Vehicle lighting device and vehicle lamp

Abstract

To provide a vehicular illuminating device that can maintain lighting even if an input voltage is decreased, and a vehicular lighting fixture.SOLUTION: A vehicular illuminating device according to an embodiment comprises: a socket; a board provided on one end part side of the socket; a first circuit provided on the board; and a second circuit provided on the board. The first circuit has: a plurality of first emitting elements; and a control element electrically connected to the plurality of first emitting elements, and for controlling a value of a current flowing through the plurality of first emitting elements. The second circuit has: second light emitting elements whose number is smaller than the number of the plurality of first emitting elements; and a resistor series-connected to the second light emitting elements.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] 2. Description of the Related Art From the viewpoint of energy saving and long life, vehicle lighting devices equipped with light emitting elements such as light emitting diodes are becoming increasingly popular instead of vehicle lighting devices equipped with filaments. Furthermore, for example, a vehicle lighting device that integrates a plurality of vehicle lighting devices for different purposes has been proposed, such as a lighting device for an automobile that has the functions of a stop lamp and a tail lamp.

[0003] In this case, the number of light-emitting elements required may differ depending on the application. For example, a light-emitting distribution in which the peripheral region of the light-emitting surface is bright is preferable for a stop lamp, while a light-emitting distribution in which the central region of the light-emitting surface is bright is preferable for a tail lamp. Therefore, a technology has been proposed in which one light-emitting element is provided for the tail lamp, and multiple light-emitting elements are provided for the stop lamp in series so as to surround it.

[0004] Here, since the voltage (input voltage) applied to a vehicle lighting device fluctuates, a standard operating voltage (rated voltage) is set. For example, in a vehicle lighting device for a general automobile, the standard operating voltage is set to about 13.5 V. Therefore, the number of light-emitting elements and the resistance value of the resistor connected in series to the light-emitting elements are set so that a predetermined total luminous flux can be obtained when the input voltage is 13.5 V.

[0005] However, there may be cases where the input voltage drops extremely. For example, when starting the engine by cranking with a starter motor, the input voltage may drop to around 6V. In such cases, there is a risk that the lighting of the vehicle lighting device may not be maintained. So, A vehicle lighting device having a stop lamp function and a tail lamp function, Even if the input voltage drops, the light can still be lit. Furthermore, it is possible to obtain a preferable light emission distribution for each of the stop lamp and the tail lamp. There was a need to develop technology that could do this. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-63252 Summary of the Invention [Problem to be solved by the invention]

[0007] The problem to be solved by the present invention is: A vehicle lighting device having a stop lamp function and a tail lamp function, Even if the input voltage drops, the light can still be lit. Furthermore, it is possible to obtain a preferable light emission distribution for each of the stop lamp and the tail lamp. The present invention provides a vehicle lighting device and a vehicle lamp. [Means for solving the problem]

[0008] The vehicle lighting device according to the embodiment is a vehicle lighting device having a stop lamp function and a tail lamp function, and includes a socket; a board provided on one end side of the socket; a first circuit provided on the board; and a second circuit provided on the board. The first circuit is the stop lamp circuit, and is made up of four series-connected one The light emitting device includes: a first light emitting element; and a control element electrically connected to the four first light emitting elements and controlling a value of a current flowing through the four first light emitting elements. The second circuit is a circuit of the tail lamp and includes one second light-emitting element and a resistor connected in series with the one second light-emitting element. The four first light-emitting elements are provided at positions surrounding the one second light-emitting element. The control element detects an input voltage; When the detected input voltage is higher than a predetermined voltage, a current is passed through the four first light-emitting elements connected in series, and when the detected input voltage is lower than the predetermined voltage, a current is passed through two of the four first light-emitting elements connected in series, and no current is passed through the other two first light-emitting elements connected in series. . [Effects of the Invention]

[0009] According to an embodiment of the present invention, A vehicle lighting device having a stop lamp function and a tail lamp function, Even if the input voltage drops, the light can still be lit. Furthermore, it is possible to obtain a preferable light emission distribution for each of the stop lamp and the tail lamp.It is possible to provide a vehicle lighting device and a vehicle lamp. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic perspective view illustrating a vehicle lighting device according to an embodiment of the present invention; [Figure 2] 2 is a cross-sectional view of the vehicle lighting device taken along line AA in FIG. 1. [Figure 3] FIG. 10 is a circuit diagram of a circuit according to a comparative example. [Figure 4] FIG. 2 is a circuit diagram illustrating a first circuit and a second circuit. [Figure 5] FIG. 2 is a schematic partial cross-sectional view illustrating a vehicle lamp. DETAILED DESCRIPTION OF THE INVENTION

[0011] 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.

[0012] (Vehicle lighting device) The vehicle lighting device 1 according to this embodiment can be installed in, for example, an automobile or a railcar. The vehicle lighting device 1 can also be used for multiple purposes. For example, the vehicle lighting device 1 may serve as both a stop lamp and a tail lamp, or may serve as both a position lamp and a turn signal lamp. In the following, a case where the vehicle lighting device 1 serves as both a stop lamp and a tail lamp will be described as an example.

[0013] FIG. 1 is a schematic perspective view illustrating a vehicle lighting device 1 according to the present embodiment. FIG. 2 is a cross-sectional view of the vehicle lighting device 1 taken along line AA in FIG. As shown in FIGS. 1 and 2, a vehicle lighting device 1 includes, for example, a socket 10, a light-emitting module 20, a power supply unit 30, and a heat transfer unit 40.

[0014] The socket 10 includes, for example, a mounting portion 11, a bayonet 12, a flange 13, heat dissipation fins 14, and a connector holder 15. The mounting portion 11 is provided, for example, 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 can be columnar. 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.

[0015] The bayonet 12 is provided, for example, on the side surface of the mounting portion 11. The bayonet 12 protrudes, for example, toward the outside of the vehicle lighting device 1. The bayonet 12 faces the flange 13. A plurality of bayonets 12 may be provided. The bayonet 12 is used when mounting the vehicle lighting device 1, for example, to a housing 101 of a vehicle lamp 100 described below. The bayonet 12 can be used for a twist lock.

[0016] The flange 13 has, for example, a plate shape. The flange 13 has, for example, a substantially circular plate shape. A side surface of the flange 13 is located outward of the vehicle lighting device 1 with respect to a side surface of the bayonet 12.

[0017] The heat dissipation fin 14 is provided, for example, on the side of the flange 13 opposite to the mounting portion 11 side. At least one heat dissipation fin 14 can be provided. For example, the socket 10 illustrated in FIG. 1 is provided with a plurality of heat dissipation fins 14. The plurality of heat dissipation fins 14 can be arranged side by side in a predetermined direction. The heat dissipation fin 14 has, for example, a plate or cylindrical shape.

[0018] The connector holder 15 is provided, for example, on the side of the flange 13 opposite to 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 sealing member 105a therein is inserted into the connector holder 15.

[0019] The socket 10 has the function of holding the light-emitting module 20 and the power supply unit 30, and the function of conducting heat generated in the light-emitting module 20 to the outside. Therefore, the socket 10 is preferably made of a material with high thermal conductivity. For example, the socket 10 can be made of a metal such as an aluminum alloy.

[0020] In recent years, it has become desirable for the socket 10 to be lightweight and capable of efficiently dissipating heat generated in the light-emitting module 20. Therefore, it is more preferable that the socket 10 be formed from, for example, a highly thermally conductive resin. The highly thermally conductive resin includes, for example, a resin and a filler using an inorganic material. The highly thermally conductive resin is, for example, a resin such as PET (Polyethylene terephthalate) or nylon mixed with a filler using carbon, aluminum oxide, or the like.

[0021] If the socket 10 contains a highly thermally conductive resin and has the mounting portion 11, bayonet 12, flange 13, heat dissipation fins 14, and connector holder 15 integrally molded, the heat generated in the light-emitting module 20 can be efficiently dissipated. The weight of the socket 10 can also be reduced. In this case, the mounting portion 11, bayonet 12, flange 13, heat dissipation fins 14, and connector holder 15 can be integrally molded using injection molding or the like. Alternatively, the socket 10, power supply portion 30, and heat transfer portion 40 can be integrally molded using insert molding or the like.

[0022] The light emitting module 20 includes, for example, a first circuit 21, a second circuit 22, a substrate 23, a frame portion 24, and a sealing portion 25. The first circuit 21 may be, for example, a stop lamp circuit. The second circuit 22 may be, for example, a tail lamp circuit. The first circuit 21 and the second circuit 22 will be described in detail later.

[0023] The substrate 23 has a plate-like shape. The planar shape of the substrate 23 is, for example, a rectangle. The substrate 23 is provided on one end side of the socket 10. The substrate 23 is, for example, adhered to the upper surface of the heat transfer section 40. If the heat transfer section 40 is not provided, the substrate 23 is adhered to the socket 10 (for example, the bottom surface 11a1 of the recess 11a). In this case, it is preferable that the adhesive be an adhesive with high thermal conductivity. For example, the adhesive can be an adhesive mixed with a filler using an inorganic material.

[0024] Substrate 23 can be formed from, for example, inorganic materials such as ceramics (e.g., aluminum oxide, aluminum nitride, etc.), or organic materials such as paper phenol, glass epoxy, etc. Substrate 23 may also be a metal core substrate in which the surface of a metal plate is coated with an insulating material. When first circuit 21 and second circuit 22 generate a large amount of heat, it is preferable to form substrate 23 using a material with high thermal conductivity from the perspective of heat dissipation. Examples of materials with high thermal conductivity include ceramics such as aluminum oxide, aluminum nitride, etc., highly thermally conductive resins, and metal core substrates. Substrate 23 may have a single-layer structure or a multi-layer structure.

[0025] The frame portion 24 is provided on the substrate 23. The frame portion 24 has a frame shape and is adhered to the substrate 23. In the area surrounded by the frame portion 24, a light emitting element 21a (corresponding to an example of a first light emitting element) and a light emitting element 22a (corresponding to an example of a second light emitting element) are arranged. The frame portion 24 is formed from, for example, a resin. The resin can be, for example, a thermoplastic resin such as PBT (polybutylene terephthalate), PC (polycarbonate), PET, nylon, PP (polypropylene), PE (polyethylene), or PS (polystyrene).

[0026] The frame 24 can have a function of defining the formation area of ​​the sealing portion 25 and a function of a reflector. Therefore, the frame 24 can contain titanium oxide particles or a white resin in order to improve reflectance.

[0027] Also, the frame portion 24 can be omitted. However, if the frame portion 24 is provided, the utilization efficiency of the light emitted from the light-emitting elements 21 a, 22 a can be improved. Furthermore, since the area where the sealing portion 25 is formed can be reduced, the light-emitting module 20 can be made smaller, and therefore the vehicle lighting device 1 can be made smaller.

[0028] The sealing portion 25 is provided inside the frame portion 24. The sealing portion 25 is provided so as to cover the area surrounded by the frame portion 24. The sealing portion 25 is provided so as to cover the light-emitting elements 21a, 22a. The sealing portion 25 contains a light-transmitting resin. The sealing portion 25 is formed, for example, by filling the inside of the frame portion 24 with resin. The filling of the resin is performed, for example, using a dispenser. The resin to be filled is, for example, silicone resin. When the frame portion 24 is omitted, for example, a dome-shaped sealing portion 25 is provided on the substrate 23.

[0029] Furthermore, the sealing portion 25 may contain a phosphor. The phosphor may be, for example, a YAG-based phosphor (yttrium-aluminum-garnet-based phosphor). However, the type of phosphor may be changed as appropriate to obtain a predetermined emission color depending on the application of the vehicle lighting device 1.

[0030] In addition, an optical element 26 can be provided as necessary. The optical element 26 can be provided, for example, on the sealing portion 25. The optical element 26 can be, for example, a convex lens, a concave lens, a light guide, or the like.

[0031] The power supply unit 30 includes, for example, a power supply terminal 31 a, a power supply terminal 31 b, a power supply terminal 31 c, and a holder 32. As will be described later, the first circuit 21 and the second circuit 22 share a common ground (see FIG. 4). Therefore, power supply terminals 31a to 31c are provided, as shown in FIG. 1. In the following, a case where power supply terminals 31a to 31c are provided will be illustrated as an example, but the number of power supply terminals can be changed as appropriate depending on the number of circuits, the use of the ground, etc.

[0032] The power supply terminals 31a to 31c may be rod-shaped. One end of each of the power supply terminals 31a to 31c protrudes from the bottom surface 11a1 of the recess 11a. The power supply terminals 31a to 31c may be arranged side by side in a predetermined direction. One end of each of the power supply terminals 31a to 31c is soldered to the wiring patterns 23a and 23b provided on the substrate 23. The other end of each of the power supply terminals 31a to 31c is exposed inside the hole of the connector holder 15. The connector 105 is fitted to the end of each of the power supply terminals 31a to 31c exposed inside the hole of the connector holder 15. The power supply terminals 31a to 31c are made of a metal such as a copper alloy. The shape, arrangement, material, etc. of the power supply terminals 31a to 31c are not limited to those exemplified above and may be changed as appropriate.

[0033] As described above, the socket 10 is preferably made of a material with high thermal conductivity. However, materials with high thermal conductivity may be electrically conductive. For example, metals such as aluminum alloys and highly thermally conductive resins containing a carbon filler are electrically conductive. Therefore, the holding portion 32 is provided to insulate the power supply terminals 31a-31c from the electrically conductive socket 10. The holding portion 32 also functions to hold the power supply terminals 31a-31c. If the socket 10 is made of an insulating highly thermally conductive resin (e.g., a highly thermally conductive resin containing an aluminum oxide filler), the holding portion 32 can be omitted. In this case, the socket 10 holds the power supply terminals 31a-31c. The holding portion 32 is made of, for example, an insulating resin. The holding portion 32 can be press-fitted into a hole 10a provided in the socket 10 or adhered to the inner wall of the hole 10a.

[0034] The heat transfer member 40 is provided, for example, between the substrate 23 and the bottom surface 11a1 of the recess 11a. The heat transfer member 40 can be adhered, for example, to the bottom surface 11a1 of the recess 11a. The adhesive used to adhere the heat transfer member 40 to the bottom surface 11a1 of the recess 11a is preferably an adhesive with high thermal conductivity. The adhesive can be, for example, the same adhesive used to adhere the substrate 23 and the heat transfer member 40.

[0035] The heat transfer portion 40 can also be embedded in the bottom surface 11a1 of the recess 11a by insert molding. The heat transfer portion 40 can also be attached to the bottom surface 11a1 of the recess 11a via a layer of thermally conductive grease (heat dissipation grease). There are no particular limitations on the type of thermally conductive grease, but it can be, for example, modified silicone mixed with a filler using a material with high thermal conductivity (for example, ceramics such as aluminum oxide or aluminum nitride).

[0036] The heat transfer section 40 is provided to facilitate the transfer of heat generated in the light-emitting module 20 to the socket 10. For this reason, the heat transfer section 40 is preferably made of a material with high thermal conductivity. The heat transfer section 40 has a plate shape and can be made of a metal such as aluminum, an aluminum alloy, copper, or a copper alloy. It should be noted that if the amount of heat generated in the light-emitting module 20 is small, the heat transfer section 40 may be omitted.

[0037] Next, the first circuit 21 and the second circuit 22 will be further described. First, a circuit 121 and a circuit 122 according to the comparative example will be described. FIG. 3 is a circuit diagram of a circuit 121 and a circuit 122 according to a comparative example. The circuit 121 is a stop lamp circuit. As shown in Fig. 3, the circuit 121 has four light-emitting elements 21a, a resistor 121a, and a diode 121b. The four light-emitting elements 21a, the resistor 121a, and the diode 121b are connected in series.

[0038] The circuit 122 is a tail lamp circuit. As shown in Fig. 3, the circuit 122 includes a light-emitting element 22a, a resistor 122a, and a diode 122b. The light-emitting element 22a, the resistor 122a, and the diode 122b are connected in series.

[0039] Since there is variation in the forward voltage characteristics of the light-emitting elements 21a and 22a, if a constant voltage is applied between the anode terminals (power supply terminals 31a and 31b) and the ground terminal (power supply terminal 31c), the brightness (luminous flux, luminance, luminous intensity, illuminance) of the light emitted from the light-emitting elements 21a and 22a will vary. Therefore, the resistance value of resistor 121a connected in series to light-emitting element 21a is changed in accordance with the forward voltage characteristics of light-emitting element 21a, so that the value of the current flowing through light-emitting element 21a falls within a predetermined range. Furthermore, the resistance value of resistor 122a connected in series to light-emitting element 22a is changed in accordance with the forward voltage characteristics of light-emitting element 22a, so that the value of the current flowing through light-emitting element 22a falls within a predetermined range.

[0040] If the value of the current flowing through the light-emitting elements 21 a and 22 a is within a predetermined range, the brightness of the light emitted from the light-emitting elements 21 a and 22 a can be kept within a predetermined range. In other words, the circuits 121 and 122 according to the comparative example are resistance-driven circuits.

[0041] Here, the voltage (input voltage) applied to the vehicle lighting device fluctuates. For example, in the case of a vehicle lighting device for a general automobile, the standard operating voltage (rated voltage) is set to about 13.5 V. Therefore, the resistance values ​​of resistors 121 a and 122 a are set so that a predetermined total luminous flux is obtained when the input voltage is 13.5 V.

[0042] However, there are cases where the input voltage drops dramatically. For example, when starting the engine by cranking with a starter motor, the input voltage may drop to around 6V.

[0043] Generally, the forward voltage drop of the light-emitting elements 21a and 22a is about 3 V. Therefore, in the circuit 121 in which four light-emitting elements 21a and resistor 121a are connected in series, the voltage drop becomes 12 V or more. Therefore, when starting the engine, the circuit 121, which is the stop lamp circuit, cannot maintain illumination. Furthermore, the input voltage may fluctuate even while the vehicle is running. For example, in the case of a vehicle lighting device for an automobile, the input voltage may fluctuate within a range of 9 V or more and 16 V or less. Therefore, even if the input voltage fluctuates within this range, it may become impossible to maintain the stop lamp circuit 121 lit, or the required total luminous flux may not be obtained.

[0044] FIG. 4 is a circuit diagram illustrating the first circuit 21 and the second circuit 22. As shown in FIG. As described above, the first circuit 21 is, for example, a stop lamp circuit. The first circuit 21 is provided on a substrate 23. As shown in FIG. 4, the first circuit 21 has, for example, a plurality of light-emitting elements 21a, diodes 21b, and control elements 21c. For example, as shown in FIGS. 1 and 4, the first circuit 21 may be provided with four light-emitting elements 21a. However, the number of light-emitting elements 21a is not limited to the example shown.

[0045] 1, a plurality of light-emitting elements 21a, diodes 21b, and control elements 21c are provided on a substrate 23. The plurality of light-emitting elements 21a, diodes 21b, and control elements 21c are connected in series via a wiring pattern 23a. The first circuit 21 is electrically connected to a power supply terminal 31a and a power supply terminal 31c via the wiring pattern 23a.

[0046] The light emitting element 21a may be, for example, a light emitting diode, an organic light emitting diode, a laser diode, or the like. The light-emitting element 21a may be a chip-type light-emitting element, a surface-mounted light-emitting element such as a PLCC (Plastic Leaded Chip Carrier) type, or a light-emitting element having a lead wire such as a bullet-type light-emitting element. The light-emitting element 21a illustrated in FIGS. 1 and 2 is a chip-type light-emitting element. In this case, if the light-emitting element 21a is a surface-mounted light-emitting element or a light-emitting element having a lead wire such as a bullet-type light-emitting element, the frame portion 24 and the sealing portion 25 described above can be omitted. However, in consideration of miniaturization of the light-emitting module 20 and, ultimately, the vehicle lighting device 1, a chip-type light-emitting element is preferable. The following describes, as an example, a case where the light-emitting element 21a is a chip-type light-emitting element.

[0047] The chip-shaped light-emitting element 21a can be mounted on the wiring pattern 23a by COB (Chip On Board). The chip-shaped light-emitting element 21a may be, for example, 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 number, size, arrangement, etc. of the light-emitting elements 21a are not limited to those exemplified, and can be changed as appropriate depending on the size of the vehicle lighting device 1, the purpose of the first circuit 21, etc.

[0048] The diode 21b is electrically connected between the power supply terminal 31a and the light-emitting element 21a and the control element 21c. The diode 21b is provided, for example, to prevent a reverse voltage from being applied to the light-emitting element 21a and the control element 21c and to prevent pulse noise from being applied from the reverse direction to the light-emitting element 21a and the control element 21c. The diode 21b is, for example, a surface-mounted diode or a diode with leads. The diode 21b illustrated in FIG. 1 is a surface-mounted diode.

[0049] The control element 21c is electrically connected between the diode 21b and the plurality of light-emitting elements 21a. Since the forward voltage characteristics of the light-emitting elements 21a vary, if the voltage applied between the power supply terminal 31a and the power supply terminal 31c is kept constant, the brightness (luminous flux, luminance, luminous intensity, illuminance) of the light emitted from the light-emitting elements 21a varies. Furthermore, if the input voltage fluctuates, the brightness of the light emitted from the light-emitting elements 21a fluctuates. Therefore, the control element 21c controls the value of the current flowing through the plurality of light-emitting elements 21a. For example, the control element 21c keeps the value of the current flowing through the plurality of light-emitting elements 21a approximately constant. The control element 21c may include, for example, a mirror circuit, a constant current circuit using a constant current diode, a current limiter circuit using a transistor, a constant current IC, or the like.

[0050] Furthermore, if multiple light-emitting elements 21a are connected in series, a drop in the input voltage may reduce the value of the current flowing through the multiple light-emitting elements 21a, potentially making it impossible to obtain the required total luminous flux. Therefore, the control element 21c detects the input voltage and can change the number of light-emitting elements 21a through which current flows depending on the detected input voltage. For example, as shown in FIG. 4, when the input voltage is higher than a predetermined voltage, the control element 21c flows current through four light-emitting elements 21a connected in series. When the input voltage is lower than the predetermined voltage, the control element 21c flows current through two light-emitting elements 21a connected in series and does not flow current through the other two light-emitting elements 21a connected in series. In this way, a drop in the input voltage can prevent the value of the current flowing through the two light-emitting elements 21a from decreasing. Therefore, when the input voltage drops, the required total luminous flux can be ensured and fluctuations in the total luminous flux can be suppressed.

[0051] As described above, the second circuit 22 is, for example, a tail lamp circuit. The second circuit 22 is provided on a substrate 23. As shown in FIG. 4, the second circuit 22 has, for example, a light-emitting element 22a, a diode 22b, and a resistor 22c. As shown in FIG. 1, the light-emitting element 22a, the diode 22b, and the resistor 22c are provided on the substrate 23. The light-emitting element 22a, the diode 22b, and the resistor 22c are connected in series via a wiring pattern 23b. The second circuit 22 is electrically connected to the power supply terminal 31b and the power supply terminal 31c via the wiring pattern 23b.

[0052] The light-emitting element 22a may be the same as the light-emitting element 21a described above. However, the number of light-emitting elements 22a is less than the number of light-emitting elements 21a. For example, as shown in Figures 1 and 4, the second circuit 22 may be provided with one light-emitting element 22a. However, a plurality of light-emitting elements 22a may be provided.

[0053] In this case, for a stop lamp, an emission distribution in which the peripheral area of ​​the light exit surface (for example, the surface of the optical element 26 opposite the sealing portion 25) is bright is preferable, and for a tail lamp, an emission distribution in which the central area of ​​the light exit surface is bright is preferable.

[0054] Therefore, for example, it is preferable to provide one light-emitting element 22a in the second circuit 22 for use as a tail lamp. Also, it is preferable to provide multiple light-emitting elements 21a in the first circuit 21 for use as a stop lamp. In this case, the multiple light-emitting elements 21a can be provided in positions surrounding the light-emitting element 22a. In this way, a preferable light emission distribution can be obtained whether the vehicle lighting device 1 is used as a tail lamp or a stop lamp.

[0055] The diode 22b is electrically connected between the power supply terminal 31b and the light-emitting element 22a and the control element 22c. The diode 22b is provided, for example, to prevent a reverse voltage from being applied to the light-emitting element 22a and to prevent pulse noise from being applied to the light-emitting element 22a from the reverse direction. The diode 22b may be similar to the diode 21b described above.

[0056] Resistor 22c is electrically connected between diode 22b and light-emitting element 22a. Similar to light-emitting element 21a, light-emitting element 22a also has variations in forward voltage characteristics, and therefore, if the voltage applied between power supply terminal 31b and power supply terminal 31c is kept constant, variations occur in the brightness (luminous flux, luminance, luminous intensity, illuminance) of the light emitted from light-emitting element 22a.

[0057] Therefore, to keep the brightness of the light emitted from the light-emitting element 22a within a predetermined range, the value of the current flowing through the light-emitting element 22a is controlled to be within a predetermined range by the resistor 22c connected in series to the light-emitting element 22a. In this case, the resistance value of the resistor 22c is changed to keep the value of the current flowing through the light-emitting element 22a within the predetermined range.

[0058] The resistor 22c may be, for example, a surface-mount resistor, a resistor with leads (metal oxide film resistor), or a film resistor formed by screen printing, etc. The resistor 22c illustrated in FIG. 1 is a film resistor.

[0059] The film resistor is made of, for example, ruthenium oxide (RuO2). The film resistor is formed by, for example, screen printing and firing. If the resistor 22c is a film resistor, the contact area between the resistor 22c and the substrate 23 can be increased, thereby improving heat dissipation. In addition, productivity can be improved and variations in resistance value can be suppressed.

[0060] If the resistor 22c is a surface-mount resistor or a resistor with leads, a resistor 22c having an appropriate resistance value is selected according to the forward voltage characteristics of the light-emitting element 22a. If the resistor 22c is a film resistor, the resistance value can be increased by removing a portion of the resistor 22c. For example, a portion of the film resistor can be easily removed by irradiating it with laser light. The number and size of the resistors 22c are not limited to those exemplified above and can be changed as appropriate according to the number and specifications of the light-emitting elements 22a.

[0061] Furthermore, passive or active elements used to configure a light-emitting circuit may be further provided in at least one of the first circuit 21 and the second circuit 22. For example, at least one of the first circuit 21 and the second circuit 22 may further be provided with a capacitor, a positive temperature coefficient thermistor, a negative temperature coefficient thermistor, an inductor, a surge absorber, a varistor, a transistor such as an FET or a bipolar transistor, an integrated circuit, an arithmetic element, or the like.

[0062] As described above, the first circuit 21 having the plurality of light-emitting elements 21a is provided with the control element 21c. Therefore, even if the input voltage drops extremely (for example, to about 6V), it is possible to maintain the lighting of the plurality of light-emitting elements 21a and maintain the required total luminous flux. Furthermore, the control element 21c can change the number of light-emitting elements 21a through which current flows depending on the input voltage, so it is possible to ensure the required total luminous flux and suppress fluctuations in the total luminous flux.

[0063] In this case, instead of the resistor 22c, a control element 21c can also be provided in the second circuit 22. However, since the number of light-emitting elements 22a provided in the second circuit 22 is smaller than the number of light-emitting elements 21a provided in the first circuit 21, even if the input voltage drops significantly, it is easy to maintain the lighting of the light-emitting elements 22a and to maintain the required total luminous flux. Furthermore, the resistor 22c is cheaper and smaller than the control element 21c. Therefore, providing the resistor 22c in the second circuit 22 allows for reduction in cost and size of the vehicle lighting device 1.

[0064] (vehicle lighting fixtures) Next, the vehicle lamp 100 will be illustrated. In the following, as an example, a case will be described in which the vehicular lamp 100 is a rear combination light installed in an automobile. However, the vehicular lamp 100 is not limited to a rear combination light installed in an automobile. The vehicular lamp 100 may be any vehicular lamp that is installed in an automobile, a railroad car, or the like and has multiple uses.

[0065] FIG. 5 is a schematic partial cross-sectional view illustrating the vehicle lamp 100. As shown in FIG. As shown in FIG. 5, the vehicle lamp 100 includes, for example, the vehicle lighting device 1, a housing 101, a cover 102, an optical element 103, a seal member 104, and a connector 105.

[0066] The vehicle lighting device 1 is attached to the housing 101. The housing 101 holds the mounting portion 11. The housing 101 is box-shaped with one end open. The housing 101 is formed, for example, from a light-opaque resin. The bottom surface of the housing 101 is provided with a mounting hole 101a into which the portion of the mounting portion 11 provided 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. Note that although the case where the mounting hole 101a is directly provided in the housing 101 has been exemplified, a mounting member having the mounting hole 101a may also be provided on the housing 101.

[0067] When attaching the vehicle lighting device 1 to the vehicle lamp 100, the portion of the mounting portion 11 where the bayonet 12 is provided is inserted into the mounting hole 101a, and the vehicle lighting device 1 is rotated. Then, for example, the bayonet 12 is held in a fitting portion provided on the periphery of the mounting hole 101a. This type of attachment method is called a twist lock.

[0068] 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.

[0069] Light emitted from the vehicle lighting device 1 is incident on the optical element 103. The optical element 103 reflects, diffuses, guides, and collects the light emitted from the vehicle lighting device 1, and forms a predetermined light distribution pattern. For example, the optical element 103 illustrated in FIG. 5 is a reflector. In this case, the optical element 103 reflects the light emitted from the vehicle lighting device 1 and forms a predetermined light distribution pattern.

[0070] 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.

[0071] When the vehicle lighting device 1 is attached to the vehicle lamp 100, the seal member 104 is sandwiched between the flange 13 and the housing 101. Therefore, the seal member 104 can seal the internal space of the housing 101. Furthermore, the elastic force of the seal member 104 presses the bayonet 12 against the housing 101. Therefore, the vehicle lighting device 1 can be prevented from detaching from the housing 101.

[0072] The connector 105 is fitted to the ends of the power supply terminals 31a to 31c exposed inside the connector holder 15. A power source (not shown) and the like are electrically connected to the connector 105. Therefore, by fitting the connector 105 to the ends of the power supply terminals 31a to 31c, the first circuit 21 and the second circuit 22 can be electrically connected to the power source (not shown) and the like.

[0073] 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.

[0074] 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. [Explanation of symbols]

[0075] REFERENCE SIGNS LIST 1 vehicle lighting device, 10 socket, 11 mounting portion, 20 light emitting module, 21 first circuit, 21a light emitting element, 21c control element, 22 second circuit, 22a light emitting element, 22c resistor, 23 substrate, 31a to 31c power supply terminal, 100 vehicle lighting fixture, 101 housing

Claims

1. A vehicle lighting device having a stop lamp function and a tail lamp function, Socket and; a substrate provided on one end side of the socket; a first circuit disposed on the substrate; a second circuit disposed on the substrate; Equipped with the first circuit is a circuit for the stop lamp, four first light-emitting elements connected in series; a control element electrically connected to the four first light-emitting elements and configured to control a value of a current flowing through the four first light-emitting elements; and the second circuit is a circuit for the tail lamp; one second light-emitting element; a resistor connected in series with the one second light-emitting element; and the four first light-emitting elements are provided at positions surrounding the one second light-emitting element, The control element detects an input voltage; When the detected input voltage is higher than a predetermined voltage, a current is caused to flow through the four first light-emitting elements connected in series; When the detected input voltage is lower than the predetermined voltage, a current is passed through two of the four first light-emitting elements connected in series, and no current is passed through the other two first light-emitting elements connected in series.

2. the control element keeps the values ​​of the currents flowing through the four first light-emitting elements substantially constant; 2. The vehicle lighting device according to claim 1, wherein the resistor controls a value of a current flowing through the one second light-emitting element to fall within a predetermined range.

3. The vehicle lighting device according to claim 1 or 2; a housing to which the vehicle lighting device is attached; A vehicle lighting fixture equipped with:

Images