Abstract: A high resolution radiation sensitive imager includes a radiation sensitive photoconductive target for forming an image in response to incident radiation, a light sensitive cathode arranged in spaced apart relationship with the target, and an addressable light source coupled to the photocathode for causing the photocathode to emit electrons at localized sites for reading an image on the target.

Abstract: A phototimer for x-rays or gamma rays controls the exposure of a radiological imaging device. The phototimer sensor comprises a film of a radiosensitive dielectric material, such as thallium bromide, sandwiched between upper and lower metal layers. This film can be about ten microns thick or less, so as to be thin enough to be radiolucent, but still produce sufficient charge carriers under exposure to x-ray or gamma ray radiation. A phototimer circuit arrangement coupled to the metal layers can be configured as a current amplifier or as a voltage amplifier. A cooling arrangement can be incorporated to maintain the sensor at a low temperature to reduce or eliminate thermally activated dark current. The phototimer can be incorporated into a large area radiological imager.

Abstract: A magnetic pickup for an electronic amplification system of a stringed musical instrument wherein the variable electrical signal produced in response to the string traversing the lines of flux from a permanent magnet is generated by a Hall effect sensor, thereby eliminating the usual inductively coupled coil(s). The invention is disclosed in embodiments employing bar and horseshoe magnets with the sensor positioned on the opposite or on the same side of the magnet as the string. The sensor is an essentially planar device which may be positioned in a plane substantially normal to the lines of flux in contact with or spaced a predetermined distance from the associated magnet or positioned in a plane non-perpendicular to the lines of flux, or adjustably positioned with respect to the direction of flux lines to achieve the desired degree of sensitivity.