Abstract: A color cathode ray tube apparatus of this invention includes an electron gun. In the electron gun, an intermediate electrode is arranged at the mechanical center between a focus electrode and anode electrode that form a rotationally symmetric bi-potential lens. A disk-like intermediate electrode is arranged at the mechanical center between the focus electrode and intermediate electrode. The disk-like intermediate electrode has an electron beam hole with a diameter larger in the vertical direction than in the horizontal direction. The intermediate electrode has a circular electron beam hole. Voltages are applied to the disk-like intermediate electrode and intermediate electrode such that they form an electron lens similar to that formed when the disk-like intermediate electrode does not exist. Therefore, an electron beam spot is focused in an optimal manner on the entire surface of a phosphor screen, and elliptic distortion is decreased. A good image is displayed on the entire surface of the phosphor screen.

Abstract: A method of storing data in a non-volatile memory medium which permits data writing in a memory area after old data thereof is erased is presented. The method includes the steps of providing a data-storage area in each of a plurality of non-volatile memories with respect to each of different data types, and writing incoming data of a given data type in a corresponding data-storage area in a first one of the non-volatile memories while a second one of the non-volatile memories is being subjected to data erasure of the given data type after a corresponding data-storage area in the second one of the non-volatile memories is filled with the incoming data of the given data type.

Abstract: A hydrogenated or fluorinated carbon protective film is formed on a disk through a plasma CVD method by use of a hydrocarbon-containing reaction gas as a raw material, where the disk comprises a non-magnetic substrate on which a non-magnetic undercoat film and a magnetic film are successively formed, wherein the protective film has a thickness of 2.2 g/cm3 or more.

Abstract: In an electron gun for a color cathode ray tube apparatus of this invention, one intermediate electrode is arranged between a final acceleration electrode and a focus electrode that make up a main lens, and a voltage divided by a voltage dividing resistor for dividing a voltage to be applied to the final acceleration electrode is applied to the intermediate electrode. A dynamic voltage which increases along with an increase in deflection amount of an electron beam is applied to the focus electrode, and a dielectric portion is formed between the final acceleration electrode and the focus electrode. This dielectric portion is formed on the intermediate electrode. Hence, elliptical distortion of electron beam spots is decreased on the entire surface of a phosphor screen, thereby providing a color cathode ray tube apparatus with a good performance on the entire surface of the phosphor screen.