Apparatus for electrostatically transferring images formed by photoelectrophoresis. The color balance of the images which are made up of electrically photosensitive particles on a transparent conductive substrate are modified during electrostatic transfer by exposure to electromagnetic radiation to which at least a portion of the particles are sensitive.

The invention provides a method and apparatus for correcting shading distortion in a source of scanned video signal. A multiple location store is provided for storing a signal indicative of the shading correction required at each of a number of selected, spaced apart points in the scannable region of the source and signal interpolation means is provided for interpolating between the stores values of correction in both line and frame scan directions for other points in the region. The invention a...

An image gate is used for selectively directing the optical image from an X-ray image intensifier tube to cameras located on the sides of and in line with the optical image path. The image gate has semitransparent mirrors which park substantially upright in juxtaposition to the optical path. Either mirror may be shifted to a diagonal position in the beam path so as to transmit an image in one direction and reflect an image in another. A quick acting damping mechanism shifts each mirror on a comb...

Real time raster scanning of a field is provided by rotating an N-sided prismatic mirror about its axis of symmetry. N may be any integer equal to or greater than two. Mirror faces on the prism are aligned with respect to the axis of rotation such that each face deviates the look angle of a detector by an amount equal to one resolution element (for contiguous scan lines). Rotation about the axis of symmetry produces a scan pattern similar to that of a TV system. The scan pattern is reconstructed...

The invention relates to image analysis systems which provide for the computation of primary and secondary parameters of detected features in a field of view, typically relating to their geometrical or densitometric properties. The primary parameters relating to each feature are accurately associated therewith by means of a coincidence circuit which generates an anticoincidence pulse immediately following the completion of scanning of each detected feature in the field of view. A first computer ...

The invention provides a method of analyzing the features in a field of view in which information arising from features which are truncated by one or more edges of the field of view, is inhibited. Methods and apparatus for performing a chord size distribution on scanned video signal are described together with methods and apparatus for correcting associated parameter information derived from scanned video signal. Two types of solution are envisaged. According to one solution, all information sig...

An image converter comprising, between two transparent electrodes connected to a d.c. supply source, a layer of nematic liquid crystal and a layer of photoconductive material located against each other. An image to be converted is projected onto the photoconductive layer and the liquid crystal layer is illuminated by an auxiliary light source.

In the improved image orthicon the source of electrons required for the electron beam is obtained from a metal-oxide composite material, eliminating the thermal emitter and associated sources of heat and noise. The same metal-oxide composite material is used as the thin film target on which the image is formed, stored, and read. Image retention from preceeding frames is reduced to essentially zero and the orthicon structure is improved by elimination of the fragile thin glass targets in present ...

An image magnifier and intensifier has a vacuum flask upon one end of which lies a photo-cathode. The image-producing ray bundle releases at its surface electrons depending upon the intensity distribution in its cross-section. They are represented electronically-optically at high acceleration voltage upon a screen located upon the other end of the flask. The photo-cathode represents a calotte having a curvature which differs from the middle to the edge and an opening directed toward the screen. ...

The invention concerns image analysis systems employing a source of scanned video signal and threshold detector means for generating a binary signal whose value depends on the fulfilment or otherwise of the detection criterion. Means are provided for accumulating at least the low frequency content of the video signal and deriving therefrom a correcting voltage for application to the detector means to reduce variations between the peak value of the video signal corresponding to the background of ...