基本信息
摘要：A method of manufacturing a plastic coding disk or a coding ruler uses a plastic sheet that has transmittancy over 90% and can sustain high temperature up to 120 degree Celsius as a base; furthermore, the thickness of the base is less than 0.5mm and is preferably made of polyester (PET) or polycarbonate (PC). First, a layer of chromel-alumel thin film of approximately 1μm is vapor deposited on the base; subsequently, a photo resisting agent is coated on top of the chromel-alumel thin film, forming a layer of photo resisting film of 1 to 3 um in thickness; a film master plate with optical grating pattern of a coding disk or a coding ruler drawn by a light plotting machine is placed on the photo resisting film, followed by a photo sensitization under the exposure of a parallel light irradiation; the un-sensitized photo resisting film is then washed away; after soaking and etching the plastic sheet in an etching solution for several tens of seconds, sensitized photo resisting film is washed away so as to complete the fabrication of the optical grating pattern of the coding disk or the coding ruler; finally, a disc-shaped coding disk or a strip-shaped coding ruler used for an encoder or an optical ruler is made by placing the optical grating pattern in an optical stamping machine and punching it with automatic alignment.
摘要附图：
