Vehicle lamp

• US 8,007,146 B2
• Filed: 08/28/2008
• Issued: 08/30/2011
• Est. Priority Date: 09/14/2007
• Status: Expired due to Fees

• Current Assignee: Koito Manufacturing Company Limited
• Original Assignee: Koito Manufacturing Company Limited
• Inventors: Oishi, Kazutami, Hayakawa, Michihiko, Tatara, Naohisa
• Primary Examiner(s): MAY, ROBERT J
• Application Number:
  US12/200,308
• Publication Number:
  US 20090073706A1
• Time in Patent Office: 1,097 Days
• Field of Search: 362464-466, 362467-468
• US Class Current: 362/464
• CPC Class Codes: B60Q 1/1423 Automatic dimming circuits, i.e. switching between high beam and low beam due to change of ambient light or light level in road traffic
• CPC Class Codes: B60Q 2300/056 Special anti-blinding beams, e.g. a standard beam is chopped or moved in order not to blind
• CPC Class Codes: B60Q 2300/41 preceding vehicle
• CPC Class Codes: B60Q 2300/42 oncoming vehicle
• CPC Class Codes: F21S 41/255 Lenses with a front view of circular or truncated circular outline
• CPC Class Codes: F21S 41/635 by moving refractors, filters or transparent cover plates

Abstract

A vehicle lamp is arranged to switch between a low beam and a high beam. The high beam illuminates a first illumination area, which lies ahead of and square to a center of a vehicle, and a second illumination area, which includes portions lying horizontally further leftwards and right wards and vertically further upwards than the first illumination area. When switching from the low beam to the high beam, the luminous intensity of the second illumination area is increased and thereafter the luminous intensity of the first illumination area is increased. When switching from the high beam to the low beam, the luminance intensity of the first illumination area is decreased and thereafter the luminance intensity of the second illumination area is decreased.

Claims

1. A vehicle lamp arranged to switch between a low beam and a high beam, the high beam illuminating a first illumination area, which lies ahead of and square to a center of a vehicle, and a second illumination area, which includes portions lying horizontally further leftwards and right wards and vertically further upwards than the first illumination area, the vehicle lamp comprising:

a lighting control means arranged to control a lighting state of the vehicle lamp so that when switching from the low beam to the high beam, the lighting control means increases the luminous intensity of the second illumination area and thereafter increases the luminous intensity of the first illumination area, and when switching from the high beam to the low beam, the lighting control means decreases the luminance intensity of the first illumination area and thereafter decreases the luminance intensity of the second illumination area; and

a preceding vehicle detection means for detecting a vehicle ahead of a subject vehicle, wherein the lighting control means is arranged to switch from the low beam to the high beam when an inter-vehicle distance to a preceding vehicle detected by the preceding vehicle detection means is equal to or larger than a first predetermined distance,

wherein the lighting control means increases the luminous intensity of only the second illumination area when the inter-vehicle distance to the preceding vehicle is equal to or larger than the first predetermined distance and increases the luminous intensity of the first illumination area when the inter-vehicle distance is equal to or larger than a second predetermined distance which is larger than the first predetermined distance.

2. A vehicle lamp as set forth in claim 1 wherein the second illumination area is defined as any of an annular area which surrounds the first illumination area, areas lying horizontally leftwards and rightwards of the first illumination area or an area lying vertically upwards of the first illumination area.