Abstract: A liquid crystal shutter construction (18), suitable for a glass shield and a welding glass filter, which shutter construction is able to switch between a high light absorbing dark state and a low light absorbing transparent state, and vice versa, comprising low twisted nematic type liquid crystal cells with a twisting angle between 0.degree. and just below 90.degree., and an electronic circuit output generating a variable cell driving voltage higher than about twice the threshold voltage for at least one of the liquid crystal cells and with a polarity switching frequency of less than 1 Hertz.

Abstract: Mounting of a solid state imaging sensor in a film scanner support body with an axis of the sensor in precision alignment with a scan axis of the scanner. The sensor is precision mounted on a support frame forming part of a sensor package with the sensor axis aligned with a line of sensor leads extending from the sensor support frame. The sensor package is then mounted on a scanner support body with the sensor leads abuting an insulator material reference datum surface that holds the sensor axis in precision alignment relative to a film scan axis.

Abstract: A liquid crystal welding glass structure whose density increases when welding is commenced includes two liquid crystal cells which are mounted between polarization filters which have an extinguishing effect on one another. When mounting the filters, the filters are turned so that their respective angular dependencies on the optical density counteract one another. With the intention of improving this compensating effect, the brushing/rubbing of the mutually opposing limiting walls which determine the direction of the molecules is limited to at least one of the component cells whose relative angular displacement differs from 90.degree. and is smaller than or coincident with 85.degree.. The angle is preferably between 20.degree. and 85.degree..

Abstract: Film handling apparatus for a multipass scanner and printer system has film receiving chambers at opposite ends of the apparatus above the film track to receive and temporarily store the coiled film between forward and reverse film transport phases. Film diversion spring fingers are provided at least at the film entry end of the film track between the track and bottom opening to the chamber to allow insertion of the film in one direction and diversion of the film into the chamber when the film transport direction is reversed.