Vehicle headlamp

• US 6,891,333 B2
• Filed: 09/02/2003
• Issued: 05/10/2005
• Est. Priority Date: 09/03/2002
• Status: Active Grant

• Current Assignee: Koito Manufacturing Company Limited
• Original Assignee: Koito Manufacturing Company Limited
• Inventors: Ishida, Hiroyuki, Tatsukawa, Masashi, Sazuka, Kiyoshi
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): Alemu, Ephrem
• Application Number:
  US10/652,241
• Publication Number:
  US 20040120158A1
• Time in Patent Office: 616 Days
• Field of Search: 315/77, 315/82, 315/76, 362543-545, 362/538, 362/539, 362/517, 362/507, 362/459, 362/800
• US Class Current: 315/82
• CPC Class Codes: B60Q 1/04 the devices being headlights
• CPC Class Codes: F21S 41/143 the main emission direction of the LED being parallel to the optical axis of the illuminating device
• CPC Class Codes: F21S 41/148 the main emission direction of the LED being perpendicular to the optical axis
• CPC Class Codes: F21S 41/153 arranged in a matrix
• CPC Class Codes: F21S 41/155 Surface emitters, e.g. organic light emitting diodes [OLED]
• CPC Class Codes: F21S 41/336 with discontinuity at the junction between adjacent areas
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

A vehicle headlamp is constituted to have a plurality of lamp units having light-emitting diodes as light sources. At that time, three types of lamp units of different radiation modes; that is, a projector-type lamp unit, direct-projection-type lamp units, and a reflection-type lamp unit, are used as the plurality of lamp units. As a result, a low-beam light distribution pattern obtained as a merged light distribution pattern formed from the light rays output from these three types of lamp units can be readily formed in a desired pattern geometry and a desired distribution of luminous intensity.

Claims

1. A vehicle headlamp operable to form a predetermined light distribution pattern comprising:

a plurality of lamp units employing semiconductor light-emitting elements as light sources, wherein

the plurality of lamp units include a lamp unit of direct projection type which is constructed to radiate direct light output from the light source ahead of the lamp by way of a condenser lens provided forward of the light source; and

at least one type of lamp unit selected from a lamp unit of projector type which is constructed to reflect light output to be converged in a forward direction from a light source by means of a reflector and to radiate the reflected light ahead of a lamp by way of a projection lens provided ahead of the reflector, and from a lamp unit of reflection type which is constructed to reflect light output from the light source ahead of the lamp by means of the reflector.

2. The vehicle headlamp according to claim 1, wherein the light distribution pattern is a low-beam light distribution pattern, and a cut-off line of the low-beam light distribution pattern is formed by means of the lamp unit of projector type.

3. A vehicle headlamp operable to form a predetermined light distribution pattern comprising:

a plurality of lamp units employing semiconductor light-emitting elements as light sources, wherein

the plurality of lamp units include a lamp unit of direct projection type; and

at least one type of lamp unit selected from a lamp unit of projector type, and a lamp unit of reflection type.

4. The vehicle headlamp according to claim 3, further comprising a light source, a reflector, and a projection lens and wherein the lamp unit of projector type reflects light output from the light source to be converged in a forward direction by means of the reflector and radiates the reflected light by way of the projection lens provided ahead of the reflector.

5. The vehicle headlamp according to claim 3, further comprising a light source and a condenser lens, and wherein the lamp unit of direct projection type radiates direct light output from the light source by way of the condenser lens provided forward of the light source.

6. The vehicle headlamp according to claim 3, further comprising a light source and a reflector, and wherein the lamp unit of reflection type reflects light output from the light source by means of the reflector.

7. The vehicle headlamp according to claim 3, wherein the light distribution pattern is a low-beam light distribution pattern, and a cut-off line of the low-beam light distribution pattern is formed by means of the lamp unit of projector type.