JP6692141B2 - Vehicle lighting - Google Patents

Description

  The present invention relates to a vehicular lamp using a reflecting device such as a DMD (digital micromirror device) capable of selectively reflecting incident light, and more particularly to a vehicular lamp having improved thermal reliability of the reflecting device. Is.

  As a vehicle lighting device for an automobile, a headlamp (headlight) for controlling light distribution using a DMD is under study. The DMD has a large number of movable micromirrors arrayed on an integrated circuit. By incorporating the DMD into a part of the optical path of a headlamp and controlling the driving of the micromirrors, the light emitted from the light source is micro-converted. It is possible to realize light irradiation with a desired light distribution pattern by selectively reflecting with a mirror.

  However, generally provided DMD has few high heat resistance, and when applied to an automobile headlamp that requires a light source with high luminous intensity, the DMD is easily damaged by heat generated by the light source, Thermal reliability issues arise. Although there are DMDs with high heat resistance, they are large and expensive, and thus are difficult to apply to headlamps for automobiles.

  Patent Document 1 proposes a technique in which a lamp unit and a light source unit are separately configured and both are optically connected by an optical fiber. According to this technique, it is possible to cool the light source in an independent form, and it is possible to improve the cooling efficiency.

JP, 2005-138727, A

  The technique of Patent Document 1 is a technique for enhancing the cooling effect of the light source unit, and is not intended to prevent the temperature rise of the lamp unit, and also to suppress the temperature rise of the lamp unit. There is no disclosure of the technical idea of. Therefore, in a headlamp to which a DMD is applied, it is not clear whether the technique of Patent Document 1 is effective in preventing the temperature rise of the DMD, and the problem of thermal reliability in the DMD is solved. Hard to do. Such a problem is not limited to the DMD, and can be applied to a reflection device having another configuration that can selectively reflect incident light.

  An object of the present invention is to provide a vehicular lamp that solves the problem of thermal reliability in a reflecting device that can selectively reflect incident light.

A vehicular lamp of the present invention includes a lamp unit including a DMD that selectively reflects incident light, a light source unit that includes a light source, and a light guide unit that guides light emitted from the light source unit to the lamp unit. A lamp unit and at least one other lamp unit not including a DMD are disposed inside the lamp housing, the light source unit is disposed outside the lamp housing, and the light guide unit is a lamp including the DMD. The unit is configured to guide light to at least one other lamp unit among the other lamp units, and heat generated by the light source can be dissipated outside the lamp housing.

In the present invention, a lamp unit including a DMD includes a first optical means for projecting light from the light guide light sources units to the DMD with light guiding means, a second optical means for projecting the light from the DMD It is a composition. Further, in the present invention, the light source unit is arranged in a region excluding the region directly below the lamp unit. The DMD is preferably located in the lower region within the lamp housing.

  In the present invention, at least one other lamp unit is disposed inside the lamp housing together with the lamp unit, and the light guide means is in addition to the lamp unit, at least one other lamp unit among the other lamp units. It may be configured to guide light to.

According to the present invention, the lamp unit including the DMD is disposed inside the lamp housing, and the light source unit as the light source of the lamp unit is disposed outside the lamp housing, so that the heat generated in the light source unit is generated by the lamp housing. The heat is dissipated outside the lamp or is shielded by the lamp housing, so that the temperature rise in the lamp unit or the DMD can be suppressed, and the thermal reliability of the DMD can be improved.

1 is a schematic perspective view of a vehicle equipped with the headlamp of Embodiment 1. FIG. 1 is a schematic front view of the headlamp of Embodiment 1. FIG. FIG. 3 is a perspective view of the DMD unit and the light source unit according to the first embodiment. FIG. 3 is a vertical cross-sectional view of the DMD unit according to the first embodiment. The schematic front view of the headlamp of Embodiment 2. FIG. FIG. 6 is a vertical cross-sectional view of the DMD unit according to the second embodiment. The schematic front view of the headlamp of Embodiment 3.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic perspective view of a vehicle equipped with a headlamp of an automobile according to a first embodiment of the present invention. The headlamp HL1 is configured as a right headlamp (R-HL) mounted on the right front portion of the vehicle body BD of the car CAR, and includes a lamp housing 100 fixedly supported on the front portion of the engine room ER of the vehicle body BD. The lamp housing 100 is provided with three lamp units LU1, LU2 and LU3.

  FIG. 2 is a schematic front view in which a part of the headlamp HL1 is cut away. The lamp housing 100 is configured by attaching a translucent front cover 102 to a front opening of a container-shaped lamp body 101. The lamp units LU1, LU2, LU3 are arranged laterally in the lamp housing 100, and the lamp unit LU1 on the right side in FIG. 2 is a reflecting device for selectively reflecting incident light in the present invention. Is a lamp unit including a DMD (hereinafter referred to as a DMD unit), and the central lamp unit LU2 is a low beam unit as another lamp unit in the present invention. The lamp unit LU3 on the left side is a clearance unit as one of the other lamp units in the present invention, although it is not directly related to the present invention.

  The DMD unit LU1 is configured as a lamp unit whose light distribution can be set to an arbitrary light distribution pattern under the control of the DMD, as will be described later in detail. The low beam unit LU2 is composed of a so-called projector-type lamp here, and a detailed description thereof will be omitted. However, light in a low beam distribution provided with a light source, a reflection mirror, a projection lens, a shade for shading, and the like. It is a lamp unit that performs irradiation. The clearance unit LU3 is composed of a light source and a reflection mirror, and functions as a clearance lamp (vehicle side light) as one of the marker lights.

  FIG. 3 is an external perspective view of the DMD unit LU1 and the light source unit LSU optically connected to the DMD unit LU1 by the optical fiber 1. One end 11 of the optical fiber 1 made of a light guide member is connected to the light source unit LSU, and the other end 12 is connected to the DMD unit LU1. The light emitted from the light source unit LSU is made incident on one end 11 of the optical fiber 1, guided inside the optical fiber 1 and made incident on the DMD unit LU1 from the other end 12.

  The light source unit LSU includes a light emitting element 2 such as an LD (laser diode) or an LED (light emitting diode) as a light source. The light emitting element, here the LED 2, is mounted on a circuit board 21 that constitutes a light emitting circuit, and emits light by supplying a predetermined electric power from the light emitting circuit. A heat sink 22 is integrally provided on the circuit board 21, and heat generated by the LED 2 can be radiated by the heat sink 22. An optical connector 23 is arranged at a position facing the circuit board 21, and the one end 11 of the optical fiber 1 is optically coupled by the optical connector 23. The light emitted from the LED 2 by the optical connector 23 enters the one end 11 of the optical fiber 1. An electric cord 24 is connected to the circuit board 21 and is supplied with external electric power such as a vehicle battery.

  The light source unit LSU is arranged in a region that is not immediately below the DMD unit LU1 or the lamp housing 100. For example, as shown in FIG. 1, it is arranged at a position behind the lamp housing 100 in the engine room ER of the automobile CAR. In this example, it is arranged at a rear position of the radiator Ra arranged in the engine room ER.

  As shown in FIG. 3, the DMD unit LU1 is configured with a base body 3 processed into a predetermined shape as a base body. The base body 3 has a light incident portion 4, a first optical portion 5, a DMD 6, and a first optical portion 5. The two optical parts 7 are integrally assembled. The optical axis of the second optical unit 7, here the lens optical axis Ox, is oriented parallel to the straight traveling direction of the car CAR, that is, the lamp optical axis (not shown) of the headlamp HL1.

  FIG. 4 is a schematic vertical sectional view of the internal structure of the DMD unit LU1. The light incident part 4 is arranged at the highest position of the DMD unit LU1 and includes an optical connector 41 to which the other end 12 of the optical fiber 1 is connected. The other end 12 of the optical fiber 1 is optically coupled to the optical connector 41, the light guided to the other end 12 of the optical fiber 1 is incident, and the incident light is input to the first optical unit 5. Project it toward.

  The first optical unit 5 is provided to reflect the light projected from the light incident unit 4 toward the DMD 6, and has a parabolic surface shape in which an incident point of the light incident from the optical fiber 1 is substantially a focus. It is configured as a parabolic reflecting mirror having a light reflecting surface 51. The parabolic reflecting mirror 5 is arranged so as to face the light incident portion 4 slightly obliquely downward in the forward direction along the lens optical axis Ox, and the light divergently emitted from the light incident portion 4 is parabolic. The light is reflected by the reflecting mirror 5 as a substantially parallel light beam and projected on the DMD 6.

  The DMD 6 is disposed below the light incident portion 4 and obliquely in the rearward and downward direction along the lens optical axis Ox with respect to the first optical portion 5, and reflects the light reflected by the parabolic reflector 5. Receive light. The DMD 6 is capable of selectively turning on / off a large number of micromirrors by controlling a signal input to the integrated circuit as described above. In FIGS. 3 and 4, a micromirror structure composed of these micromirrors is conceptually indicated by reference numeral 61. In this micromirror structure 61, the micromirror which is turned on reflects the light reflected by the parabolic reflector 5 toward the second optical section 7. The light projected on the micromirror in the off-driving state is not reflected toward the second optical unit 7. As the DMD 6, the one provided for consumer use is applied here, and therefore the heat resistance is not so high.

  The second optical unit 7 is composed of a projection lens of a convex lens system supported in an annular lens frame 71, and its lens optical axis Ox is directed parallel to the lamp optical axis of the headlamp HL1. Is arranged so that the focal point thereof is near the micromirror assembly 61 of the DMD 6. The projection lens 7 projects the light reflection pattern formed by the micromirror structure 61 of the DMD 6 to the front area by irradiating the light area of the lamp front area with the light flux reflected by the micromirror which is driven on.

  The DMD unit LU1 configured as described above is disposed in the lamp housing 100 and supported by the lamp body 101. Further, the other end 12 of the optical fiber 1 is connected to the light incident portion 4 by the optical connector 41. The DMD unit LU1 installed in the lamp housing 100 prevents dust and the like existing in the external environment from adhering to the parabolic reflector 5, the micro mirror of the DMD 6, and the projection lens 7 due to the airtightness of the lamp housing 100, and Waterproof property is obtained. This ensures the reliability of the DMD unit LU1 with respect to the external environment.

  In the headlamp HL1 of the first embodiment, when the DMD unit LU1 is turned on, that is, when the light source unit LSU emits light, the light emitted from the LED 2 is guided to the DMD unit LU1 via the optical fiber 1. The light guided and incident on the light incident part 4 is reflected by the parabolic reflector 5 and projected on the DMD 6, and is reflected by the micromirror structure 61 of the DMD 6 as a desired light pattern. The reflected light pattern is projected by the projection lens 7 toward the front of the lamp, and light irradiation with a desired light distribution pattern is performed.

  Here, when the light source unit LSU emits light, heat is generated in the emitted LED 2. This heat is transferred to the heat sink 22 supporting the circuit board 21, and is radiated from there. On the other hand, the generated heat causes a temperature rise in a member near the light source unit LSU due to radiation. This radiant heat will also affect the lamp housing 100, but most of it is shielded by the lamp housing 100, so it is rarely transferred to the DMD unit LU1.

  Particularly, in the first embodiment, the light source unit LSU is arranged at the position behind the lamp housing 100, and is not arranged in the region directly below the DMD unit LU1 or the region directly below the lamp housing 100. The DMD unit LU1 is hardly heated by the upward convection of warm air due to the heat generated in the light source unit LSU. Further, by disposing the light source unit LSU at this position, a part of the heat generated in the light source unit LSU is transferred to the bonnet (not shown) covering the engine room ER and is radiated from there. It can also be expected to enhance the heat dissipation effect.

  When it is unavoidable to dispose the light source unit LSU in the region directly below the lamp housing 100, it is preferable to dispose the light source unit LSU as far away from the lower surface of the lamp housing 100 as possible. In this case, as shown in FIG. 1, it is arranged in the engine room ER in the vicinity of the radiator Ra so that the radiator cooling fan (not shown) can utilize the air flow generated in the radiator Ra to obtain the heat radiation effect. May be.

  Further, in the first embodiment, the DMD 6 of the DMD unit LU1 is arranged at a low position in the DMD unit LU1, so that when the DMD unit LU1 is installed in the lamp housing 100, the DMD 6 is located in the lower part of the lamp housing 100. Will be located in the area. That is, when the interior of the lamp housing 100 is vertically divided into an upper region and a lower region, or vertically divided into an upper region, an intermediate region, and a lower region, the lamp housing 100 is further divided into a larger number. Sometimes, it is located in a lower region of the lamp housing 100, which is divided into the lowermost part or the vicinity thereof.

  Therefore, when the temperature inside the lamp housing 100 rises, for example, when the light source of the low beam unit LU2 installed inside the lamp housing 100 together with the DMD unit LU1 emits light, heat is generated, and this heat causes the inside of the lamp housing 100 to rise. Even when the temperature rises, the heated air in the lamp housing 100 flows and stays in the upper region by convection, so that the influence of heat on the DMD 6 arranged in the lower region can be suppressed. .. Also from this, the temperature rise of the DMD 6 in the lamp housing 100 can be suppressed, and the thermal reliability of the DMD 6 can be further enhanced.

  As described above, in the headlamp HL1 of the first embodiment, it is possible to prevent the temperature of the DMD from rising due to the heat generated in the light source unit LSU. Therefore, even when the DMD having the low heat resistance is applied to the DMD configuring the DMD unit LU1. The thermal reliability of DMD can be improved. In other words, there is no need to use an expensive DMD having high heat resistance, which is advantageous in achieving cost reduction.

  FIG. 5 is a schematic front view of the headlamp HL2 of the second embodiment, and FIG. 6 is a vertical sectional view of a DMD unit LU1A applied to the headlamp HL2. The same reference numerals are given to the parts equivalent to the DMD unit LU1 of the first embodiment. The second embodiment is the same as the first embodiment in that the DMD unit LU1A is incorporated in the lamp housing 100, the light source unit LSU is arranged outside the lamp housing 100, and both are optically connected by the optical fiber 1. However, the light incident portion 4, the first optical portion 5, and the DMD 6 that constitute the DMD unit LU1A are configured so that the mutual vertical positions are reversed.

  That is, the light incident part 4 is arranged at the lowermost side of the DMD unit LU1A, and the parabolic reflector (first optical part) 5 arranged opposite to this is arranged in the light incident part 4 in the direction along the lens optical axis Ox. It is located at a slightly higher position than. Further, the DMD 6, which is arranged to face the parabolic reflecting mirror 5 in the direction along the lens optical axis Ox, is arranged above the light incident portion 4 at a position slightly higher than the parabolic reflecting mirror 5.

  In this DMD unit LU1A, the light guided through the optical fiber 1 connected to the light source unit LSU is incident from the light incident part 4, and the first optical part 5, the DMD 6, and the second optical part 7 move to the lamp front area. The light irradiation with a desired light distribution pattern is the same as in the first embodiment. Further, since the DMD unit LU1A is incorporated in the lamp housing 100 and the light source unit LSU is disposed outside the lamp housing 100, the heat generated in the light source unit LSU is shielded by the lamp housing 100, and the DMD unit LU1A is provided. The same applies to the suppression of the heating.

  On the other hand, in the second embodiment, the DMD 6 of the DMD unit LU1A is arranged at a high position in the DMD unit LU1A, that is, in the upper region or the intermediate region in the lamp housing 100 described above. Therefore, even if it is unavoidable that the light source unit LSU is arranged in the region directly below the DMD unit LU1A or the region directly below the lamp housing 100, even if the lower surface of the lamp housing 100 is heated by the light source unit LSU. The distance from the bottom surface to the DMD 6 can be increased, and the effect of radiant heat from the lower surface can be mitigated. Thereby, the temperature rise of the DMD 6 can be suppressed, and the thermal reliability of the DMD 6 can be further enhanced.

  FIG. 7 is a schematic front view of the headlamp HL3 of the third embodiment. The same parts as those in the second embodiment are designated by the same reference numerals. In the third embodiment, the light source of the low beam unit LU2 that is housed in the lamp housing 100 together with the DMD unit LU1A is removed, and the low beam unit LU2 is also optically connected to the light source unit LSU by an optical fiber 1A. Has been done.

  Here, a light distributor 14 is interposed in the optical fiber 1 connected to the light source unit LSU, and the optical fiber 1A branched by the light distributor 14 is connected. One optical fiber 1 is connected to the DMD unit LU1A as in the second embodiment, and the other optical fiber 1A is connected to the low beam unit LU2. The structure in which the other end of the optical fiber 1A is connected to the low beam unit LU2 can be connected using an optical connector as in the connection to the DMD unit LU1A.

  In the third embodiment, when the light source unit LSU emits light, the light emitted from the light source unit LSU is guided through the optical fiber 1 and is also distributed to the optical fiber 1A by the optical distributor 14 on the way. 1, 1A respectively enter the DMD unit LU1A and the low beam unit LU2. The incident light is radiated from the DMD unit LU1A to the lamp front region, and in the low beam unit LU2, it is radiated to the lamp front region with a required light distribution by the reflection mirror and the projection lens which form the projector structure.

  In the third embodiment, since the low beam unit LU2 does not generate heat even when the low beam unit LU2 is turned on, the air in the lamp housing 100 is not heated, and the temperature of the DMD 6 of the DMD unit LU1A rises. To be prevented. Particularly, as in the second embodiment, the DMD of the DMD unit LU1A is arranged in the upper region or the intermediate region in the lamp housing 100, and is effective when it is necessary to consider the temperature rise due to convection of warm air in the lamp housing 100. Is.

  Compared to the first and second embodiments, the third embodiment can prevent thermal damage to the DMD 6 due to heat generated when the low beam unit LU2 is turned on, and further improve the thermal reliability of the DMD 6. The third embodiment can be similarly applied to the DMD unit LU1 of the first embodiment.

  When the DMD units LU1 and LU1A and the low beam unit LU2 are required to be independently controlled for lighting, a plurality of light sources capable of independently emitting light are provided in the light source unit LSU, and each light source and each light source are provided. The units may be optically connected by independent optical fibers. Alternatively, a shutter may be built in the light distributor 14 so that light is selectively guided to the optical fibers 1 and 1A.

  Further, as shown by a phantom line in FIG. 7, as for the clearance unit LU3 of the headlamp HL3, the light source unit LSU is optically coupled by the optical fiber 1B, and the clearance unit LU3 is turned on by the light source unit LSU. Good. Since the clearance unit LU3 is often lit alone, it is preferable that the optical fiber 1B be connected to the light source unit LSU independently of the optical fibers 1 and 1A.

  As shown in the third embodiment, in the headlamp in which at least one other lamp unit is arranged in the lamp housing 100 together with the DMD unit, at least one of the other lamp units is also guided. It may be configured to be connected to the light source unit via the light means.

  The DMD unit in the present invention is not limited to the configurations described in the above embodiments. For example, the first optical unit (first optical unit) may be a lens system instead of a reflecting mirror, and the second optical unit (second optical unit) may be a reflecting mirror instead of a lens system. Further, the light guiding means in the present invention is not limited to the optical fiber, and may be a rod-shaped translucent member capable of guiding light or a member such as a prism.

  The light source unit according to the present invention has a separate structure independent of the DMD unit, and is not limited to the structure described in the above embodiments as long as it is arranged outside the lamp housing. Further, the type of light source is not limited to the light emitting element (semiconductor light emitting element), and an incandescent light bulb or a discharge light bulb can be applied.

  The lamp housing according to the present invention may be configured as a lamp housing having only a DMD unit or a plurality of other lamp units as long as it has a housing structure having at least a DMD unit. When only the DMD unit is installed in the lamp housing, the DMD unit may be configured to perform DMD control capable of irradiating light with high beam light distribution, low beam light distribution, or other light distribution.

  The vehicle lamp to which the present invention is applied is a lamp including a lamp unit including a reflecting device that selectively reflects incident light such as DMD, and is applied to an illumination lamp other than a headlamp or a marking lamp. can do.

1 Optical fiber (light guide)
2 LED (light source: light emitting element)
3 Base Body 4 Light Incident Section 5 First Optical Section (First Optical Means: Parabolic Reflector)
6 DMD (Reflector that selectively reflects incident light)
7 Second optical unit (second optical means: projection lens)
100 lamp housing HL (R-HL), HL1, HL2 head lamp (vehicle lamp)
LU1 DMD unit (lamp unit)
LU2 low beam unit (other lamp unit)
LU3 clearance lamp unit (other lamp units)
LSU Light source unit CAR Automotive BD Body ER Engine room Ra Radiator

Claims (4)

A lamp unit including a DMD (digital micromirror device) that selectively reflects incident light, a light source unit equipped with a light source, and a light guide unit that guides light emitted from the light source unit to the lamp unit. includes an optical means, the interior of the lamp housing, and the lamp unit, at least one other lamp unit does not include a DMD is arranged, the light source unit is disposed outside of the lamp housing, the light guide means Is configured to guide light to a lamp unit including the DMD and at least one other lamp unit among the other lamps, and allows heat generated by the light source to be dissipated outside the lamp housing. A vehicle lamp characterized by: Lamp unit comprising the DMD comprises before the first optical means for projecting light from said light source unit is guided to the DMD in Kishirubeko means, a second optical means for projecting the light from the DMD The vehicle lamp according to claim 1. The vehicular lamp according to claim 1 or 2, wherein the light source unit is arranged in a region excluding a region directly below the lamp unit including the DMD .   The vehicular lamp according to any one of claims 1 to 3, wherein the DMD is disposed in a lower region of the lamp housing.

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