1
John D Fergason, Jeffrey K Fergason, Arthur L Berman, James L Fergason: Eye protection device for welding helmets. OSD Envizion Company, Renner Otto Boisselle & Sklar, May 4, 1993: US05208688 (132 worldwide citation)

Light transmission control device includes band pass filter for transmitting light of a wavelength or group of wavelengths and partially blocking transmission of light of a different wavelength or group of wavelengths, and variable optical filter for controllably transmitting light of a wavelength o ...


2
Jeffrey K Fergason, John D Fergason: Liquid crystal lens driver electronics for eye protection, high speed shuttering with consistent performance. OSD Envizion, Howell & Haferkamp LC, May 12, 1998: US05751258 (77 worldwide citation)

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 ...


3
Jeffrey K Fergason, John D Fergason: Liquid crystal lens assembly for eye protection. Optical Shields, Renner Otto Boisselle & Sklar, December 24, 1991: US05074647 (77 worldwide citation)

A light control device includes a light shutter having a pair of polarizers and a liquid crystal device operative in response to a prescribed input to control transmission of light therethrough, and a variable polarizer optically aligned with respect to said light shutter and operative to control li ...


4
Jeffrey K Fergason, Arthur L Berman, James L Fergason, John D Fergason: Eye protection device for welding helmets which reduces obliquely incident light. OSD Envizion Company, Renner Otto Boisselle & Sklar, May 7, 1996: US05515186 (52 worldwide citation)

A welding helmet and lens therefor includes a shield and a lens including a two identical optical components, each including a polarizer, a further polarizer (analyzer) optically between said optical components and effectively shared as an output device from one optical component and an input device ...


5
Jeffrey K Fergason, John D Fergason: Electro-optic light shutter and frame assembly with integrated switching mechanism. OSD Envizion Company, Renner Otto Boisselle & Sklar, December 27, 1994: US05377032 (49 worldwide citation)

A frame assembly for a light shutter including a frame structure for enclosing an electro-optic shutter assembly, the frame structure having a front surface which can be positioned opposite a cover lens, and a switch for controlling an operation mode of the electro-optic shutter assembly, the switch ...


6
John D Fergason: Remote control for auto-darkening lens systems and method. LightSwitch Safety Systems, Renner Otto Boisselle & Sklar, March 11, 2008: US07342210 (43 worldwide citation)

A wireless remote control is provided for an auto-darkening lens (ADL) system used in a welding helmet, respirator system or other device to control or to adjust settings of an ADL of a controllable light shutter. A display system facilitates providing information indicating the operative settings a ...


7
John D Fergason: Detector system for detecting the occurrence of welding. OSD Envizion Company, Renner Otto Boisselle & Sklar, September 28, 1993: US05248880 (39 worldwide citation)

A sensor circuit for detecting light hazards or bright light sources that will cause discomfort. The sensor and sensor electronics which provide a wide sensitivity range which is fully automatically adjustable, and which has the ability to detect point sources of light. The sensor further has the ab ...


8
John D Fergason, Jeffrey K Fergason: Detector system for detecting the occurrence of welding using detector feedback. OSD Envizion Company, Renner Otto Boisselle & Sklar, October 12, 1993: US05252817 (34 worldwide citation)

A power supply circuit for a liquid crystal welding lens or shutter develops a relatively low voltage AC signal for driving or powering the liquid crystal shutter to the clear state and two relatively higher or larger magnitude AC electrical signals for initially driving the shutter to the dark stat ...


9
Jeffrey K Fergason, John D Fergason: Helmet with high performance head and face protection utilizing molded composite materials and method. ILIXCO, Renner Otto Boisselle & Sklar, January 12, 1999: US05857215 (32 worldwide citation)

A welding helmet having high structual integrity is formed of a single sheet of composite material, such as Kevlar fabric impregnated with a phenolic thermoset resin; a viewing port in the front of the helmet includes a welding lens is either of fixed or automatically darkening type; and curves, ben ...


10
John D Fergason: Welding lens with integrated display and method. OSD Envizion, Howell & Haferkamp L C, May 23, 2000: US06067129 (31 worldwide citation)

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 wi ...