Optrel Ag

Oprel Ag

Emil Ackermann

A glare protection device for a welding protective mask includes an active electro-optical protective filter () and an electronic circuit (). An UV-detector (UVD), which serves as an optical sensor, detects the welding light and, via an evaluation circuit (), generates a signal (sin) for controlling of the protective filter (). The signal corresponds to the detected UV intensity. The UV-detector includes a fluorescent layer (F) with an absorption in the UV range and an emission in the long-wave range corresponding to the spectral sensitivity of an assigned Si-photo detector (SD). This results in a simple and safe controlling of the protective filter, which is uninfluenced by the effects of extraneous light.

Antiglare device for welding protective masks

In the invention, an active electrooptical filter cartridge comprises a flat housing (10, 12, 16) forming a closed cavity, which is completely filled with an optical transmissive resin (44, 52, 56, 60, 62) and an active device (14). The active device (14) is completely surrounded and fixed by the resin and comprises as components an LC panel (30, 32) positioned between light-transmissive portions (24, 28) of opposite main walls (10, 16) of the housing, a sensor means (34, 36) for detecting incident light on the filter cartridge, a circuit means (38) for controlling the LC panel (30, 32) in response to an output from the sensor means (34, 36), and a power supply means (40, 42) for operating the active device (14). The filter cartridge can be manufactured with the same dimensions as a passive, darkened filter glass, e.g. for use in welding helmets.

Electrooptical filter cartridge and a method for manufacturing the same

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.

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Wattwil, Switzerland

Emil Ackermann