Abstract: A cathode ray tube comprises an envelope, an electron beam source positioned at one end of the envelope, a target positioned at another end of the envelope, a mesh electrode positioned opposite to the target, and an electrostatic lens means positioned between the electron beam source and the mesh electrode. The lens means has a high-tension electrode and a low-tension electrode positioned along the electron beam path to focus the electron beam. The low-tension electrode is divided into four arrow or zig-zag patterns to deflect the electron beam. The length l between the electron beam source and the mesh electrode and the length x of the high-tension electrode are selected to optimize the magnification, aberration and landing error of the electrostatic lens means.

Abstract: Control circuit for use with an image pickup tube permits highlights of an image to be scanned appropriately by a scanning electron beam by increasing the beam current fed to the cathode of the image pickup tube and prevents unwanted oscillations typically found when such beam currents are increased. The control circuit first determines whether the output from the image pickup tube exceeds a predetermined level and produces a control signal to be added to the normal beam current and also uses this control signal to control a vertical deflection circuit to shift the scanning electron beam upwardly toward a region on the photoelectric transducer of the image pickup tube that has already been scanned, thereby providing negative feedback and preventing unacceptable oscillations in the output signal.

Abstract: An image pick-up tube is disclosed which includes an envelope, an electron beam source positioned at one end of the envelope, a target positioned at another end of the envelope opposite to the electron beam source and at least one electrostatic lens positioned between the electron beam source and the target. The lens includes a first electrode and a second electrode respectively deposited on the inner surface of the envelope and a lead electrode connected to the second electrode is deposited on the inner surface of the envelope across the first electrode but isolated therefrom.

Abstract: A cathode ray tube comprises an envelope, an electron gun having a beam limiting aperture, a first electrode, a second electrode, a third electrode and a mesh electrode, the first, second and third electrodes constituting electrostatic lens system to focus the electron beam, the second electrode being a deflection electrode of arrow or zig-zag patterns to deflect the electron beam, wherein if distance between the beam limiting aperture and the mesh electrode is l, length of the second electrode is made (1/3 l-1/10 l) and (1/3 l+1/10 l), and distance between the beam limiting aperture and the center of the second electrode is made (1/2 l-1/3 l) to (1/2 l).

Abstract: A cathode ray tube comprises an envelope, an electron beam source positioned at one end of the envelope, a target positioned at another end of the envelope, and an electrostatic lens means positioned between the electron beam source and the target. The lens means has a first cylindrical electrode and a second cylindrical electrode positioned along the electron beam path to focus the electron beam. The second cylindrical electrode is divided into four patterned electrodes, and each of the deflection electrodes has a lead which is formed across the first cylindrical electrode but is isolated therefrom. The portion of the leads is positioned to cause a predeflection to the electron beam.