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:
Jul. 26, 2016
Filed:
May. 21, 2014
Takuya Nagano, Yokohama, JP;
Takuya Nagano, Yokohama, JP;
RICOH COMPANY, LTD., Tokyo, JP;
Abstract
An image-reading lens includes front-group and rear-group lens systems which are arranged on an object side and an image side, respectively. The front-group lens system includes equal to or less than 5 lenses which include at least one positive lens and at least one negative lens, and the rear-group lens system includes one negative lens. An angle of view of an entire system of the image-reading lens is equal to or more than 56°. The front-group and rear-group lens systems are structured such that with respect to a change in a distance between the front-group and rear-group lens systems, a change in a focal length of the entire system of the image-reading lens is small, and a change in an image plane is large, and by adjusting the distance between the front-group and rear-group lens systems, a required lens performance is obtained.