DISK TYPE RECORDING MEDIUM

摘要

PURPOSE:To improve the picture quality and S/N ratio of a reproduced image by selecting and prescribing the characteristics of conductive carbon black. CONSTITUTION:The primary grains of conductive carbon black have <=25mum, favorably <=20mum mean grain size by an electron microscope method and >=200ml/100g oil absorption (mechanical method) by JIS K6221 are used to form a disk body 1 which has a center hole 2. The shape of bits is as shown by 3.