US 5,510,609 AGranted

Electrically controllable optical filter element

AssigneeOptrel AG

InventorEmil Ackermann

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Abstract

The anti-dazzle assembly comprises an optical filter element whose optical transmission is electrically controllable and an electronic control unit including a light sensitive sensor operatively connected to the optical filter element. The electronic control unit is adapted to vary the optical transmission of the optical filter element in response to the amount of light falling on the light sensitive sensor. This anti-dazzle assembly is controlled such that the intensity of light falling on the exposed surface of the sensor is selectively measured at a plurality of different area portions of this surface. The highest value is selected and used to influence the degree of optical transmission of the filter element. In this way, the anti-dazzle assembly can be controlled much more efficiently insofar as the dangerous high intensity point-shaped light sources are clearly recognized, but strong ambient light does not have a negative influence on the control of the filter element.

Claims9

Dependent claims

A method for controlling an anti-dazzle assembly comprising an optical filter element whose optical transmission is electrically controllable, and an electronic control means including a light sensitive sensor means operatively connected to said optical filter element, said electronic control means being adapted to vary the optical transmission of said filter element in response to the amount of light falling on said light sensitive sensor means, the method comprising the steps of:

projecting the light sources in the area covered by said light sensitive sensor means on the exposed surface of said light sensitive sensor means;
selectively measuring the intensity of said projected light sources and producing output signals indicative of the intensity of said projected light sources by means of a plurality of surface area elements of said exposed surface of said light sensitive sensor means;
selecting the output signal of a surface area element, said selected surface area element producing an output signal indicating that the portion of said projected light sources exposed to said selected surface area element is more intense than the portions of said projected light sources exposed to the other of said plurality of surface area elements;
and
using exclusively said output signal of said selected surface area element for the control of the optical transmission of said optical filter element.

2 more elements

An anti-dazzle assembly comprising:

an optical filter element whose optical transmission is electrically controllable;
an electronic control means including a light sensitive sensor means operatively connected to said optical filter element, said electronic control means being adapted to vary the optical transmission of said optical filter element in response to the amount of light falling on said light sensitive sensor means;
means for projecting on to the exposed surface of said light sensitive sensor means sources of light present in the room area covered by said light sensitive sensor means;
said light sensitive sensor means comprising a plurality of optoelectric transducer elements in a grid or screen like arrangement, each of said plurality of transducer elements being capable of producing an output signal indicative of the measure of the intensity of the projected light sources exposed to each of said plurality of transducer elements, the output signal of each of said optoelectric transducer elements being individually accessible;
and
said electronic control means comprising an electronic circuit means for detecting and selecting an output signal, said selected output signal being produced by said transducer element measuring the highest intensity of the projected light sources exposed to said plurality of transducer elements, said electrical control means using said selected output signal being for controlling said optical transmission of said optical filter element.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/301,357Filed 6 Sep 1994
Priority: DE 43 30 817.113 Sep 1993
Granted: 23 Apr 1996
Term ends: Not estimatedThe source records don’t support an estimate.

Classification10 codes

A42B 3/22
Face protection devices: visors
A61F 9/023
Use of special optical filters, e.g. multiple layers, filters for protection against laser light or light from nuclear explosions, screens with…:…
G02C 7/101
Filters, e.g. for facilitating adaptation of the eyes to the dark; Sunglasses: having an electro-optical light valve
H05B 47/11
In response to determined parameters: by determining the brightness or colour temperature of ambient light