Back to results
US 5,287,144 AGranted
Image forming apparatus having transfer charger which is controlled according to ambient conditions
AssigneeCanon Kabushiki Kaisha
InventorAtsushi Takeda
Life of this patent
Estimating the term…
Abstract
The resistivities of a transfer material or a transfer material carrying sheet change depending on the variation in the ambient conditions, the materials of the transfer material and the charge-up of the transfer material carrying sheet. Therefore, even if the charging by the transfer charger is maintained constant, the image transfer operation is not stable. An image transfer apparatus in which the charging amount by the transfer charger is controlled in accordance with the resistivities to stabilize the image transfer operation is disclosed The transfer charger will be controlled in accordance with an electric current flowing through a contact member when a transfer material passes between the contact member and a transfer material carrying sheet.
Claims51
An image forming apparatus, comprising:
- an image bearing member;
- means for forming a toner image on said image bearing member;
- transfer material carrying means for carrying a transfer material to an image transfer position to receive the toner image from said image bearing member, said transfer material carrying means including a transfer material carrying member for carrying the transfer material;
- contacting member contactable to said transfer material carrying member at a side of said member that is contactable to the transfer material;
- discharging means for applying electric charge to the transfer material carried on the transfer material carrying means;
- and
- control means for controlling an output of said discharging means in accordance with an electric current which flows through said contacting member when the transfer material passes between said transfer material carrying member and said contacting member.
4 more elements
An image forming apparatus, comprising:
- an image bearing member;
- means for forming a toner image on said image bearing member;
- transfer material carrying means for carrying a transfer material to an image transfer position to receive the toner image from said image bearing member, said transfer material carrying means including a transfer material carrying member for carrying the transfer material;
- a contacting member contactable to said transfer material carrying member at a side of said member that is contactable to the transfer material;
- discharging means for applying electric charge to the transfer material carried on the transfer material carrying member;
- constant current control means for maintaining a constant current supply to said contacting member as the transfer material passes between said carrying member and said contacting member;
- and
- second control means for controlling an output of said discharging means in accordance with a voltage during constant current control by said constant current control means.
5 more elements
An image forming apparatus, comprising:
- a recording material carrying member for carrying a recording material;
- image forming means for forming a toner image on the recording material carried on said recording material carrying member;
- contacting member contactable to said recording material carrying member;
- and
- control means for controlling an image forming condition of said image forming means in accordance with a current through said contacting member when the recording material passes between said recording material carrying member and said contacting member.
2 more elements
An image forming apparatus, comprising:
- a recording material carrying member for carrying a recording material;
- image forming means for forming a toner image on the recording material carried on said recording material carrying member;
- a contacting member contactable to said recording material carrying member;
- constant current control means for maintaining constant the current supplied to said contacting member as the recording material passes between said carrying member and said contacting member;
- and
- second control means for controlling an image forming condition in accordance with a voltage during constant current control by said constant current control means.
3 more elements
An image forming apparatus, comprising:
- a recording material carrying member for carrying a recording material;
- image forming means for forming a toner image on the recording material carried on said recording material carrying member;
- attracting means for electrostatically attracting the recording material to said recording material carrying member, said attracting means having an attracting member on a recording material carrying side of said recording material carrying member;
- and
- control means for controlling an image forming condition of said image forming means in accordance with a current through said attracting means when the recording material passes between said recording material carrying member and said contacting member.
2 more elements
An image forming apparatus, comprising:
- a recording material carrying member for carrying a recording material;
- image forming means for forming a toner image on the recording material carried on said recording material carrying member;
- attracting means for electrostatically attracting the recording material to said recording material carrying member, said attracting means having an attracting member on a recording material carrying side of said recording material carrying member;
- constant current control means for maintaining a constant current supply to said attracting member as the recording material passes between said recording material carrying member and said attracting member;
- and
- a second control means for controlling an image forming condition of said image forming means in accordance with a voltage during constant current control by said constant current control means.
3 more elements
Dependencies are inferred from the claim text.