The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 18, 2001
Filed:
Nov. 24, 1998
Yoshiaki Kawai, Ebina, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
An image reading apparatus which is capable of detecting a foreign particle interfering with an image reading operation includes a reference image plate, an image reading device, a peak value detector, a first memory, a comparator, and an error output controller. The reference image plate has a reference white image on the surface of the plate, and the first memory stores a first reference value. The image reading device reads such a reference white image for one line in a main scanning direction. The peak value detector detects a smallest data among the data which are included in the reference white image read by the image reading device. Then, the comparator compares the smallest data detected by the peak value detector with the first reference value. Finally, the error output controller outputs a white image error when the smallest data is smaller than the first reference value.