in parallel so that long sides of the light-emitting surface22aare adjacent to each other.

When viewing the vehicle luminaire1from a direction along the central axis1a, one of the light-emitting elements22can be provided at a position that overlaps the central axis1aof the vehicle luminaire1. In this case, it is preferable that the center of the one light-emitting element22overlaps the central axis1aof the vehicle luminaire1. One of the remaining light-emitting elements22can be provided on a left side of the light-emitting element22provided at the position that overlaps the central axis1a. The remaining one light-emitting element22can be provided on a right side of the light-emitting element22provided at the position that overlaps the central axis1a.

Note that, details relating to arrangement of the three light-emitting elements22and the like will be described later.

The diode23can be provided on a side of the board21which is opposite to the heat transfer part40. The diode23can be electrically connected to the wiring pattern21a. The diode23can be connected to the three light-emitting elements22in series. The diode23can be provided so that a reverse voltage is not applied to the light-emitting elements22, and a pulse noise from the reverse direction is not applied to the light-emitting elements22. For example, the diode23can be set as a surface mounting type diode, a diode including a lead wire, or the like. The diode23illustrated inFIG. 1is the surface mounting type diode.

The resistor24can be provided on a side of the board21which is opposite to the heat transfer part40side. The resistor24can be electrically connected to the wiring pattern21a. For example, the resistor24can be set as a surface mounting type resistor, a resistor (metal oxide film resistor) including a lead wire, a film-shaped resistor formed by using a screen printing method or the like, or the like. Note that, the resistor24illustrated inFIG. 1is the film-shaped resistor.

For example, a material of the film-shaped resistor can be set as ruthenium oxide (RuO2). For example, the film-shaped resistor can be formed by using a screen printing method and a baking method. When the resistor24is the film-shaped resistor, a contact area between the resistor24and the board21can be enlarged, and thus thermal radiation properties can be improved. In addition, a plurality of the resistors24can be formed at a time. Accordingly, productivity can be improved. In addition, a variation in a resistance value in the plurality of resistors24can be suppressed.

Here, since a variation exists in forward voltage characteristics of each of the light-emitting elements22, when an application voltage between an anode terminal and a ground terminal is set to be constant, a variation occurs in the brightness (luminous flux, luminance, luminous intensity, and illuminance) of light emitted from the light-emitting element22. Accordingly, a value of a current flowing to the light-emitting element22is set to be within a predetermined range by the resistor24so that the brightness of light emitted from the light-emitting element22enters a predetermined range. In this case, the value of the current flowing to the light-emitting element22is set to be within the predetermined range by changing a resistance value of the resistor24.

In a case where the resistor24is a film-shaped resistor, when a part of the resistor24is removed, the resistance value can be increased. For example, the part of the resistor24can be easily removed by irradiating the resistor24with laser light. When the resistor24is a surface mounting type resistor, a resistor including a lead wire, or the like, the resistor24having an appropriate resistance value can be selected in correspondence with the forward voltage characteristics of the light-emitting element22. The number, size, arrangement, and the like of the resistor24are not limited to the exemplary configuration, and can be appropriately changed in correspondence with specifications of the light-emitting element22, and the like.

A pull-down resistor can also be provided for detection of disconnection, prevention of erroneous lighting, and the like in the light-emitting element22. In addition, a covering part that covers the wiring pattern21a, the film-shaped resistor, and the like can also be provided. For example, the covering part can contain a glass material.

Next, description will be further given of arrangement of the three light-emitting elements22, and the like.

In the case of the vehicle luminaire1provided in an automobile, in a luminous region200that is short in the upper and lower direction (approximately vertical direction), and is long in the right and left direction (approximately horizontal direction), it may be required for luminance to be uniform as can as possible (to suppress occurrence of unevenness in luminance). For example, in the luminous region200, when unevenness in luminance occurs, there is a concern that luminous intensity distribution standards determined from the viewpoint of safety may not be satisfied.

As illustrated inFIG. 4to be described later, in the case of the vehicle luminaire1provided in an automobile, it is preferable to employ the luminous region200having a rectangular shape in which long sides are aligned in the upper and lower direction. For example, when a length of each of the long sides of the rectangular luminous region200is set as L1 (mm), a length of each of short sides is set as L2 (mm), L1/L2 can be set to 2.3 to 3.5. For example, the length L1 of the long side of the luminous region200can be set to 3.8 to 4.2 (mm), and the length L2 of the short side can be set to 1.2 to 1.6 (mm). Preferably, the length L1 of the long side of the luminous region200can be set to 4.0 (mm), and the length L2 of the short side can be set to 1.4 (mm).

In addition, it may be required to enlarge a difference between luminance inside the luminous region200and luminance at the periphery of the luminous region200. For example, when the difference between the luminance inside the luminous region200and the luminance at the periphery decreases, luminous intensity distribution determined from the viewpoint of safety may not be satisfied. For example, a maximum value of the peripheral luminance is preferably set to 10% or less of average luminance inside the luminous region200. In this case, when a light-shielding member is provided on a light emission side of the light-emitting element22to shield light at the periphery of the luminous region200, the difference between luminance inside the luminous region200and luminance at the periphery can be enlarged. However, in this case, a part of light emitted from the light-emitting element22is absorbed by the light-shielding member, and thus light-emitting efficiency decreases.

FIG. 3is a schematic plan view illustrating a light-emitting element122and arrangement thereof according to a comparative example.

The surface mounting type light-emitting element122includes a package122b, and a light-emitting surface122aprovided in an upper end of the package122b. In addition, when mounting the light-emitting element122in the wiring pattern21a, it is necessary to prevent short-circuit with an adjacent light-emitting elements122from occurring.

Accordingly, when arranging light-emitting surfaces122aof three pieces of the light-emitting elements122inside the luminous region200, as illustrated inFIG. 3, it is necessary to provide a gap between a plurality of the packages112b. When a gap is provided between the packages122b, in a right and left direction inside the luminous region200, it is difficult to reduce a dimension between the light-emitting surfaces122a. At the inside of the luminous region200, when the dimension between the light-emitting surfaces122ais enlarged, luminance between the light-emitting surfaces122adecreases, and unevenness in luminance increases.

In addition, typically, a planar shape of each of the light-emitting surfaces122aof the light-emitting elements122is an approximately square shape. As described above, at the inside of the luminous region200, a length of the light-emitting surface122ain the right and left direction is limited by a dimension between the light-emitting surfaces122a. In addition, when the planar shape of the light-emitting surface122ais the approximately square shape, a length of the light-emitting surface122ain the upper and lower direction becomes the same as the length in the right and left direction. Accordingly, it is difficult to enlarge an area of the light-emitting surface122a, and it is also difficult to suppress unevenness in luminance at the inside of the luminous region200.

FIG. 4is a schematic plan view illustrating the light-emitting element22and arrangement of the light-emitting element22according to this embodiment.

As illustrated inFIG. 4, three pieces of the light-emitting elements22can be provided inside the luminous region200in parallel in the right and left direction. The surface mounting type light-emitting element22includes a package22band a light-emitting surface22aprovided in an upper end of the package22b. For example, the center of the three light-emitting surfaces22acan be provided on a line segment that passes through the central axis1aof the vehicle luminaire1, and is parallel to the long side of the luminous region200.

As in the light-emitting element122, a gap is provided between a plurality of the packages22b. Accordingly, in the right and left direction inside of the luminous region200, it is difficult to reduce a dimension between a plurality of the light-emitting surfaces22a. At the inside of the luminous region200, a length of the light-emitting surface22ain the right and left direction is limited by a dimension between the light-emitting surfaces22a, and thus it is difficult to enlarge a length of the light-emitting surface22ain the right and left direction.

Here, in the light-emitting element22according to this embodiment, as illustrated inFIG. 4, the planar shape of the light-emitting surface22ais set as an approximately rectangular shape. In this case, the light-emitting element22can be provided inside the luminous region200so that long sides of the light-emitting surface22aare aligned in parallel in the right and left direction. That is, at the inside of the luminous region200having the approximately rectangular shape with the central axis1aset as the center, the three light-emitting elements22are provided in parallel in a direction in which long sides of the light-emitting surface22aare aligned in parallel in a direction in which short sides of the luminous region200are parallel.

When the planar shape of the light-emitting surface22ais the approximately rectangular shape, the length of the light-emitting surface22ain the upper and lower direction can be enlarged in comparison to the length of the light-emitting surface22ain the right and left direction. Accordingly, even when the length of the light-emitting surface22ain the right and left direction cannot be enlarged, an area of the light-emitting surface22acan be enlarged. When the area of the light-emitting surface22acan be enlarged, it is easy to suppress unevenness in luminance inside the luminous region200. For example, in the right and left direction inside the luminous region200, an inter-center distance (pitch dimension) P (mm) of the light-emitting surfaces22acan be set to, for example, 1.2 to 1.6 (mm).

In this case, when the length of the light-emitting surface22ain the upper and lower direction is excessively enlarged, there is a concern that a difference between luminance inside the luminous region200and luminance at the periphery becomes excessively small. Accordingly, it is preferable that the length La (mm) of the light-emitting surface22ain the upper and lower direction is set to, for example, 0.8 to 1.4 (mm). In this case, the length Lb (mm) of the light-emitting surface22ain the right and left direction can be set to, for example, 0.7 to 1.0 (mm).

FIG. 5is a schematic plan view illustrating a light-emitting element and arrangement of the light-emitting element according to another embodiment.

As illustrated inFIG. 5, two light-emitting elements22and one light-emitting element25can be provided inside the luminous region200in parallel in the right and left direction. The light-emitting element25can be set as a surface mounting type light-emitting element. Accordingly, the light-emitting element25includes a package25band a light-emitting surface25athat is provided in an upper end of the package25b. The center between two light-emitting surfaces22aand the center of one light-emitting surface25acan be provided, for example, on a line segment that passes through the central axis la of the vehicle luminaire1, and is parallel to the long sides of the luminous region200.

That is, when viewing the vehicle luminaire1from a direction along the central axis1a, the light-emitting surface25aof the light-emitting element25has an approximately square shape, and the light-emitting surfaces22aof the two light-emitting elements22have an approximately rectangular shape.

At the inside of the luminous region200having an approximately rectangular shape with the central axis1aset as the center, the light-emitting element25is provided in parallel between the light-emitting elements22.

The two light-emitting elements22are provided so that long sides of the light-emitting surfaces22aare aligned in parallel in a direction in which the short sides of the luminous region200are parallel.

For example, a length of a side of the light-emitting surface25aof which a planar shape is an approximately square shape can be set to be approximately the same as the length La (mm) of the light-emitting surface22ain the upper and lower direction. That is, the length of the side of the light-emitting surface25acan be set to be approximately the same as the length La (mm) of the long side of the light-emitting surface22a.

As described above, in the luminous region200, the length L1 (mm) of the long side and the length L2 (mm) of the short side are within a predetermined range. Accordingly, when the number of the light-emitting elements is set to 3, at the inside of the luminous region200, unevenness in luminance may be likely to occur. For example, when the length L1 (mm) of the long side of the luminous region200is long, a distance between the light-emitting surface22aand the light-emitting surface25ais enlarged, and thus at the inside of the luminous region200, luminance between the light-emitting surface22aand the light-emitting surface25amay decrease. In this case, it is preferable that the length of the light-emitting surface25ain the right and left direction is set to be longer than the length of the light-emitting surface22ain the right and left direction. In this configuration, it is possible to suppress luminance between the light-emitting surface22aand the light-emitting surface25afrom being decreased at the inside of the luminous region200.

In this case, it is preferable that (Lb+La+Lb)/L1 becomes 0.6 or greater. According to this, since sufficient luminance can be obtained at the inside of the luminous region200, a region with low luminance is suppressed from occurring at the inside of the luminous region200. That is, in the luminous region200, occurrence of unevenness in luminance can be suppressed.

FIGS. 6A to 6Care schematic plan views illustrating a light-emitting element and arrangement of the light-emitting element according to still another embodiment.

As illustrated inFIG. 6A, at the inside of the luminous region200, two light-emitting elements22(corresponding to an example of the third light-emitting elements) and one light-emitting element26(corresponding to an example of the second light-emitting element) can be provided in parallel in the right and left direction. The light-emitting element26can be set as the surface mounting type light-emitting element. Accordingly, the light-emitting element26includes a package26band a light-emitting surface26aprovided in an upper end of the package26b. The center of two light-emitting surfaces22aand the center of the one light-emitting surface26acan be provided, for example, on a line segment that passes through the central axis1aof the vehicle luminaire1and is parallel to the long side of the luminous region200.

That is, when viewing the vehicle luminaire1from a direction along the central axis1a, the light-emitting surface26aof the light-emitting element26has an approximately square shape, and the light-emitting surfaces22aof the two light-emitting elements22have an approximately rectangular shape.

At the inside of the luminous region200having an approximately rectangular shape with the central axis1aset as the center, the light-emitting element26is provided in parallel between the light-emitting elements22.

The two light-emitting elements22are provided so that long sides of the light-emitting surface22aare aligned in parallel in a direction in which the short sides of the luminous region200face each other.

For example, a length of a side of the light-emitting surface26aof which a planar shape is an approximately square shape can be set to be approximately the same as a length Lb (mm) of the light-emitting surface22ain the right and left direction. That is, the length of the side of the light-emitting surface26acan be set to be approximately the same as the length Lb (mm) of a short side of the light-emitting surface22a.

As described above, in the luminous region200, the length L1 (mm) of the long side and the length L2 (mm) of the short side are within a predetermined range. Accordingly, when the length L1 (mm) of the long side of the luminous region200is short, luminance near the center of the luminous region200may be excessively high. In this case, an area of the light-emitting surface26aof the light-emitting element26provided near the center of the luminous region200can be reduced. In this configuration, in the luminous region200, occurrence of unevenness in luminance can be suppressed.

As illustrated inFIG. 6B, at the inside of the luminous region200, two light-emitting elements26(corresponding to an example of second light-emitting elements), and one light-emitting element25(corresponding to an example of a first light-emitting element) can be provided in parallel in the right and left direction. The center of two light-emitting surfaces26aand the center of one light-emitting surface25acan be provided, for example, on a line segment that passes through the central axis1aof the vehicle luminaire1, and is parallel to the long side of the luminous region200.

That is, when viewing the vehicle luminaire1from a direction along the central axis1a, the light-emitting surface25aof the light-emitting element25has an approximately square shape, and the light-emitting surfaces26aof the two light-emitting elements26have an approximately square shape.

At the inside of the luminous region200having an approximately rectangular shape with the central axis1aset as the center, the light-emitting element25is provided in parallel between the light-emitting elements26.

The light-emitting surface25aof the light-emitting element25is larger than each of the light-emitting surfaces26aof the light-emitting elements26.

As described above, in the luminous region200, the length L1 (mm) of the long side and the length L2 (mm) of the short side are within a predetermined range. Accordingly, a difference between luminance inside the luminous region200and luminance of the periphery of the luminous region200may be excessively small depending on the lengths. For example, in the right and left direction, luminance of the periphery of ends of the luminous region200may be excessively high. In this case, in the right and left direction, an area of the light-emitting surfaces26aof the light-emitting elements26provided near the ends of the luminous region200can be reduced. Note that, as illustrated inFIG. 6B, the light-emitting surfaces26acan be set to have an approximately square shape. In this configuration, a difference between luminance inside the luminous region200and luminance of the periphery of the luminous region200can be enlarged.

As illustrated inFIG. 6C, at the inside of the luminous region200, two light-emitting elements125(corresponding to an example of the third light-emitting elements) and one light-emitting element25(corresponding to an example of the second light-emitting element) can be provided in parallel in the right and left direction. The center of two light-emitting surfaces125aand the center of one light-emitting surface25acan be provided on a line segment that passes through the central axis1aof the vehicle luminaire1and is parallel to the long side of the luminous region200.

That is, when viewing the vehicle luminaire1from a direction along the central axis1a, the light-emitting surface25aof the light-emitting element25has an approximately square shape, and the light-emitting surfaces125aof the two light-emitting elements125have an approximately rectangular shape.

At the inside of the luminous region200having an approximately rectangular shape with the central axis1aset as the center, the light-emitting element25is provided in parallel between the light-emitting elements125.

The two light-emitting elements125are provided so that long sides of the light-emitting surfaces125aare aligned in parallel in a direction in which the short sides of the luminous region200are parallel.

As described above, in the luminous region200, the length L1 (mm) of the long side and the length L2 (mm) of the short side are within a predetermined range. Accordingly, a difference between luminance inside the luminous region200and luminance of the periphery of the luminous region200may be excessively small depending on the lengths. For example, in the right and left direction, luminance of the periphery of ends of the luminous region200may be excessively high. In this case, in the right and left direction, an area of the light-emitting surfaces125aof the light-emitting elements125provided near the ends of the luminous region200can be reduced. Note that, as illustrated inFIG. 6C, the light-emitting surfaces125acan be set to have an approximately rectangular shape. Long sides of the light-emitting surfaces125acan be aligned in parallel in a direction in which the short sides of the luminous region200face each other. In this configuration, a difference between luminance inside the luminous region200and luminance of the periphery of the luminous region200can be enlarged.

FIG. 7Ais a schematic plan view illustrating a light-emitting element and arrangement of the light-emitting element according to still another embodiment.

FIG. 7Bis a schematic cross-sectional view of the arrangement of the light-emitting element inFIG. 7Ain a direction of line B-B.

As illustrated inFIG. 7A, at the inside of the luminous region200, three light-emitting elements27can be provided in parallel in the right and left direction. Since the light-emitting elements27are chip-shaped light-emitting elements, upper surfaces of the light-emitting elements27become light-emitting surfaces22a. The light-emitting elements27can be provided so that long sides of the light-emitting surfaces22aare aligned in parallel in the right and left direction.

As illustrated inFIG. 7B, for example, the light-emitting elements27can be mounted on a board21by chip on board (COB). The chip-shaped light-emitting elements27can be set as a vertical electrode type light-emitting element, an upper electrode type light emitting element, a flip chip type light-emitting element, or the like.

In addition, a frame-shaped frame part28can be provided to surround the three light-emitting elements27. When viewing the vehicle luminaire1from a direction along the central axis1a, an external shape of the frame part28can be set to an approximately rectangular shape. When viewing the vehicle luminaire1from a direction along the central axis1a, an opening of the frame part28can be set to an approximately rectangular shape. The opening of the frame part28can be set as the luminous region200.

The frame part28can be provided on the board21. The frame part28can be bonded to the board21. The frame part28can be formed from a resin. For example, the resin can be a thermoplastic resin such as polybutylene terephthalate (PBT), polycarbonate (PC), PET, nylon, polypropylene (PP), polyethylene (PE), and polystyrene (PS). In addition, particles such as titanium oxide can be mixed in the resin to improve reflectance with respect to light emitted from the light-emitting elements27. In addition, the frame part28can be formed from, for example, a white resin.

As illustrated inFIG. 7B, an inner wall surface of the frame part28can be set as a surface that is approximately orthogonal to a surface of the board21, or can be set as an inclined surface28a. The inclined surface28ais inclined in a direction to be spaced apart from the central axis of the frame part28as being spaced apart from the board21. When the inner wall surface of the frame part28is the inclined surface28a, light incident to the inner wall surface is likely to be emitted toward the front side of the vehicle luminaire1. That is, the frame part28can have a function of a reflector.

A sealing part29can be provided on an inner side of the frame part28. The sealing part29is provided to cover the inner side of the frame part28. The sealing part29can be formed from a material having translucency. The sealing part29can be formed by filling the inner side of the frame part28with a resin. Filling with the resin can be performed, for example, by using a dispenser or the like. For example, the filling resin can be set as a silicone resin or the like.

A phosphor can be contained in the sealing part29. In addition, a wavelength conversion sheet (sheet containing the phosphor) can also be provided on the light-emitting surfaces22aof the light-emitting elements27. The wavelength conversion sheet can be obtained by dispersing a granular phosphor inside a resin sheet having translucency. For example, the phosphor can be set as an yttrium-aluminum-garnet-based phosphor (YAG-based phosphor). However, the type of the phosphor can be appropriately changed so as to obtain a desired emission color in correspondence with the use of the vehicle luminaire1or the like.

FIGS. 8A to 8Dare schematic plan views illustrating a light-emitting element and arrangement of the light-emitting element according to still another embodiment.

As illustrated inFIG. 8A, a chip-shaped light-emitting element27aincluding the light-emitting surface22aillustrated inFIG. 5, a chip-shaped light-emitting element27bincluding the light-emitting surface25aillustrated inFIG. 5, the frame part28that surrounds the elements, and the sealing part29provided on an inner side of the frame part28can also be provided.

As illustrated inFIG. 8B, a chip-shaped light-emitting element27aincluding the light-emitting surface22aillustrated inFIG. 6A, a chip-shaped light-emitting element27cincluding the light-emitting surface26aillustrated inFIG. 6A, the frame part28that surrounds the elements, and the sealing part29provided on an inner side of the frame part28can also be provided.

As illustrated inFIG. 8C, a chip-shaped light-emitting element27cincluding the light-emitting surface26aillustrated inFIG. 6B, a chip-shaped light-emitting element27bincluding the light-emitting surface25aillustrated inFIG. 6B, the frame part28that surrounds the elements, and the sealing part29that is provided on an inner side of the frame part28can also be provided.

As illustrated inFIG. 8D, a chip-shaped light-emitting element27dincluding the light-emitting surface125aillustrated inFIG. 6C, a chip-shaped light-emitting element27bincluding the light-emitting surface25aillustrated inFIG. 6C, the frame part28that surrounds the elements, and the sealing part29that is provided on an inner side of the frame part28can also be provided.

Note that, an electrode may be included in a light-emitting surface of a chip-shaped light-emitting element. For example, an electrode may be included in a light-emitting surface of the vertical electrode type light-emitting element, or a light-emitting surface of the upper electrode type light-emitting element.

An operation and an effect of the chip-shaped light-emitting elements are similar as in the case of the above-described surface mounting type light-emitting element, and thus detailed description thereof will be omitted.

Next, the vehicle lighting tool100will be described.

Note that, in the following description, as an example, description will be given of a case where the vehicle lighting tool100is the front combination light that is provided in automobiles. However, the vehicle lighting tool100is not limited to the front combination light that is provided in automobiles.

FIG. 9is a schematic partial cross-sectional view for illustrating the vehicle lighting tool100.

As illustrated inFIG. 9, the vehicle luminaire1, the housing101, a cover102, an optical element unit103, a sealing member104, and the connector105can be provided in the vehicle lighting tool100.

The housing101holds the mounting part11. The housing101has a box shape in which one end side is opened. For example, the housing101can be formed from a resin or the like through which light is not transmitted. An attachment hole101a, into which a portion of the mounting part11where the bayonet12is provided is inserted, can be provided in a bottom surface of the housing101. A concave part, into which the bayonet12provided in the mounting part11is inserted, can be provided in a peripheral edge of the attachment hole101a. Note that, description was given of a case where the attachment hole101ais directly provided in the housing101, but an attaching member including the attachment hole101amay be provided in the housing101.

When mounting the vehicle luminaire1to the vehicle lighting tool100, the portion of the mounting part11where the bayonet12is provided is inserted into the attachment hole101a, and the vehicle luminaire1is rotated. In this case, the bayonet12is held to a fitting part provided in the peripheral edge of the attachment hole101a. This attachment method is referred to as twist-lock.

The cover102can be provided to cover an opening of the housing101. The cover102can be formed from a resin or the like having translucency. The cover102can be set to have a function of a lens or the like.

Light emitted from the vehicle luminaire1is incident to the optical element unit103. The optical element unit103can carry out reflection, diffusion, guiding, condensing, formation of a predetermined luminous intensity distribution pattern, and the like with respect to the light emitted from the vehicle luminaire1. For example, the optical element unit103illustrated inFIG. 9is a reflector. In this case, the optical element unit103reflects the light emitted from the vehicle luminaire1to form a predetermined luminous intensity distribution pattern.

The sealing member104is provided between the flange13and the housing101. The sealing member104can have an annular shape. The sealing member104can be formed from a material such as a rubber and a silicone resin which have elasticity.

When the vehicle luminaire1is mounted to the vehicle lighting tool100, the sealing member104is sandwiched between the flange13and the housing101. Accordingly, an internal space of the housing101is hermetically sealed by the sealing member104. In addition, the bayonet12is pressed against the housing101due to an elastic force of the sealing member104. Accordingly, the vehicle luminaire1can be suppressed from being detached from the housing101.

The connector105can be fitted to the ends of the plurality of power-supply terminals31exposed to the inside of the hole10b. A power-supply (not illustrated) or the like is electrically connected to the connector105. Accordingly, when the connector105is fitted to the ends of the power-supply terminals31, the power-supply (not illustrated) or the like and the light-emitting element are electrically connected. The sealing member105ais provided to prevent water from intruding into the hole10b. When the connector105including the sealing member105ais inserted into the hole10b, the hole10bis water-tightly sealed.