Abstract: A welding helmet includes a shutter assembly with an electronically controlled liquid crystal shutter in a compact housing for physical mounting near the face area of a protective shell. The electronic controls provide for the customary auto-darkening function as well as two user selectable fixed shade settings which permit the user to fix the shutter shade in one of a plurality of preselected and factory set shade settings. When fixed at a shade setting, the user is given a visual indication that the helmet is not in an auto-darkening mode. The housing allows for two PC boards to be mounted above and below the optical shutter, with a flexible cable interconnecting the two PC boards so as to not interfere with or obscure the user's vision. The controls are all single function, readily accessible and continuous so that multiple operation of any one control does not switch the associated function off, allowing a user to continuously operate any control repeatedly to ensure its selection.

Abstract: An integral indicator or display for a welding lens, which has a twisted nematic liquid crystal cell light shutter, includes plural independently operable twisted nematic liquid crystal cell indicator portions integral with the light shutter twisted nematic liquid crystal cell, indicia associated with respective indicator portions to indicate an operating characteristic of the welding lens, circuitry for operating the lens and the indicator portions, and one or more switches for stepping the circuit through respective settings of operating characteristics, such as shade darkness, sensitivity and delay time. The indicator is dark when the light shutter is dark, and the light shutter may include in optical series with the twisted nematic liquid crystal cell, a birefringent liquid crystal cell light shutter which is faster acting than the twisted nematic liquid crystal cell and can be driven to various shades at respective speeds depending on applied electric field.

Abstract: A welder's eyeshield includes a helmet having a face portion with a lens window provided thereon, a liquid crystal assembly mounted on the lens window, an optical filter juxtaposed with the liquid crystal assembly on the lens window, the optical filter being made of a plastic material compounded with a dye material for attenuating infrared and ultraviolet light, and a control circuit electrically connected to the liquid crystal assembly for controlling light transmissivity of the liquid crystal assembly.

Abstract: A switch activating system for an automatically darkening lens system and an automatically darkening lens system including such a switch activating system, includes a cover plate through at least part of which a scene may be viewed, a support, a pair of switch electrodes, one switch electrode positioned in relatively fixed relation with said support, the other switch electrode being positioned for movement with respect to said one switch electrode selectively to make electrical connection therewith in response to deflecting of said cover plate. The automatically darkening lens assembly also includes a controllable light shutter for controlling transmission of light for viewing therethrough, and a circuit for operating said light shutter and affecting operating characteristics thereof.

Abstract: Electro-optical glazing structures having total-reflection and semi-transparent and totally-transparent modes of operation which are electrically-switchable for use in dynamically controlling electromagnetic radiation flow in diverse applications.

Abstract: Electro-optical glare protection device is disclosed for use with protective glasses, protective helmets or protective masks with at least one optical detector, especially a photodiode, with an electro-optical glare protection plate incorporating at least one liquid crystal cell, and with an electronic circuit for the adjustment and setting of the optical transmission of this glare protection plate. The protective device comprises a non-optical detector and a switch connected to the electronic circuit for adjusting the optical transmission of the glare protection plate. The switch links the signals produced by these detectors with each other as an and/or circuit. The electronic circuit generates corresponding switch signals.

Abstract: A method and a safety device for the protection of a user's eye, or other radiation sensitive system, from a pulsed radiation emitted by a radiation source by means of an electro-optical shutter used in conjunction with the radiation source. The electro-optical sutter defines the field of view of the user or of the system and is capable of being switched by an electrical voltage signal from a transparent state to an opaque state within a response time .DELTA.t.sub.r. The method comprises applying to the electro-optical shutter the electrical voltage signal at an operational time interval .DELTA.t.sub.o, prior to the emission of each radiation pulse and keeping the electro-optical shutter in its opaque state until the radiation pulse is emitted. The operational time interval .DELTA.t.sub.o is at least slightly longer than the response time .DELTA.t.sub.r so that, by the time of emission of each radiation pulse, the electro-optical shutter is in its opaque state.

Abstract: The invention relates to a protective device of the type having a body (1) and a filtering unit (10) supported by said body and acting as a visor, said filtering unit being electrically shiftable between at least two light transmitting conditions and comprising, for this purpose, one or more LC cells. The filtering unit (10) is made wholly or at least to a major extent of polymer material and is designed as a panoramic visor which is darkenable over its entire area. Said one or more LC cells are in the form of a foil and extend over the entire area of the panoramic visor. The invention is of special interest for welding helmets with automatically controlled darkening.

Abstract: An imaging system that can tolerate high intensity optical beams without a reduction in the system's field-of-view, comprises an imager, a fiber array positioned at the image plane of the imager, a sensor array positioned at the output end of the fiber array, a panel display positioned in proximity of the fiber array and an image processor for electronically processing the information from the sensor array.

Abstract: A power supply circuit for a liquid crystal welding lens or shutter provides a consistent and stable regulated power signal for driving or powering the liquid crystal shutter for maintaining stable performance over the life of the power supply and a battery level indicator feature to provide advance warning of degraded device performance.