Bookbinding device and image forming apparatus

An image forming apparatus comprising:

• image forming means for sequentially forming images on sheets;
• collecting means for collecting the sheets with images printed thereon, into a bundle;
• a bookbinding path along which the sheet bundle from the collecting means is sequentially subjected to a bookbinding process;
• sheet bundle conveying means located on the bookbinding path for conveying the sheet bundle from the collecting means;
• adhesive applying means located at an adhesive application position on the bookbinding path for applying an adhesive to an end surface of the sheet bundle;
• a cover sheet feeding path on which, at a cover binding position located downstream of the adhesive application position, a cover sheet is fed from a direction crossing the bookbinding path;
• cover binding means located at the cover binding position for binding the sheet bundle to the cover sheet;
• cover binding control means for controlling the cover binding means;
• and
• conveying roller means for carrying out the bundle from the cover binding position;
• wherein the cover binding means comprises:
• a back folding press member located at the cover binding position for back-folding the cover sheet;
• and
• a back rest plate member located downstream of the back folding press member for backing up the cover sheet,
• the cover binding control means controls the back folding press member so that the back folding press member executes a back folding process with a small gap formed between the back rest plate member and a back of the sheet bundle;
• controls such that after the back folding process, the back of the sheet bundle is abutted against the back rest plate member to cool the adhesive;
• controls such that after a cooling time for the adhesive elapses, the back rest plate member is retracted from the bookbinding path to outside the path;
• and varies the cooling time depending on a thickness of the sheet bundle.

A bookbinding device comprising:

• collecting means for collecting sheets with images printed thereon, into a sheet bundle;
• a bookbinding path having sheet bundle conveying means and along which the sheet bundle from the collecting means is sequentially subjected to a bookbinding process;
• adhesive applying means located at an adhesive application position on the bookbinding path for applying an adhesive to an end surface of the sheet bundle;
• a cover sheet feeding path on which, at a cover binding position located downstream of the adhesive application position, a cover sheet is fed from a direction crossing the bookbinding path;
• cover binding means located at the cover binding position for binding the sheet bundle to the cover sheet;
• cover binding control means for controlling the cover binding means;
• and
• conveying roller means for carrying the sheet bundle out from the cover binding position,
• wherein the cover binding means comprises:
• a back folding press member located at the cover binding position for back-folding the cover sheet;
• and
• a back rest plate member located downstream of the back folding press member for backing up the cover sheet;
• wherein the cover binding control means controls:
• the back folding press member so that the back folding press member executes a back folding process to the cover sheet while forming a predetermined gap between the back rest plate member and a back of the sheet bundle with the adhesive thereon;
• the sheet bundle and the cover sheet with the adhesive therebetween to abut against the back rest plate member for a predetermined time period changed according to a thickness of the sheet bundle to thereby cool the adhesive after the back folding process;
• and retracting the back rest plate member from the bookbinding path to outside the path after an adhesive cooling time elapses.

A bookbinding device comprising:

• collecting means for collecting sheets with images printed thereon, into a sheet bundle;
• a bookbinding path having sheet bundle conveying means and along which the sheet bundle from the collecting means is sequentially subjected to a bookbinding process;
• adhesive applying means located at an adhesive application position on the bookbinding path for applying an adhesive to an end surface of the sheet bundle;
• a cover sheet feeding path on which, at a cover binding position located downstream of the adhesive application position, a cover sheet is fed from a direction crossing the bookbinding path;
• cover binding means located at the cover binding position for binding the sheet bundle with an adhesive at an end thereof, to the cover sheet;
• cover binding control means for controlling the cover binding means;
• and
• conveying roller means for carrying the sheet bundle out from the cover binding position,
• wherein the cover binding means comprises:
• a back folding press member located at the cover binding position for back-folding the cover sheet;
• and
• a back rest plate member located downstream of the back folding press member for backing up the cover sheet;
• wherein the cover binding control means controls such that the adhesive at the end of the sheet bundle folded by the folding press member is cooled by the back rest plate member, and after a predetermined time for cooling the adhesive set to be different according to a thickness of the sheet bundle, the back rest plate member is retracted from the bookbinding path to outside the path.