Patent Description:
From the viewpoint of energy saving and long service life, vehicle lighting devices equipped with light emitting elements such as light emitting diodes are becoming more popular instead of vehicle lighting devices equipped with filaments.

Further, in recent years, there has been a demand for high luminous flux in vehicle lighting devices. In this case, by increasing the number of light emitting elements provided in the vehicle lighting device, it is possible to increase the luminous flux of the vehicle lighting device.

However, if only the number of light emitting elements is increased, it is difficult to achieve a desired luminance distribution. In this case, for example, if the luminance distribution in a peripheral region of a light exit surface and the luminance distribution in a central region of the light exit surface becomes unbalanced, it may be difficult to form a desired light distribution pattern.

Thus, it has been desired to develop a technique that can achieve a desired luminance distribution even if the number of light emitting elements is increased.

<CIT> relates to a vehicular lighting instrument semiconductor light source light source unit including a light source portion and a socket portion. <CIT> relates to a vehicular luminaire and a vehicular lamp. <CIT> relates to a vehicular lighting system used for combining a variety of uses in a simple construction and to provide a vehicular lighting tool.

The problem to be solved by the invention is to provide a vehicle lighting device and a vehicle lamp that can achieve a desired luminance distribution even if the number of light emitting elements is increased.

A vehicle lighting device of the invention includes a socket; a substrate provided on one end portion side of the socket; one first light emitting element provided on the substrate; and four second light emitting elements provided on the substrate. A square luminance distribution region orthogonal to a central axis of the vehicle lighting device is defined on light irradiation sides of the first light emitting element and the second light emitting elements. A center of the luminance distribution region overlaps the central axis of the vehicle lighting device. The luminance distribution region is equally divided into four square first regions whose corners overlap the center of the luminance distribution region. Each of the four first regions is equally divided into nine square second regions. A length of one side of the second region is <NUM>. When XY coordinates of the center of the luminance distribution region are located at (<NUM>, <NUM>), a center of the first light emitting element is located at (<NUM>, <NUM>), and centers of the four second light emitting elements are located at (<NUM>, <NUM>), (-<NUM>, <NUM>), (<NUM>, -<NUM>), and (-<NUM>, -<NUM>). A luminance of the luminance distribution region is <NUM>% or more of a total luminance of light emitted from the vehicle lighting device. In twenty second regions arranged along sides of the luminance distribution region, a luminance of one of the second regions is <NUM>% or less of the total luminance. In sixteen second regions provided inside the twenty second regions, the luminance of one of the second regions is <NUM>% or more and <NUM>% or less of the total luminance.

A vehicle lamp according to an embodiment includes the vehicle lighting device; and a casing body to which the vehicle lighting device is installed.

According to the embodiments of the invention, it is possible to provide a vehicle lighting device and a vehicle lamp that can achieve a desired luminance distribution even if the number of light emitting elements is increased.

Hereinafter, embodiments will be illustrated with reference to the drawings. Moreover, in each drawing, the same reference numerals are given to the same constituent components, and detailed description thereof will be omitted as appropriate.

Also, arrows X, Y, and Z in each diagram represent directions orthogonal to each other. For example, the arrow X represents the horizontal or vertical direction, the arrow Y represents the vertical or horizontal direction, and the arrow Z represents the front-back direction. For example, the arrow Z may be a direction along a central axis 1a of a vehicle lighting device <NUM>.

The vehicle lighting device <NUM> according to this embodiment may be installed in, for example, an automobile or a railroad vehicle. Examples of the vehicle lighting device <NUM> provided in an automobile include those used for front combination lights (for example, appropriate combination of daytime running lamps (DRL), position lamps, turn signal lamps, etc.), rear combination lights (for example, appropriate combination of stop lamps, tail lamps, turn signal lamps, back lamps, fog lamps, etc.) and the like. However, the applications of the vehicle lighting device <NUM> are not limited thereto.

<FIG> is a schematic perspective diagram for illustrating the vehicle lighting device <NUM> according to this embodiment.

<FIG> is a cross-sectional diagram of the vehicle lighting device <NUM> in <FIG>, taken along a line A-A.

As shown in <FIG> and <FIG>, the vehicle lighting device <NUM> is provided with, for example, a socket <NUM>, a light emitting module <NUM>, a power feeding portion <NUM> and a heat transfer portion <NUM>.

The socket <NUM> includes, for example, a mounting portion <NUM>, a bayonet <NUM>, a flange <NUM>, a heat radiation fin <NUM>, and a connector holder <NUM>.

The mounting portion <NUM> is provided, for example, on a surface of the flange <NUM> opposite to a side on which the heat radiation fin <NUM> is provided. An external shape of the mounting portion <NUM> may be columnar. An external shape of the mounting portion <NUM> is, for example, cylindrical. The mounting portion <NUM> has, for example, a recess portion 11a opening at an end portion opposite to the flange <NUM> side.

The bayonet <NUM> is provided on a side surface of the mounting portion <NUM>, for example. The bayonet <NUM> protrudes toward the outside of the vehicle lighting device <NUM>, for example. The bayonet <NUM> faces the flange <NUM>. A plurality of bayonet <NUM> may be provided. The bayonet <NUM> is used when the vehicle lighting device <NUM> is mounted to, for example, a casing body <NUM> of a vehicle lamp <NUM> to be described later. The bayonet <NUM> may be used for twist locks.

The flange <NUM> has, for example, a plate shape. The flange <NUM> has, for example, a disk shape. The side surface of the flange <NUM> is located outside the vehicle lighting device <NUM> than a side surface of the bayonet <NUM>.

The heat radiation fin <NUM> is provided, for example, on the side of the flange <NUM> opposite to the mounting portion <NUM> side. At least one heat radiation fin <NUM> may be provided. For example, the socket <NUM> illustrated in <FIG> is provided with a plurality of heat radiation fins <NUM>. The plurality of heat radiation fins <NUM> may be arranged side by side in a predetermined direction. The heat radiation fins <NUM> are, for example, plate-shaped or tubular.

The connector holder <NUM> is provided, for example, on the side of the flange <NUM> opposite to the mounting portion <NUM> side. The connector holder <NUM> may be arranged side by side with the heat radiation fins <NUM>. The connector holder <NUM> has a tubular shape, and a connector <NUM> having a sealing member 105a to be described later is inserted therein.

The socket <NUM> has a function of holding the light emitting module <NUM> and the power feeding portion <NUM> and a function of transmitting heat generated in the light emitting module <NUM> to the outside. Thus, it is preferable to form the socket <NUM> from a material having high thermal conductivity. For example, the socket <NUM> may be formed from a metal such as an aluminum alloy.

Moreover, in recent years, it is desired that the socket <NUM> may efficiently radiate the heat generated in the light emitting module <NUM> and be lightweight. Thus, it is more preferable to form the socket <NUM> from, for example, a high thermal conductive resin. The high thermal conductive resin includes, for example, a resin and a filler using an inorganic material. The high thermal 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.

Assuming that the socket <NUM> includes a high thermal conductive resin and is integrally formed with the mounting portion <NUM>, the bayonet <NUM>, the flange <NUM>, the heat radiation fin <NUM>, and the connector holder <NUM>, heat generated in the light emitting module <NUM> may be efficiently radiated. Also, the weight of the socket <NUM> may be reduced. In this case, the mounting portion <NUM>, the bayonet <NUM>, the flange <NUM>, the heat radiation fin <NUM>, and the connector holder <NUM> may be integrally formed using an injection molding method or the like. Alternatively, for example, the socket <NUM>, the power feeding portion <NUM>, and the heat transfer portion <NUM> may be integrally formed using an insert molding method or the like.

The power feeding portion <NUM> includes, for example, a plurality of power feeding terminals <NUM> and a holding portion <NUM>.

The plurality of power feeding terminals <NUM> may be rod-shaped. The plurality of power feeding terminals <NUM> may be arranged side by side in a predetermined direction. One end portion of the plurality of power feeding terminals <NUM> protrudes from a bottom surface 11a1 of the recess portion 11a. One end portion of the power feeding terminals <NUM> is soldered to a wiring pattern 21a provided on a substrate <NUM>. The other end portion of the plurality of power feeding terminals <NUM> is exposed to the inside of a hole of the connector holder <NUM>. The connector <NUM> is fitted to the end portion of the plurality of power feeding terminals <NUM> exposed to the inside of the hole of the connector holder <NUM>. The plurality of power feeding terminals <NUM> are made of metal such as copper alloy, for example. Moreover, the shape, arrangement, material, and the like of the plurality of power feeding terminals <NUM> are not limited to the examples, and may be changed as appropriate.

As previously mentioned, the socket <NUM> is preferably formed from a material having high thermal conductivity. However, materials having high thermal conductivity may have electrical conductivity. For example, metals such as aluminum alloys or high thermal conductive resins containing carbon-based fillers have electrical conductivity. Thus, the holding portion <NUM> is provided to insulate between the plurality of power feeding terminals <NUM> and the socket <NUM> having electrical conductivity. The holding portion <NUM> also has a function of holding the plurality of power feeding terminals <NUM>. Note that if the socket <NUM> is made of an insulating, high thermal conductive resin (for example, a high thermal conductive resin containing a filler using aluminum oxide), the holding portion <NUM> may be omitted. In this case, the socket <NUM> holds the plurality of power feeding terminals <NUM>. The holding portion <NUM> is made of, for example, an insulating resin. For example, the holding portion <NUM> may be press-fitted into a hole 10a provided in the socket <NUM> or adhered to an inner wall of the hole 10a.

The heat transfer portion <NUM> is provided, for example, between the substrate <NUM> and the bottom surface 11a1 of the recess portion 11a. The heat transfer portion <NUM> may be adhered to the bottom surface 11a1 of the recess portion 11a, for example. The adhesive that bonds the heat transfer portion <NUM> and the bottom surface 11a1 of the recess portion 11a preferably has high thermal conductivity. For example, the adhesive may be an adhesive mixed with a filler using an inorganic material. The inorganic material is preferably a material having high thermal conductivity (for example, ceramics such as aluminum oxide and aluminum nitride).

Moreover, the heat transfer portion <NUM> may be embedded in the bottom surface 11a1 of the recess portion 11a using an insert molding method. Further, the heat transfer portion <NUM> may also be attached to the bottom surface 11a1 of the recess portion 11a via a layer containing heat conductive grease (heat radiation grease). There is no particular limitation on the type of heat conductive grease, but for example, the heat conductive grease may be a mixture of modified silicone and a filler using a material having high thermal conductivity (for example, ceramics such as aluminum oxide and aluminum nitride).

The heat transfer portion <NUM> is provided to facilitate transfer of heat generated in the light emitting module <NUM> to the socket <NUM>. Thus, it is preferable to form the heat transfer portion <NUM> from a material having a high thermal conductivity. The heat transfer portion <NUM> has a plate shape and may be made of metal such as aluminum, an aluminum alloy, copper, or a copper alloy, for example.

Note that the heat transfer portion <NUM> may be omitted when the heat generated in the light emitting module <NUM> is small.

The light emitting module <NUM> (the substrate <NUM>) is provided on one end portion side of the socket <NUM>, for example. The light emitting module <NUM> (the substrate <NUM>) is adhered to the heat transfer portion <NUM>, for example. When the heat transfer portion <NUM> is omitted, the light emitting module <NUM> (the substrate <NUM>) is adhered to the bottom surface 11a1 of the recess portion 11a, for example. The adhesive for bonding the light emitting module <NUM> (the substrate <NUM>) may be, for example, the same as the adhesive for bonding the heat transfer portion <NUM> and the bottom surface 11a1 of the recess portion 11a.

The light emitting module <NUM> includes the substrate <NUM>, light emitting elements <NUM>, a frame portion <NUM>, a sealing portion <NUM>, an optical element <NUM>, and an element <NUM>, for example.

The substrate <NUM> has a plate shape. The planar shape of the substrate <NUM> is, for example, quadrangle. The substrate <NUM> may be made of, for example, an inorganic material such as ceramics (e.g. aluminum oxide or aluminum nitride), or an organic material such as paper phenol or glass epoxy. Also, the substrate <NUM> may be a metal core substrate in which the surface of a metal plate is coated with an insulating material. When the amount of heat generated by the light emitting elements <NUM> is large, it is preferable to form the substrate <NUM> using a material having high thermal conductivity from the viewpoint of heat radiation. Examples of materials having high thermal conductivity include ceramics such as aluminum oxide and aluminum nitride, high thermal conductive resins, and metal core substrates. Moreover, the substrate <NUM> may have a single layer structure or may have a multilayer structure.

Further, the substrate <NUM> includes the wiring pattern 21a. The wiring pattern 21a is provided on a surface of the substrate <NUM>. The wiring pattern 21a contains, for example, a material whose main component is silver or a material whose main component is copper.

Light emitting elements <NUM> are provided on the substrate <NUM> (on a side opposite to the heat transfer portion <NUM> side). The light emitting element <NUM> is electrically connected to the wiring pattern 21a. A plurality of light emitting elements <NUM> are provided. For example, five light emitting elements <NUM> may be provided.

The light emitting element <NUM> may be, for example, a light emitting diode, an organic light emitting diode, a laser diode, or the like.

The light emitting element <NUM> may be a chip-shaped light emitting element. If the chip-shaped light emitting element <NUM> is configured, the light emitting module <NUM> may be miniaturized, and thus the vehicle lighting device <NUM> may be miniaturized, compared to the case of using a surface-mounted light emitting element or a bullet-shaped light emitting element having lead wires.

The light emitting element <NUM> may be mounted on the wiring pattern 21a by COB (Chip On Board). The light emitting element <NUM> may be, for example, any of an upper electrode type light emitting element, an upper and lower electrode type light emitting element, and a flip chip type light emitting element.

The planar shape of the light emitting element <NUM> (the shape of a light exit surface) may be quadrangle.

<FIG> is a schematic plan diagram for illustrating the arrangement of the five light emitting elements <NUM>.

<FIG> is a schematic diagram of the five light emitting elements <NUM> viewed from the direction (Z direction) along the central axis 1a of the vehicle lighting device <NUM>. To avoid complication, components other than the five light emitting elements <NUM> are omitted in the diagram.

Also, in <FIG>, a luminance distribution region <NUM> is defined. The shape of the luminance distribution region <NUM> is square. One side of the luminance distribution region <NUM> is parallel to the X direction. The other side of the luminance distribution region <NUM> is parallel to the Y direction.

In other words, the square luminance distribution region <NUM> orthogonal to the central axis 1a of the vehicle lighting device <NUM> is defined on light irradiation sides of the five light emitting elements <NUM>.

A center of the luminance distribution region <NUM> overlaps the central axis 1a of the vehicle lighting device <NUM>.

The luminance distribution region <NUM> is equally divided into four square regions <NUM> (corresponding to an example of first regions) whose corners overlap the center of the luminance distribution region <NUM>. Each of the four regions <NUM> is equally divided into nine square regions <NUM> (corresponding to an example of second regions). A length of one side of the luminance distribution region <NUM> is, for example, <NUM>. A length of one side of the region <NUM> is, for example, <NUM>. A length of one side of the region <NUM> is, for example, <NUM>.

For example, as shown in <FIG>, one light emitting element 22a (corresponding to an example of a first light emitting element) is located at the center of the luminance distribution region <NUM> (the position of the central axis 1a of the vehicle lighting device <NUM>). For example, a center of the light emitting element 22a overlaps the center of the luminance distribution region <NUM>.

Four light emitting elements 22b (corresponding to an example of a second light emitting element) surrounding the light emitting element 22a are provided. For example, a center of the light emitting element 22b overlaps a corner of the region <NUM>, which has a corner overlapping the center of the luminance distribution region <NUM>, which is diagonally opposite the corner overlapping the center of the luminance distribution region <NUM>.

For example, when the XY coordinates of the center of the luminance distribution region <NUM> are (<NUM>, <NUM>), the center of the light emitting element 22a is located at (<NUM>, <NUM>), and the centers of the four light emitting elements 22b are located at (<NUM>, <NUM>), (-<NUM>, <NUM>), (<NUM>, -<NUM>), (-<NUM>, -<NUM>.

In this way, the light emitting element 22a is located at the center of the luminance distribution region <NUM>. Further, the light emitting element 22b is provided in each of the four regions <NUM> surrounding the center of the luminance distribution region <NUM>. Thus, it becomes easy to perform isotropic light irradiation in the XY directions.

Further, a luminance of the luminance distribution region <NUM> is <NUM>% or more of a luminance (total luminance) of light emitted from the vehicle lighting device <NUM> (the light emitting module <NUM>).

Further, in twenty regions <NUM> arranged along sides of the luminance distribution region <NUM>, a luminance of one of the regions <NUM> is <NUM>% or less of the total luminance.

Further, in sixteen regions <NUM> provided inside the twenty regions <NUM> arranged along the sides of the luminance distribution region <NUM>, the luminance of one of the regions <NUM> is <NUM>% or more and <NUM>% or less of the total luminance.

The planar shapes of the light emitting element 22a and the light emitting element 22b may be square or rectangular. In this case, the planar shapes of the light emitting element 22a and the light emitting element 22b may be the same or different.

The planar dimensions of the light emitting element 22a and the light emitting element 22b may be the same or different. For example, the planar dimensions of the light emitting element 22b may be larger than, the same as, or smaller than the planar dimensions of the light emitting element 22a.

That is, at least one of the planar shape and planar dimension of the light emitting element 22b may be the same as that of the light emitting element 22a. Alternatively, the planar shape and planar dimensions of the light emitting element 22b may be different from those of the light emitting element 22a.

For example, a length of one side of the light emitting element 22a having a square planar shape may be about <NUM>. For example, a length of one side of the light emitting element 22b having a square planar shape may be about <NUM>.

Also, as shown in <FIG>, the sides of the light emitting element 22a and the sides of the light emitting element 22b may be parallel. As described above, the light emitting element 22a and the light emitting element 22b may be upper and lower electrode type light emitting elements. When upper and lower electrode type light emitting elements are connected in series, the polarity of the lower electrode of one light emitting element differs from the polarity of the lower electrode of an adjacent light emitting element. Thus, it is preferable to increase the creepage distance by increasing the distance between the wiring pattern 21a on which one light emitting element is mounted and the wiring pattern 21a on which the adjacent light emitting element is mounted. If the sides of the light emitting element 22a and the sides of the light emitting element 22b are parallel, even if the distance between the center of the light emitting element 22a and the center of the light emitting element 22b is the same, the distance between the wiring patterns 21a can be reduced. Thus, it is possible to suppress the occurrence of a short circuit or the like.

The frame portion <NUM> is provided on the substrate <NUM>. The frame portion <NUM> has a frame shape and is adhered to the substrate <NUM>. The plurality of light emitting elements <NUM> are provided in a region surrounded by the frame portion <NUM>. The frame portion <NUM> is made of resin, for example. The resin may be, for example, a thermoplastic resin such as PBT (polybutylene terephthalate), PC (polycarbonate), PET, nylon, PP (polypropylene), PE (polyethylene), or PS (polystyrene).

The frame portion <NUM> may have a function of defining the formation range of the sealing portion <NUM> and a function of a reflector. Thus, the frame portion <NUM> may contain titanium oxide particles or the like, or may contain white resin, in order to improve the reflectance.

Also, the frame portion <NUM> may be omitted. However, if the frame portion <NUM> is provided, the utilization efficiency of the light irradiated from the light emitting element <NUM> can be improved. Moreover, since the range in which the sealing portion <NUM> is formed may be reduced, the light emitting module <NUM> may be miniaturized and thus the vehicle lighting device <NUM> may be miniaturized.

The sealing portion <NUM> is provided inside the frame portion <NUM>. The sealing portion <NUM> is provided so as to cover the region surrounded by the frame portion <NUM>. The sealing portion <NUM> is provided so as to cover the light emitting element <NUM>. The sealing portion <NUM> contains a translucent resin. The sealing portion <NUM> is formed, for example, by filling the inside of the frame portion <NUM> with resin. Filling of the resin is performed using a dispenser or the like, for example. The filling resin is, for example, a silicone resin.

Moreover, when the frame portion <NUM> is omitted, for example, the dome-shaped sealing portion <NUM> is provided on the substrate <NUM>.

Moreover, the sealing portion <NUM> 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 appropriately changed according to the application of the vehicle lighting device <NUM> such that a predetermined emission color is obtained.

The optical element <NUM> may be provided over the sealing portion <NUM>. The optical element <NUM> may be, for example, a convex lens, a concave lens, a light guide, or the like. The optical element <NUM> illustrated in <FIG> is a convex lens. Note that the optical element <NUM> is not necessarily required and may be omitted. However, when the optical element <NUM> is provided, it is easier to obtain a predetermined light distribution characteristics.

The element <NUM> may be a passive element or an active element configured to construct a light emitting circuit including the light emitting elements <NUM>. The element <NUM> is provided, for example, around the frame portion <NUM> and electrically connected to the wiring pattern 21a.

The element <NUM> may be, for example, a resistor 26a, a diode 26b, a control element 26c, or the like.

However, the type of the element <NUM> is not limited to the examples, and may be changed as appropriate according to the configuration of the light emitting circuit including the light emitting elements <NUM>. For example, in addition to the above, the element <NUM> may be a capacitor, a positive temperature coefficient thermistor, a negative temperature coefficient thermistor, a Zener diode, 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.

The resistor 26a is provided on the substrate <NUM>. The resistor 26a is electrically connected to the wiring pattern 21a. The resistor 26a may be, for example, a surface-mounted resistor, a resistor having lead wires (metal oxide film resistor), or a film-like resistor formed using a screen printing method or the like. Note that the resistor 26a illustrated in <FIG> is a film-like resistor.

The material of the film-like resistor is, for example, ruthenium oxide (RuO<NUM>). The film-like resistor is formed using, for example, a screen printing method and a firing method. If the resistor 26a is a film-like resistor, a contact area between the resistor 26a and the substrate <NUM> may be increased, and heat radiation can be improved. Also, a plurality of resistors 26a may be formed at once. Thus, productivity can be improved. Moreover, it is possible to suppress variations in resistance values of the plurality of resistors 26a.

Here, since the forward voltage characteristics of the light emitting elements <NUM> vary, if the voltage applied between an anode terminal and a ground terminal is constant, variations occur in the brightness of the light irradiated from the light emitting elements <NUM> (luminous flux, luminance, luminous intensity, illuminance). Thus, the resistor 26a connected in series with the light emitting elements <NUM> keeps the value of the current flowing through the light emitting elements <NUM> within a predetermined range such that that the brightness of the light irradiated from the light emitting elements <NUM> is within a predetermined range. In this case, by changing the resistance value of the resistor 26a, the value of the current flowing through the light emitting elements <NUM> is kept within a predetermined range.

If the resistor 26a is a surface-mounted resistor or a resistor having lead wires, the resistor 26a having an appropriate resistance value is selected according to the forward voltage characteristics of the light emitting elements <NUM>. If the resistor 26a is a film-like resistor, the resistance value may be increased by removing part of the resistor 26a. For example, by irradiating a film-like resistor with laser light, part of the film-like resistor may be easily removed. Note that the number, size, arrangement, etc. of the resistors 26a are not limited to the examples, and may be appropriately changed according to the number and specifications of the light emitting elements <NUM>, and the like.

The diode 26b is provided on the substrate <NUM>. The diode 26b is electrically connected to the wiring pattern 21a. The diode 26b is electrically connected between the power feeding terminal <NUM> and the light emitting element <NUM> as well as the control element 26c. For example, the diode 26b is provided to prevent reverse voltage from being applied to the light emitting element <NUM> and the control element 26c and to prevent pulse noise from being applied to the light emitting element <NUM> and the control element 26c from the reverse direction. The diode 26b is, for example, a surface-mounted diode or a diode having lead wires. The diode 26b illustrated in <FIG> is a surface-mounted diode.

Here, the voltage (input voltage) applied to the vehicle lighting device <NUM> may fluctuate. For example, the operating standard voltage (rated voltage) of the vehicle lighting device <NUM> for general automobiles is about <NUM>. However, the input voltage may fluctuate due to the voltage drop of the battery, the operation of the alternator, the influence of the circuit, etc. Thus, the operating voltage range (voltage fluctuation range) is defined in the vehicle lighting device <NUM> for automobiles. The operating voltage range is, for example, 9V or higher and 16V or lower.

Also, for example, in a case where a forward voltage Vf of the light emitting elements <NUM> is <NUM>. 8V, when the five light emitting elements <NUM> are connected in series and the input voltage is close to <NUM> V, almost no current flows through the five light emitting elements <NUM>, and the total luminous flux of the vehicle lighting device <NUM> becomes less than the specified value. Moreover, the resistor 26a and the diode 26b are also connected in series to the five light emitting elements <NUM>. Thus, it becomes more difficult to ensure the total luminous flux of the vehicle lighting device <NUM> near a lower limit of the operating voltage range.

Thus, the light emitting module <NUM> is provided with the control element 26c.

<FIG> is a circuit diagram of the light emitting module <NUM>.

As shown in <FIG>, the control element 26c is electrically connected between the resistor 26a and the five light emitting elements <NUM>.

The control element 26c is provided on the substrate <NUM>. The control element 26c is electrically connected to the five light emitting elements <NUM> (22a, 22b) via the wiring pattern 21a.

The control element 26c detects the input voltage and changes the number of the light emitting elements <NUM> through which the current flows according to the detected input voltage. In this case, the control element 26c may change the number of the light emitting elements 22b through which the current flows according to the detected input voltage. For example, when the input voltage is higher than a predetermined voltage, the control element 26c causes current to flow through the five light emitting elements <NUM> (22a, 22b) connected in series. When the input voltage is lower than the predetermined voltage, the control element 26c causes the current to flow through three light emitting elements <NUM> (22a, 22b) connected in series, and not flow through the other two light emitting elements <NUM> (22b) connected in series.

If the control element 26c is provided, it is possible to prevent the current flowing through the three light emitting elements <NUM> from decreasing when the input voltage drops. Thus, the required total luminous flux can be ensured when the input voltage drops.

Here, in order to achieve a total luminous flux of <NUM> lm (lumen) ±<NUM>%, when the five light emitting elements <NUM> are red light emitting diodes having an operating voltage of <NUM> V to <NUM> V, an applied power is 3W to 4W, and an ambient temperature is <NUM>, the junction temperature of the light emitting element <NUM> is about <NUM>° C to <NUM> ° C. However, since the difference between the junction temperature immediately after lighting and the junction temperature <NUM> minutes after lighting increases, the rate of change of the luminous flux increases. When the rate of change of the luminous flux increases, for example, a driver of a vehicle may feel uncomfortable.

Thus, the control element 26c may have a soft start circuit. For example, the control element 26c makes the current flowing through the five light emitting elements <NUM> (22a, 22b) immediately after lighting <NUM>% or more and <NUM>% or less of the current flowing through the five light emitting elements <NUM> (22a, 22b) <NUM> minutes after lighting.

Moreover, the temperature of the region of the substrate <NUM> where the five light emitting elements <NUM> (22a, 22b) are provided may reach <NUM>° C or higher. In such cases, the junction temperature should not exceed a maximum junction temperature (e.g. <NUM>° C).

Thus, the control element 26c may have a derating circuit. For example, the control element 26c detects the ambient temperature, and when the ambient temperature is <NUM>° C or higher and <NUM>° C or lower, the power applied to the five light emitting elements <NUM> (22a, 22b) is made <NUM>% or more and <NUM>% or less of a rated power. By doing so, it is possible to prevent the junction temperature of the five light emitting elements <NUM> (22a, 22b) from exceeding the maximum junction temperature.

In one embodiment of the invention, the vehicle lamp <NUM> including the vehicle lighting device <NUM> may be provided. Both the description of the above-described vehicle lighting device <NUM> and the modifications of the vehicle lighting device <NUM> (for example, those in which a person skilled in the art appropriately adds, deletes, or changes the design of components and which have the features of the invention) may be applied to the vehicle lamp <NUM>.

In the following description, as an example, the case where the vehicle lamp <NUM> is a rear combination light provided in an automobile will be described. However, the vehicle lamp <NUM> is not limited to a rear combination light provided in an automobile. The vehicle lamp <NUM> may be configured as long as it is provided in an automobile, railroad vehicle, or the like.

<FIG> is a schematic partial cross-sectional diagram for illustrating the vehicle lamp <NUM>.

As shown in <FIG>, the vehicle lamp <NUM> includes, for example, the vehicle lighting device <NUM>, the casing body <NUM>, a cover <NUM>, an optical element <NUM>, a sealing member <NUM>, and the connector <NUM>.

The vehicle lighting device <NUM> is installed in the casing body <NUM>. The casing body <NUM> holds the mounting portion <NUM>. The casing body <NUM> has a box shape with one end portion open. The casing body <NUM> is made of, for example, resin that does not transmit light. A bottom surface of the casing body <NUM> is provided with a mounting hole 101a into which a portion of the mounting portion <NUM> provided with the bayonet <NUM> is inserted. A recess portion into which the bayonet <NUM> provided on the mounting portion <NUM> is inserted is provided on the periphery of the mounting hole 101a. Although the case where the casing body <NUM> is directly provided with the mounting hole 101a is illustrated, the casing body <NUM> may be provided with a mounting member having the mounting hole 101a.

When the vehicle lighting device <NUM> is installed on the vehicle lamp <NUM>, the portion of the mounting portion <NUM> provided with the bayonet <NUM> is inserted into the mounting hole 101a, to rotate the vehicle lighting device <NUM>. Then, for example, the bayonet <NUM> is held by a fitting portion provided on the periphery of the mounting hole 101a. Such an installation method is called a twist lock.

The cover <NUM> is provided to close the opening of the casing body <NUM>. The cover <NUM> is made of translucent resin or the like. The cover <NUM> may also have functions such as a lens.

The light emitted from the vehicle lighting device <NUM> enters the optical element <NUM>. The optical element <NUM> reflects, diffuses, guides, and collects the light emitted from the vehicle lighting device <NUM>, and forms a predetermined light distribution pattern. For example, the optical element <NUM> illustrated in <FIG> is a reflector. In this case, the optical element <NUM> reflects the light emitted from the vehicle lighting device <NUM> to form a predetermined light distribution pattern.

The sealing member <NUM> is provided between the flange <NUM> and the casing body <NUM>. The sealing member <NUM> has an annular shape and is made of an elastic material such as rubber or silicone resin.

When the vehicle lighting device <NUM> is installed on the vehicle lamp <NUM>, the sealing member <NUM> is sandwiched between the flange <NUM> and the casing body <NUM>. Thus, the internal space of the casing body <NUM> may be sealed by the sealing member <NUM>. Also, the elastic force of the sealing member <NUM> presses the bayonet <NUM> against the casing body <NUM>. Thus, it is possible to prevent the vehicle lighting device <NUM> from detaching from the casing body <NUM>.

The connector <NUM> is fitted to the end portion of the power feeding terminal <NUM> exposed inside the connector holder <NUM>. A power source or the like is electrically connected to the connector <NUM>. Thus, by fitting the connector <NUM> to the end portion of the power feeding terminal <NUM>, the light emitting element <NUM> may be electrically connected to the power source or the like.

Claim 1:
A vehicle lighting device (<NUM>), comprising:
a socket (<NUM>);
a substrate (<NUM>) provided on one end portion side of the socket (<NUM>);
one first light emitting element (22a) provided on the substrate (<NUM>); and
four second light emitting elements (22b) provided on the substrate (<NUM>),
wherein a square luminance distribution region orthogonal to a central axis of the vehicle lighting device (<NUM>) is defined on light irradiation sides of the first light emitting element (22a) and the second light emitting elements (22b);
a center of the luminance distribution region overlaps the central axis of the vehicle lighting device (<NUM>);
the vehicle lighting device (<NUM>) being characterized in that
the luminance distribution region is equally divided into four square first regions whose corners overlap the center of the luminance distribution region;
each of the four first regions is equally divided into nine square second regions;
a length of one side of the second region is <NUM>;
when XY coordinates of the center of the luminance distribution region are (<NUM>, <NUM>), a center of the first light emitting element (22a) is located at (<NUM>, <NUM>), and centers of the four second light emitting elements (22b) are located at (<NUM>, <NUM>), (-<NUM>, <NUM>), (<NUM>, -<NUM>), (-<NUM>, -<NUM>);
a luminance of the luminance distribution region is <NUM>% or more of a total luminance of light emitted from the vehicle lighting device (<NUM>);
in twenty second regions arranged along sides of the luminance distribution region, a luminance of one of the second regions is <NUM>% or less of the total luminance; and
in sixteen second regions provided inside the twenty second regions, the luminance of one of the second regions is <NUM>% or more and <NUM>% or less of the total luminance.