OPTICAL RECORDING MEDIUM

摘要

PURPOSE:To make production simple and cost low and to improve an SN ratio by providing an optical recording layer consisting of a cholesteric high-polymer liquid crystal contg. a light absorbent and adjusting the spiral pitch of the liquid crystal in such a manner that light is selectively reflected from visible light to a near IR wavelength region. CONSTITUTION:The optical recording layer consisting of the cholesteric high- polymer liquid crystal contg. the light absorbent is provided. The spiral pitch of the cholesteric high-polymer liquid crystal is so adjusted as to selectively reflect light from the visible light to the near IR wavelength region. The cholesteric high-polymer liquid crystal has the spiral arrangement of the liquid crystal group and has the selective wavelength reflectivity of the light corresponding to the periodic pitch of the spiral structure. The light absorbent which has large absorption in the wavelength region of the light beams and has a relatively high m.p. is preferable. The substantial amt. of the light absorbent to be added is increased and the effect of light absorption is increased; in addition the uniform high-polymer liquid crystal layer is formed if the light absorbent such as vanadyl phthalocyanine preliminarily subjected to addition polymn. with a polymer such as cyloxane or vinyl polymer is used.