发明授权
- 专利标题： Toner concentration sensor and toner concentration control method
- 专利标题（中）： 墨粉浓度传感器和墨粉浓度控制方法
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申请号： US12770986申请日： 2010-04-30
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公开(公告)号： US08380092B2公开(公告)日： 2013-02-19
- 发明人: Hirotada Seki , Akinori Kimata , Satoru Sasaki , Natsuyo Higashi , Hiroaki Takatsu
- 申请人： Hirotada Seki , Akinori Kimata , Satoru Sasaki , Natsuyo Higashi , Hiroaki Takatsu
- 申请人地址： JP Tokyo
- 专利权人： Konica Minolta Business Technologies, Inc.
- 当前专利权人： Konica Minolta Business Technologies, Inc.
- 当前专利权人地址： JP Tokyo
- 代理机构： Buchanan Ingersoll & Rooney PC
- 优先权： JP2009-119069 20090515
- 主分类号： G03G15/08
- IPC分类号： G03G15/08
摘要：
In this toner concentration sensor, as the magnetic permeability of a two-component developer 3 containing toner and carrier in a two-component developing unit 1 has changed with changing TC ratio of the two-component developer, the oscillation frequency of a first oscillation circuit 20 having a detection coil 5 changes, on the other hand the oscillation frequency of a second oscillation circuit 30 having a reference coil 6 does not change. While, changes in temperature conditions cause the oscillation frequency of the second oscillation circuit to change in the same way as the oscillation frequency of the first oscillation circuit. Therefore, utilizing a difference between the oscillation frequencies of the first and second oscillation circuits makes it possible to cancel out changes in the temperature conditions so that a value corresponding to only the magnetic permeability of the two-component developer can be obtained. Thus, detection errors of toner concentration due to temperature changes can be reliably prevented.