Image forming apparatus having an automatic toner

专利名称：Image forming apparatus having an

automatic toner supplier

发明人：Shin Yamauchi申请号：US07/315149申请日：19890224公开号：US05107301A公开日：19920421

摘要：An image forming apparatus includes an automatic toner supplier for detectinga toner density using a toner sensor and automatically supplying a toner when the tonerdensity is decreased. The toner sensor is automatically initialized when initial use of theimage forming apparatus is started so as to generate an analog voltage signal having apredetermined level corresponding to a reference toner density. That is, an outputvoltage from the toner sensor is converted into a digital signal by an analog/digital (A/D)converter. A comparator compares this digital signal with a reference voltage

corresponding to the reference toner density. An arithmetic-logic unit adds/subtracts adigital adjustment value in accordance with a comparison result from the comparator.This adjustment value is converted by a digital/analog (D/A) converter into an analogcontrol voltage signal and is applied to the toner sensor. That is, the control voltages areconverged by a loop including the toner sensor, the A/D converter, the comparator, thearithmetic-logic unit, and the D/A converter so as to set the output voltage signal fromthe toner sensor at the predetermined level corresponding to the reference tonerdensity.

申请人：KABUSHIKI KAISHA TOSHIBA

代理机构：Foley & Lardner

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