Title:
【発明の名称】画像形成装置
Document Type and Number:
Japanese Patent JP2577231
Kind Code:
B2
Abstract:
PURPOSE:To accurately measure the humidity of the periphery of a developing device by providing a temperature measuring circuit which has a temperature sensor and finding relative or absolute humidity or a mixing ratio by a controller according to its measurement information and the information of a humidity sensor. CONSTITUTION:The secondary output of a transformer T1 is supplied to the controller 18 through a rectifier D1 and a stabilizing circuit Q1 and also supplied to a humidity measuring circuit 21 through a rectifier D2, so that it is connected to a temperature and humidity sensor 19. The circuit 21 applies a bias by a power circuit 37, the output of a temperature sensor 19b is put within a specific voltage range by an operational amplifier 32, and the output of a terminal P3 is supplied to the A/D converter of the controller 18. A humidity sensor 19a is supplied with an oscillation output whose amplitude and frequency are constant through the circuit 31, and the output is rectified by a detecting circuit 34 through a capacitor C2, smoothed by an integrating circuit 35, and inputted to the A/D converter of the controller 18 through an operational amplifier 36. The controller controls a primary high voltage power source 4a, a grid bias 4b, and a developing bias power source 1a to accurately measure variation at the periphery of a developing device 1, thereby compensating variation in development characteristics.
Inventors:
SUZUKI KOJI
Application Number:
JP24386487A
Publication Date:
January 29, 1997
Filing Date:
September 30, 1987
Export Citation:
Assignee:
CANON KK
International Classes:
G03G15/00; G03G21/00; G01N27/12; (IPC1-7): G03G15/00; G01N27/12
Domestic Patent References:
| JP61296250A | ||||
| JP61159144A | ||||
| JP5670450A | ||||
| JP5669660A | ||||
| JP59133572A | ||||
| JP6156566U |
Attorney, Agent or Firm:
Hiroyuki Niwa