WO1990013451A1

WO1990013451A1 - An anti-dazzlement device with liquid cristals

Info

Publication number: WO1990013451A1
Application number: PCT/IT1990/000047
Authority: WO
Inventors: Sergio Fornara
Original assignee: Sergio Fornara
Priority date: 1989-05-05
Filing date: 1990-05-03
Publication date: 1990-11-15
Also published as: IT8947920A0; IT1231369B

Abstract

The device consists in a screen (1) with liquid cristals or similar of triangular shape, for covering the dazzlement area of the windscreen (P), automatically operated, according to the light intensity of the headlights of the vehicle coming in the opposite sense, by the photocell (2) turned in the driving direction and which, by means of the control circuit (3), it causes the envoy of the current coming from the accumulator battery (B) to the electrodes (4 and 5) of the screen (1).

Description

"AN ANTI-DAZZLEMENT DEVICE WITH LIQUID CRISTALS"

The present invention concerns an anti-dazzlement device consisting of a screen comprising liquid cristals or other similar materials, provided for automatically varying its' own transparency and therefore alternatively make that sur¬ face portion of the windscreen interested, according to the needs, opaque or transparent.

It is the aim of the present invention to eliminate the considerable risk factor for the safety of the driver and of the persons in the vehicle, consisting in the night daz¬ zlement phenomenon that may occur in a sudden and violent manner by the headlights of a vehicle coming in the opposi¬ te sens, or in a continuous manner, when due to intense traffic of vehicles on the opposite lane, especially when the road is wet and even if the vehicles are not driving with main headlights.

From a careful study of the dazzlement phenomenon it has resulted that the dazzlement of the driver comes from a very small part of the visual surface, approximately of triangular elongated shape which, with respect to the dri- ver, starts from about that point put in front of his eyes and extends until the edge of the windscreen, slightly get¬ ting down to the left (to the right in those countries whe¬ re the circulation is on the left).

• • •/ • • _* This triangle corresponds to the possible directions of th headlights of the vehicles coming in opposite direction to the eyes of the driver himself.

For eliminating the dazzlement it will be sufficient to ap propriately screen that area so that the visual part out o said screening and that remains completely free allows the driver to completely see the central part and all of the right part of the lane, and therefore continue driving wit safety, being in the condition of seeing the vehicles in front of him and the edge of the road.

Furthermore, if a screen with an appropriate transparency is used, it will be possible to reckognizing also the vehi cles driving on the opposite lane by means of their head¬ lights, thus allowing a nearly complete view.

The realization of a screened area as described above allows a positive defense against dazzlement also when driving a curve, because when taking a left curve the screen protects from dazzlement and when taking a right curve the light will not hurt the driver.

The solution to the problems above described is obtained b means of the device according to the present invention, consisting of a screen comprising one or more sectors of triangular shape with one or more liquid cristal layers or similar, applied to the windscreen or to any other fix or movable transparent support. The automatic control device consists in photocells for t determination of the insertion and disinsertion and the e ventual adjusting of the transparency of said screen.

In a possible variant the automatic device may be replace by a manual intervention..

The advantages obtained by means of the present invention may be described as follows:

- immediate automatic insertion with following automatic disinsertion, according to the needs of the moment; this possibility of automatic insertion and disinsertion is ab solutely necessary because, when there is no dazzlement, the driver must have the most complete view and in consi¬ deration of the need of overtaking, mainly in the screene area.

- A correct placing of the screen to the driver. The anti dazzlement screen has a limited width - 5 to 10 cm - and according to the height of the driver also the position o said screen is varied: infact, if an average position is chosen at an average height, for small people the screen will be unsufficient in the lower part, while for tall pe pie it will be unsufficient in the upper part, and in the lower part the view will be reduced without unnecessarily - Adaptation of the screen's functioning to the optical sensibility of the driver fay varying the minimum intensity of the dazzling light for which the screen has been insert¬ ed.

- An eventual automatic adjusting of the screening funct¬ ioning (transparency) of the screen according to the in- tensiity of the dazzling light that might replace in an optimal way the automatic insertion and disinsertion con- trol.

The present invention will be described more in detal here- inbelow according to the drawings that show a preferred em¬ bodiment thereof.

Figure 1 shows the windscreen of a vehicle with the ope¬ rating device.

Figure 2 shows a possible electric scheme.

Figure 3 shows a screen provided with bands for the lower adjustment.

Relating to the details of the figures, the device consist in a screen 1 with liquid cristals or similar, of triangu¬ lar shape, for covering the dazzlement area of the wind¬ screen P and automatically operated, according to the in-

• « •/ • _* • tensity of the light of .the headlights of the vehicles com ing from the opposite side, by a photocell 2 turned in the driving direction which, by means of the control circuit 3 causes the envoy of the current coming from the accumulato battery B to the electrodes 4 and 5 of the screen 1.

The eventual adjustment of the minumum intensity of the dazzling light that causes the insertion of the device may be performed manually by the driver according to his own sensibility.

In a preferred variant, the height of the screen 1 is ad¬ justed by manually operating or disactivating the bands 6 into which said screen 1 is devided, by the driver, who will adapt it to his own height.

In a further variant, also for this kind of adjustment an automatic control may be provided.

Furthermore, the liquid cristals or the similar material may be provided photosensible, and therefore directly ad¬ justed by the dazzling light.

In this case a considerable semplification of the realiza- tion of the anti-dazzling screen would be obtained, but probably above mentioned adjustments for sensibility, transparency and position would be more complicated.

• • •/ • • • For what concerns possible realization variants, in corre¬ spondence to the upper part of the windscreen and more in general of the further glass-surfaces of the vehicle, a screen may be provided with a fix or variable width with automatic and/or manual control, for preventing the sun-,o in any case the daylight-dazzlement.

Claims

1. An anti-dazzlement device with liquid cristals characteri zed in a screen (1) with liquid cristals or similar, of triangular shape for coveering the dazzling area of the windscreen (P), automatically operated acccording to the intensity of the light intensity of the headlights of the vehicles coming in the opposite sense, by a photocell (2) turned in driving direction which, by means of the contro circuit (3), causes the envoy of the current coming from the accumulator battery (B) to the electrodes (4 and 5) o the screen (1) .

2. An anti-dazzlement device according to claim 1, characte- rized in that the height of the screen (1) may be adjuste operating or disactivating the parallel bands (6) into which the screen (1) is devided, manually by the driver w will adjust it to his own height.

3. An anti-dazzlement device according to claim 1, characte¬ rized in that the adjusting from the inside of the screen (1) may be automatically performed.

4. An anti-dazzlement device according to claim 1, characte- rized in that the liquid cristals, or similar, are photo- sensible and therefore adjusted by the same dazzling light

5. An anti-dazzlement device according to claim 1, characte¬ rized in a screen (1) with a fix or variable width, with manual and/or automatic control for preventing the sun- or in any case the daylight dazzlement, placed in correspon¬ dence to the upper part of the windscreen and in generale of the other glass surfaces of the vehicle.