A mixed-field type of vidicon

A new type of vidicon has been developed. It uses magnetic focus and electrostatic deflection. Since both fields are superimposed in the same space, Focus Projection and Scanning (FPS) is accomplished simultaneously. In this way, vidicon tubes af very compact size can be realized (typically a format). The electron optics of this FPS System will be outlined. At unity magnification, excellent landing and edge-focus conditions are achieved. Signal output is high (0.5µA) and resolution up to 800 TV lines has been realized with 350 volts as the highest voltage. For a tube of given size, various performance factors such as resolution, shading and deflection sensitivity can be balanced by design such as to enhance some factors at the expense of others. This mutual interdependence will be briefly discussed. It will also be shown that the ceiling of performance for this combination of crossed-fields is higher than for-similar devices using sequential, rather than simultaneous focusing and deflection.