US 2003/0169600 A1Published application

Led-type vehicular lamp having uniform brightness

AssigneeKoito Manufacturing Co., Ltd.

InventorYasuyuki Amano

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Abstract

A vehicular lamp which radiates light emitted by LED light sources through indirect illumination and which has uniform brightness. Light emitted from the LED light sources is directed upward and formed into parallel beams by Fresnel lenses, and the parallel beams are reflected by a reflector in a frontward direction of the lamp. The reflector is divided into sub reflectors that differ in height and angle of forward inclination according to the areas on which the parallel light beams impinge. The distance between each of the LED light sources and the corresponding one of the Fresnel lenses increases in proportion to a decrease in the height of the corresponding one of the sub reflectors, and the intensity of the luminous flux impinging on each of the Fresnel lenses decreases in proportion to the decrease in the height of the corresponding one of the sub reflectors. Hence, the intensity of the luminous flux impinging on the reflecting surface of each of the sub reflectors decreases in proportion to the decrease in the projected area in the forward direction of the lamp, and thus the sub reflectors have a uniform luminance and the entire reflecting surface of the reflector appears uniform in brightness.

Claims18

Dependent claims

A vehicular lamp comprising:

a plurality of LED light sources;
a plurality of lenses for forming parallel light beams from light from corresponding ones of said LED light sources, said lenses being disposed such that said parallel light beams are directed in the same direction;
a reflector for reflecting said parallel light beams from said lenses in a forward direction of said lamp, said reflector being divided into a plurality of sub reflectors arranged parallel to one another and according to areas on which the parallel light beams from said lenses impinge, a length of said sub reflectors with respect to a direction of radiation of said parallel light beams from said lenses decreasing stepwise from one side of said reflector to the opposite side of said reflector, an angle of inclination of each of said sub reflectors with respect to said forward direction of said lamp increasing in proportion to a decrease in length of the sub reflector in the direction of radiation of said parallel light beams with respect to an adjacent one of said sub reflector, and a distance between each of said LED light sources and the corresponding one of said lenses increasing stepwise in proportion to said decrease in length of the corresponding one of said sub reflectors in said direction of radiation of said parallel light beams;
and
a translucent cover disposed on a front side of said reflector.

2 more elements

A vehicular lamp comprising:

a plurality of LED light sources;
a plurality of lenses for forming parallel light beams from light from corresponding ones of said LED light sources, said lenses being disposed such that said parallel light beams are directed in the same direction;
a reflector for reflecting said parallel light beams from said lenses in a forward direction of said lamp, said reflector being divided into a plurality of sub reflectors arranged parallel to one another and according,to areas on which the parallel light beams from said lenses impinge, a length of said sub reflectors with respect to a direction of radiation of said parallel light beams from said lenses decreasing stepwise from one side of said reflector to the opposite side of said reflector, an angle of inclination of each of said sub reflectors with respect to said forward direction of said lamp increasing stepwise from said one side of said reflector to said opposite side of said reflector, and a distance between each of said LED light sources and the corresponding one of said lenses increasing stepwise from said one side of said reflector to said opposite side of said reflector such that said reflector appears of substantially uniform brightness when viewed from a position in front of said lamp;
and
a translucent cover disposed on a front side of said reflector.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/244,606Filed 17 Sep 2002
Priority: JP P.2001-28658520 Sep 2001
Published: 11 Sep 2003
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

B60Q 1/2696
The devices being primarily intended to indicate the vehicle, or parts thereof, or to give signals, to other traffic: mounting of devices using LEDs
F21S 43/14
Characterised by the type of light source: light emitting diodes [LED]
F21S 43/40
Signalling devices specially adapted for vehicle exteriors, e.g. brake lamps, direction indicator lights or reversing lights: characterised by the…
B60Q
Arrangement of signalling or lighting devices, the mounting or supporting thereof or