Vehicle lighting devices and vehicle lamps

Abstract

The present invention provides a vehicle lighting device and a vehicle lamp that do not have excessively large planar dimensions on a substrate on which multiple light-emitting elements and circuit elements are provided. [Solution] The vehicle lighting device comprises a rectangular substrate, four chip-shaped first light-emitting elements arranged in series on one surface of the substrate at positions that are rotationally symmetrical with respect to the center of the substrate, a frame having a substantially square outline that surrounds the four first light-emitting elements, a first protective element provided around the frame to protect the light-emitting elements from surges, and a control element provided around the frame to control the illumination of the light-emitting elements. The centers of each of the four first light-emitting elements coincide with the diagonals of the frame. When the planar dimension of the rectangular area on the substrate on which the four first light-emitting elements are mounted is L1 (mm) and the planar dimension of the substrate is B1 (mm), the following equation is satisfied. 0.16≦L1(mm) / B1(mm)≦0.25

Description

[Technical Field]

[0001] FIELD An embodiment of the present invention relates to a vehicle lighting device and a vehicle lamp. [Background technology]

[0002] From the perspective of energy conservation and extended lifespan, vehicle lighting systems equipped with light-emitting elements such as LEDs are becoming more widespread, replacing vehicle lighting systems equipped with lamps that have filaments.

[0003] Here, a technology is proposed in which light emitted from a vehicle lighting device is directed into a light guide, guided in the direction in which the light guide extends, and also irradiates light to the outside from the light guide. If a light guide is provided, it is possible to illuminate a wide area with a single vehicle lighting device, and to improve the design and visibility.

[0004] Generally, light guides have a long, rectangular shape. Vehicle lighting devices allow light to enter the light guide from one end in the direction of its extension. Therefore, it is preferable for vehicle lighting devices to have light distribution characteristics close to those of a point light source. Furthermore, to illuminate a wider area via the light guide, a higher luminous flux is desired for vehicle lighting devices. In this case, by providing multiple light-emitting elements in a narrow area, it is possible to achieve light distribution characteristics close to those of a point light source while simultaneously increasing luminous flux.

[0005] However, if multiple light-emitting elements are placed in a narrow area, and the current flowing through the light-emitting elements is increased to achieve higher luminous flux, the temperature of the area containing the multiple light-emitting elements may become too high. Furthermore, since circuit elements are located near the area containing the multiple light-emitting elements, if the temperature of the area containing the multiple light-emitting elements becomes high, the temperature of the circuit elements may also become too high.

[0006] In this case, increasing the distance between the region where multiple light-emitting elements are provided and the circuit element can suppress the temperature of the circuit element from rising. However, doing so increases the planar dimensions of the substrate on which the multiple light-emitting elements and the circuit element are provided, making it difficult to miniaturize the vehicle lighting device.

[0007] Therefore, there was a need for the development of a technology that could suppress the excessive increase in the planar dimensions of the substrate on which the multiple light-emitting elements and circuit elements are mounted, even when multiple light-emitting elements are provided in a narrow area. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-247061 Summary of the Invention [Problem to be solved by the invention]

[0009] The problem that the present invention aims to solve is to provide a vehicle lighting device and a vehicle lamp that can suppress the excessive increase in the planar dimensions of the substrate on which the multiple light-emitting elements and circuit elements are provided, even when multiple light-emitting elements are provided in a narrow area. [Means for solving the problem]

[0010] The vehicle lighting device according to this embodiment comprises: a substrate with a rectangular planar shape; four first light-emitting elements having a chip-like shape and being provided on one surface of the substrate at positions that are rotationally symmetrical with respect to the center of the substrate and connected in series; a frame-shaped portion having a substantially square planar contour and being provided on one surface of the substrate, surrounding the four first light-emitting elements; a first protective element provided on one surface of the substrate around the frame portion to protect the four first light-emitting elements from surges; and a control element provided on one surface of the substrate around the frame portion to control the illumination of the four first light-emitting elements. When viewed from a direction along the central axis of the vehicle lighting device, the center of the frame portion coincides with the center of the substrate. The centers of each of the four first light-emitting elements coincide with the diagonals of the frame portion. The vehicle lighting device satisfies the following formula when the planar dimension of the rectangular area on the substrate where the four first light-emitting elements are mounted is L1 (mm) and the planar dimension of the substrate is B1 (mm). 0.16≦L1(mm) / B1(mm)≦0.25 [Effects of the Invention]

[0011] According to an embodiment of the present invention, it is possible to provide a vehicle lighting device and a vehicle lamp that can prevent the planar dimensions of the substrate on which multiple light-emitting elements and circuit elements are arranged from becoming excessively large, even when multiple light-emitting elements are arranged in a small area. [Brief explanation of the drawings]

[0012] [Figure 1] This is a schematic perspective view illustrating a vehicle lighting device according to this embodiment. [Figure 2] This is a cross-sectional view of the vehicle lighting device shown in Figure 1, along line AA. [Figure 3] This is a schematic plan view of the light-emitting module. [Figure 4] This is a schematic plan view of a light-emitting module according to another embodiment. [Figure 5] This is a schematic partial cross-sectional view illustrating a vehicle light fixture. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments will be illustrated with reference to the drawings. In the drawings, like components are designated by like reference numerals and detailed descriptions thereof will be omitted where appropriate.

[0014] (Vehicle lighting equipment)

[0015] The vehicle lighting device 1 according to this embodiment can be installed in, for example, an automobile or a railway vehicle. Examples of the vehicle lighting device 1 installed in an automobile include a front combination light or a rear combination light installed outside the vehicle cabin, and an instrument panel installed inside the vehicle cabin. However, the uses of the vehicle lighting device 1 are not limited to these. Furthermore, as will be described later, the vehicle lighting device 1 is preferably used for applications in which light is irradiated via a light guide, but can also be used for applications in which light is irradiated without using a light guide.

[0016] FIG. 1 is a schematic perspective view illustrating a vehicle lighting device 1 according to the present embodiment. Figure 2 is a cross-sectional view of the vehicle lighting device 1 in Figure 1, along line AA. Fig. 3 is a schematic plan view of the light emitting module 20. Fig. 3 is a schematic view of the light emitting module 20 when viewed from a direction along the central axis 1a of the vehicle lighting device 1.

[0017] As shown in Figures 1 and 2, the vehicle lighting device 1 is provided with, for example, a socket 10, a light-emitting module 20, a power supply unit 30, and a heat transfer unit 40.

[0018] The socket 10 includes, for example, a mounting portion 11, a bayonet 12, a flange 13, a heat dissipation fin 14, and a connector holder 15.

[0019] The mounting portion 11 is provided on the surface of the flange 13 opposite to the side on which the heat dissipation fins 14 are provided. The outer shape of the mounting portion 11 is, for example, cylindrical. The mounting portion 11 has, for example, a recess 11a that opens at the end opposite to the flange 13 side.

[0020] The bayonet 12 is provided, for example, on the side of the mounting portion 11. The bayonet 12 protrudes outward from the vehicle lighting device 1. The bayonet 12 faces the flange 13. Multiple bayonets 12 can be provided. The bayonet 12 is used when mounting the vehicle lighting device 1 to, for example, the housing 101 of the vehicle lamp 100, which will be described later. The bayonet 12 can be used in a twist lock.

[0021] The flange 13 is, for example, roughly disc-shaped. The side surface of the flange 13 is located further outward from the vehicle lighting device 1 than the side surface of the bayonet 12.

[0022] The heat dissipation fins 14 are provided on the flange 13 on the side opposite to the mounting portion 11. At least one heat dissipation fin 14 can be provided. For example, as shown in Figure 1, multiple heat dissipation fins 14 can be provided on the socket 10. Multiple heat dissipation fins 14 can be arranged in a predetermined direction. The heat dissipation fins 14 are, for example, plate-shaped or cylindrical.

[0023] The connector holder 15 is provided on the opposite side of the flange 13 from the mounting portion 11. The connector holder 15 can be provided alongside the heat dissipation fins 14. The connector holder 15 is cylindrical, and a connector 105 having a seal member 105a therein is inserted into the connector holder 15.

[0024] The socket 10 has the function of holding the light-emitting module 20 and the power supply unit 30, and the function of transferring heat generated in the light-emitting module 20 to the outside. For this reason, it is preferable that the socket 10 be made of a material with high thermal conductivity. The socket 10 can be made of a metal such as an aluminum alloy, for example.

[0025] The socket 10 can also be made of, for example, a highly thermally conductive resin. A highly thermally conductive resin is, for example, a resin such as PET (Polyethylene terephthalate) or nylon mixed with a filler such as carbon or aluminum oxide. If the socket 10 contains a highly thermally conductive resin, the heat generated in the light-emitting module 20 can be efficiently dissipated. Furthermore, the weight of the socket 10 can be reduced.

[0026] The power supply unit 30 includes, for example, a plurality of power supply terminals 31 and a holding unit 32 . The plurality of power supply terminals 31 can be arranged, for example, along one side of the substrate 21. The plurality of power supply terminals 31 can be rod-shaped. One end of each of the plurality of power supply terminals 31 protrudes from the bottom surface 11a1 of the recess 11a. One end of each of the plurality of power supply terminals 31 is soldered to the wiring pattern 21a provided on the substrate 21. The other end of each of the plurality of power supply terminals 31 is exposed inside the hole of the connector holder 15. The connector 105 is fitted into the plurality of power supply terminals 31 exposed inside the hole of the connector holder 15. The plurality of power supply terminals 31 are formed, for example, from a metal such as a copper alloy.

[0027] When socket 10 is formed using, for example, a highly thermally conductive resin containing a carbon-based filler or a metal, socket 10 becomes conductive. Therefore, holding portion 32 is provided to insulate multiple power supply terminals 31 from conductive socket 10. Note that when socket 10 is formed using an insulating highly thermally conductive resin (for example, a highly thermally conductive resin containing an aluminum oxide-based filler), holding portion 32 can be omitted. For example, holding portion 32 can be press-fitted into a hole provided in socket 10 or adhered to the inner wall of the hole.

[0028] The heat transfer unit 40 is provided between the socket 10 and the light-emitting module 20 (substrate 21). As shown in Figures 1 and 2, the heat transfer unit 40 is provided, for example, inside a recess 11b that opens into the bottom surface 11a1 of the recess 11a. For example, the heat transfer unit 40 can be bonded to the inner wall of the recess 11b, attached to the inside of the recess 11b via thermal conductive grease (heat dissipation grease), or embedded inside the recess 11b by an insert molding method. The heat transfer unit 40 can also be bonded to the bottom surface 11a1 of the recess 11a.

[0029] The heat transfer element 40 is formed from a material with high thermal conductivity. For example, the heat transfer element 40 can be formed from metals such as aluminum, aluminum alloys, copper, and copper alloys. In cases where the socket 10 is made of metal, the heat transfer element 40 can be omitted.

[0030] As shown in Figures 1 and 3, the light-emitting module 20 includes, for example, a substrate 21, a light-emitting element 22 (corresponding to an example of a first light-emitting element), a frame portion 23, a sealing portion 24, and a circuit element 25.

[0031] The substrate 21 is provided on one end of the socket 10. In this case, the center 21b of the substrate 21 can be positioned to coincide with the central axis 1a of the vehicle lighting device 1. The substrate 21 can be bonded, for example, to the heat transfer section 40. If the heat transfer section 40 is omitted, the substrate 21 can be bonded, for example, to the bottom surface 11a1 of the recess 11a.

[0032] The substrate 21 is plate-shaped. The planar shape of the substrate 21 (shape when viewed from a direction along the central axis 1a of the vehicle lighting device 1) is, for example, rectangular. The substrate 21 can be formed from, for example, inorganic materials such as ceramics (e.g., aluminum oxide or aluminum nitride), or organic materials such as paper phenol or glass epoxy. The substrate 21 may also be a metal core substrate in which the surface of a metal plate is coated with an insulating material. Furthermore, the substrate 21 may have a single-layer structure or a multi-layer structure.

[0033] Furthermore, a wiring pattern 21a is provided on the surface of the substrate 21. The wiring pattern 21a is made of, for example, a material containing silver as a main component or a material containing copper as a main component. Furthermore, a covering portion can be provided to cover the wiring pattern 21a. The covering portion may include, for example, a glass material.

[0034] The light-emitting element 22 is provided on one side of the substrate 21 (the side opposite to the socket 10). The light-emitting element 22 is electrically connected to the wiring pattern 21a. Multiple light-emitting elements 22 can be provided. The light-emitting module 20 illustrated in Figure 3 is provided with four light-emitting elements 22. Multiple light-emitting elements 22 can be connected in series.

[0035] The light emitting element 22 may be, for example, a light emitting diode, an organic light emitting diode, a laser diode, or the like.

[0036] The light-emitting element 22 can be a chip-shaped light-emitting element. If the light-emitting element 22 is a chip-shaped light-emitting element, it becomes easy to provide a plurality of light-emitting elements 22 in a small area. If a plurality of light-emitting elements 22 is provided in a small area, it becomes easy to make the light distribution characteristics of the light-emitting module 20 closer to the light distribution characteristics of a point light source.

[0037] The chip-shaped light-emitting element 22 can be mounted on the wiring pattern 21a by COB (Chip On Board). The chip-shaped light-emitting element 22 may be any of an upper electrode type light-emitting element, a top and bottom electrode type light-emitting element, and a flip-chip type light-emitting element. The planar shape of the chip-shaped light-emitting element 22 (the shape when viewed from a direction along the central axis 1a of the vehicle lighting device 1) is, for example, a rectangle. The planar shape of the light-emitting element 22 illustrated in Fig. 3 is a square. For example, the length of one side of the light-emitting element 22 having a square planar shape can be 0.20 mm or more and 2.00 mm or less.

[0038] The frame portion 23 is provided on one surface of the substrate 21. The frame portion 23 is adhered to the substrate 21. The frame portion 23 has a frame shape and surrounds the plurality of light-emitting elements 22. The frame portion 23 is formed from, for example, a thermoplastic resin. The frame portion 23 can have a function of defining the formation area of ​​the sealing portion 24 and a function of a reflector.

[0039] The sealing portion 24 is provided inside the frame portion 23. The sealing portion 24 is provided so as to cover the area enclosed by the frame portion 23. The sealing portion 24 is provided so as to cover a plurality of light-emitting elements 22. The sealing portion 24 contains a light-transmitting resin. The resin is, for example, a silicone resin. The sealing portion 24 may also contain a phosphor.

[0040] Here, for example, if the vehicle lighting device 1 is used to emit light via the light guide 103, the end of the light guide 103 is positioned opposite the frame portion 23, as shown in Figures 1 to 3. In this case, if the light-emitting module 20 has light distribution characteristics close to those of a point light source, the light emitted from the light-emitting module 20 can be efficiently incident onto the light guide 103. Therefore, the utilization efficiency of the light emitted from the light-emitting module 20 can be improved.

[0041] 3, four light-emitting elements 22 can be provided at positions that are rotationally symmetrical with respect to one another about the center 21b of the substrate 21. In this way, it is possible to obtain a light-emitting module 20 that has light distribution characteristics similar to those of a point light source.

[0042] In this case, for example, the side surfaces of the four light-emitting elements 22 can be made approximately parallel to the sides of the substrate 21. Furthermore, the centers of the four light-emitting elements 22 can be provided at positions that overlap with a circle having a diameter of 0.30 mm or more and 5.00 mm or less and that is centered on the center 21b of the substrate 21.

[0043] As described above, the frame 23 can also function as a reflector. Therefore, as shown in Fig. 3, the center 23a of the frame 23 is preferably positioned so as to overlap with the central axis 1a of the vehicle lighting device 1 (the center 21b of the substrate 21).

[0044] Furthermore, when four light-emitting elements 22 are provided, it is preferable that the planar shape of the frame portion 23 contour (the shape when viewed from a direction along the central axis 1a of the vehicle lighting device 1) be approximately square, as shown in Figure 3. In this case, for example, the sides of the light-emitting elements 22 can be made approximately parallel to the sides of adjacent light-emitting elements 22 that are opposite to that side.

[0045] Furthermore, it is preferable that the center of each of the four light-emitting elements 22 be positioned so as to coincide with the diagonal of the frame portion 23, which has a planar shape that is approximately square. In this way, the four light-emitting elements 22 can be efficiently arranged in a narrow area, and the light distribution characteristics of the light-emitting module 20 (vehicle lighting device 1) having the four light-emitting elements 22 can be made closer to the light distribution characteristics of a point light source. In addition, if the four light-emitting elements 22 can be arranged in a narrow area, it is possible to increase the luminous flux. If the luminous flux can be increased, it is possible to illuminate a wider area with light using a light guide 103 having a long shape, and to improve the design and visibility.

[0046] The circuit element 25 can be a passive element or an active element used to configure a light-emitting circuit having the light-emitting element 22. The circuit element 25 is provided on one surface of the substrate 21. The circuit element 25 is provided, for example, around the periphery of the frame portion 23 and is electrically connected to the wiring pattern 21a.

[0047] The circuit elements 25 illustrated in Figures 1 and 3 are a protection element 25a (corresponding to an example of a first protection element), a control element 25b, a protection element 25c (corresponding to an example of a second protection element), and a resistor 25d. However, the circuit elements 25 are not limited to those illustrated. For example, the circuit elements 25 may be a capacitor, a positive characteristic thermistor, a negative characteristic thermistor, an inductor, a surge absorber, a varistor, an integrated circuit, a computing element, etc.

[0048] The protection element 25a is provided, for example, to protect the multiple light-emitting elements 22 from surges (e.g., negative surges or positive surges). The protection element 25a can be, for example, a field-effect transistor.

[0049] The control element 25b controls the illumination of multiple light-emitting elements 22. For example, the control element 25b controls the current flowing to the light-emitting elements 22 according to the ambient temperature of the light-emitting elements 22, or changes the number of light-emitting elements 22 to be illuminated based on the voltage applied to the vehicle lighting device 1. The control element 25b can be an integrated circuit capable of performing, for example, temperature derating control and total luminous flux control. The control element 25b illustrated in Figures 1 and 3 is a surface-mount integrated circuit.

[0050] The protection element 25c is connected in parallel with four light-emitting elements 22 that are connected in series. The protection element can be, for example, a TVS (Transient Voltage Suppressor) diode.

[0051] The resistor 25d can be connected in series with, for example, multiple light-emitting elements 22. The resistor 25d is provided, for example, to adjust variations in the forward voltage characteristics of the light-emitting elements 22 or to suppress excessive current flow to the light-emitting elements 22. The resistor 25d can be, for example, a surface-mount resistor, a resistor with leads (metal oxide film resistor), or a film-type resistor formed using a screen printing method. Note that the resistor 25d exemplified in Figures 1 and 3 is a film-type resistor.

[0052] Here, as mentioned above, by providing multiple light-emitting elements 22 in a small area and increasing the current flowing through the light-emitting elements 22 to achieve high luminous flux, it is possible to use one vehicle lighting device 1 and light guide 103 to irradiate light over a wider area and improve design and visibility.

[0053] However, in this manner, the temperature of the region where the multiple light-emitting elements 22 are provided (for example, the region surrounded by the frame portion 23) becomes high. As shown in Figures 1 and 3, since the circuit element 25 is provided near the region where the multiple light-emitting elements 22 are provided, when the temperature of the region where the multiple light-emitting elements 22 are provided becomes high, the temperature of the circuit element 25 also becomes high. If the temperature of the circuit element 25 becomes too high, depending on the type of circuit element 25, its function may deteriorate, it may fail, or its lifespan may be shortened. For example, protective elements 25a and control elements 25b are more susceptible to functional deterioration due to temperature rise than resistors 25d and capacitors.

[0054] In this case, for example, increasing the distance between the frame portion 23 and the protective element 25a and the control element 25b can prevent the temperature of the protective element 25a and the control element 25b from becoming too high. However, doing so increases the planar dimensions of the substrate 21. In recent years, there has been a demand for miniaturization of the vehicle lighting device 1, but if the planar dimensions of the substrate 21 increase, it becomes difficult to miniaturize the vehicle lighting device 1.

[0055] As a result of their investigation, the inventors have found that when four chip-shaped light-emitting elements 22 are placed in positions that are rotationally symmetric with respect to the center 21b of the substrate 21, optimizing the relationship between the planar dimension B1 (mm) of the rectangular substrate 21 and the planar dimension L1 (mm) of the rectangular region on the substrate 21 where the four light-emitting elements 22 are mounted can suppress the temperature of the protection element 25a and the control element 25b from becoming too high, and also suppress the increase in the planar dimension B1 (mm) of the substrate 21.

[0056] According to the inventor's findings, when L1 (mm) / B1 (mm) is less than 0.16, the temperature of the protection element 25a and the control element 25b can be prevented from becoming too high, but the planar dimension B1 (mm) of the substrate 21 becomes too large, preventing the vehicle lighting device 1 from being miniaturized. When L1 (mm) / B1 (mm) is greater than 0.25, the planar dimension B1 (mm) of the substrate 21 becomes small, allowing the vehicle lighting device 1 to be miniaturized. However, the distance between the four light-emitting elements 22 and the protection element 25a and the control element 25b becomes short, causing the temperatures of the light-emitting elements 22, the protection element 25a, and the control element 25b to increase due to thermal interference. If the temperatures of the light-emitting elements 22, the protection element 25a, and the control element 25b become too high, the function of the vehicle lighting device 1 may be degraded or the life of the vehicle lighting device 1 may be shortened.

[0057] Therefore, it is preferable to set the condition to "0.16 ≤ L1 (mm) / B1 (mm) ≤ 0.25". In this way, it is possible to suppress the temperature of the protection element 25a and the control element 25b from becoming too high, and also to suppress the increase in the planar dimensions of the substrate 21.

[0058] As shown in Figure 3, if the planar shape of the substrate 21 is square, the planar dimension B1 (mm) can be the length of the side of the substrate 21. If the planar shape of the substrate 21 is rectangular, the planar dimension B1 (mm) can be the length of the longer side of the substrate 21.

[0059] The planar dimension L1 (mm) of the area on which the four light-emitting elements 22 are mounted can be the maximum dimension between the side surfaces of two of the light-emitting elements 22 on the side of the substrate 21 in a direction parallel to the edge of the substrate 21.

[0060] 3, when the planar dimension of the protection element 25a is Q1 (mm) and the planar dimension of the control element 25b is X1 (mm), it is preferable to set them so that "Q1 (mm) ≦ L1 (mm) ≦ X1 (mm)." In this way, when the relationship between the planar dimension L1 (mm) and the planar dimension B1 (mm) is set to "0.16 ≦ L1 (mm) / B1 (mm) ≦ 0.25," it becomes easy to arrange the protection element 25a and the control element 25b around the area where the four light-emitting elements 22 are mounted.

[0061] When the planar shape of the protection element 25a is a square, the planar dimension Q1 (mm) of the protection element 25a can be the length of a side of the protection element 25a. When the planar shape of the protection element 25a is a rectangle, the planar dimension Q1 (mm) can be the length of a long side of the protection element 25a.

[0062] When the planar shape of the control element 25b is a square, the planar dimension X1 (mm) of the control element 25b can be the length of a side of the control element 25b. When the planar shape of the control element 25b is a rectangle, the planar dimension X1 (mm) can be the length of a long side of the control element 25b.

[0063] Furthermore, the current density of each of the four light-emitting elements 22 is 25 A / cm². 2 More than 100A / cm 2 It is preferable that the value be set to 0.16≦L1(mm) / B1(mm)≦0.25. In this way, when the relationship between the planar dimension L1 and the planar dimension B1 (mm) is set to 0.16≦L1(mm) / B1(mm)≦0.25, it is possible to prevent the temperatures of the protection element 25a and the control element 25b from becoming too high due to the heat from the light emitting elements 22. In addition, when the current density of each of the four light emitting elements 22 is set to 25 A / cm 2 More than 100A / cm 2 If the current density of each of the four light emitting elements 22 is set to 25 A / cm or less, it is easy to set the total luminous flux of the four light emitting elements 22 to 420 lumens (lm) or more and 1000 lumens (lm) or less. 2 More than 100A / cm 2If the temperature is set to the value below, it is possible to prevent the temperature of the protection element 25a and the control element 25b from becoming too high, and it is easy to ensure a sufficient total luminous flux.

[0064] Furthermore, when the four light-emitting elements 22 are positioned in a rotationally symmetrical manner with respect to the center 21b of the substrate 21, it is preferable that the outline of the inner wall of the frame portion 23, when viewed from a direction along the central axis 1a of the vehicle lighting device 1, be approximately square, as shown in Figure 3. In this case, as shown in Figure 3, the center 23a of the frame portion 23 can be made to coincide with the center 21b of the substrate 21. This makes it easier to bring the light distribution characteristics of the light-emitting module 20 closer to those of a point light source.

[0065] Furthermore, when viewed from a direction along the central axis 1a of the vehicle lighting device 1, the inner wall of the frame portion 23 can be made substantially parallel to the outer edge of the area on which the four light-emitting elements 22 are mounted. Also, when viewed from a direction along the central axis 1a of the vehicle lighting device 1, it is preferable that the centers of each of the four light-emitting elements 22 coincide with the diagonals of the frame portion 23. In this way, it becomes even easier to bring the light distribution characteristics of the light-emitting module 20 closer to those of a point light source.

[0066] In this case, the vehicle lighting device 1 may be mounted on the housing 101 of the vehicle lamp 100 such that its central axis 1a is horizontal or near horizontal. That is, the vehicle lighting device 1 may be used for so-called horizontal lighting. When the vehicle lighting device 1 is used for horizontal lighting, in Figure 3, the side of the light-emitting module 20 on which the multiple power supply terminals 31 are provided is positioned downward in the direction of gravity. Therefore, when the vehicle lighting device 1 is used for horizontal lighting, the heat generated in the light-emitting element 22 and the circuit element 25 is more easily transferred upward in the direction of gravity.

[0067] Here, the amount of heat generated may differ depending on the type of circuit element 25. For example, the amount of heat generated by the control element 25b and the resistor 25d will be greater than that generated by the protection element 25a. Therefore, it is preferable to place the control element 25b and the resistor 25d, which generate more heat, in the upper region of the substrate 21 in the direction of gravity.

[0068] 3, when a line segment 21c (corresponding to an example of a first line segment) is defined that passes through center 21b of substrate 21 and is parallel to the side of substrate 21 on which multiple power supply terminals 31 are provided, control element 25b and resistor 25d can be provided in an area of ​​line segment 21c opposite to the side on which multiple power supply terminals 31 are provided. Elements that generate relatively little heat, such as protection element 25a and a capacitor, can be provided in an area of ​​line segment 21c on the side on which multiple power supply terminals 31 are provided.

[0069] In other words, when the vehicle lighting device 1 is used for horizontal illumination, the control element 25b can be provided in the region of the substrate 21 above the line segment 21c in the direction of gravity. The protective element 25a can be provided in the region of the substrate 21 below the line segment 21c in the direction of gravity.

[0070] In this way, heat generated in the control element 25b and the resistor 25d can be dissipated upward in the direction of gravity, thereby reducing thermal interference between the light-emitting element 22, the control element 25b, and the resistor 25d, thereby preventing the temperature of the light-emitting element 22 and the control element 25b from becoming too high, which could result in a deterioration in the functions of these elements or a shortened lifespan.

[0071] Furthermore, as shown in Figure 3, if a line segment 21d (corresponding to an example of a second line segment) is defined that passes through the center 21b of the substrate 21 and is perpendicular to the line segment 21c, the control element 25b can be provided in the region on one side of the line segment 21d, and the resistor 25d can be provided in the region on the other side of the line segment 21d.

[0072] That is, when the vehicle lighting device 1 is used for horizontal lighting, the resistor 25d can be provided in an area of ​​the substrate 21 opposite the side on which the control element 25b is provided, of the line segment 21d, which is above the line segment 21c in the direction of gravity and passes through the center 21b of the substrate 21 and is perpendicular to the line segment 21c.

[0073] In this way, the control element 25b and the resistor 25d can be efficiently arranged in a small area, so that the planar dimension B1 (mm) of the substrate 21 can be reduced, and ultimately the vehicle lighting device 1 can be made more compact.

[0074] Furthermore, the protective element 25c is more susceptible to a decrease in function due to a rise in temperature than the resistor 25d. In this case, heat is dissipated more easily near the corners of the substrate 21 than near the center of the substrate 21. Therefore, as shown in FIG. 3, it is preferable to provide the protective element 25c nearer the corners of the substrate 21 than the resistor 25d. In this way, even if the protective element 25c is provided above the line segment 21c in the direction of gravity due to installation space or other considerations, heat dissipation from the protective element 25c is facilitated, and a temperature rise in the protective element 25c can be suppressed.

[0075] Fig. 4 is a schematic plan view of a light-emitting module 20a according to another embodiment, as viewed from a direction along the central axis 1a of the vehicle lighting device 1. As shown in FIG. 4, the light emitting module 20a includes a substrate 21, a light emitting element 22a, a frame portion 23, a sealing portion 24, and a circuit element 25, for example.

[0076] The light emitting element 22a may be a chip-shaped light emitting element, similar to the light emitting element 22 described above. The planar shape of the chip-shaped light emitting element 22a (the shape when viewed from a direction along the central axis 1a of the vehicle lighting device 1) is, for example, a quadrangle. The planar shape of the light emitting element 22a illustrated in FIG. 4 is a square. For example, the length of one side of the light emitting element 22a having a square planar shape may be 0.20 mm or more and 1.60 mm or less.

[0077] The circuit element 25 may include a protection element 25a1 (corresponding to an example of a first protection element), a control element 25b, a protection element 25c, and a resistor 25d. The protection element 25a illustrated in FIG. 3 is a field-effect transistor, but the protection element 25a1 may be a diode.

[0078] 4, five light-emitting elements 22a can be provided. In this case, four light-emitting elements 22a connected in series can be provided at positions that are rotationally symmetrical about the center 21b of the substrate 21. Also, one light-emitting element 22a can be provided at the center 21b of the substrate 21. That is, when viewed from a direction along the central axis 1a of the vehicle lighting device 1, four light-emitting elements 22a (corresponding to an example of a first light-emitting element) connected in series and one light-emitting element 22a (corresponding to an example of a second light-emitting element) can be provided whose center overlaps with the center 21b of the substrate 21. In this way, the light emitting module 20a can have light distribution characteristics close to those of a point light source.

[0079] Furthermore, when five light-emitting elements 22a are provided, it is preferable that the planar shape of the outline of the frame portion 23 (the shape when viewed from a direction along the central axis 1a of the vehicle lighting device 1) be substantially square, as shown in Fig. 4. In this case, for example, the sides of the light-emitting elements 22a can be made substantially parallel to the sides of the adjacent light-emitting elements 22a that face the sides.

[0080] The centers of the four light-emitting elements 22a are preferably located at positions that overlap with the diagonals of the substantially square frame 23. The centers of the four light-emitting elements 22a can be located at positions that overlap with a circle that is centered on the center 21b of the substrate 21 and has a diameter of 1.00 mm or more and 5.00 mm or less.

[0081] In this way, the five light-emitting elements 22a can be efficiently arranged in a narrow area, and the light distribution characteristics of the light-emitting module 20a (vehicle lighting device 1) having the five light-emitting elements 22a can be made closer to those of a point light source. Furthermore, if the five light-emitting elements 22a can be provided in a narrow area, it is possible to increase the luminous flux. If the luminous flux can be increased, it is possible to illuminate a wider area with light using a light guide 103 having a long shape, and to improve the design and visibility.

[0082] 3, it is preferable to set the relationship "0.16≦L1a(mm) / B1(mm)≦0.25." In this way, it is possible to prevent the temperatures of the protection element 25a1 and the control element 25b from becoming too high, and also possible to prevent the planar dimensions of the substrate 21 from becoming too large.

[0083] As shown in Figure 4, the planar dimension L1a (mm) of the area in which the five light-emitting elements 22a are mounted can be the maximum dimension between the side surfaces on the corner side of the substrate 21 of each of the two light-emitting elements 22a arranged at rotationally symmetric positions in a direction parallel to the diagonal of the substrate 21.

[0084] Furthermore, similar to the light-emitting module 20 illustrated in Figure 3, it is preferable to ensure that "Q1a(mm)≦L1a(mm)≦X1(mm)". In this way, when the relationship between the planar dimension L1a(mm) and the planar dimension B1(mm) is "0.16≦L1a(mm) / B1(mm)≦0.25", it becomes easy to arrange the protective element 25a1 and the control element 25b around the area where the five light-emitting elements 22 are mounted.

[0085] If the planar shape of the protective element 25a1 is rectangular, the planar dimension Q1a (mm) can be the length of the longer side of the protective element 25a1.

[0086] Furthermore, the current density of one light-emitting element 22a is 25 A / cm². 2 More than 100A / cm 2It is preferable that the value be set to 0.16≦L1a(mm) / B1(mm)≦0.25. In this way, when the relationship between the planar dimension L1a (mm) and the planar dimension B1 (mm) is set to 0.16≦L1a(mm) / B1(mm)≦0.25, it is possible to prevent the temperatures of the protection element 25a1 and the control element 25b from becoming too high due to the heat from the light emitting element 22a. In addition, when the current density of one light emitting element 22a is set to 25 A / cm 2 More than 100A / cm 2 If the current density of one light emitting element 22a is 25 A / cm or less, it is easy to make the total luminous flux of the five light emitting elements 22a 420 lumens (lm) or more and 1000 lumens (lm) or less. 2 More than 100A / cm 2 If the temperature is set to the value below, it is possible to prevent the temperature of the protection element 25a1 and the control element 25b from becoming too high, and it is easy to ensure a sufficient total luminous flux.

[0087] Furthermore, when the four light-emitting elements 22a are positioned in a rotationally symmetrical manner with respect to the center 21b of the substrate 21, it is preferable that the outline of the inner wall of the frame portion 23, when viewed from a direction along the central axis 1a of the vehicle lighting device 1, be approximately square, as shown in Figure 4. In this case, as shown in Figure 4, the center 23a of the frame portion 23 can be made to coincide with the center 21b of the substrate 21. This makes it easier to bring the light distribution characteristics of the light-emitting module 20a closer to those of a point light source.

[0088] Furthermore, when viewed from a direction along the central axis 1a of the vehicle lighting device 1, it is preferable that the centers of the four light-emitting elements 22a coincide with the diagonals of the frame portion 23, and the center of one light-emitting element 22a coincides with the center 23a of the frame portion 23. This makes it even easier to bring the light distribution characteristics of the light-emitting module 20a closer to those of a point light source.

[0089] Furthermore, when the vehicle lighting device 1 is used for horizontal lighting, the arrangement of the plurality of power supply terminals 31, the protection element 25a1, the control element 25b, and the resistor 25d can be the same as the arrangement in FIG.

[0090] For example, as shown in Figure 4, the control element 25b and the resistor 25d can be placed in the region of the line segment 21c opposite to the side where the multiple power supply terminals 31 are provided (the region on the upper side in the direction of gravity). Elements that generate relatively little heat, such as the protection element 25a1 and capacitors, can be placed in the region of the line segment 21c on the side where the multiple power supply terminals 31 are provided (the region on the lower side in the direction of gravity).

[0091] In this way, the heat generated in the control element 25b and the resistor 25d can be dissipated upward in the direction of gravity, thereby reducing thermal interference between the light-emitting element 22a, the control element 25b, and the resistor 25d. As a result, it is possible to prevent the temperature of the light-emitting element 22a and the control element 25b from becoming too high, which could lead to a decrease in the function of these elements or a shortened lifespan.

[0092] Furthermore, the control element 25b can be provided in the region on one side of the line segment 21d, and the resistor 25d can be provided in the region on the other side of the line segment 21d. In this way, the control element 25b and the resistor 25d can be efficiently arranged in a narrow area, so the planar dimension B1 (mm) of the substrate 21 can be reduced, and consequently the vehicle lighting device 1 can be miniaturized.

[0093] (vehicle lighting fixtures) In one embodiment of the present invention, a vehicle lighting fixture 100 equipped with a vehicle lighting device 1 can be provided. The above-described vehicle lighting device 1 and its variations (for example, a light-emitting module 20a, or a vehicle lighting fixture 1 equipped with the features of the present invention, with additions, deletions, or design changes made as appropriate by those skilled in the art) can all be applied to the vehicle lighting fixture 100.

[0094] In the following explanation, we will use the example that the vehicle lighting fixture 100 is a front combination light installed on an automobile. However, the vehicle lighting fixture 100 is not limited to a front combination light installed on an automobile. The vehicle lighting fixture 100 can be any vehicle lighting fixture installed on an automobile, railway vehicle, etc.

[0095] Figure 5 is a schematic partial cross-sectional view illustrating a vehicle lighting fixture 100. As shown in FIG. 5, the vehicle lamp 100 includes, for example, the vehicle lighting device 1, a housing 101, a cover 102, a light guide 103, a seal member 104, and a connector 105.

[0096] The vehicle lighting device 1 is mounted on the housing 101. The housing 101 holds the mounting portion 11. The housing 101 has a box shape with one end open. The housing 101 is made of, for example, a resin that does not transmit light. A mounting hole 101a is provided on the bottom surface of the housing 101 into which the portion of the mounting portion 11 with the bayonet 12 is inserted. A recess is provided around the periphery of the mounting hole 101a into which the bayonet 12 provided on the mounting portion 11 is inserted. Although the example shows the mounting hole 101a being directly provided on the housing 101, a mounting member having the mounting hole 101a may also be provided on the housing 101.

[0097] When attaching the vehicle lighting device 1 to the vehicle lamp 100, the portion of the mounting part 11 with the bayonet 12 is inserted into the mounting hole 101a, and the vehicle lighting device 1 is rotated. Then, for example, the bayonet 12 is held in place by a fitting portion provided on the periphery of the mounting hole 101a. This type of mounting method is called a twist lock.

[0098] The cover 102 is provided so as to cover the opening of the housing 101. The cover 102 is made of a light-transmitting resin or the like. The cover 102 may also have a function such as a lens.

[0099] The light guide 103 has an elongated shape, with one end facing the light-emitting portion of the vehicle lighting device 1 (light-emitting modules 20, 20a). For example, the end of the light guide 103 faces a plurality of light-emitting elements 22 (22a). Light emitted from the vehicle lighting device 1 is incident on the light guide 103. The light guide 103 guides the incident light to the other side of the light guide 103 and illuminates a predetermined area with light. If the light guide 103 is provided, a single vehicle lighting device 1 can be used to illuminate a wider area with light or to improve visibility. Furthermore, the design and visibility can be improved by appropriately changing the shape of the light guide 103. The light guide 103 can be formed from, for example, a translucent resin or glass.

[0100] The seal member 104 is provided between the flange 13 and the housing 101. The seal member 104 has an annular shape and is made of an elastic material such as rubber or silicone resin.

[0101] The connector 105 is fitted onto the ends of the multiple power supply terminals 31 that are exposed inside the connector holder 15. The lighting circuit and other components are electrically connected to the connector 105. Therefore, by fitting the connector 105 onto the ends of the multiple power supply terminals 31, the lighting circuit and other components can be electrically connected to the light-emitting element 22 (22a).

[0102] Furthermore, a seal member 105a is provided on the connector 105. When the connector 105 having the seal member 105a is inserted into the inside of the connector holder 15, the inside of the connector holder 15 is sealed so as to be watertight.

[0103] Although several embodiments of the present invention have been described above, these embodiments are presented by way of example only and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, modifications, etc. can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as set forth in the claims. Furthermore, the above-described embodiments can be implemented in combination with each other.

[0104] The following are additional notes regarding the embodiments described above.

[0105] (Appendix 1) A substrate with a rectangular planar shape; four first light-emitting elements each having a chip shape, provided on one surface of the substrate at positions rotationally symmetrical to one another about the center of the substrate, and connected in series; The contour has a planar shape that is approximately square, is provided on one side of the substrate, and has a frame-shaped portion that surrounds the four first light-emitting elements; A first protective element is provided on one side of the substrate, around the frame portion, to protect the four first light-emitting elements from surges; On one side of the substrate, provided around the frame portion, is a control element that controls the illumination of the four first light-emitting elements; Equipped with When viewed from a direction along the central axis of the vehicle lighting device, the center of the frame portion coincides with the center of the substrate. The center of each of the four first light-emitting elements coincides with the diagonal of the frame portion, Let L1 (mm) be the planar dimension of the rectangular region on the substrate on which the four first light-emitting elements are mounted. A vehicle lighting device that satisfies the following formula, given that the planar dimension of the aforementioned substrate is B1 (mm). 0.16≦L1(mm) / B1(mm)≦0.25

[0106] (Appendix 2) The vehicle lighting device according to Appendix 1, wherein, when viewed from a direction along the central axis of the vehicle lighting device, the center of the vehicle lighting device coincides with the center of the substrate, and further comprises a second light-emitting element connected in series with the four first light-emitting elements.

[0107] (Appendix 3) The vehicle lighting device is used for horizontal lighting, the control element is provided in a region of the substrate that is above, in a direction of gravity, a first line segment that passes through a center of the substrate and is parallel to a side of the substrate; 3. The vehicle lighting device according to claim 1, wherein the first protection element is provided in a region of the substrate that is lower than the first line segment in the direction of gravity.

[0108] (Appendix 4) a resistor provided on one surface of the substrate and connected in series to the four first light-emitting elements; The vehicle lighting device according to Appendix 3, wherein the resistor is located above the first line segment in the direction of gravity, passes through the center of the substrate, and is located in a region of the substrate opposite to the side on which the control element is provided, on a second line segment perpendicular to the first line segment.

[0109] (Appendix 5) The vehicle lighting device is used for horizontal lighting, a second protection element provided on one surface of the substrate and connected in parallel to the four first light-emitting elements; The vehicle lighting device according to any one of appendices 1 to 4, wherein the second protection element is provided in an area of ​​the substrate on the opposite side of a second line segment that passes through the center of the substrate and is perpendicular to the first line segment, in the direction of gravity, from the side on which the control element is provided.

[0110] (Appendix 6) The current density of each of the four first light-emitting elements is 25 A / cm 2 More than 100A / cm 2 A vehicle lighting device according to any one of appendixes 1 to 5 below.

[0111] (Appendix 7) A vehicle lighting device according to any one of appendices 1 to 6; a light guide into which light emitted from the vehicle lighting device is incident; A vehicle lighting fixture equipped with: [Explanation of symbols]

[0112] 1 Vehicle lighting device, 1a central axis, 10 socket, 11 mounting part, 20 light-emitting module, 20a light-emitting module, 21 substrate, 21b center, 22 light-emitting element, 22a light-emitting element, 23 frame part, 23a center, 24 sealing part, 25 circuit element, 25a protection element, 25a1 protection element, 25b control element, 25c protection element, 25d resistor, 100 vehicle lamp, 101 housing, 103 light guide

Claims

1. A substrate having a rectangular planar shape; four first light-emitting elements each having a chip shape, provided on one surface of the substrate at positions rotationally symmetrical to one another about the center of the substrate, and connected in series; a frame-shaped frame portion having a substantially square planar outline, provided on one surface of the substrate, and surrounding the four first light-emitting elements; a first protection element provided on one surface of the substrate around the periphery of the frame portion, for protecting the four first light-emitting elements from surges; a control element provided on one surface of the substrate around the periphery of the frame portion, the control element controlling lighting of the four first light-emitting elements; Equipped with When viewed from a direction along a central axis of the vehicle lighting device, a center of the frame portion overlaps with a center of the substrate, the centers of the four first light emitting elements overlap with a diagonal line of the frame portion; a planar dimension of a rectangular area of ​​the substrate on which the four first light-emitting elements are mounted is defined as L1 (mm); A vehicle lighting device that satisfies the following formula, where B1 (mm) is the planar dimension of the substrate. 0.16≦L1 (mm) / B1 (mm)≦0.25

2. 2. The vehicle lighting device according to claim 1, further comprising a second light-emitting element whose center overlaps with the center of the substrate when viewed from a direction along the central axis of the vehicle lighting device and whose center is connected in series with the four first light-emitting elements.

3. The vehicle lighting device is used for horizontal lighting, the control element is provided in a region of the substrate that is above, in a direction of gravity, a first line segment that passes through a center of the substrate and is parallel to a side of the substrate; The vehicle lighting device according to claim 1 , wherein the first protection element is provided in a region of the substrate that is lower in the direction of gravity than the first line segment.

4. a resistor provided on one surface of the substrate and connected in series to the four first light-emitting elements; 4. The vehicle lighting device according to claim 3, wherein the resistor is provided in a region of the substrate opposite to the side on which the control element is provided, of a second line segment that is above the first line segment in the direction of gravity, passes through the center of the substrate, and is perpendicular to the first line segment.

5. The vehicle lighting device is used for horizontal lighting, a second protection element provided on one surface of the substrate and connected in parallel to the four first light-emitting elements; 3. The vehicle lighting device according to claim 1, wherein the second protection element is provided in a region of the substrate opposite to the side on which the control element is provided, the region being above a first line segment that passes through the center of the substrate and is parallel to an edge of the substrate in the direction of gravity, and a second line segment that passes through the center of the substrate and is perpendicular to the first line segment.

6. The current density of each of the four first light-emitting elements is 25 A / cm ２ Above, 100A / cm ２ 3. The vehicle lighting device according to claim 1, wherein:

7. The vehicle lighting device according to claim 1; a light guide into which light emitted from the vehicle lighting device is incident; A vehicle lighting fixture equipped with:

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