| 摘要 |
PROBLEM TO BE SOLVED: To detect a trouble with no intermediary of a person and to permit refeed processing, or the like, by comparing a print data on a paper with an expected data to be outputted in a printer, deciding that a trouble has occurred it the difference exceeds a threshold level and informing the fat to the print request side. SOLUTION: A data to be written on a drum 12 is previously developed on a memory in a print control section 15 and then a drum 12 is turned to deliver the writing data data sequentially to a laser emitting unit 13. A sheet printed with the data by the drum 12 is monitored by means of a scanning element 14. If toner is not attracted as expected because of a dust adhering to the sheet, print results being read in by means of the scanning element 14 differs from an expected print data. The difference is summed simply in units of pixel numbers and when the sum exceeds a threshold level, a decision is made that a print is blurred and trouble detection is effected. |
