JP2012252838A - Vehicular lamp unit - Google Patents

Abstract

【Task】
Provided is a vehicular lamp unit that can realize cost reduction by reducing the number of parts and that can accurately position each lens.
[Solution]
A lens group including a plurality of lenses arranged on an optical axis extending in the vehicle front-rear direction, a lens barrel holding the plurality of lenses, and arranged on the vehicle rear side of the lens group, and passes through the lens group A light source that emits light emitted forward, and at least one of the plurality of lenses and the lens barrel include an outer peripheral portion of the one lens and the lens The lens barrel is integrally formed with the inner peripheral surface of the lens barrel being fixed.
[Selection] Figure 1

Description

  The present invention relates to a vehicular lamp unit, and more particularly, to a vehicular lamp unit including a projection lens including a plurality of lenses.

  2. Description of the Related Art Conventionally, a projector-type vehicular lamp that is configured to fix a projection lens to a lens barrel using a fixing means such as a press ring is known (for example, see Patent Document 1).

  In Patent Document 1, the projection lens is inserted into the lens barrel from the front end side of the lens barrel and positioned, and then fixed to the lens barrel using fixing means such as a press ring.

JP 2006-341696 A

  However, in the vehicular lamp described in Patent Document 1, in order to correct the chromatic aberration of the projection lens, the additional lens must be fixed to the barrel using some fixing means. There is a problem that the cost increases as a whole. There is also a problem that each lens cannot be accurately fixed to the lens barrel because the assembly error when fixing the projection lens to the lens barrel and the error when mounting the additional lens to the lens barrel are accumulated. .

  The present invention has been made in view of such circumstances, and it is possible to achieve cost reduction by reducing the number of parts, and it is possible to achieve a vehicle lamp that can accurately position each lens. The purpose is to provide units.

  In order to achieve the above object, the invention according to claim 1 is a lens group including a plurality of lenses arranged on an optical axis extending in the vehicle front-rear direction, a lens barrel holding the plurality of lenses, A vehicle lamp unit including a light source that is disposed on a vehicle rear side of the lens group and emits light that is transmitted forward through the lens group and is at least one of the plurality of lenses. The lens barrel is integrally formed with the outer peripheral portion of the one lens and the inner peripheral surface of the lens barrel being fixed.

  According to the first aspect of the present invention, at least one of the plurality of lenses and the lens barrel are integrally molded and configured as one component, thereby realizing a reduction in cost by reducing the number of components. It becomes possible to do.

  According to the first aspect of the present invention, since one lens and the lens barrel are integrally formed and configured as one component, the step of manually combining one lens and the lens barrel is omitted. It becomes possible.

  In addition, according to the first aspect of the present invention, since one lens and the lens barrel are integrally molded, the other lens is highly accurate with respect to the lens barrel (and the lens integrally molded therein). It becomes possible to position to.

  According to a second aspect of the present invention, in the first aspect of the present invention, the projection lens has a two-group configuration including a concave lens and a convex lens.

  According to the second aspect of the present invention, it is possible to prevent color separation from occurring in the light distribution pattern due to the chromatic aberration by using the concave lens and the convex lens appropriately designed so that the chromatic aberration is corrected. A possible vehicle lamp unit can be configured.

  According to a third aspect of the present invention, in the first aspect of the present invention, the projection lens includes a diffractive lens including a lens surface provided with a diffraction grating for reducing chromatic aberration, and a group of two lenses including a convex lens. It is the structure.

  According to the third aspect of the invention, by using a diffractive lens and a convex lens that are appropriately designed so that chromatic aberration is corrected, it is possible to prevent color separation from occurring in the light distribution pattern due to chromatic aberration. It is possible to configure a vehicular lamp unit that can be used.

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein at least one of the plurality of lenses and the lens barrel respectively inject resin into a mold, It is integrally formed by cooling and solidifying, and the peripheral surface of the lens barrel is subjected to light leakage prevention treatment.

  According to the fourth aspect of the present invention, it is possible to prevent the light from the light source from leaking from the resin-made lens barrel to become uncontrollable light (light leakage, stray light).

  According to the present invention, it is possible to provide a vehicular lamp unit capable of realizing cost reduction by reducing the number of components and capable of positioning each lens with high accuracy.

It is a perspective view of the vehicle lamp unit 10 used as a vehicle headlamp. (A) The front view of the vehicle lamp unit 10, (b) It is sectional drawing cut | disconnected by the vertical plane containing the optical axis AX. (A) The front view of the vehicle lamp unit 10 (modification), (b) It is sectional drawing cut | disconnected by the vertical plane containing the optical axis AX. It is a perspective view of the vehicle lamp unit 20 used as a vehicle headlamp. (A) is a front view, (b) is a sectional view cut along a vertical plane including the optical axis AX, (c) is an enlarged view in a circle in FIG. 5 (b).

  Hereinafter, a vehicle lamp unit 10 according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view of a vehicular lamp unit 10 used as a vehicular headlamp, FIG. 2 (a) is a front view, and FIG. 2 (b) is a sectional view cut along a vertical plane including an optical axis AX.

  As shown in FIG. 1, the vehicular lamp unit 10 is a so-called direct projection type lamp unit, and includes a heat radiating member 11, a light source 12, a lens barrel 13, a first lens 14, a second lens 15, and the like.

  The heat radiating member 11 includes a base plate 11c including a vertical surface 11a on the vehicle front side and a vertical surface 11b on the vehicle rear side perpendicular to an optical axis AX (lamp optical axis) extending in the vehicle longitudinal direction, and a vertical surface on the vehicle rear side. 11d includes heat dissipating fins 11d fixed to 11b.

  The light source 12 includes a plurality of blue LED chips 12a (for example, 1 mm square chips × 8) mounted on a substrate K fixed to the vertical surface 11a of the heat dissipation member 11 on the vehicle front side. Each LED chip 12a is arranged in a line and symmetrically with respect to the optical axis AX along a horizontal line H orthogonal to the optical axis AX with the light emitting surface facing the front side of the vehicle. Each LED chip 12a is covered with a yellow phosphor (for example, YAG phosphor). Each LED chip 12a is individually controlled to light according to control from a control device (not shown) connected thereto. The amount of heat generated from the light source 12 is radiated by the action of the heat radiating member 11. The light source 12 may be a halogen bulb, an HID bulb, an LD (laser diode), or the like.

  The lens barrel 13 is a circular base end portion 13a fixed to the vertical surface 11a on the vehicle front side of the heat dissipation member 11, and a cylindrical tube body 13b extending from the base end portion 13a to the vehicle front side along the optical axis AX. Etc. The lens barrel 13 (base end portion 13a) is fixed to the vertical surface 11a on the vehicle front side of the heat dissipation member 11 so that its axis (center axis) coincides with the optical axis AX.

  In the present embodiment, as shown in FIG. 2B, the inner peripheral surface 13c of the lens barrel 13 is sequentially arranged from the light source 12 side toward the tip end side of the lens barrel 13 (that is, from the light source 12 side to the irradiation direction). In order, the first lens 14 and the second lens 15 are arranged. The optical axes of the first lens 14 and the second lens 15 substantially coincide with the axis of the lens barrel 13. The second lens 15 and the first lens 14 are appropriately designed by a known method so that chromatic aberration is corrected. Further, the arrangement order of the first lens 14 and the second lens 15 may be opposite to the above. That is, the arrangement order of the first lens 14 and the second lens 15 is not limited.

  In addition, the 1st lens 14 and the 2nd lens 15 may be arrange | positioned closely, and may be arrange | positioned with a certain amount of space | interval. When the two are brought into close contact with each other, it is preferable that the gap between the two is filled with a transparent adhesive layer (preferably, an adhesive layer having a refractive index close to that of the lens material) to fix them closely. By sticking in this way, the Fresnel loss is reduced and the efficiency is further improved.

  The first lens 14 is a concave lens (concave lens with relatively low power) having a concave front surface and a concave rear surface. From the viewpoint of correcting chromatic aberration, the first lens 14 is preferably made of a material having low refraction and high dispersion.

  The first lens 14 and the lens barrel 13 are integrally formed with high accuracy in a state where the outer peripheral surface of the first lens 14 and the inner peripheral surface of the lens barrel 13 are fixed using a mold, and are configured as one part. (See FIG. 2 (b) and FIG. 3 (b)).

  As described above, the first lens 14 and the lens barrel 13 are integrally formed using a mold and are configured as one component, and therefore, the step of manually combining the first lens 14 and the lens barrel 13 is omitted. Is possible. Further, as will be described later, the second lens 15 can be positioned with high accuracy with respect to the first lens 14.

  Next, a method for integrally molding the first lens 14 and the lens barrel 13 will be described.

  For example, as shown in FIG. 2B, the first lens 14 and the lens barrel 13 are integrally formed by injecting the same transparent resin (acrylic, polycarbonate, or the like) into a mold, cooling, and solidifying. Can be considered (general injection molding). In this case, the light from the light source 12 leaks from the lens barrel 13 made of a transparent resin, and there is a risk of becoming uncontrollable light (light leakage, stray light). In order to prevent this, it is preferable to subject the outer peripheral surface of the lens barrel 13 to a surface treatment (light leakage prevention treatment) such as black coating or embossing.

  Alternatively, as shown in FIG. 3B, the first lens 14 is molded with a transparent resin (for example, acrylic or polycarbonate), and the lens barrel 13 is molded with an opaque resin (for example, black resin) in the same mold. Thus, it is also conceivable to integrally mold both (two-color molding). In this way, it is possible to use a resin having properties suitable for the lens for the first lens 14 and a resin having properties suitable for the lens barrel that holds the first lens 14 to the lens barrel 13. It becomes.

  Alternatively, the first lens 14 is molded by injecting a transparent resin (for example, acrylic or polycarbonate) around the lens barrel 13 made of a non-transparent material (for example, metal) inserted into the mold, and both are integrally molded. It is also conceivable (insert molding).

  Alternatively, the lens barrel 13 is formed by injecting a resin (for example, acrylic, polycarbonate, or black resin) around the first lens 14 made of a transparent material (for example, glass) inserted into the mold, and the two are integrated. It is also possible to mold (insert molding).

  As shown in FIG. 2B, a ring-shaped contact surface 13 d extending in the circumferential direction is formed near the tip of the inner peripheral surface 13 c of the lens barrel 13.

  The second lens 15 is an aspherical convex lens (convex lens having relatively high power) having a convex surface on the front side of the vehicle and a flat or convex surface on the rear side of the vehicle. From the viewpoint of correcting chromatic aberration, the second lens 15 is more preferably made of a material having low refraction and high dispersion.

  As shown in FIG. 2B, the second lens 15 is moved from the front end side of the lens barrel 13 until the outer peripheral area (ring-shaped area) of the surface on the vehicle rear side comes into contact with the ring-shaped contact surface 13d. It is inserted into the lens barrel 13. Thus, the second lens 15 is positioned with respect to the lens barrel 13 (and the first lens 14 and the light source 12 integrally formed therewith) in the optical axis AX direction.

  The second lens 15 is fitted in the lens barrel 13. Thereby, the 2nd lens 15 is positioned with respect to the lens-barrel 13 (and the 1st lens 14 integrally molded with this, and the light source 12) regarding the radial direction.

  As described above, since the first lens 14 and the lens barrel 13 are integrally molded with high precision using a mold, the second lens 15 is replaced with the lens barrel 13 (and the first lens 14 molded integrally therewith). , And the light source 12) can be positioned with high accuracy.

  The positioned second lens 15 is fixed to the lens barrel 13 using a known fixing means (for example, snap-fit structure, welding, screw, adhesive).

  In the snap-fit structure, a claw portion (an elastic claw portion integrally molded with the same resin as that of the lens barrel 13) is provided at the tip of the lens barrel 13, and this claw portion is engaged with the second lens 15 so that the first lens 15 is engaged. The two lenses 15 are fixed. Welding is a method of fixing the second lens 15 and the lens barrel 13 formed of resin. For example, laser welding is performed on the bonding surface (ring-shaped contact surface 13d where the outer peripheral region (ring-shaped region) of the second lens 15 is in contact) between the second lens 15 and the lens barrel 13 formed of resin. This is done by irradiating light. Note that the second lens 15 positioned as described above can be fixed to the lens barrel 13 using a known pressing ring.

  The optical axis of the second lens 15 positioned and fixed as described above substantially coincides with the optical axis of the first lens 14 and the axis of the lens barrel 13. Further, the vehicle rear side focal point F (synthetic focal point) of the lens group including the second lens 15 and the first lens 14 is located in the vicinity of the light source 12.

  As described above, according to the vehicular lamp unit 10 of the present embodiment, the first lens 14 and the lens barrel 13 are integrally formed using a mold and configured as one component. It is possible to reduce the cost by reducing the cost.

  Further, according to the vehicle lamp unit 10 of the present embodiment, the first lens 14 and the lens barrel 13 are integrally molded using a mold and configured as one part, and therefore the first lens 14 is manually formed. And the step of combining the lens barrel 13 can be omitted.

  Further, according to the vehicle lamp unit 10 of the present embodiment, the first lens 14 and the lens barrel 13 are integrally formed with high precision using a mold, and therefore the second lens 15 is replaced with the lens barrel 13 ( And it becomes possible to position with high precision with respect to the 1st lens 14 integrally molded with this, and the light source 12).

  Further, according to the vehicular lamp unit 10 of the present embodiment, the light emitted from the light source 12 (the light source image of the light source 12) is transmitted forward through the lens group including the second lens 15 and the first lens 14. Irradiated. Since the chromatic aberration of the lens group composed of the second lens 15 and the first lens 14 is corrected, the projection image of the light source 12 is projected on a virtual vertical screen (for example, disposed about 25 m ahead of the front end of the vehicle). The blur due to the chromatic aberration of the contour is corrected well, and a light distribution preferable as a vehicle headlamp can be formed.

  As described above, according to the vehicle lamp unit 10 of the present embodiment, by using the first lens 14 that is a concave lens and the second lens 15 that is a convex lens that are appropriately designed so that chromatic aberration is corrected. Thus, it is possible to configure the vehicular lamp unit 10 that can prevent color separation from occurring in the light distribution pattern due to chromatic aberration.

  The light distribution pattern formed by the projected light source image may be a passing beam, a traveling beam, or an intermediate beam pattern.

  Next, a modified example will be described.

  In the above embodiment, the example in which the vehicular lamp unit 10 is a so-called direct projection type lamp unit has been described, but the present invention is not limited thereto. For example, the vehicle lamp unit 10 may be a projector-type lamp unit.

  In the above embodiment, the lens barrel 13 includes the cylindrical body 13b having a circular cross section orthogonal to the axis thereof, and the diameters of the first lens 14 and the second lens 15 are the same as the diameter of the lens barrel 13. Although it has been described that the lens is substantially the same and circular when viewed from the front, the present invention is not limited to this. For example, the lens barrel 13 may include a cylindrical body having a rectangular cross section perpendicular to the axis thereof, and the first lens 14 and the second lens 15 may be rectangular lenses when viewed from the front.

  In the above embodiment, the first lens 14 and the lens barrel 13 are integrally molded, and the configuration example in which the second lens 15 is inserted and fixed from the distal end side of the lens barrel 13 has been described. It is not limited to this. For example, the second lens 15 and the lens barrel 13 may be integrally formed, and the first lens 14 may be inserted from the base end side of the lens barrel 13 to be positioned and fixed.

  Moreover, although the said embodiment demonstrated the example using two lenses, the 1st lens 14 and the 2nd lens 15, this invention is not limited to this. A configuration using three or more lenses including the first lens 14 and the second lens 15 may be used. For example, the structure which further uses the 3rd lens (not shown) inserted and inserted and fixed from the base end side of the lens-barrel 13 may be sufficient.

  In order to increase the transmittance, an AR coat or the like may be applied to the lens surfaces of the lenses 14 and 15.

  Further, in order to blur the light distribution pattern, the lens surfaces of the lenses 14 and 15 (preferably the front surface of the second lens 15 on the front side of the vehicle) may be subjected to processing such as embossing or microtexture (fine irregularities). .

  Moreover, you may make a part of lens surface of each lens 14 and 15 into a free-form surface for the purpose of changing a light distribution pattern intentionally.

  Moreover, although the said embodiment and each modification demonstrated the example whose 1st lens 14 is a concave lens (refractive lens), this invention is not limited to this. For example, the first lens 14 may be a diffractive lens.

  Hereinafter, a vehicle lamp unit 20 using a diffraction lens as the first lens 14 will be described with reference to the drawings.

  4 is a perspective view of a vehicular lamp unit 20 using a diffractive lens as the first lens 14, FIG. 5A is a front view, and FIG. 5B is a cross-sectional view cut along a vertical plane including the optical axis AX. FIG.5 (c) is an enlarged view in the circle | round | yen in FIG.5 (b).

  The vehicular lamp unit 20 of the present modification is the same as the above embodiment except that a diffractive lens is used as the first lens 14.

  The second lens 15 that is a refractive lens bends short-wave light well and the long-wave light is less likely to bend, but the first lens 14 that is a diffractive lens has a characteristic that long-wave light bends better. Yes. In this modification, chromatic aberration is corrected based on this characteristic by combining the first lens 14 and the second lens 15. As a method for providing the first lens 14 with a diffraction grating 14a for reducing chromatic aberration, for example, a method similar to the method described in International Publication No. WO2009 / 028686 can be used.

  The first lens 14 is a diffractive lens having a convex front surface and a convex rear surface. The vehicle front side surface of the first lens 14 is a convex lens surface having a larger curvature than the vehicle front side surface of the second lens 15. The first lens 14 is thinner than the second lens 15 and has a substantially uniform thickness. The diffraction grating 14 a is provided on the vehicle front side surface of the first lens 14. The second lens 15 and the first lens 14 are appropriately designed by a known method so that chromatic aberration is corrected. Note that the arrangement order of the first lens 14 and the second lens 15 may be reversed. That is, the arrangement order of the first lens 14 and the second lens 15 is not limited.

  Also with the vehicular lamp unit 20 of the present modification, it is possible to achieve the same effects as the vehicular lamp unit 10 of the above embodiment.

  In addition, according to the vehicular lamp unit 20 of the present modification, the following effects can be further achieved.

  Conventionally, in the field of vehicle lamps, it is known to provide a diffraction grating on the convex lens surface of one convex lens for the purpose of improving chromatic aberration (for example, International Publication No. WO2009 / 028686).

  However, the convex lens described in the publication is thick and has a non-uniform thickness.

  For this reason, there is a problem that it is extremely difficult to provide a diffraction grating on the convex lens surface of the convex lens described in the publication using a mold. In addition, since the curvature of the convex lens surface of the convex lens described in the publication is small, there is a problem that sufficient diffraction efficiency cannot be obtained even if a diffraction grating is provided on the convex lens surface.

  According to the vehicular lamp unit 20 of the present modified example, the convex lens (second lens 15) that is thick and non-uniform is not the front surface (convex surface) of the vehicle, but is thinner than the second lens 15. Since the diffraction grating 14a is provided on the front surface of the first lens 14 having a substantially uniform thickness (a convex lens surface having a larger curvature than the front surface of the second lens 15), it is easy to use a mold. It is possible to provide the diffraction grating 14a.

  Further, according to the vehicle lamp unit 20 of the present modification, the diffraction grating 14a is provided on the convex lens surface having a larger curvature than the front surface of the second lens 15, so that the diffraction efficiency can be improved. It becomes.

  As described above, according to the vehicle lamp unit 20 of the present modification, the first lens 14 that is a diffractive lens and the second lens 15 that is a convex lens are appropriately designed so that chromatic aberration is corrected. Thus, it is possible to configure the vehicular lamp unit 20 that can prevent color separation from occurring in the light distribution pattern due to chromatic aberration.

  Further, according to the vehicle lamp unit 20 of the present modification example, since the diffractive lens is used as the first lens 14, the refractive power of the second lens 15 is suppressed, and the overall focus is shortened (high NA). In addition, the size of the vehicular lamp unit 20 in the optical axis direction can be reduced.

  Here, the dimension in the optical axis direction of the vehicular lamp unit 10 of the above embodiment will be examined.

  In the vehicle lamp unit 10 of the above embodiment, the first lens 14 having a negative power (concave lens) and the second lens 15 having a positive power 15 (convex lens) are used for condensing light. As a result, the dimension of the vehicular lamp unit 10 in the optical axis direction becomes longer.

  On the other hand, the vehicular lamp unit 20 of the present modification includes a first lens 14 (diffractive lens) that functions in the same manner as a convex lens having positive power and a second lens 15 (convex lens) having positive power. Since it is the structure which uses and condenses, compared with the vehicle lamp unit 10 of the said embodiment, a focal distance becomes short and, as a result, the optical axis direction dimension of the vehicle lamp unit 20 becomes short.

  As described above, according to the vehicular lamp unit 20 of the present modification, it is possible to configure the vehicular lamp unit 20 having a shorter dimension in the optical axis direction than in the first embodiment.

  Further, according to the vehicle lamp unit 20 of the present modification, since the diffractive lens is used as the first lens 14, it is possible to reduce the lens thickness of the second lens 15 and the like.

  Furthermore, according to the vehicle lamp unit 20 of the present modification, a diffractive lens is used as the first lens 14, and the curvature of the diffractive surface (vehicle front side surface) can be increased. It becomes possible to improve the diffraction efficiency.

  The above embodiment is merely an example in all respects. The present invention is not construed as being limited to these descriptions. The present invention can be implemented in various other forms without departing from the spirit or main features thereof.

DESCRIPTION OF SYMBOLS 10 ... Lamp unit, 11 ... Radiation member, 12 ... Light source, 12a ... Chip, 13 ... Lens tube, 13a ... Base end part, 13b ... Cylindrical body, 13c ... Inner peripheral surface, 13d ... Contact surface, 14 ... 1st Lens, 15 ... second lens, 20 ... lamp unit

Claims (4)

A lens group including a plurality of lenses arranged on an optical axis extending in the vehicle longitudinal direction;
A lens barrel holding the plurality of lenses;
A light source that is disposed on the vehicle rear side of the lens group and emits light that is transmitted forward through the lens group;
In the vehicular lamp unit provided with
At least one of the plurality of lenses and the lens barrel are integrally formed with an outer peripheral portion of the one lens and an inner peripheral surface of the lens barrel fixed. Vehicle lamp unit.   The vehicular lamp unit according to claim 1, wherein the lens group has a two-group configuration including a concave lens and a convex lens.   2. The vehicular lamp unit according to claim 1, wherein the lens group has a two-group configuration including a diffractive lens including a lens surface provided with a diffraction grating for reducing chromatic aberration and a convex lens. . At least one of the plurality of lenses and the lens barrel are integrally molded by injecting resin into a mold, cooling and solidifying, respectively.
4. The vehicular lamp unit according to claim 1, wherein a light leakage prevention process is performed on a peripheral surface of the lens barrel.

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