Abstract: A display system 10 including liquid crystal eyewear 22 for producing a three dimensional (3-D) or stereoscopic image (i.e., an image having depth) is provided by liquid crystal shutters (41L, 41R) in the liquid crystal eyewear which are used to view two dimensional images. The shutter alternates between transmissive and non-transmissive states in order to present different images to the right and left eyes thereby presenting the viewer with a three dimensional image. The synchronization and coordination of the shutters includes a delay (65, ts) to accommodate the switching time and latency of the liquid crystal eyewear and signal transmission. The liquid crystal eyewear may be connected into the display system in a wired (12a) or wireless (12b) manner. Wireless connection can be made with infrared light emitting diodes (21b, 21c, 71) transmitting infrared light to the eyewear.

Abstract: Stereoscopic eyewear (10) enables a viewer to see a three dimensional image from a two dimensional image which is projected or displayed on a screen. The eyewear may be coordinated with the two dimensional image either with a signal transmitted through a cable (40) or with an infrared (IR) transmitter (200, 201) and receiver. The IR transmitter may include two sources of IR light to increase the likelihood of reception by the transmitter. The IR transmitter may have a curved bottom (202) covered with Velcro™ material (203) for attachment to another piece of Velcro™. The curved bottom in combination with the Velcro™ enables control of the orientation of the IR transmitter. When the eyewear is connected via a cable, guide bars (61, 62) or a cable loop (42, 43, 44) can be included to provide strain relieve. The shutter or lens of the eyewear may be made from a liquid crystal cell (11L, 11R).

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 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: 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, bends, folds and steps in the composite material and trim pieces in the viewing port area and about the peripheral rim of the helmet shell provide additional stiffening for the helmet. A method of making a welding helmet of a single sheet of composite material includes pre-forming the composite material to a shape similar to that of the finished molding helmet shape, and placing the pre-shaped composite material in a compression mold and closing the mold to mold the composite material to shape while curing the composite material by applying heat other otherwise assisting in the curing of the composite material; and mounting a welding lens in a viewing port of the welding helmet.

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.

Abstract: 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 for the other optical component, the transmissive axes of respective polarizers of said optical components being operatively oriented relative to one another to improve extinction of light incident on said lens at prescribed angles. The lens may be used in other optical systems.

Abstract: 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 being mounted on the front surface whereby pressure applied to the cover lens activates the switch. The frame assembly can be inserted and used in a welding helmet or other protective eyewear having a standard sized lens aperture.

Abstract: A driving circuit for a liquid crystal shutter or for other devices that reduces the power drain on the portable power supply and has the characteristic of fast response time. Accurate voltage regulation also is provided by referencing an accurate reference voltage supplied by a diode.

Abstract: 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 state and then for maintaining the shutter in the dark state; a variable frequency circuit for varying the frequency of the driving signal to the shutter to minimize power usage in the dark state and to avoid flicker in the clear state; and power saving and battery level indicator features are included.

Abstract: 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 ability to distinguish low power stable light generated from a small welding arc from bright ambient light or even direct sunlight.

Abstract: 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 or group of wavelengths, the band pass filter and variable optical filter being cooperative to provide at least three light transmitting modes, including maximum transmission, minimum transmission, and a third mode less transmissive than the maximum, the device being operative to minimum transmissive mode upon being driven by a maximum energy input, the device also being operative to maximum transmissive mode upon being driven by a lesser energy input, and such third transmission mode occurring in response to no power or a failure of power or adequate power for energizing the device to the maximum or minimum transmissive mode.

Abstract: 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 light transmitted therethrough in response to a prescribed input; the light shutter is operative relatively fast in response to application of electric field to reduce light transmission and the variable polarizer is operative in the event of a power loss, which would cause the light shutter to stop light blocking, to provide a safety light blocking function. The light control device may be employed in a welding helmet or other device intended to provide protection to the eyes of an individual or other animate or inanimate object from selected electromagnetic energy, such as that produced by welding or other source.