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:
Oct. 20, 1998
Filed:
Dec. 06, 1995
Hidefumi Nishigai, Ebina, JP;
Masao Hattori, Ebina, JP;
Fuji Xerox Co., Ltd., Tokyo, JP;
Abstract
An article 1 to be prevented from forgery previously contains an optical semiconductor, the mixing ratio of which is predetermined. Under the condition that a light source 6 is turned off, microwaves are emitted to the article 1 to be prevented from forgery through a feed phone 5. These microwaves are reflected on the article 1 to be prevented from forgery and supplied to a receiving section 8 through a feed phone 7, so that the receiving level of the microwaves can be measured. Next, the light source 6 is turned on, and the receiving level of the microwaves is measured in the same manner. When an optical semiconductor is irradiated with rays of light, it is excited, so that the microwave reflection factor is enhanced. Accordingly, the receiving level in the case where the light source 6 is turned on is higher than the receiving level in the case where the light source 6 is turned off.