Patent ID: 6624417
Filing Date: 2003-09-23
Classification: G01N

Abstract:
A plastic identifying apparatus (1, 21, 31, 41, 51) to identify by what type of plastic in predetermined plural types an object made of plastic to be identified (4) is formed, characterized by comprising:a light source (2, 3, 3a, 3b) irradiating to said object to be identified a detecting light (L2, L2a, L2b) of which wavelength is in an absorption wavelength band to increase the light absorptance of at least one type plastic in said plural types, and a reference light (L1) of which wavelength is different from said wavelength of said detecting light; a light receiving means (5, 5a, 5b, 5c) receiving a transmitted light or reflected light of said reference light and said detecting light from said object to be identified, and outputting a reference value expressing the quantity of light received of said reference light and a detecting value expressing the quantity of light received of said detecting light; and an identifying means (7) computing a proportion of or difference between said reference value and said detecting value, and identifying, based on the computed value, by what type of plastic in said plural types said object to be identified is formed.