Abstract: A display device is formed by a matrix of surface-stabilized bi-stable ferroelectric liquid crystal elements each being separately settable by a matrix driver. To provide brightness control or color in the display, all the elements of the matrix are set in accordance with a portion of a signal for display and the amount of light passing through the matrix for that setting is controlled in accordance with the binary significance of the respective portion of the signal. This control is produced by varying one of the activation duration or intensity of a light source, such as sets of fluorescent tubes in accordance with the binary significance of the brightness information in the input signal. Half of the frame time (T) is used for the numerous setting operations on the matrix of elements and half is used for the backlighting operations of the various settings.

Abstract: A computerized tomographic apparatus is described in which a wide fan of radiation scans a patient by rotating therearound, the fan being substantially flat and being maintained in alignment with a selected cross-sectional slice of a patient's body. Radiation emergent from the body along many substantially linear paths across the slice is detected by a detector means including a vacuum tube device containing a photo-cathode and, spaced therefrom, semiconductive means. Electrons emitted from the photo-cathode in response to light incident thereon (the light emanating from X-ray sensitive scintillating material) are accelerated towards the semiconductive means and impact thereon causing the generation of electrical signals indicative of the amount of X-radiation falling on the scintillating material.