CS211149B1 - Headlight for motor vehicles - Google Patents

Description

BACKGROUND OF THE INVENTION The present invention relates to a headlamp, in particular for a motor vehicle, comprising a reflector in the focus of which a horizontal and light source of cylindrical shape, a refractor and an aperture for deflecting a reflector of a non-directional light beam are disposed. this leads to an increase in the photometric distance of visibility and thus to an increase in the safe speed of the motor vehicle when driving in the dark and in sinful weather conditions.

The hitherto known headlamps with a transversely and horizontally arranged light source of cylindrical shape produce a luminous image resulting from the integral representation of this light source with a bow-shaped paraboloid reflector which is laterally extended by vertical strip lenses or refractor prisms. In the vertical section, the light spot is symmetrical about the optical axis of the headlamp, where it also reaches the maximum luminance value. As a result, the luminous intensity decreases from the distance given by the intersection of the axis of the headlamp with the road, as the geometric distance of visibility increases, and the photometric distance of visibility decreases as the luminance contrast decreases.

In the case of external headlamps, the effect of this arrangement has been reduced by designing headlamps with relatively large reflector focal lengths, which on the one hand reduced the angular dimension of the blurring zone and reduced the vertical dimension of the light image, but on the other .

These drawbacks are eliminated in the headlight according to the invention, in which an increase in the light concentration at the upper limit of light and darkness of the light beam and the creation of a light image with asymmetrical luminous intensity in vertical section is solved by comparing the elemental images of the light source with the reflector. optical axis of the headlamp. Comparison of the elementary image to the reference line which is then a new interface between light and darkness, is performed by designing a refractor in its vertical cross-sections in a wedge shape so that in the refractor, wherein the vertical angle is an elementary view _"of the light source reflector to the horizontal greater than that of the angle a. _{In the} reference line, the wedge base is on the road side and in the area of the refractor where the unevenness of the two angles is opposite, the wedge base is on the upper edge of the headlamp. For a replacement cylindrical shape light source of diameter a and length X and for a reflector of focal length omez limited by the apex and edge D diameter, the refractive angle θ in a given cutting profile varies continuously or discreetly over a certain length of the scattering element within the range; which is determined by:

(0.2 * 1.5). (<* _v - » _vo )“ i, - 0 - arcsin Jn.sin J arcsin (n ^- '.sin i,) - © jj (1) where

(i) - the angle of incidence of the beam coming from the focus of the reflector onto the inside surface of the refractor n - the refractive index of the refractor

The angle of the maximum vertical dimension of the elemental representation of the light source by the reflector is determined from:

cos ² (<o / 2)

2f .sin κ

1. - Sin ² ? . sin ² ^ + d.Vcotg ² * + sin ² «j. sin ² ^

2f

L tg (^ / 2) .cosψ (2) where tg v. (1 - cos ¥>) * = are tg ..... 1 + tg ^ cos <p

L - distance of control projection

Ψ - focal guide angle (PP) with optical headlamp 2 ψ - azimuth angle relative to the vertical y of the headlamp at max '

The angle ^"C -vo wherein the horizontal reference line 2 of the headlight is determined in a range up

(3). 0.16 1 _ ₅ “» max ^- - ' ⁽⁰ ' ⁷³ '- + 1.83) + 4.34. 10 <fv max (3)

In the front view of the headlamp (- x), the surfaces of the refractor containing the wedge-shaped profile of the same inclination direction are separated by a maximum of four curves given by:

in cos ² («> / 2):. sin K '2f 2f + -. tgd / 2).

. [1.¼

COS ψ (4)

According to the purpose of the headlamp limiting! the size of the reflector focal length a and the dimensions of the light source can be applied to the wedge-shaped vertical profile of the refractor only inside, or only outside of these dividing curves according to (5), so that the refractor performs only one-way shift This unidirectional shift of the elementary map is also applied when the value of the position angle and _{yQ of the} reference line _approaches its limit values -a 'α' v min 'v max

The attached drawing shows a front view and a vertical sectional view of a headlamp according to the invention, which consists of a reflector 6, a refractor 6, a light source g which is mounted horizontally in the focal point F of the reflector and an aperture.

The light source has the shape of a cylinder of diameter průměru and length £ and the reflector £ of the shape of the rotating paraboloid of focal length £ is limited by the apex _{0 0} and the edge £ diameter. The engagement angle θ is given as the angle of the polar conductor FP with the optical axis j of the headlight. The front view of the headlamp shows curves of the same vertical dimensions of the elementary representations of the light source in relation to the maximum dimension. Harder is indicated by waveform separation curves according to the equation (5), which divide the area of the refractor £ to zone in the same direction of inclination of the wedge shape and show the geometric-refractor £ in which the elementary image of the light source just touches the selected reference line £ y ₀ ·

The dividing curves are determined as a function of the azimuth angle θ relative to the vertical y in polar coordinates, where the polar radius is given in dependence on the guide angle θ - 2f.tg (0/2). It is also here. The profile of the refractor 8 is shown in a general vertical section in which the refractive angle changes continuously or discreetly. In order to improve the sharpness of the light and dark boundary, the refractor 6 is provided with graduated lens scattering lenses such that the ratio h / r determining the amount of lens scattering is designed in direct proportion to the vertical angle of the elemental image. .

Claims (3)

1. A headlamp, in particular for motor vehicles, comprising a reflector, a refractor, a cylindrically shaped light source disposed horizontally and transversely by the center of gravity of a reflector and a screen for shielding a non-reflector beam, characterized by: of diameter (d) and reflector (1) of focal length (f) and output diameter (D), the refractor (2) is shaped so that it has a wedge-shaped profile in vertical sections whose refractive angle (Θ) is given by: (0.2 +1.5). ( _«In - ^and y0) = i - Θ - arcsinjn.sin | arcsinin ^-1 .sin (ij) - © jJ (1) where i | - angle of incidence of the focal beam on the inner surface of the refractor (2) n - refractive index of the refractor (2) and _y - angle of vertical dimension of the elemental representation of the light source (3) by the reflector (1): cos ² (<P / 2) Γ / -5-5 “/ -2-2-2 ~ 1 and - ............... sin κ-. χ. in 1 - sin 0. sin ψ + d. in cotg κ + sin φ. sin ψ + ⁱⁿ 2f LJ 2f + -. tg (0/2) .cosψ L (2) 211149 4 tgv. (1 - cos?) <C = arctg a 1 + tg os cosý L - distance of the control projection <P - angle of the focal parade (FP) of the paraboloid (1) with the optical axis (x) of the headlamp Ψ - the azimuth angle relative to the vertical (y). headlight angle (° _y0) is the angle from the horizontal reference line (z) of the headlamp whose value is in the extended ^"Eži" in minutes ^to "max" ^{klJe d} 2 (-. cos (4f ^v <pmax 2f - · tg 1 L (φ max "In min" 2 ' 2 φ max , D 2.arctg (- '4f ) and (3). 0.16 "in max" 77 · · and whose base is on the side of the road. ¹ > 5 (0.73 · - + 1.83) + 4.34.10 ⁵ .fd (4) «- = C“ ₀ ^{on the side} ® of the upper edge of the headlamp and for e _y Vo na Headlamp according to claim 1, characterized in that the refractor (2) has a wedge-shaped profile in vertical sections only on a surface inside or on a surface outside the dividing curves given by: cos (Φ / 2) Γ / o 2 ~ / 2 2 2 ~ 1 ° ^{vo =} ....... * 2 ' ^{sin K} ' L ¹ '' ¹ ”3in ⁺ O.Vcotg x + sin P.sin vj + 2f +. tg (0/2). cos Ψ L (5) Third headlamp according to claim 1 or 2, characterized TLM that the ratio (h / r) of the width (H) and the radius (R) of band lenses, refractor (2) is directly úmšrný ratio (a _y / a _{y max} ^ instantaneous (and _y ) and the maximum (? _{y fflax} ) angle of the vertical dimension of the elemental representation of the light source (3) by the reflector (1).