Abstract When information recording is conducted by converting a non-colored state of a recording film into a colored state, use is made of a recording light having a wavelength in such a range that an absorbance of the non-colored state is higher than an absorbance of the colored state. When information erasing is conducted by converting a non-colored state of a recording film into a colored state, use is made of an erasing light having a wavelength in such a range that an absorbance of the non-colored state of the recording film is higher than an absorbance of the colored state. Accordingly, the present invention has the advantage of a great change of color being exhibited in the recording film, thus enabling optimal recording and erasing of information.
A method for recording information via a photorecording medium having a recording film comprising a photochromic material, said method being characterized by a step for irradiating a recording light onto a recording film to convert the film from its non-colored state into its colored state, said recording film having such a property that an absorbance distribution of said non-colored state overlaps with an absorbance distribution of said colored state in the vicinity of the respective peaks of both said distributions and said recording light having a wavelength in such a range that the absorbance of said non-colored state of the recording film is higher than the absorbance of said colored state, wherein the recording light has a wavelength at which the absorbance ratio between the non-colored state and the colored state of the recording film is a maximum.
Claim 2
Independent Claim
138 words
A method for recording information via a photorecording medium having a recording film comprising a photochromic material, said method being characterized by a step for irradiating a recording light onto a recording film to convert the film from its non-colored state into its colored state, said recording film having such a property that an absorbance distribution of said non-colored state overlaps with an absorbance distribution of said colored state in the vicinity of the respective peaks of both said distributions and said recording light having a wavelength in such a range that the absorbance of said non-colored state of the recording film is higher than the absorbance of said colored state, wherein the recording light has a wavelength at which the absorbance ratio between the non-colored state and the colored state of the recording film is a maximum.