Patent ID: 7401878
Filing Date: 2008-07-22
Classification: B41J

Abstract:
1. An imaging apparatus, comprising: a print media tray for holding a stack of print media; a controller; and a print engine communicatively coupled to said controller, said print engine including: a media detection device mechanically engaged with a stack of print media, said media detection device having a movable indicator having a surface with distinct reflectance characteristics; and a reflectance sensor for reading a reflectance of said surface, and outputting a signal to said controller indicative of at least one characteristic of said stack of print media, wherein said at least one characteristic of said stack of print media is a stack height of said stack of print media, and wherein said media detection device comprises: a wheel having a plurality of reflectance characteristics, said plurality of reflectance characteristics representing different stack heights; and a drive mechanism coupled between said stack of print media and said wheel, wherein said wheel is rotated by said drive mechanism based on said stack height of said stack of print media, said reflectance sensor reading a particular location of said wheel corresponding to said stack height of said stack of print media.