[54] METHOD AND APPARATUS FOR DECOLORIZATION, AND IMAGE FORMING APPARATUS
[75] Inventors: Yuki Abe; Rikuzou Kouzuki;
Masakazu Okamoto; Yasunori
Mikata; Masatsugu Tabata; Shigeki
Inoue; Sadao Tanimoto, all of Kobe;
Yosfaihiro Ucbimoto, Osaka; Katsumi
Murofushi; Yoshikazu Hosoda, both
of Kawasaki, all of Japan
[73] Assignees: Bando Chemical Industries. Ltd.,
Hyogo; Showa Denko KabusMki
Kaisha, Tokyo, both of Japan
[21] Appl. No.: 974,122
[22] Filed: Nov. 10,1992
[30] Foreign Application Priority Data
Nov. 11, 1991 [JP] Japan 3-294552
Nov. 15, 1991 [JP] Japan 3-300048
[51] Int. CI.* G03G 21/00
[52] U.S. CI 430/97; 430/10;
430/19; 283/85; 428/916; 8/103
[58] Field of Search 430/10, 19, 97, 944;
283/85; 428/916; 8/103
[56] References Cited
U.S. PATENT DOCUMENTS
4,992,347 2/1991 Hawkins et al 430/10
5,045,420 9/1991 Hosono et al 430/45
5,166,041 11/1992 Murofushi et al 430/339
FOREIGN PATENT DOCUMENTS
0468465A1 1/1992 European Pat. Off. .
2202497 8/1972 Germany 430/97
3007296 9/1981 Germany 430/19
3919312A1 12/1989 Germany .
127711 11/1978 Japan 430/19
OTHER PUBLICATIONS
Patent Abstracts of Japan, vol. 11, No. 261 (P-609)(2708) 25 Aug. 1987 & JP-A-62 067 560 (RICOH) 27 Mar. 1987 *abstract*.
Primary Examiner—Roland Martin
Attorney, Agent, or Firm—Wenderoth, Lind & Ponack
[57] ABSTRACT
A sheet of paper, plastic or the like on which an image has been formed using a toner that is photochemically decolorizable by absorption of near infrared rays is illuminated with near infrared rays under the state wherein the image is heated to a temperature equal to or higher than the glass-transition temperature of a binding resin of the toner. The color of the toner can thereby be easily and rapidly eliminated. This enables the reuse of the sheet to be realized easily and at a low cost.
27 Claims, 23 Drawing Sheets
