Motor vehicle headlamp with a narrow outlet window

• US 4,456,948 A
• Filed: 04/12/1982
• Issued: 06/26/1984
• Est. Priority Date: 04/14/1981
• Status: Expired due to Term

• Current Assignee: Cibie Projecteurs
• Original Assignee: Cibie Projecteurs
• Inventors: Brun, Norbert
• Primary Examiner(s): Lechert, Jr., Stephen J.
• Application Number:
  US06/367,777
• Time in Patent Office: 806 Days
• Field of Search: 362/268, 362/61, 362/83, 362/298, 362/299, 362/300, 362/301, 362/307, 362/308, 362/310, 362/311, 362/328, 362/331, 362/335, 362/339, 362/340, 362/346, 362/347, 362/350
• US Class Current: 362/268
• CPC Class Codes: F21S 41/26 Elongated lenses
• CPC Class Codes: F21S 41/275 Lens surfaces, e.g. coatings or surface structures
• CPC Class Codes: F21S 41/28 Cover glass
• CPC Class Codes: F21S 41/321 the reflector being a surface of revolution or a planar surface, e.g. truncated
• CPC Class Codes: F21S 41/323 the reflector having two perpendicular cross sections having regular geometrical curves of a distinct nature
• CPC Class Codes: F21S 41/365 successively reflecting the light
• CPC Class Codes: F21S 41/40 characterised by screens, non-reflecting members, light-shielding members or fixed shades

Abstract

A motor vehicle headlamp comprising in combination an optical system for recovering flux having a rectilinear focal segment and an optical system for rectifying images having a focal segment coinciding with the former and able to produce a beam of rays of controlled directivity passing through a narrow light window, while preserving a high luminous efficiency. The flux recovery system is constituted by an elliptical paraboloid, an hyperbolic paraboloid or their optical equivalents. By using various combinations of optical elements, it is possible to arrange the flux recovery system both in the axis of the rays leaving the headlamp, as well as on the side of the body work or on the lower part of the latter.

Claims

1. A motor vehicle headlamp comprising in combination

(a) an optical system for recovering flux, chosen from the group consisting of elliptical and hyperbolic paraboloids of the fourth degree, said flux recovery system having a rectilinear first focal segment so as to be able to create from a substantially pinhole light source a beam of light rays all passing through the focal segment and all being substantially parallel to the direction of a plane perpendicular to the focal segment, and

(b) an optical system for rectifying images having a second focal segment coinciding with the first focal segment and able to transform the beam leaving the flux recovery system into a beam of rays having controlled directivity passing through a narrow light window.

2. A motor vehicle headlamp according to claim 1 wherein said focal segment is horizontal with a dimension equal to the width of the light window.

3. A motor vehicle headlamp according to claim 1, wherein said focal segment is vertical with a dimension equal to the height of the light window.

4. A motor vehicle headlamp according to claim 1, wherein said the focal segment is axial.

5. A motor vehicle headlamp according to claim 1, comprising one of the following optical combinations:

space="preserve" listing-type="tabular">______________________________________ BIK AIIK BJK AIJK BDK AIDK BEK AIEK BHIK AIHIK BHJK AIHJK BGK AIGK BFK AIFK BHIK AIHIK BHJK AIHJK B'"'"'IK AIIK B'"'"'GK AIGK B'"'"'HIK AIHIK CIK AJIK CGK AJGK CHIK AJHIK CEK AJEK CHIK AJHIK B'"'"'EK AIEK B'"'"'HIK AIHIK, ______________________________________

wherein

A is a paraboloid of revolution meaning a mirror whereof the reflecting surface is obtained by the rotation of a parabola about its focal axis;

B is an elliptical paraboloid of the first type meaning a reflecting surface comprising a real horizontal focal segment;

B'"'"' is an elliptical paraboloid of the second type--meaning a reflecting surface identical to that of B but whereof the real focal segment is vertical;

C is a hyperbolic paraboloid meaning a reflecting surface having a vertical and virtual focal segment;

D is a divergent cone meaning a reflecting surface having the geometric shape of a cone of revolution and which is struck from the outside by the light rays;

E is a convergent cone meaning a reflecting surface having the geometric shape of a cone of revolution and which is struck from the inside by the light rays;

F is a cylindrical mirror having a divergent parabolic profile meaning a reflecting surface defined geometrically as a cylinder whereof the directrix is parabolic and whereof the convexity is directed towards the light source;

G is a cylindrical mirror having a convergent parabolic profile meaning a reflecting surface defined geometrically as a cylindrical, whereof the directrix is a parabola and which turns its concavity towards the light source;

H is a plane mirror inclined at an angle of 45°

with respect to incident light rays and deflects them by a right angle;

I is a convergent cylindrical lens or a convergent Fresnel lens;

J is a divergent cylindrical lens or a divergent Fresnel lens;

K is a headlamp closing glass.

6. A headlamp according to any one of claims 1 to 5 wherein said flux recovery system is located in the axis of the light rays emanating from the headlamp.