Patent ID: 9361805
Filing Date: 2016-06-07
CPC Classification: G09B

Claim Text:
1. A system for page detection using light attenuators, which is applied in a book to detect an opened page of the book, wherein the book has N pages and each page has a page detection area, where N is an integer greater than one, the system comprising: at most M light attenuators installed side by side in the page detection area of each of the N pages for allowing an external light source to pass through the at most M light attenuators thereby attenuating intensity of the external light source, where M is an integer greater than one and M<N; M light sensing devices installed in an area of the book corresponding to the at most M light attenuators so as to detect attenuated intensities of the light source after the external light passes through the at most M light attenuators; and a controller connected to the M light sensing devices for determining the opened page based on a ratio of the intensities of the light source detected by the M light sensing devices on each page, wherein the at most M light attenuators are each a polarizer, and each of the at most M light attenuators has a different polarization angle for attenuating the intensity of the external light source according to the polarization angle.