Abstract: A light source unit capable of considerably reducing the size of a vehicular lamp. An LED is mounted on an optical axis extending in the longitudinal direction of the vehicle with its light output directed upward, and a reflector is provided above the LED having a first reflecting surface for collecting the light emitted by the LED and reflecting the light generally in the direction of the optical axis Ax. The reflector is formed by a reflective coating formed on the surface of a translucent block covering the LED. Consequently, the size of the reflector can be considerably reduced as compared with reflectors employed in conventional vehicular lamps. Moreover, since the LED used as a light source emits little heat, the reflector can be designed without having to take into account the influence of heat generated by the light source. Furthermore, the LED can be treated substantially as a point light source so that proper reflection control can be carried out even if the size of the reflector is reduced.

Abstract: A light source unit capable of considerably reducing the size of a vehicular lamp. An LED is mounted on an optical axis extending in the longitudinal direction of the vehicle with its light output directed upward, and a reflector is provided above the LED having a first reflecting surface for collecting the light emitted by the LED and reflecting the light generally in the direction of the optical axis Ax. The first reflecting surface is formed in such a manner that a distance L in a vertical direction from the LED to the first reflecting surface is approximately 10 mm in a preferred embodiment. Consequently, the size of the reflector can be considerably reduced as compared with reflectors employed in conventional vehicular lamps. Moreover, the LED used as a light source emits little heat, the reflector can be designed without having to take into account the influence of heat generated by the light source.

Abstract: A vehicular headlamp capable of moving an auxiliary light distribution pattern in the horizontal direction by pivoting an auxiliary lamp fixture unit in which degradation in the visibility of the road surface ahead of the vehicle caused by movement of an auxiliary light distribution pattern is substantially reduced. The brightness of a low-beam light distribution pattern formed by a headlamp unit is partially reinforced with auxiliary light distribution patterns formed by a pair of auxiliary lamp fixture units. When the vehicle turns, one of the auxiliary light distribution patterns is moved in the same direction with an upward displacement, whereby sufficient visibility ahead of the vehicle is assured. As a result of this movement, the hot zone of the auxiliary light distribution pattern is separated from the hot zone of the low-beam light distribution pattern.

Abstract: A first lamp unit and a second lamp unit are arranged in two vertically-spaced stages within a lamp chamber, which is formed by a lamp body and a light-transmitting cover, in such a manner that the second lamp unit is disposed over the first lamp unit. The second lamp unit is so constructed that at least part of reflected light from a reflector can pass through the light-transmitting cover disposed forwardly of the first lamp unit. The direction of radiation of the beam from the second lamp unit can point downward, so that the light can be directed toward a zone of the road near and ahead of the vehicle.

Abstract: A movable shade 26 for shielding a part of light emitted from a light source 22a toward a reflecting surface 24a of a reflector 24 is moved between two positions in a longitudinal direction by a shade driving device 28 according to a vehicle running situation, thereby changing a region in which the reflecting surface of the reflector 24 is to be utilized. More specifically, light emitted toward an outer peripheral region 24a2 of the reflecting surface 24a is shielded to permit only light incidence on an inner peripheral region 24a1 thereof when the movable shade 26 is moved to a forward position, while light emitted toward the inner peripheral region 24a1 of the reflecting surface 24a is shielded to permit only light incidence on the outer peripheral region 24a2 when the movable shade 26 is moved to a rearward position.

Abstract: A method of designing a reflective surface of a reflector used in a vehicle lamp includes a first base curve generating step of generating a first base curve Q; a second base curve generating step of generating a plurality of second base curves R; and a surface shape generating step of generating a surface shape of the reflective surface RS, based on the first base curve and the plurality of second base curves, wherein the first base curve generating step includes repeating a step of generating one partial curve Qi and thereafter generating a subsequent partial curve Qi+1 so as to be connected to the partial curve, thereby generating one first base curve Q consisting of a plurality of partial curves Qi connected to each other, and wherein each partial curve Q1 is generated based on a shape parameter according thereto.

Abstract: A method of designing a reflective surface of a reflector used in a vehicle lamp includes a first base curve generating step of generating a first base curve Q; a second base curve generating step of generating a plurality of second base curves R; and a surface shape generating step of generating a surface shape of the reflective surface RS, based on the first base curve and the plurality of second base curves, wherein the first base curve generating step includes repeating a step of generating one partial curve Qi and thereafter generating a subsequent partial curve Qi+1 so as to be connected to the partial curve, thereby generating one first base curve Q consisting of a plurality of partial curves Qi connected to each other, and wherein each partial curve Qi is generated based on a shape parameter according thereto.

Abstract: A lighting unit for a low beam is provided with a movable shade constituted to take a shielding position in which a part of light incident on a reflector from a light source is shielded and a shielding release position in which the shielding is released. When a vehicle speed exceeds a predetermined set vehicle speed, or when a vehicle turns toward the opposite lane side, the movable shade is moved to the shielding release position, thereby adding auxiliary light distribution patterns P(B) and P(C) having cutoff lines CLb and CLc above cutoff lines CL1 and CL2 of a low beam distribution pattern P(L) to the low beam distribution pattern P(L) to carry out beam irradiation. Thus, the visibility of a distant road is enhanced.

Abstract: A designing method of a reflective surface RS according to the present invention has a step of generating an XY curve Q on an XY plane including the X-axis (optical axis) and Y-axis; a step of, at each of a plurality of base points P existing on the XY curve Q, generating an XZ curve R on a plane (UZ plane) including the base point P and being parallel to a reflection direction of light at the base point P and normal to the XY plane; and a step of generating a surface shape of the reflective surface RS, based on the XY curve Q and the plurality of XZ curves R. This substantiates a method of designing a reflective surface of a reflector in a vehicle lamp with improved controllability of a light distribution pattern and with improved efficiency of a designing work.

Abstract: A vehicular headlamp capable of moving an auxiliary light distribution pattern in the horizontal direction by pivoting an auxiliary lamp fixture unit in which degradation in the visibility of the road surface ahead of the vehicle caused by movement of an auxiliary light distribution pattern is substantially reduced. The brightness of a low-beam light distribution pattern formed by a headlamp unit is partially reinforced with auxiliary light distribution patterns formed by a pair of auxiliary lamp fixture units. When the vehicle turns, one of the auxiliary light distribution patterns is moved in the same direction with an upward displacement, whereby sufficient visibility ahead of the vehicle is assured. As a result of this movement, the hot zone of the auxiliary light distribution pattern is separated from the hot zone of the low-beam light distribution pattern.

Abstract: A vehicle headlamp including a light source bulb installed on an optical axis that extends in a longitudinal direction of a vehicle, a reflector having a reflective surface for reflecting a light from the light source bulb forward, and a shade for blocking part of a light directly irradiated from the light source bulb. Still further, the shade is comprised of a shade body that surrounds a front-end portion of the light source bulb around the optical axis and a mount stay that supports the shade body and an outer circumferential surface of the shade body is provided with a corrugated diffusion portion formed thereon so as to diffusely reflect a light admitted thereto.

Abstract: A designing method of a reflective surface RS according to the present invention has a step of generating an XY curve Q on an XY plane including the X-axis (optical axis) and Y-axis; a step of, at each of a plurality of base points P existing on the XY curve Q, generating an XZ curve R on a plane (UZ plane) including the base point P and being parallel to a reflection direction of light at the base point P and normal to the XY plane; and a step of generating a surface shape of the reflective surface RS, based on the XY curve Q and the plurality of XZ curves R. This substantiates a method of designing a reflective surface of a reflector in a vehicle lamp with improved controllability of a light distribution pattern and with improved efficiency of a designing work.

Abstract: A vehicular headlamp comprising a discharge bulb provided with an arc tube having a discharge light-emitting portion extending in a fore-to-aft direction, an outer tube tubularly surrounding the arc tube, and a glare protection film formed on an outer peripheral surface of the outer tube over a predetermined angular range such that upper edges of the glare protection film are located on left and right sides of the outer peripheral face, and a reflector that securely supports the discharge bulb and reflects light from the discharge light-emitting portion of the discharge bulb forward, characterized in that the discharge bulb is securely supported by the reflector so that the upper edges of the glare protection film are located substantially at an equal height, that is, the upper edges are disposed in a horizontal plane.

Abstract: A vehicle head lamp in which an outer cover is provided in front of a light-distribution control unit, and substantially horizontally extending decorative lines are formed by glare-reducing steps on the inner surface of the outer cover.

Abstract: A bulb 14 is arranged in such a manner that the lower end of a filament 16 of the bulb 14 coincides with an optical axis Ax of a reflector 10. Horizontal cut line forming steps 12aH out of a plurality of light distribution steps 12a constituting a reflecting surface 12 extend over such upper and lower areas as to interpose phantom lines Lh1, Lh2 on the reflecting surface 12 therebetween. The phantom lines will correspond to the horizontal cut lines. Vertical sections of these horizontal cut line forming steps in both upper and lower areas are set to parabolas, each having a short focus, and to parabolas, each having a long focus, respectively. The horizontal cut lines are formed by taking advantage of the luminous fluxes of reflecting light from both areas. Each parabola having a short focus is connected to the corresponding parabola having a long focus at the apex thereof smoothly. As a result, the horizontal cut line forming steps 12aH can be reduced into a single step without steps and bends.

Abstract: A vehicular headlamp has a reflector which is so optically designed as to provide, by reflecting light from a light source, a basic beam pattern of approximately semicircular shape wholly disposed below the horizon, with a top edge cutoff extending horizontally. A front lens is stepped to produce a lower beam pattern by raising part of the basic beam pattern and by horizontally expanding the rest of the basic beam pattern. The top edge cutoff of the lower beam pattern is as clearcut as that of the basic beam pattern. Either of two different lower beam patterns required for vehicles keeping to the right and for those keeping to the left is producible merely by changing the optical design of the front lens.