JP5591097B2 - Optical unit - Google Patents

Description

  The present invention relates to an optical unit, and more particularly to an optical unit used for a vehicular lamp.

  Patent Document 1 discloses an optical unit for a vehicular lamp that reflects light emitted from a semiconductor light emitting element with a reflector and irradiates the front of the vehicle through a projection lens. In this optical unit, the reflector has a substantially elliptical spherical reflecting surface, the semiconductor light emitting element is disposed at the first focal point of the reflecting surface, and the rear focal point of the projection lens is disposed at the second focal point. The light emitted from the semiconductor light emitting element is reflected by the reflecting surface of the reflector, passes through the rear focal point of the projection lens, enters the projection lens, and is emitted forward of the vehicle.

JP 2003-317513 A

  In the conventional optical unit described above, the semiconductor light emitting element and the rear focal point of the projection lens are arranged on the optical axis of the optical unit. That is, the first focal point and the second focal point of the reflecting surface of the reflector are arranged on the optical axis of the optical unit. Therefore, the conventional optical unit has room for improvement in reducing the size of the optical unit.

  This invention is made | formed in view of such a condition, The objective is to provide the technique which miniaturizes the optical unit used for a vehicle lamp.

  In order to solve the above-described problems, an aspect of the present invention is an optical unit, and the optical unit is an optical unit used in a vehicle lamp that irradiates light from a light-emitting element. A reflector having an elliptical reflecting surface and reflecting the light of the light emitting element fixed to the light emitting element mounting portion; and a projection lens for irradiating the light reflected by the reflector forward of the lamp. The light emitting element mounting portion is located near the first focal point of the reflecting surface, the rear focal point of the projection lens is located near the second focal point of the reflecting surface, and the lamp front-rear direction position of the first focal point of the reflecting surface is the second focal point. It is characterized by being in front of the same or second focus.

  According to this aspect, since the front-rear dimension of the optical unit can be reduced, the optical unit can be reduced in size.

  In the above aspect, the reflector may reflect the light emitted from the light emitting surface of the light emitting element in the normal direction of the light emitting surface so as to pass through the central axis extending in the front-rear direction of the projection lens. According to this, the luminous flux utilization factor of the light irradiated from the light emitting element can be increased.

  In the above aspect, the first focal point of the reflecting surface may overlap the projection lens when the optical unit is viewed from the front. According to this, since the vertical dimension of the optical unit can be reduced, the optical unit can be further downsized.

  ADVANTAGE OF THE INVENTION According to this invention, the technique which miniaturizes the optical unit used for a vehicle lamp can be provided.

1 is a schematic vertical sectional view of a vehicular lamp including an optical unit according to Embodiment 1. FIG. 3 is a schematic diagram of a light distribution pattern formed by the optical unit according to Embodiment 1. FIG. It is a general | schematic vertical sectional view of the optical unit which concerns on a comparative example. 2 is a schematic vertical sectional view of the optical unit according to Embodiment 1. FIG.

  The present invention will be described below based on preferred embodiments with reference to the drawings. The same or equivalent components, members, and processes shown in the drawings are denoted by the same reference numerals, and repeated descriptions are omitted as appropriate. The embodiments do not limit the invention but are exemplifications, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

(Embodiment 1)
FIG. 1 is a schematic vertical sectional view of a vehicular lamp including the optical unit according to the first embodiment. The vehicular lamp 1 according to the present embodiment is a vehicular headlamp device having a pair of headlamp units arranged on the left and right sides in front of the vehicle. Since the pair of headlamp units have substantially the same configuration except that they have a symmetrical structure, FIG. 1 shows the structure of one headlamp unit as the vehicular lamp 1.

  As shown in FIG. 1, the vehicular lamp 1 according to the present embodiment includes a lamp body 2 having an opening on the front side of the vehicle, and a translucent cover 4 attached so as to cover the opening of the lamp body 2. Prepare. The translucent cover 4 is made of translucent resin or glass. An optical unit 100 is accommodated in the lamp chamber 3 formed by the lamp body 2 and the translucent cover 4.

  The optical unit 100 is a so-called projector-type optical unit, and includes a heat sink 110, a reflector 130, and a projection lens 150. The optical unit 100 is an optical unit for forming a low beam light distribution pattern. The optical unit 100 is arranged so that its optical axis X extends in the vehicle front-rear direction, and is connected to the lamp body 2. In the present embodiment, the front-rear direction of the optical unit 100 and the front-rear direction of the vehicle are the same.

  The heat sink 110 is a member on which a light emitting element as a light source is mounted, and also functions as a member that supports the reflector 130 and the projection lens 150. The heat sink 110 has a back surface portion 112 and a light emitting element mounting portion 114.

  The back surface portion 112 has a substantially flat plate shape, and is arranged so that its main surface faces the lamp front-rear direction. A screw hole is provided in an upper portion of the back surface portion 112, and an aiming screw 6 rotatably supported on the wall surface of the lamp body 2 is screwed into the screw hole. Further, a joint receiving portion 116 is provided at the lower portion of the back surface portion 112 so as to protrude rearward of the lamp, and a leveling shaft 8 that penetrates the wall surface of the lamp body 2 and extends forward of the lamp is provided in the joint receiving portion 116. It is connected. A ball joint ball portion 8a is formed at the tip of the leveling shaft 8, and a spherical space is formed in the joint receiving portion 116 along the shape of the ball joint ball portion 8a. The joint receiving portion 116 and the leveling shaft 8 are connected by the ball joint ball portion 8 a being accommodated in the spherical space of the joint receiving portion 116. Further, the leveling shaft 8 is connected to a leveling actuator 10. The vehicular lamp 1 can adjust the optical axis X of the optical unit 100 vertically and horizontally by an aiming screw 6, a leveling shaft 8 and a leveling actuator 10.

  The light emitting element mounting portion 114 extends forward from the main surface of the back surface portion 112 facing the front of the lamp. The light emitting element mounting portion 114 has a light emitting element mounting surface 114a, and the light source module 200 having the light emitting element 202 is fixed to the light emitting element mounting surface 114a. The heat sink 110 is made of, for example, aluminum die cast, and the back surface portion 112 and the light emitting element mounting portion 114 are integrally formed.

  The light source module 200 is, for example, a light emitting diode (LED), and includes a light emitting element 202 and a substrate 204 that supports the light emitting element 202. The substrate 204 is a thermally conductive insulating substrate made of ceramic or the like. An electrode (not shown) that transmits electric power to the light emitting element 202 is formed on the substrate 204.

  The reflector 130 is a member for reflecting the light of the light emitting element 202 fixed to the light emitting element mounting portion 114. The reflector 130 has a dome shape, and is fixed to the light emitting element mounting portion 114 so as to cover the upper side of the light emitting surface of the light emitting element 202. In the reflector 130, a first reflecting surface 132 and a second reflecting surface 134 for reflecting the light emitted from the light emitting element 202 are formed inside. The first reflecting surface 132 is constituted by a part of a spheroid having the optical axis X as a central axis. That is, the first reflecting surface 132 is a substantially elliptical reflecting surface. The first reflecting surface 132 extends from the end of the reflector 130 on the light emitting element 202 side to a predetermined region. The second reflecting surface 134 has a predetermined shape, and extends from the front end portion (the end portion opposite to the light emitting element 202 side) of the first reflecting surface 132 to the end portion of the reflector 130 on the projection lens 150 side. Yes. In the reflector 130, the light emitting element mounting portion 114 is positioned in the vicinity of the first focal point F1 of the first reflecting surface 132 (therefore, the light emitting element 202 is positioned in the vicinity of the first focal point F1), and the second of the first reflecting surface 132 is. The rear focal point F of the projection lens 150 is positioned in the vicinity of the focal point F <b> 2, and is disposed on the rear side of the lamp with respect to the projection lens 150.

  The projection lens 150 is a lens for irradiating the light reflected by the reflector 130 to the front of the lamp, and is composed of a plano-convex aspheric lens having a convex front surface and a flat rear surface. The projection lens 150 projects the light source image formed on the rear focal plane including the rear focal point F onto the virtual vertical screen in front of the lamp as a reverse image. The projection lens 150 is provided on the optical axis X with its peripheral edge fixed to the light emitting element mounting portion 114. The rear focal point F of the projection lens 150 is disposed in the vicinity of the second focal point F2 of the first reflecting surface 132.

  The optical unit 100 has a shade 170. The shade 170 has a substantially flat plate shape, and is mounted with a light emitting element so that the tip (ridge line) of one side thereof is positioned in the vicinity of the second focal point F2 of the first reflecting surface 132 and the rear focal point F of the projection lens 150. It is fixed to the part 114. The tip portion located in the vicinity of the second focal point F2 and the rear focal point F has a shape corresponding to the cut-off line of the low beam light distribution pattern.

  Part of the light emitted from the light emitting element 202 is reflected toward the rear focal point F of the projection lens 150 by the first reflecting surface 132 of the reflector 130. A part of the light traveling toward the rear focal point F is selectively cut by the shade 170, and the rest enters the projection lens 150. This light that has entered the projection lens 150 through the rear focal point F is irradiated from the projection lens 150 to the front of the lamp as cut-off line forming light A for forming a cut-off line of a low beam light distribution pattern to be described later. Further, another part of the light emitted from the light emitting element 202 is reflected by the second reflecting surface 134, passes above the rear focal point F, and enters the projection lens 150. This light that has passed over the rear focal point F and entered the projection lens 150 is irradiated from the projection lens 150 to the front of the lamp as diffusion portion forming light B for forming the diffusion portion of the low beam light distribution pattern. Further, another part of the light emitted from the light emitting element 202 is reflected by the first reflecting surface 132 toward the second reflecting surface 134 and further reflected by the second reflecting surface 134 to be above the rear focal point F. And enters the projection lens 150. This light reflected twice by the first reflecting surface 132 and the second reflecting surface 134 and incident on the projection lens 150 is irradiated from the projection lens 150 to the front of the lamp as the diffused portion forming light B. The diffusing portion forming light B is irradiated from the projection lens 150 as light downward from the cut-off line forming light A.

  A light distribution pattern formed by the optical unit 100 configured as described above will be described. FIG. 2 is a schematic diagram of a light distribution pattern formed by the optical unit according to the first embodiment. Note that FIG. 2 shows a light distribution pattern formed on a virtual vertical screen arranged at a predetermined position in front of the lamp, for example, at a position 25 m ahead of the lamp.

  As shown in FIG. 2, a low beam light distribution pattern PL is formed by the optical unit 100. This low-beam light distribution pattern PL is a light distribution pattern that is considered so as not to give glare to the forward vehicle or pedestrian when passing on the left side. The low beam light distribution pattern PL has an opposite lane side cut-off line CL1 extending in parallel with the horizontal line H on the right side of the vertical line V at the upper end. Further, the low beam light distribution pattern PL has a lane side cut-off line CL2 extending in parallel with the horizontal line H at a position higher than the opposite lane side cut-off line CL1 on the left side of the vertical line V. Further, the low beam light distribution pattern PL has an oblique cutoff line CL3 connecting the opposite lane side cutoff line CL1 and the own lane side cutoff line CL2. The oblique cut-off line CL3 extends from the end of the own lane side cut-off line CL2 on the vertical line V side to the upper left obliquely at an inclination angle of 45 °. The oncoming lane side cut-off line CL1, the own lane side cut-off line CL2, and the oblique cut-off line CL3 are lines created by the aforementioned tip portion of the shade 170. In addition, the low beam light distribution pattern PL includes a diffusion portion PD extending below each cutoff line.

  The opposite lane side cut-off line CL1, the own lane side cut-off line CL2, and the oblique cut-off line CL3 of the low beam light distribution pattern PL are formed by the cut-off line forming light A emitted from the optical unit 100. Further, the diffusion portion PD of the low beam light distribution pattern PL is formed by the diffusion portion forming light B emitted from the optical unit 100.

  Next, the optical unit 100 according to this embodiment will be described in detail. FIG. 3 is a schematic vertical sectional view of an optical unit according to a comparative example. FIG. 4 is a schematic vertical sectional view of the optical unit according to the first embodiment. 3 and 4, the back surface portion of the heat sink is omitted.

  As illustrated in FIG. 3, the optical unit 300 according to the comparative example includes a heat sink 310, a reflector 330, and a projection lens 350. The heat sink 310 includes a light emitting element mounting portion 314 that extends in the lamp front-rear direction. The light emitting element mounting portion 314 has a light emitting element mounting surface 314a facing upward in the vertical direction. The light source module 200 is fixed to the light emitting element mounting surface 314a so that the normal line of the light emitting surface of the light emitting element 202 extends in the vertical direction. The reflector 330 has a substantially elliptical reflecting surface 332. In the reflector 330, the light emitting element mounting portion 314 is positioned in the vicinity of the first focus F1 of the reflecting surface 332 (therefore, the light emitting element 202 is positioned in the vicinity of the first focus F1), and the projection lens 350 is positioned in the vicinity of the second focus F2. Is arranged on the rear side of the lamp with respect to the projection lens 350 so that the rear focal point F of the projector is located.

  In the optical unit 300 according to the comparative example, the rear focal point F of the light emitting element 202 and the projection lens 350 is disposed on the optical axis X of the optical unit 300. That is, the first focal point F1 and the second focal point F2 of the reflecting surface 332 are arranged on the optical axis X. And the 1st focus F1 is located in the lamp back side rather than the 2nd focus F2. Accordingly, the length L in the lamp front-rear direction from the front end of the projection lens 350 to the rear end of the reflector 330 that affects the dimension of the optical unit 300 in the lamp front-rear direction (front-rear dimension) is from the front end of the projection lens 350 to the rear focal point F. A distance N between the second focal point F2 and the first focal point F1, which is substantially the same as the rear focal point F, and a length O from the first focal point F1 to the rear end of the reflector 330. It becomes the sum of.

  On the other hand, in the optical unit 100 according to the present embodiment, the light emitting element mounting surface 114a of the light emitting element mounting portion 114 is inclined toward the lamp rear side. Therefore, in the light source module 200, the normal line of the light emitting surface of the light emitting element 202 is inclined to the rear of the lamp from the vertical direction. And the 1st focus F1 of the 1st reflective surface 132 has the lamp front-back direction position located ahead of the 2nd focus F2. That is, the light emitting element 202 is disposed on the front side of the lamp from the rear focal point F of the projection lens 150. Therefore, the length L from the front end of the projection lens 150 to the rear end of the reflector 130 is the length M from the front end of the projection lens 150 to the rear focal point F, and the second focal point F2 that is substantially coincident with the rear focal point F. And the total length P to the rear end. In addition, the part located in the rear end of the reflector 130 is a part in which the 1st reflective surface 132 was formed inside.

  Since the length M from the front end of the projection lens to the rear focal point F is determined according to the size and shape of the projection lens, it can be said that the length from the rear focal point F to the rear end of the reflector determines the longitudinal dimension of the optical unit 100. When the focal length N is fixed and the length from the rear focal point F to the rear end of the reflector is to be changed, the first focal point F1 rotates about the second focal point F2. Therefore, the ellipse having the first focal point F1 and the second focal point F2 as the focal point rotates about the second focal point F2. At this time, as in the comparative example, when the first focal point F1 is located behind the lamp F2 from the second focal point F2, the length from the rear focal point F to the rear end of the reflector is the inter-focal distance N and the first focal point F1 to the reflector. This is the sum of the distance O to the rear end. On the other hand, when the first focal point F1 is positioned in front of the lamp with respect to the second focal point F2 as in the present embodiment, or when the first focal point F1 and the second focal point F2 have the same position in the front-rear direction of the lamp, the rear focal point F starts. The length to the rear end of the reflector is the distance P from the second focal point F2 to the rear end of the reflector.

  Here, the ellipse is line symmetric with respect to the short axis. Therefore, with the first focal point F1 and the second focal point F2 aligned in the vertical direction, that is, the state in which the major axis of the ellipse extends in the vertical direction, a predetermined angle is set so that the first focal point F1 is displaced backward from the lamp. From the first focal point F1 when the major axis is tilted to the rear end of the reflector, and from the second focal point F2 when the major axis is tilted by the same angle so that the first focal point F1 is displaced forward of the lamp The length P to the rear end of the reflector is equal. Therefore, when the position of the first focal point F1 in the longitudinal direction of the lamp is the same as that of the second focal point F2 or in front of the second focal point F2, the length from the rear focal point F to the rear end of the reflector is shortened by the distance N between the focal points. can do. Thereby, since the front-back dimension (depth dimension) of the optical unit 100 can be made small, the optical unit 100 can be reduced in size.

  In the optical unit 100 according to the present embodiment, the reflector 130 passes the light D irradiated from the light emitting surface of the light emitting element 202 in the normal direction of the light emitting surface through the central axis extending in the front-rear direction of the projection lens 150. Reflect on. Since the light emitting element 202 has a directivity characteristic in which the normal direction of the light emitting surface has the highest luminous intensity, the light D irradiated in the normal direction is incident on the center of the projection lens 150, so that the irradiation light of the light emitting element 202 is irradiated. The luminous flux utilization factor can be increased. In the optical unit 100 according to the present embodiment, the central axis extending in the front-rear direction of the projection lens 150 coincides with the optical axis X.

  As shown in FIG. 4, the first focal point F <b> 1 of the first reflecting surface 132 is located closer to the optical axis X than the outer peripheral edge of the projection lens 150. Therefore, when the optical unit 100 is viewed from the front, the first focal point F1 of the first reflecting surface 132 overlaps the projection lens 150. Thereby, since the vertical dimension of the optical unit 100 can be reduced, the optical unit 100 can be further downsized. Alternatively, this makes it possible to avoid an increase in the vertical dimension of the optical unit 100 due to the front-rear direction position of the first focal point F1 being the same as the second focal point F2 or in front of the second focal point F2. The light emitting element mounting portion 114 is located outside the region through which light emitted from the light emitting element 202 passes. Therefore, the light emitting element mounting portion 114 does not hinder the formation of the low beam light distribution pattern PL by the optical unit 100.

  The “near first focus F1,” “near second focus F2,” and “near rear focus F” are the positions of the respective focal points and the light distribution patterns described above that are close to the respective focal points. This includes a possible area, for example, an assembling error range area when the optical unit is manufactured. The “substantially flat plate shape” and “substantially elliptic surface shape” include each shape and a shape close to each shape, for example, a shape having a dimensional error during manufacturing. The “substantially elliptical shape” includes a shape in which a plurality of steps are formed based on the elliptical surface.

  As described above, the optical unit 100 according to the present embodiment is an optical unit that is used in the vehicular lamp 1 that irradiates the light emitted from the light emitting element 202, and has the substantially elliptical first reflecting surface 132. 130. The light emitting element mounting portion 114 is disposed in the vicinity of the first focal point F1 of the first reflecting surface 132, the rear focal point F of the projection lens 150 is disposed in the vicinity of the second focal point F2, and the position of the first focal point F1 in the longitudinal direction of the lamp is determined. It is set to be the same as the second focus F2 or in front of the second focus F2. Thereby, since the front-rear dimension of the optical unit 100 can be reduced as compared with the configuration in which the lamp front-rear direction position of the first focal point F1 is set behind the second focal point F2, the optical unit 100 is reduced in size. be able to. Thereby, size reduction of the vehicle lamp 1 can be achieved.

  The present invention is not limited to the above-described embodiments, and various modifications such as design changes can be added based on the knowledge of those skilled in the art, and the embodiments to which such modifications are added are also described in the present invention. It is included in the scope of the invention. A new embodiment in which a modification is added to the above-described embodiment has the effects of the combined embodiment and the modification.

  DESCRIPTION OF SYMBOLS 1 Vehicle lamp, 100 Optical unit, 114 Light emitting element mounting part, 130 Reflector, 132 1st reflective surface, 134 2nd reflective surface, 150 Projection lens, 202 Light emitting element, F Back focus, F1 1st focus, F2 2nd focus.

Claims (3)

An optical unit used in a vehicular lamp that emits light from a light emitting element,
A light emitting element mounting portion;
A reflector for reflecting the light of the light emitting element, which has a substantially elliptical reflecting surface and is fixed to the light emitting element mounting portion;
A projection lens for irradiating the light reflected by the reflector in front of the lamp, and
The light emitting element mounting portion is located near the first focal point of the reflecting surface, the rear focal point of the projection lens is located near the second focal point of the reflecting surface, and the lamp front-rear direction position of the first focal point of the reflecting surface is An optical unit that is the same as or in front of the second focal point.   2. The optical unit according to claim 1, wherein the reflector reflects light irradiated from a light emitting surface of a light emitting element in a normal direction of the light emitting surface so as to pass through a central axis extending in the front-rear direction of the projection lens.   The optical unit according to claim 1 or 2, wherein the first focal point of the reflecting surface overlaps with the projection lens when the optical unit is viewed from the front.

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