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US 8,526,858 B2Granted
Image forming apparatus having color and transparent developing devices
AssigneeCanon Kabushiki Kaisha
InventorMasayuki Tamaki
Life of this patent
Estimating the term…
Abstract
In an image forming apparatus having a color developing device and a transparent developing device the triboelectric chargeability of the transparent toner by a developer carrying member provided in the transparent developing device is made higher than a triboelectric chargeability of a color toner by a developer carrying member provided in the color developing device.
Claims12
An image forming apparatus comprising:
- a color developing device for developing with a color toner an electrostatic image formed on a photosensitive member, said color developing device including a fixed magnet provided with a plurality of magnetic poles, a developer carrying member which is rotated around the fixed magnet and carries a color developer comprising a color toner and a carrier, and a layer thickness regulating member which is provided opposed to the developer carrying member and regulates a layer thickness of the carried color developer;
- and
- a transparent developing device for developing with a transparent toner an electrostatic image formed on a photosensitive member, said transparent developing device including a fixed magnet provided with a plurality of magnetic poles, a developer carrying member which is rotated around the fixed magnet and carries a transparent developer comprising a transparent toner and a carrier, and a layer thickness regulating member which is provided opposed to the developer carrying member and regulates a layer thickness of the carried transparent developer,
- wherein a distance from a downstream one of adjacent magnetic poles of the same polarity of the fixed magnet of said transparent developing device with respect to a developer carrying member rotational direction to a position opposing the layer thickness regulating member is longer than a distance from a downstream one of adjacent magnetic poles of the same polarity of the fixed magnet of said color developing device with respect to the developer carrying member rotational direction to the position opposing the layer thickness regulating member.
1 more element
An image forming apparatus comprising:
- a color developing device for developing with a color toner an electrostatic image formed on a photosensitive member, said color developing device including a fixed magnet provided with a plurality of magnetic poles, a developer carrying member which is rotated around the fixed magnet and carries a color developer comprising a color toner and a carrier, and a layer thickness regulating member which is provided opposed to the developer carrying member and regulates a layer thickness of the carried color developer;
- and
- a transparent developing device for developing with a transparent toner an electrostatic image formed on a photosensitive member, said transparent developing device including a fixed magnet provided with a plurality of magnetic poles, a developer carrying member which is rotated around the fixed magnet and carries a transparent developer comprising a transparent toner and a carrier, and a layer thickness regulating member which is provided opposed to the developer carrying member and regulates a layer thickness of the carried transparent developer,
- wherein a magnetic confining force between the layer thickness regulating member of said transparent developing device and a magnetic pole of the fixed magnet provided at an upstream side with respect to a developer carrying member rotational direction is larger than a magnetic confining force between the layer thickness regulating member of said color developing device and a magnetic pole of the fixed magnet provided at an upstream side with respect to the developer carrying member rotational direction.
1 more element
Dependencies are inferred from the claim text.