JPS6477269A - Light quantity checking method for picture reader - Google Patents

Abstract

PURPOSE:To execute a light quantity checking excellent in the point of convenience to use by reading and checking the data of a white document for checking the light quantity provided outside the maximum document reading range of a document reading main scanning direction on the way of a picture data reading. CONSTITUTION:A picture reader, when the reading command of a document 11 is recognized, inputs the data of a document 2 for reference white data at this side from a reading starting point and a picture data processing circuit 10 executes the light quantity checking of a light source 6. At this time, when the light quantity shortage of the light source 6 is detected and the reading action of the document 11 is stopped, simultaneously, the light quantity shortage of the light source 6 is reported. When the light quantity is decided to be sufficient, the reading action of the document 11 is started, the document reading in one main scanning direction is executed, and thereafter, the data of a white document 3 for checking light quantity outside the maximum reading range the document reading main scanning direction are checked. At the time of the light quantity shortage, a reading action is stopped, the light quantity shortage of the light source 6 is reported, and when the light quantity is sufficient, the document reading in a next main scanning direction is executed, and thereafter, the above-mentioned action is repeated.