Multi-stack information carrier with electrochromic materials

An optical scanning device for scanning an information carrier (610) by means of an optical beam (602) having a wavelength, said information carrier comprising at least two information stacks (611, 612), wherein each stack comprises a counter electrode, an electrolyte layer and an information layer comprising an electrochromic material whose optical properties at the wavelength of the optical beam depend on a potential difference applied between the information layer and the counter electrode, said optical scanning device comprising means (601) for generating the optical beam, means (603, 605) for focusing said optical beam on an information layer and means for applying a potential difference between the information layer and the counter electrode of a stack.

A method of reading information from an information carrier by means of an optical beam having a wavelength, said information carrier comprising at least two information stacks, wherein each stack comprises a counter electrode, an electrolyte layer and an information layer comprising an electrochromic material whose optical properties at the wavelength of the optical beam depend on a potential difference applied between the information layer and the counter electrode, said method comprising the steps of applying a potential difference between the information layer and the counter electrode of the information stack from which information is to be read and focusing the optical beam on the information layer of said stack.

A method of recording information on an information carrier by means of an optical beam having a wavelength, said information carrier comprising at least two information stacks, wherein each stack comprises a counter electrode, an electrolyte layer and an information layer comprising an electrochromic material whose optical properties at the wavelength of the optical beam depend on a potential difference applied between the information layer and the counter electrode, said method comprising the step of focusing the optical beam on the information layer of the information stack on which information is to be recorded in order to locally reduce the ability of the electrochromic material to take up or release electrons.

A method of recording information on an information carrier by means of an optical beam having a wavelength, said information carrier comprising at least two information stacks, wherein each stack comprises a counter electrode, an electrolyte layer having a temperature-dependent mobility threshold and an information layer comprising an electrochromic material whose optical properties at the wavelength of the optical beam depend on a potential difference applied between the information layer and the counter electrode, said method comprising the steps of focusing the optical beam on the information layer of the information stack on which information is to be recorded in order to locally heat the electrolyte layer of said stack to above said mobility threshold, and applying a potential difference between the information layer and the counter electrode of said stack.