EP 0292130 B1 19921230 - TONER CONCENTRATION DETECTION
Title (en)
TONER CONCENTRATION DETECTION
Publication
Application
Priority
JP 7486987 U 19870519
Abstract (en)
[origin: EP0292130A2] A toner concentration detecting device for detecting a toner concentration of a two component developer includes a differential transformer (1) which is connected to an oscillating drive (2) and a phase detecting circuit (3). A variable capacitance diode (VCD) is connected between a primary coil (101) and the secondary coils (102, 103) and a variable resistor (VR) is provided to supply the variable capacitance diode (VCD) with a variable DC voltage thereby to select the capacitance of the diode (VCD).
IPC 1-7
IPC 8 full level
G01N 27/00 (2006.01); G01N 27/72 (2006.01); G03G 15/08 (2006.01)
CPC (source: EP)
G03G 15/0853 (2013.01)
Citation (examination)
PATENT ABSTRACTS OF JAPAN, vol. 9, no. 329 (P-416)(2052), 24 décembre 1985 ; & JP-A-60154275 (HITACHI KINZOKU), 13.08.85
Designated contracting state (EPC)
DE FR GB
DOCDB simple family (publication)
EP 0292130 A2 19881123; EP 0292130 A3 19890614; EP 0292130 B1 19921230; DE 3877054 D1 19930211; DE 3877054 T2 19930429; JP H0633484 Y2 19940831; JP S63187160 U 19881130
DOCDB simple family (application)
EP 88303863 A 19880428; DE 3877054 T 19880428; JP 7486987 U 19870519