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:
Aug. 11, 2009
Filed:
Dec. 15, 2005
Yohtaroh Ichimura, Kanagawa, JP;
Shinichi Iwasa, Kanagawa, JP;
Takayuki Erikawa, Kanagawa, JP;
Yukihiro Nakamura, Kanagawa, JP;
Yohtaroh Ichimura, Kanagawa, JP;
Shinichi Iwasa, Kanagawa, JP;
Takayuki Erikawa, Kanagawa, JP;
Yukihiro Nakamura, Kanagawa, JP;
Hitachi Global Storage Technologies Netherlands B.V., Amsterdam, NL;
Abstract
Embodiments of the invention provide a method for setting a light source parameter in order to recognize an identification mark on an object surface. In one embodiment, a grayscale image is generated by setting the light volume of the light source to a given value. Plural thresholds each for binarizing the grayscale image in density are set. The inter-class variance values to be produced respectively according to the thresholds are calculated and the largest inter-class variance value is selected as the peak inter-class variance value from the inter-class variance values calculated. The light volume is changed to a plurality of different values. Peak inter-class variance values are obtained respectively for the values and the largest peak inter-class variance value is selected as the maximum inter-class variance value from the peak inter-class variance values obtained. The object surface is irradiated by the light source whose light volume is set to a value which would give the maximum inter-class variance value.