(12) United States Patent ao) Patent No.: Us 7,503,492 B2
Matushima et al. (45) Date of Patent: Mar. 17,2009
(54) OPTICAL INFORMATION READING
APPARATUS AND RELATED INFORMATION
(75) Inventors: Takeshi Matushima, Kariya (JP);
Motoaki Watabe, Aichi-ken (JP)
(73) Assignee: Denso Wave Incorporated, Tokyo (JP)
( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 868 days.
(21) Appl.No.: 10/893,879
(22) Filed: Jul. 20, 2004
(65) Prior Publication Data
US 2005/0051627 Al Mar. 10, 2005
(30) Foreign Application Priority Data
Sep. 8,2003 (JP) 2003-315537
(51) Int. CI.
G06K 7/10 (2006.01)
G06K 7/14 (2006.01)
(52) U.S. CI 235/454; 235/494; 235/439
(58) Field of Classification Search 235/454,
235/498, 462.1, 462.09, 462.32, 439, 494 See application file for complete search history.
(56) References Cited
U.S. PATENT DOCUMENTS
A guide light indicating a rectangular reading portion, smaller than an imaging visual field of an area sensor, is irradiated on a reading objective. A control unit, under the irradiated guide light, causes the area sensor to capture a first image. Then, the control unit detects the position of the guide light based on captured first image data. Then, with no irradiation of the guide light, the control unit causes the area sensor to capture a second image. The control unit then estimates an existing region of a two-dimensional code in the second image. The control unit selects, as a processing objective, only a code that is completely contained in the reading portion and executes the decode processing only forthe selected code. When failed in a reading operation, the control unit expands a processing objective region and executes the decode processing again.
19 Claims, 8 Drawing Sheets