Abstract: A pick-up tube includes a generally cylindrical envelope having a faceplate at one end thereof and a cathode in the other end. A photoconductive target electrode is adjacent to the faceplate and a mesh assembly is disposed in spaced relation adjacent to the target electrode, between the target electrode and the cathode. The mesh assembly comprises a mesh electrode disposed between a frustro-conically shaped mesh support ring and a dished, spring-like mesh damping ring. The mesh damping ring is fixedly attached at a plurality of points around its periphery to the mesh electrode and the mesh support ring. The mesh damping ring is compressed into a reversal of its dished shape and assumes an undulatory configuration contacting the mesh electrode periodically around the inner periphery of the damping ring thereby retaining the mesh electrode with reduced microphonics.

Abstract: A light conductor is utilized in a vidicon type pick-up tube to transmit light from a light source to the tube target for biasing the dark current of the target. The light conductor is preferably a bifurcated glass rod having a stem and two branches defining a crotch region. The light that is transmitted through the stem into the branches is selectively attenuated by filling in the crotch region with either glass redistributed from portions of the stem and branches or with additional glass. By controlling the light transmission with predetermined amounts of glass, the illumination and, hence, the dark current of the target can also be controlled.

Abstract: An electron tube, preferably a camera tube, has an improved structure for supporting and centering a cylindrical electrode within a tubular envelope having a precisely formed inner surface. The support structure comprises a centering ring that has a plurality of radial sectors formed to a ring circumference and a plurality of resilient radial finger-like members formed intermittent the radial sectors. The ring circumference is formed within a close spacing of the inner surface of the envelope and is attached to the electrode so that the ring circumference is substantially concentric with the outer surface of the electrode. The finger-like members of the ring are formed to define an outer diameter that is greater than the inner diameter of the envelope, so that when the electrode with the attached ring is inserted into the envelope, the members flexibly bear against the inner envelope surface and guide the ring into position without deforming the radial sectors.

Abstract: A vacuum envelope contains a photoconductive target at one end and a tubular anode electrode having light scattering properties. Light is uniformly reflected onto the target by the anode electrode from a light source mounted on the other end of the tube, outside the evacuated envelope. This uniform illumination tends to reduce build-up and decay lags at low level operating conditions. The light source is removably secured to the tube on a ceramic board incorporating an electric circuit connected to the light source for adjusting and controlling the bias light intensity.