Patent ID: 8086163
Filing Date: 2011-12-27
Classification: G03G

Abstract:
1. A sheet transport apparatus, comprising: a sheet transport path for transporting a sheet in a predetermined transport direction, a reflective type optical sensor, which has a light-emitting portion and a light-receiving portion, and in which light irradiated from the light-emitting portion to a sheet transported on the sheet transport path is reflected and reflected light from the sheet is received by the light-receiving portion to detect a presence/absence of the sheet, an irradiated light adjustment portion that adjusts a light amount of the light-emitting portion, an image memory that stores image data corresponding to an image on a sheet for each page of the sheet, a non-image region locating portion that detects an image state on a sheet based on image data stored in the image memory to locate a non-image region of the sheet, and a control portion that adjusts the light amount of the light-emitting portion by controlling the irradiated light adjustment portion based on a measured value on the non-image region located by the non-image region locating portion, wherein the control portion irradiates light from the light-emitting portion to the transported sheet and measures reflected light received by the light-receiving portion from a plurality of measurement positions set in advance on the sheet, stores the measurement positions and the measured values, determines, among image positions corresponding to the plurality of stored measurement positions, which image position is within the non-image region located by the non-image region locating portion, and adjusts a light amount of the light-emitting portion by controlling the irradiated light adjustment portion based on the measured value on the measurement position corresponding to the image position located within the non-image region.