Charge voltage control circuit and image forming apparatus which controls a charge voltage based on a discharge current
US7139501B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 12, 2004 |
| Grant date | Nov 21, 2006 |
| Priority date | — |
| Expiry date | Mar 2, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G15/0266
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An image forming apparatus includes a control voltage generation circuit which inputs a primary AC voltage to the primary side of a voltage transformer, generates a control voltage corresponding to a current generated on the secondary side of the voltage transformer in accordance with the primary AC voltage, and controls the primary AC voltage on the basis of the control voltage and a control signal, a current detection circuit which is connected, through a capacitor, to a path which supplies the current generated on the secondary side of the voltage transformer to a charge roller and detects a charge current to charge an image carrier, and a control circuit which determines the control signal on the basis of the relationship between a predetermined control signal (PRICNT) and a current value (Icap) detected by the current detection circuit in accordance with the predetermined control signal and controls the primary AC voltage to be generated by the voltage generation circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.