Patent ID: 6079892
Filing Date: 2000-06-27
Classification: B65H,G03G

Abstract:
A method for detecting an end portion of a piece of a recording medium in a recording apparatus defining a forward direction and having a recording medium guide for positioning the recording medium, in which a recording medium is irradiated with light directed to a sensing location from a light source and the position of the end portion is detected based on the amount of light reflected from said recording medium as it travels through the sensing location, comprising the steps of:determining and storing the amount of light reflected from a recording medium guide of a recording apparatus, the recording apparatus defining a forward direction;feeding a piece of a recording medium in the forward direction through the recording apparatus, to a sensing location;irradiating the recording medium from a light source as it passes the sensing location and determining the amount of light reflected from said recording medium with a reflection detector;calculating a standard level by calculating the difference between the amount of light reflected from said recording medium only (M) and the amount of light reflected from said recording medium guide only (G) and multiplying said difference by a constant C which is greater than 0 and less than 1 and then adding said product to the lesser of M and G;moving the paper through the sensing location and determining when the amount of light detected by the reflection detector equals said standard level.