Abstract: An x-ray detector element suitable for use in computer tomography has a semi-insulating semiconductor body composed of a compound semiconductor, and is operated with a constant voltage source so that it functions as an x-ray-sensitive photoconductor. A measurement instrument is connected across the voltage source for detecting the photocurrent, which is indicative of the x-rays incident on the semiconductor body.

Abstract: An x-ray electro-photographic recording material is formed of a photo-conductive layer (1) comprised of a selenium-arsenic alloy and positioned on a transparent electrode layer (4), which is positioned on a further layer (3) comprised of an x-ray luminophore and positioned on a reflective surface (2a) of a film carrier layer (2). In usage, with a positive corona charge on the free photo-conductive layer surface (1a) before x-ray exposure, the luminophore-containing layer (3), during x-ray exposure, converts a component (5) of the x-ray radiation (.gamma.) not absorbed by the photo-conductive layer (1) into visible luminescent light (6) which effects an increase of sensitivity in the photo-conductive layer (1). This recording material can be used in x-ray photograph devices.

Abstract: A device for electrophotographically copying wherein for writing a charge pattern into a suitable photo-conductive layer with differing electron mobility and hole mobility a relatively long wave length of light is used which has a penetration depth comparable with the thickness of the layer and which has a quantum energy which corresponds to the energy of deep traps for the less mobile kind of charge carriers. Due to the long life of the charge carriers in the deep traps, the newly applied charges of opposite polarity remain on the exposed locations for a relatively long time since the charge has been caught in the traps whereas the unexposed locations are repeatedly charged again to maintain an undisturbed potential such that the charge pattern is retained for a longer time even with continued exterior charging.

Abstract: A device is disclosed which is useful in an electrophotographic copier for stabilizing and increasing contrast potential. The device is employed for extinguishing a recorded, electrostatic charge image. The device has one or more light sources which provide a spectral distribution comprising a first spectral range of maximum photoconductivity production and a radiation energy which is three to ten times a radiation energy present in a second spectral range. The second spectral range is located at a wavelength determined by a maximum of a product of photoconductivity production and penetration depth. An additional radiation energy distribution in remaining portions of the spectral distribution has a radiation energy not exceeding five to ten percent of the radiation energy of the first range.