Patent ID: 7419314
Filing Date: 2008-09-02
Classification: B82Y,G02F,G03B,H04N

Abstract:
1. An optical density changing element comprising: an anode; and a cathode, wherein at least one of the anode and the cathode comprises a first compound that changes a spectral absorption spectrum of the first compound in a wavelength of 400 to 700 nm by providing an electron to or receiving an electron from the at least one of the anode and the cathode, wherein at least one of the anode and the cathode comprises a second compound that does not substantially change a spectral absorption spectrum of the second compound in a wavelength of 400 to 700 nm by providing an electron to or receiving an electron from the at least one of the anode and the cathode, and wherein the second compound has a structure represented by formula (8): wherein m represents an integer of 1 to 4; A represents an acid group, and in case m is equal to or larger than 2, A's are mutually same or different; and B represents a hydroxylamine or a catechol.