EP 0018742 B2 19880824 - METHOD OF IMPROVING MAXIMUM DENSITY AND TONAL RANGE OF ELECTROGRAPHIC IMAGES, A PHOTOCONDUCTIVE ELEMENT THEREFOR AND AN ELECTROGRAPHIC COPYING APPARATUS USING THE METHOD
Title (en)
METHOD OF IMPROVING MAXIMUM DENSITY AND TONAL RANGE OF ELECTROGRAPHIC IMAGES, A PHOTOCONDUCTIVE ELEMENT THEREFOR AND AN ELECTROGRAPHIC COPYING APPARATUS USING THE METHOD
Publication
Application
Priority
US 3066879 A 19790416
Abstract (en)
[origin: EP0018742A1] The image quality obtainable by an electrographic copying process in which an electrostatic latent image formed by imagewise exposure of a uniformly charged photoconductive layer, or otherwise, is developed with a toner can be improved if the latent image comprises discrete charge bearing zones, preferably formed by a supplementary exposure through a half-tone screen, and if additionally the toner is electrically conductive either intrinsically or as a result of electrical break-down. In this manner, the maximum density obtainable in a copy can be increased and the contrast decreased sufficiently to allow good reproduction of both continuous tone and high contrast images.
IPC 1-7
IPC 8 full level
G03G 5/14 (2006.01); G03G 13/08 (2006.01); G03G 15/04 (2006.01); G03G 15/05 (2006.01); G03G 15/09 (2006.01); G03G 15/22 (2006.01)
CPC (source: EP)
G03G 15/04027 (2013.01)
Designated contracting state (EPC)
AT BE CH DE FR GB IT NL SE
DOCDB simple family (publication)
EP 0018742 A1 19801112; EP 0018742 B1 19830810; EP 0018742 B2 19880824; AT E4435 T1 19830815; AU 536674 B2 19840517; AU 5751880 A 19801023; BR 8002337 A 19801202; DE 3014449 A1 19801030; DE 3014449 C2 19860327; DE 3064518 D1 19830915; FR 2454646 A1 19801114; FR 2454646 B1 19831209; JP H0210954 B2 19900312; JP S5619067 A 19810223
DOCDB simple family (application)
EP 80301189 A 19800415; AT 80301189 T 19800415; AU 5751880 A 19800416; BR 8002337 A 19800415; DE 3014449 A 19800415; DE 3064518 T 19800415; FR 8008381 A 19800415; JP 4924380 A 19800416