Korea Institute of Science and Technology

Daewoo Electronics Co., Ltd.

Kwang-Ryeol Lee

Kwang-Yong Eun

Keun-Mo Kim

Keum-Mo Kim

Kye-Chul Choi

A head drum is coated with double films, each having different characteristics, by forming a first diamond-like hard carbon film of high degree of hardness and then forming a second diamond-like hard carbon film of a lower degree of hardness thereon. The degree of hardness of the second film is lower than that of the first film. The double coating is performed by means of a synthesizing apparatus which comprises a reactor consisting of a power supply electrode, a workpiece support and and an annular ground electrode spaced from the stacked head drums by a predetermined distance.

VCR head drum coated with diamond-like hard carbon films and the method

An aluminum head drum for use in a video cassette recorder is coated with a protective layer comprising diamond-like carbon. The protective layer of diamond-like carbon is obtained using a plasma-enhanced chemical vapor deposition method and has a thickness ranging from 0.3 .mu.m to 2.0 .mu.m. The protective layer has a varying mechanical hardness, wherein the mechanical hardness has a maximum value at a region of the protective layer coming in contact with the aluminum head drum, decreases smoothly and continuously and reaches an minimum value at a region of the protective layer coming in contact with atmosphere. Micro-Vicker's hardness of the region of the protective layers coming in contact with a video tape is 1.5-2.0 times that of the magnetic substance constituting the video tape.

Aluminum head drum with a protective layer which smoothly and

A head drum is coated with double films, each having different characteristics, by forming a first diamond-like hard carbon film of high degree of hardness and then forming a second diamond-like hard carbon film of a lower degree of hardness thereon. The degree of hardness of the second film is lower than that of the first film. The double coating is performed by means of a synthesizing apparatus which comprises a reactor consisting of a power supply electrode, a workpiece support and an annular ground electrode spaced from the stacked head drums by a predetermined distance.

An apparatus and method for simultaneously coating a large number of cylindrical substrates employs plural pairs of power electrode and the ground electrodes connected with an independent power sources in order to promote the uniform coating of the substrates. The apparatus uses a high-frequency plasma chemical deposition method and comprises a power supply system, a gas supply system, and a vacuum system. These systems are operatively connected to a reactor. The reactor comprises plural electrodes, workpiece supports, insulators, annular ground electrodes, gas outlets and gas supply means. The method comprises a step for stacking the substrates or the workpiece supports and combining them with the electrodes, a step for introducing gas to the reactor, a step for applying power to the power electrodes, and a step or maintaining the pressure in the reactor constant.

Method and apparatus for manufacturing head drums coated with

The present invention relates to a method and an apparatus for testing the surface properties, i.e., abrasion property, friction coefficient, lubrication property, etc., of cylindrical object, e.g., VTR head drums, photocopier or laser printer drums, sewing machine spindles, fishing rod reels, etc. The apparatus of the present invention provides: a mounting means upon which a specimen of cylindrical object and a relative specimen of a flexible material is mounted and which can measure tension; a motor control unit which is connected to said mounting means so as to enable control; an amplifier electrically connected to a tension meter of said mounting means; and a computer, electrically connected to said amplifier and said motor control unit, which has been programmed to record at timed intervals the motor rotation speed and the estimated tension values, and organizes and controls all of the above said parts. Further, said mounting means including a motor where cylindrical specimen is positioned and whose revolution may be accurately controlled; a tension meter wherein each end of said relative specimen is mounted where said relative specimen is wrapped around said specimen so that at least of part of the flexible material is in contact with said specimen; and a tension meter support upon which said tension meter is mounted. According to the present invention, the abrasion and lubrication properties of cylindrical object with respect to the relative material, such as magnetic recording tape, paper, wire, etc., which could not be gauged with previous methods, may be evaluated.

Growing community of inventors

Seoul, South Korea

Kwang-Ryeol Lee