Back to results
US 7,742,712 B2Granted
Transfer bias voltage controlling apparatus
AssigneesKabushiki Kaisha Toshiba, Toshiba Tec Kabushiki Kaisha
InventorTakao Izumi
Life of this patent
Estimating the term…
Abstract
In an image forming apparatus for transferring a toner image onto a sheet by applying a transfer bias voltage to the sheet through a transfer member, there is provided a technique of preventing poor transfer from occurring by suitably controlling the transfer bias voltage according to a processing condition.
Claims20
An image forming apparatus for transferring a toner image onto a sheet by applying a transfer bias voltage to the sheet through a transfer member, comprising:
- a roughness information acquiring unit configured to acquire information relating to a surface roughness of the sheet;
- a sheet information acquiring unit configured to acquire information relating to an electric resistance of the sheet;
- an environment detecting unit configured to detect a humidity as an installation environment of the image forming apparatus;
- a voltage calculating unit configured to calculate a transfer bias voltage based on the information acquired by the sheet information acquiring unit and the humidity detected by the environment detecting unit;
- a voltage correcting unit configured to correct a voltage value of the transfer bias voltage calculated by the voltage calculating unit based on the information acquired by the roughness information acquiring unit, so that a transfer current flowing to the sheet at a time when the toner image is transferred onto the sheet becomes a specified optimum current value;
- and
- a voltage control unit configured to apply the transfer bias voltage of the voltage value corrected by the voltage correcting unit.
4 more elements
An image forming apparatus for transferring a toner image onto a sheet by applying a transfer bias voltage to the sheet through a transfer member, comprising:
- a roughness information acquiring unit configured to acquire information relating to a surface roughness of the sheet;
- a sheet information acquiring unit configured to acquire information relating to an electric resistance of the sheet;
- an environment detecting unit configured to detect a humidity as an installation environment of the image forming apparatus;
- a resistance value information acquiring unit configured to acquire information relating to an electric resistance of the transfer member;
- a first transfer voltage calculating unit configured to calculate a first transfer voltage as a voltage for the transfer member in the transfer bias voltage based on the information acquired by the resistance value information acquiring unit and a specified current value
- a second transfer voltage estimating unit configured to estimate a second transfer voltage as a voltage for the sheet in the transfer bias voltage based on the humidity detected by the environment detecting unit and the information acquired by the sheet information acquiring unit;
- a voltage correcting unit configured to correct a voltage value of the second transfer voltage estimated by the second transfer voltage estimating unit based on the information acquired by the roughness information acquiring unit, so that a transfer current flowing to the sheet at a time when the toner image is transferred onto the sheet becomes a specified optimum current value;
- and
- a voltage control unit configured to apply, as the transfer bias voltage, a sum of the first transfer voltage calculated by the first transfer voltage calculating unit and the second transfer voltage of the voltage value corrected by the voltage correcting unit.
6 more elements
An image forming apparatus for transferring a toner image onto a sheet by applying a transfer bias voltage to the sheet through a transfer member, comprising:
- a roughness information acquiring unit configured to acquire information relating to a surface roughness of the sheet;
- an environment detecting unit configured to detect a humidity and a temperature as an installation environment of the image forming apparatus;
- a resistance value calculating unit configured to calculate an electric resistance value of the transfer member and the sheet based on a voltage value at a time when a specified current is made to flow to the sheet through the transfer member;
- a transfer voltage calculating unit configured to calculate the transfer bias voltage based on the electric resistance value calculated by the resistance value calculating unit and the specified current;
- a voltage correcting unit configured to correct a voltage value of the transfer bias voltage calculated by the transfer voltage calculating unit based on the information acquired by the roughness information acquiring unit, so that a transfer current flowing to the sheet at a time when the toner image is transferred onto the sheet becomes a specified optimum current value;
- and
- a voltage control unit configured to apply, in a case where the temperature and the humidity detected by the environment detecting unit indicates a specified high temperature and high humidity environment, a sum of a specified correction voltage value according to the temperature and the humidity and the voltage value corrected by the voltage correcting unit as the transfer bias voltage.
4 more elements
An image forming apparatus for transferring a toner image onto a sheet by applying a transfer bias voltage to the sheet through a transfer member, comprising:
- a roughness information acquiring unit configured to acquire information relating to a surface roughness of the sheet;
- a sheet information acquiring unit configured to acquire information relating to an electric resistance of the sheet;
- an optimum current value setting unit configured to set an optimum value of a transfer current at a time when the toner image is transferred onto the sheet based on the information acquired by the roughness information acquiring unit and the sheet information acquiring unit;
- a voltage detecting unit configured to detect a voltage value at a time when the transfer current of the current value set by the optimum current value setting unit is made to flow to the sheet through the transfer member;
- and
- a voltage control unit configured to apply the transfer bias voltage of the voltage value detected by the voltage detecting unit.
3 more elements
Dependencies are inferred from the claim text.