Headlamp for motor vehicles with programmable light distribution

• US 4,868,721 A
• Filed: 05/12/1988
• Issued: 09/19/1989
• Est. Priority Date: 05/13/1987
• Status: Expired due to Fees

• Current Assignee: Paolo Soardo
• Original Assignee: Paolo Soardo
• Inventors: Soardo, Paolo
• Primary Examiner(s): Lazarus, Ira S.
• Assistant Examiner(s): Cox, D. M.
• Application Number:
  US07/193,462
• Time in Patent Office: 495 Days
• Field of Search: 362/61, 362/80, 362/276, 362/277, 362/280, 362/259, 362/263, 362/281, 362/282, 362/283, 362/284, 362/301, 362/319, 362/322, 362/323, 362/324, 362/66, 350/6.5, 350/6.6, 315/77.82
• US Class Current: 362/466
• CPC Class Codes: F21S 41/13 Ultraviolet light; Infrared light
• CPC Class Codes: F21S 41/14 characterised by the type of light source
• CPC Class Codes: F21S 41/16 Laser light sources
• CPC Class Codes: F21S 41/285 Refractors, transparent cover plates, light guides or filters not provided in groups F21S41/24-F21S41/28
• CPC Class Codes: F21S 41/321 the reflector being a surface of revolution or a planar surface, e.g. truncated
• CPC Class Codes: F21S 41/36 Combinations of two or more separate reflectors
• CPC Class Codes: F21S 41/365 successively reflecting the light
• CPC Class Codes: F21S 41/60 characterised by a variable light distribution
• CPC Class Codes: F21S 41/64 by changing their light transmissivity, e.g. by liquid crystal or electrochromic devices
• CPC Class Codes: F21S 41/675 by moving reflectors
• CPC Class Codes: F21W 2102/30 Fog lights
• CPC Class Codes: G02B 26/101 with both horizontal and vertical deflecting means, e.g. raster or XY scanners colour television using laser beams scanning a display screen H04N9/3129

Abstract

A headlamp for motor vehicles comprises a light source of the type adapted to generate a concentrated unidirectional pencil of light, and a motorized deflector device for intercepting the pencil of light and causing continuous rapid scanning thereof within at least one predetermined solid angle to obtain a light beam of predetermined characteristics.

Claims

1. A motor vehicle headlamp comprising a light source and optical means for distributing the light emitted by the light source in a beam of predetermined characteristics, wherein the light source is of the type adapted to generate a concentrated substantially unidirectional pencil of light, and the optical means include at least one motorized deflector device for intercepting the pencil of light and causing continuous rapid scanning thereof within at least one predetermined solid angle to obtain the light beam of predetermined characteristics.

2. A headlamp according to claim 1, wherein an electronic control unit is operatively associated with the motorized deflector device for programmable variation of the distribution of the light beam.

3. A headlamp according to claim 2, wherein a device for modulating the intensity of the pencil of light is operatively associated with the light source, and is controlled by the electronic control unit.

4. A headlamp according to claim 1, wherein the light source comprises a laser generator.

5. A headlamp according to claim 1, wherein the light source is of the discharge type.

6. A headlamp according to claim 1, wherein the light source is of the filament type.

7. A headlamp according to claim 3, wherein the light source comprises a laser generator and the modulator device is constituted by a piloting circuit of the laser generator.

8. A headlamp according to claim 3, wherein the modulator device is constituted by an optical filter.

9. A headlamp according to claim 3, wherein the modulator device is constituted by a mechanical filter.

10. A headlamp according to claim 3, wherein it further includes means for detecting the spatial position of the pencil emitted by the deflector device, which are operatively connected to the electronic unit for controlling the modulator device.

11. A headlamp according to claim 1, wherein the motorized deflector device causes the pencil of light to scan at a rate sufficient to ensure persistence of vision of the light beam.

12. A headlamp according to claim 1, wherein the deflector device includes at least one angularly movable reflective surface.

13. A headlamp according to claim 12, wherein the deflector device includes a first mirror situated in the path of the pencil of light and pivoted about a first axis, a second mirror arranged on the path of reflection of the pencil of light from the first mirror and pivoted about a second axis perpendicular to the first, and means for moving the first and second mirrors in a continuous angular reciprocating motion, in synchronism with each other.

14. A headlamp according to claim 12 wherein the deflector device includes at least one cylindrical body rotatable about its own axis and having a circumferential ring of contiguous reflective faces which converge towards the axis of the body with different inclinations and are adapted to intercept the pencil of light at an angle of incidence which is variable due to the rotation of the body.

15. A headlamp according to claim 14, wherein the reflective faces are flat.

16. A headlamp according to claim 14, wherein the reflective faces are concave.

17. A headlamp according to claim 14, wherein the reflective faces are convex.

18. A headlamp according to claim 12, wherein the deflector device includes a first disc rotatable about its own axis and having a conical lateral reflective surface with a continuously variable angle for intercepting the pencil of light, and a second disc rotatable about its own axis, which is at an angle with the axis of the first disc and having a lateral reflective surface arranged on the path of reflection of the pencil of light from the first rotary disc.

19. A headlamp according to claim 18, wherein the lateral reflective surface of the second rotary disc has a similar conformation to that of the first disc, and the rate of rotation of the second disc is equal to a multiple of that of the first disc.

20. A headlamp according to claim 18, wherein the lateral reflective surface of the second rotary disc is faceted.

21. A headlamp according to claim 1, wherein the pencil of light has different angular amplitudes in the vertical plane and the horizontal plane, of the order of one hundredth and of 2-3 hundredths of a radian respectively.

22. A headlamp according to claim 1, wherein the pencil of light has a luminous-flux intensity of the order of 500 lumens.