Automotive headlamp apparatus

• US 9,494,288 B2
• Filed: 02/28/2014
• Issued: 11/15/2016
• Est. Priority Date: 09/01/2011
• Status: Active Grant

• Current Assignee: Koito Manufacturing Company Limited
• Original Assignee: Koito Manufacturing Company Limited
• Inventors: Kobayashi, Shoji
• Primary Examiner(s): A, Minh D
• Application Number:
  US14/193,572
• Publication Number:
  US 20140175978A1
• Time in Patent Office: 991 Days
• Field of Search: 315 76- 80, 315/82, 362/475, 362/476, 362/464, 362/465
• US Class Current: 1/1
• CPC Class Codes: B60Q 1/04 the devices being headlights
• 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 2300/112 Vehicle speed
• CPC Class Codes: B60Q 2300/122 Steering angle
• CPC Class Codes: B60Q 2300/32 Road surface or travel path
• CPC Class Codes: B60Q 2300/41 preceding vehicle
• CPC Class Codes: B60Q 2300/42 oncoming vehicle
• 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 41/153 arranged in a matrix
• CPC Class Codes: F21S 41/18 Combination of light sources of different types or shapes
• CPC Class Codes: F21S 41/635 by moving refractors, filters or transparent cover plates
• CPC Class Codes: F21S 41/657 by moving light sources
• CPC Class Codes: F21S 41/663 by switching light sources by switching incandescent light sources F21S41/162
• CPC Class Codes: F21Y 2105/12 characterised by the geometrical disposition of the light-generating elements, e.g. arranging light-generating elements in differing patterns or densities

Abstract

An automotive headlamp apparatus includes a light source, in which a plurality of LED chips are arranged at intervals from each other, and a projection lens for projecting the light, emitted from the light source, toward a front area of a vehicle as a light source image. The semiconductor light-emitting elements may be located within than a focal point of the projection lens. The LED chip is arranged such that the light emitting surface of the LED chip faces the front area of the vehicle. The light emitting surface of the LED chip may be of a rectangular shape and the LED chip may be arranged such that a side of the light emitting surface is at a slant with respect to the vehicle width direction.

Claims

1. An automotive headlamp apparatus comprising:

a light source in which a plurality of semiconductor light-emitting elements are arranged at intervals from each other; and

a projection lens configured to project light, emitted from the light source, toward a front area of a vehicle as a light source image,

wherein the semiconductor light-emitting elements are located in front of a focal point of the projection lens.

2. An automotive headlamp apparatus according to claim 1, wherein the semiconductor light-emitting elements are arranged such that a light emitting surface of the semiconductor light-emitting element faces the front area of the vehicle.

3. An automotive headlamp apparatus according to claim 1, wherein the light emitting surface of the semiconductor light-emitting element is of a rectangular shape, and the semiconductor light-emitting element is arranged such that a side thereof is tilted with respect to a vehicle width direction.

4. An automotive headlamp apparatus according to claim 1, wherein the semiconductor light-emitting element and the projection lens are positioned such that a distance between the semiconductor light-emitting element and the projection lens is less than or equal to 0.98f, where f [mm] denotes a focal length of the projection lens.

5. An automotive headlamp apparatus according to claim 1, wherein the semiconductor light-emitting element and the projection lens are positioned such that a distance between the semiconductor light-emitting element and the projection lens is greater than or equal to

((P−

W)/P)×

f,

where f [mm] denotes a focal length of the projection lens, W [mm] denotes a side length of a light emitting surface of the semiconductor light-emitting element, and P [mm] denotes a pitch between the adjacent semiconductor light-emitting elements.

6. An automotive headlamp apparatus comprising:

a light source in which a plurality of semiconductor light-emitting elements are arranged in a matrix, the light source being configured to irradiate light toward a front area of a vehicle; and

a control unit configured to control the turning on and off of the plurality of semiconductor light-emitting elements included in the light source,

the plurality of semiconductor light-emitting elements including;

a plurality of first semiconductor light-emitting elements for emitting light to a first section contained in an illumination region in the front area of the vehicle; and

a plurality of second semiconductor light-emitting elements for emitting light to a second section, which is different from the first section, contained in the illumination region, wherein the second semiconductor light-emitting element has a characteristic different from that of the first semiconductor light-emitting element,

the control unit including;

a first drive unit for driving, per group, the plurality of first semiconductor light-emitting elements, which are divided into groups, wherein the number of groups is smaller than the number of first semiconductor light-emitting elements; and

a second drive unit for driving, per group, the plurality of second semiconductor light-emitting elements, which are divided into groups, wherein the number of groups is smaller than the number of second semiconductor light-emitting elements.

7. An automotive headlamp apparatus according to claim 6, wherein the first semiconductor light-emitting element is constituted by an element whose luminance differs from that of the second semiconductor light-emitting element when the same current is supplied thereto.

8. An automotive headlamp apparatus according to claim 6, wherein the first semiconductor light-emitting element is constituted by an element whose maximum forward current rating differs from that of the second semiconductor light-emitting element.

9. An automotive headlamp apparatus according to claim 6, wherein the first semiconductor light-emitting elements are arranged such that the first section contains a central portion of the illumination region, and

wherein a control unit controls the turning on and off of the first semiconductor light-emitting elements and the second semiconductor light-emitting elements such that the luminance of the first semiconductor light-emitting elements is higher than that of the second semiconductor light-emitting elements.

10. An automotive headlamp apparatus according to claim 6, wherein the plurality of semiconductor light-emitting elements are arranged such that light emitting surfaces of the semiconductor light-emitting elements face the front area of the vehicle.

11. An automotive headlamp apparatus according to claim 6, wherein a light emitting surface of each of the plurality of semiconductor light-emitting elements is of a rectangular shape, and each of the plurality of semiconductor light-emitting elements is arranged such that a side thereof is tilted with respect to a vehicle width direction.

12. An automotive headlamp apparatus according to claim 6, wherein

the plurality of first semiconductor light-emitting elements are arranged in a first block of a region where the semiconductor light-emitting elements are arranged in a matrix;

and

the plurality of second semiconductor light-emitting elements are arranged in a second block of the region where the semiconductor light-emitting elements are arranged in the matrix, the second block being different from the first block.

13. An automotive headlamp apparatus comprising:

a light source in which a plurality of semiconductor light-emitting elements are arranged at intervals from each other;

a projection lens configured to project light, emitted from the light source, toward a front area of a vehicle as a light source image; and

a magnification varying mechanism configured to vary a magnifying power of the light source image, the magnification varying mechanism being provided on the projection lens at a front side of the vehicle.

14. An automotive headlamp apparatus according to claim 13, wherein the plurality of semiconductor light-emitting elements are located in front of a focal point of the projection lens.

15. An automotive headlamp apparatus according to claim 13, wherein the semiconductor light-emitting elements are arranged such that a light emitting surface of the semiconductor light-emitting element faces the front area of the vehicle.

16. An automotive headlamp apparatus according to claim 13, wherein the light emitting surface of the semiconductor light-emitting element is of a rectangular shape, and the semiconductor light-emitting element is arranged such that a side thereof is tilted with respect to a vehicle width direction.

17. An automotive headlamp apparatus according to claim 13, wherein the magnification varying mechanism is an optical system configured such that a magnifying power change in the vehicle width direction of the light source image is larger than a magnifying power change in a vertical direction thereof.

18. An automotive headlamp apparatus according to claim 17, wherein the optical system is an anamorphic lens system.