Global Patent Index - EP 0292130 A2

EP 0292130 A2 19881123 - Toner concentration detection.

Title (en)

Toner concentration detection.

Title (de)

Tonerkonzentrationsermittlung.

Title (fr)

Détection de la concentration de toner.

Publication

EP 0292130 A2 19881123 (EN)

Application

EP 88303863 A 19880428

Priority

JP 7486987 U 19870519

Abstract (en)

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

G03G 15/08

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)

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