GB2324366A

GB2324366A - Reflector for vehicle headlamp

Info

Publication number: GB2324366A
Application number: GB9807955A
Authority: GB
Inventors: Milan Cejnek; Milan Krizak; Martin Kutac
Original assignee: Autopal sro
Current assignee: Hanon Systems Autopal Services sro
Priority date: 1997-04-18
Filing date: 1998-04-16
Publication date: 1998-10-21
Anticipated expiration: 2018-04-16
Also published as: CZ291225B6; GB9807955D0; ITMI980782A1; IT1299075B1; DE19817168A1; FR2762380A1; FR2762380B1; CZ9701183A3; GB2324366B; JPH10308105A

Abstract

A vehicle headlamp comprises a light source 2, a reflector 1 and a refractor (5, fig. 2). The refractor either has no diffractive elements or very few. The light source is shielded on the underside by an asymmetric shield 3 which serves to allow light to fall onto a region of the reflector to the left -z of the light source. This region is furnished with vertical refractive elements 7, the purpose of which is to enhance reflection of the light towards the kerb

Description

1 Headlamp for Motor Vehicles 2324366 1 Ihis invention relates to a

headIamp for motor vehicles where a system is solved which comprises a complex reflector, a refractor and a light source that forms a cut of f of light and darkness towards which the light flow is concentrated. The reflector is provided with a zone of vertical reflective elements that provide for light concentration in the space of the nearer road kerb. whereby, a sufficient visibility distance, in case a dipped light is used, as well as a good optical guidance of driver during a ride are provided.

The prior art headlamps with a complex reflector are provided with rectangular reflective elements prevailingly of a fixed value of the vertical and horizontal light deviation on the reflective reflector surface. A disadvantage of this solution is that the shape of the rectangularly shaped concentration zone does not cut out optimally the light beam passing through an asymmetric cut-out in the shade of the light source below the horizontal to a reflective surface of the reflector and after a reflection on the reflector above said horizontal to the side of the nearer road kerb - Also, the projection deviation of the elementary light source projections by said reflector are not changed continuously, namely in the vertical direction, what is necessary for forming of an optimal light beam concentration area.

2 The above mentioned drawbacks are substantially removed by a headlamp. according to the present invention which is comprised of a refractor, a light source and a reflector. The refractor can be without any deviation elements or it can be provided only with a littlespreading decorative optics. From the bottom side the light source is shaded by a shade which is provided with an asymmetric cut-out on the side nearer to the road central line which enables light passage from said light source below said headlight horizontal.

On the side nearer to the road central line the reflector is provided with a zone of approximately vertical reflective elements, model,ed on a basic parabolic shape, which is delimited by a central opening in said reflector for mounting said light source, by the reflector edge, and by the upper and the bottom line of said zone. T n vertical section, the -L reflection elements profile is such that on the upper line of said zone of said reflect-ion elements the normal line of the reflective elements is diverted under the normal line of said paraboloid and on the bottom line of said zone the normal line of said reflection elements is lifted above the normal line of said paraboloid. A sufficient side diffusion is provided by the horizontal profile of said reflection elements of the zone. Said profile may be radial, wedge-shaped or a combination of Lhe radial and the wedge-shaped profiles. Thereby, an area of light beam concentration and a part of the cut off Jnterface are formed on the side nearer to the road -kerb An optimal shape of this light-darkness interface is determined also by turning of said light source shade, whereby, in case of the headlight adjacent to the nearer road boundary this turning Is lower than as it is in case of the headlight adjacent to the road central line to prevent dazzling of the on coming driver during a ride into a bend in the direction of the nearer road kerb.

3 The invention is further illustrated with reference to the accompanying drawings, in which Figure 1 shows a front view of a reflector with a zone of vertical reflection elements, Figure 2 shows a vertical section of the headlamp and Figure 3 shows a vertical section of one reflection element and a horizontal section of several reflection elements in the zone of reflection elements of the reflector.

Embodyments of the invention are described below with reference to the accompanying drawings.

Figure 1 shows a front view of a reflector 1 and a light source 2. The light source 2 of a diameter d is shielded 13y a shield 3 from the bottom which is provided with an asymmetric cut-out on the side nearer to the central line whereby said cut-out enables passage of light from said light source 2 under the horizontal z.

in accordance with the vertical section A-A of the headlamp as shown in Figure 2 the reflector 1 is of a paraboloid shape 4...jith a focus F and a focal distance f. Further, the headlamp is also comprised of a refractor 5 which is without any optical deviation elements in this example.

On the side -z, which is nearer to the road central line, the reflector 1 is provided with a zone 6 of approximately vertical reflection elements 7 so that the upper line 8 of said zone 6 is situated above a curve 9 specified by the following formula:

4.Af.sin(p.(1+cos(p).cosV+0.02.f = d.(1+cose).sinyi 2 f R = 1 +cos 0 sin o (1) 4 where R is the polar distance of the curve 9 point, ú/ is the polar angle of the curve 9 point, 2 is the polar position vector of the paraboloidal profile of the reflector 1 and Af is the distance between the face of said light source 2 and said focus F of said basic paraboloid 4. The bottom line 10 is situated under the position vector 11 running from the central point C at the angle of 150 to the horizontal z.

In the vertical section B-B as shown in Figure 3 the profile of the reflective elements 7 is such that at the upper line 8 of said zone 6 the normal line of said reflective elements 7 is inclined below the normal line N8 of said paraboloid by an angle Av8:

1+coso d Af.cosyi - - sinVi 1 + (0.003 -. 0.3) (2) 2 In the horizontal x the normal line deviation Av,, of reflection elements 7 with regard to the paraboloid normal line is:

d AV, (0.003 - 0-3) - - (1+Cos0) (3) 4f At the bottom line 10 the normal elements 7 is lifted above -the normal line N1O of the paraboloid by an angle Av-10:

line of the reflective sin (p AVIO =. (1+COS(P). [ 0. 05. Af - 0. 15. (Af+l) 3 (4) f where 1 is length of the light source 2.

The vertical inclinations shift elementary projection of the light source 2 to the light darkness interface. Thereby, they improve visibility distance as a consequence of an improved luminous efficiency and a higher light concentration in the vicinity of the light darkness interface.

The horizontal profile of said reflective elements 7 in the horizontal section C-C as shown in Figure 3 determines the rate of light side diffusion. This profile is radial 12, wedgeshaped 13 or a combination of the wedge-shaped and the radial profile 14. At least in one place of the horizontal profile the deviation Ah of the normal line of said reflection elements 7 from the paraboloid normal line is as follows:

Af Ah= (0.175. 0.7). -.sin(p. (1+cos(p) (5 f The shade 3 of the lights source 2 is turned into the direction P by an angle v:

y = (0 - 7. 5') (6) Turning of the shade 3 is lower in the headlight adjacent to the road boundary then that in the headlight adjacent to the central line. This turning causes a 150 decrease of the light darkness interface on the side of the nearer road boundary.

Thereby, dazzling of on coming drivers during a ride into curve namely in the direction of the nearer road kerb decreased.

a is In the above specified example the light source 2 shielded bythe shade 3 is integrated into an assembly 15 with a distance light source 16.

Industrial use The headlamp with a complex reflector according to the present invention is determined for use in illuminating systems of motor vehicles operated on surface communications.

6

Claims

Claims

1_ Headlamp for motor vehicles which is comprised of a light source, a reflector, and a refractor, characterised in that said refractor (5) is entirely without any deviation elements or it is provided with little spreading decorative optics, whereby, said light source (2) is shieldedby a shade (3) from the bottom, whereby said shield (3) is provided with an asymmetric cut-out on the side nearer to the road central line, whereby said cut-out enables that light passes from said light source (2) below said headjamID horizontal (z) and said reflector (1) of basic parabolic shape (4) is provided with a zone (6) of approximately vertical reflective elements (7) on side (-z)which is nearer to the road central line so that the upper line (8) of said zone (6) is situated above the curve (9) specified by formula:

4 Af.sin(p. ('L+Cosp) cosyi+0.02.f = d. (1+cos(p) sinqi 2f R = sin (p (1) l+cos(P where (R) is polar distance of the curve (9) point, (V/) is polar angle of the curve (9) point, ((p) is polar position vector of said paraboloidal profile of said reflector (1), (f) J s focus distance of said forming paraboloid (4) (Af) is distance between the face of said light source (2) and said focus (F) of said forming paraboloid (4), (d) is the filament diameter in said light source (2) and the bottom line (10) is under the position vector (11) running from the centre (C) downwards at an angle of 15' with regard to said horizontal (z), whereby in -the vertical section B-B the profile of said reflection elements (7) is such that at the upper line (8) of 1 Ihe zone (6) of said reflective elements (7) the vertical 7 deviation (Av8)of the normal line of said reflective elements (7) and the normal line (N8) of said paraboloid is:

l+cos(P Ave = 2 f d Af-COSY1 - - sinyi 1 + (0.003---0.3) (2) 2 whereby the normal line of reflection elements (7) is inclined under the normal line (N8) of the paraboloid and in horizontal (x) it iS d AV, = (0.003 -. 0.3) - - (1+cosp) 4F at the bottom line (10) it is sin (p AX110 = f (3) (l+cos(P). [ 0. 05. Af -- 0. 15. (Af+l)] where (1) is length of the light source (2), whereby the normal line of said reflective elements (7) is lifted above the normal line (NIO) of the paraboloid and horizontal profile of said reflective elements (7) of the zone (6) in horizontal section C-C is such that at least in one place of said profile the deviation (Ah) of the normal line of said reflection elements (7) of zone (6) and the normal line of the paraboloid is:

Af Ah= (0.175 -- 0.7). -.sin(p. (1+coso) (5 f 2. The headlamp according to claim 1, characterised in that 1 the horizontal profile of said reflective elements (7) of the zone (6) according to section C-C is radial (12), wedge-shaped (13) or a combination (14) of said radial and wedge-shaped profile.

8 3. The headlamp according to claims 1 and 2, characterised in that theshield (3) of said light source (2) is turned in direction ()6) by an angle (I):

7 = (0 -.- 7.5") (6) 4. The headlamp according to claims 1, 2 or 3, characterised in that the turning angle (Z) of the shield 3 of the light source (2) is lower in the headlight adjacent to the nearer road kerb then in case of the headamp nearer to the central line.

5. The headlamp according to claim 1,2, 3 or 4 characterised in that the light source (2)shielded byl'shield (3) is integrated Jnto an assembly (15) with a distance light source (16).

6. A headlamp substantially as described herein with reference to the accompanying drawings.