A cathode ray tube is provided with an electron gun having an electron lens including a large-diameter cylinder electrode and a small-diameter cylinder electrode composed of a large-diameter cylinder portion and a small-diameter cylinder portion, and at least the large-diameter cylinder portion of the small-diameter cylinder electrode is inserted in the large-diameter cylinder electrode thereby forming the electron lens. The small-diameter cylinder portion extending in the tube axis direction of the large-diameter cylinder electrode and connected to the large-diameter cylinder electrode is expanded or bulged, or the bottom portion of the large-diameter cylinder electrode is removed while only the electrode support portion connected to the large-diameter cylinder electrode is left, so that the electrode support fixed to the outer surface of the small-diameter cylinder portion of the small-diameter cylinder electrode can pass therethrough.

An electron gun for a cathode ray tube includes a cathode assembly, a control electrode, and a screen electrode adjacent to the cathode assembly, combined, and spaced apart from each other by a gap maintainer, focusing electrodes sequentially arranged adjacent to the screen electrode, forming an auxiliary lens and a main lens, and bead glass in which portions of the cathode assembly and respective electrodes are embedded and supported.

An electron gun includes a cathode (K), a control electrode (1), an accelerating electrode (2), a first anode (3), a focus electrode (4), and a second anode (5), which electrodes are arranged in a tube axial direction at predetermined intervals; and electrode supports (11, 21, 31, 41, 51) provided to a side wall of each electrode and embedded in and secured to insulating supports (6); wherein the focus electrode (4) is cylindrical an has three different diameters respectively provided at a cathode side portion, an intermediate portion and a panel side portion, the panel side portion of the focus electrode (4) is inserted into the second anode (5) to constitute a main lens section, the inner diameter of the intermediate portion of the focus electrode (4) is smaller than the inner diameter of the panel side portion and larger than the inner diameter of the cathode side portion and the electrode support (41) is provided at the intermediate portion of the focus electrode (4). The electron gun including an electrode support (41) provided at the intermediate portion of the focus electrode (4) reduces deformation of the focus electrode (4).

A cathode ray tube includes a panel having a fluorescent screen formed on an inner surface thereof, a stem, and a neck between the panel and the stem. An electron gun is supported by a supporting structure in coaxial alignment with the neck. The electron gun has a focusing electrode which includes a first cylinder and a second cylinder having a larger diameter than the first diameter. The first cylinder has a first opening which opens toward the stem and the second cylinder has a second opening which opens toward the panel. A conductive layer is deposited on the inner surface of the cathode ray tube and receives a high voltage. An annular holder is mounted to the supporting structure so that the annular holder surrounds the first cylinder in coaxial alignment with the focusing electrode. The annular holder is a first predetermined radial distance away from the first cylinder and a second predetermined axial distance from second cylinders. A plurality of springs are mounted on the outer circumferential surface of the annular holder. The springs extend to electrically contact the conductive layer and hold the annular holder so that the annular holder is in coaxial alignment with the longitudinal axis of the cathode ray tube.

A projection type cathode ray tube has a panel and an electron gun. The electron gun has a plurality of electrodes including a cathode, a control electrode, an accelerating electrode, a first anode, a focus electrode and a second anode, which electrodes are arranged in a tube axial direction at predetermined intervals. The second anode has a first cylindrical portion at the panel side and a second cylindrical portion at the cathode side, the first cylindrical portion having a larger inner dinner diameter than the inner diameter of the second cylindrical portion. The focus electrode has a panel side cylindrical portion with an inner diameter D1 and a length L1, an intermediate cylindrical portion with an inner diameter D3 and a length L3, and a cathode side cylindrical portion with an inner diameter D2 and a length L2. The inner diameters D1, D2, and D3 are different from each other. The focus electrode also has a first funnel like connecting portion between the panel side cylindrical portion and the intermediate cylindrical portion.