RU2197681C2 - Antidazzling light - Google Patents

Abstract

FIELD: automotive industry. SUBSTANCE: proposed light has light source placed in focus of reflector shaped as paraboloid of revolution. Flux of parallel beams coming from reflector is then reflected from stack of planar relatively parallel plates of optically transparent glass with plate thickness and air gaps between them being much greater than wavelengths of visible light; then linearly polarized reflected light flux is used for illuminating roadbed. Reflector is built integral with light source for turning relative to vertical or horizontal axis and is locked in lower beam position when flux of parallel beams is reflected from stack of plates or in upper beam position when flux of parallel beams is passed directly to road. EFFECT: enhanced safety of vehicle in darkness due to reduced dazzling of drivers by oncoming traffic. 3 cl, 3 dwg

Description

 The invention relates to technical means that increase the safety of operation of motor vehicles in the dark, and can find application in the field of automotive, tractor manufacturing, as well as in other areas of technology.

 It is known to use a "dipped beam" headlight used in automotive technology, containing a light source close in size to a spotlight, placed in the focus of a reflector having the shape of a rotation paraboloid, in which the light source power is reduced to reduce glare for oncoming vehicles (compared to a far beam headlamp) light "), and the stream of parallel rays between themselves, reflected from the reflector, is directed to the part of the roadway closest to the car (Volkov AF Dalniy, light, dipped beam // Signal, 10, 11, 12, 1999 and 1, 2 , 2000; GOST 3544-75 SSBT. Headlights of high and low beam of automobiles. Technical conditions).

 This design of the headlight does not ensure the safe operation of cars in the dark. Confirmation of this is a large number of accidents and disasters that occur in the dark as a result of blindness of drivers with headlights of oncoming vehicles and their loss of visibility of the road situation.

 The aim of the invention is to increase the safety of operation of motor vehicles in the dark by reducing glare of oncoming drivers.

 This goal is achieved in the design of the headlamp containing a light source that is close in size to a point light, placed in the casing of a reflector having the shape of a paraboloid of rotation, so that the flow of parallel rays reflected from the reflector before being directed to the object of illumination, undergoes reflection at a Brewster angle from the stack of flat parallel parallel transparent dielectric plates, after which the reflected linearly polarized light stream is used to illuminate the roadway, and the thicknesses The plates and the air gaps between them are much longer than the wavelengths of visible light, while optically transparent glass is used as the dielectric, and the reflector together with the light source can be rotated relative to the vertical (or horizontal) axis with its fixation in two positions - “dipped” or “dipped” light, and in the position of “dipped” light, a stream of parallel rays is reflected from the stack of plates, and in the “dipped” light it is directly directed to the road.

 The invention consists of a point light source 1 shown in FIG. 1, placed at the focus of a reflector 2 having the shape of a rotation paraboloid, and a stack of glass plates 3 placed in a headlight housing 4 provided with a window 5. FIG. 2 shows a diagram of a dual-mode headlight with a swivel a reflector, which when the reflector is in position a) is a source of ordinary ("far") light, and when the reflector is in position c) is a source of linearly polarized ("dipped") light.

 The invention works as follows.

 Light is electromagnetic radiation in a narrow wavelength range, the source of which is excited atoms during the transition of their external electrons to the underlying orbits, which causes electromagnetic oscillations that differ in phase, amplitude and direction of vibration of the vectors of electric and magnetic tension. If among them there is a predominant direction, then such light is linearly polarized (Landsberg G.S. Optics. - M .: Nauka, 1976, 926 p.). When such a linearly polarized light enters a person’s eyes and a polarizing filter (polaroid) is placed on his way to his eyes, then depending on the orientation of this filter, more or less absorption of the stream of linearly polarized light will be observed.

 As a result, by giving automobile headlights the ability to emit polarized light and placing polarizing filters in front of the driver’s eyes, oriented towards its maximum damping, the glare of headlights of oncoming vehicles on the eyes of drivers can be practically eliminated. The light diffused from the roadway is almost completely depolarized (it returns to a chaotically oriented state), therefore, the illumination of the roadway remains practically unchanged, and the visibility of the road situation, which depends on the ratio of road illumination to the intensity of the blinding light beam of oncoming vehicles, increases sharply.

 For the manufacture of polarizing filters used by drivers, a film made, for example, of oriented crystals of hepatatite on a bonding basis, or a specially treated polymer film, can serve. Such films can be used in the vehicle interior in the form of a movable curtain mounted on the windshield, or, more convenient and cheaper, in the form of polarizing glasses for the driver.

где (по фиг.3) n₁ и n₂ - показатели преломления контактируемых диэлектриков,

- нормаль к поверхности раздела двух диэлектриков,

- поток падающего света,

- поток отраженного света, поляризованного перпендикулярно плоскости падения,

- поток преломленного света поляризованного параллельно плоскости падения.To obtain polarized headlights, the use of polarizing filters based on organic films is unsuitable, since the fraction of electromagnetic radiation of light sources that is converted into heat (more than 50%) leads to an increase in the temperature of the films and the loss of their polarizing properties. Therefore, another, simple and reliable constructive version of the polarization of light inside the headlight is proposed. In this case, the phenomenon of light polarization is used when it is reflected from the interface between two dielectrics (Landsberg G.S. Optics. - M.: Nauka, 1976, 926 p .; Krauford F. Volny. Berkeley physics course. T. 3. - M. : Nauka, 527 pp.) At an angle of incidence of unpolarized light flux equal to the Brewster angle

where (in figure 3) n ₁ and n ₂ are the refractive indices of the contacted dielectrics,

- normal to the interface between two dielectrics,

- stream of incident light,

- a stream of reflected light polarized perpendicular to the plane of incidence,

- a stream of refracted light polarized parallel to the plane of incidence.

 In the design of the proposed headlamp, one of the dielectrics is air, and the other is silicate glass. When light passes through a stack of parallel glass plates 3 (see Fig. 1), separated by air gaps (with a plate thickness and air gaps between them much longer than the wavelengths of visible light and with the number of glass plates in a stack of at least seven), a quite acceptable coefficient reflection equal to 45%.

 As a result, the design of the proposed headlights works as follows. Most of the light rays emanating from a point source of light 1 (see Fig. 1), placed in the focus of a reflector 2 having the shape of a paraboloid of revolution, after reflection from its surface, is directed in a parallel stream to a stack of glass plates 3.

The angle of incidence φ ^B is equal to the Brewster angle for a given glass, so that after reflection from foot 3, the light flux is almost completely polarized perpendicular to its plane of incidence. After that, he leaves the headlamp 4 through the window 5 transparent for light rays and is sent to the roadbed. The component of the luminous flux C passing through the stack 3 according to FIG. 3 is absorbed by a blackened surface located on the opposite side of the foot 3. The functions of the “far” and “dipped” (anti-glare) light can be combined in one headlight (Fig. 2), making its reflector rotatable relative to axis 0 with fixing it in two positions a) and c).

 The proposed design of the headlight allows for effective illumination of the roadway to eliminate the blinding effect on oncoming vehicles. At the same time, the need to reduce the speed of transport, the nervous strain of drivers and, most importantly, the number of road accidents associated with material losses and loss of life in a collision of cars, their exit into ditches, collisions with pedestrians, cyclists, vehicles standing on the sidelines, and etc.

Claims (3)

 1. An anti-glare headlight containing a light source close in size to a point light placed in the focus of a reflector having the shape of a paraboloid of rotation, characterized in that the stream of parallel rays reflected from the reflector undergoes reflection before being directed to the object of illumination at a Brewster angle from the foot of flat transparent dielectric plates parallel to each other, after which the reflected linearly polarized stream of light is used to illuminate the roadway, and the thickness of the plates in the air gaps between them are much longer than the wavelengths of visible light.  2. The headlight according to claim 1, characterized in that an optically transparent glass is used as the dielectric.  3. The headlight according to claim 1, characterized in that the reflector together with the light source is rotatable relative to the vertical or horizontal axis with fixing it in two positions - “dipped” or “dipped” light, and in the position of “dipped” light parallel rays are reflected from the foot of the plates, and in the "high beam" is directly sent to the road.

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