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Drive circuit and image forming apparatus using the same

  • US 7,502,000 B2
  • Filed: 01/31/2005
  • Issued: 03/10/2009
  • Est. Priority Date: 02/12/2004
  • Status: Expired due to Fees
First Claim
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1. A drive circuit comprising:

  • a drive transistor for feeding to a load a drive current corresponding to an input signal,wherein the drive circuit has a correction circuit that supplies a correction signal corresponding to an impedance of the load to a gate of the drive transistor to correct the drive current to be fed to the load by the drive transistor, andwherein the load is a light-emitting element, one terminal of the light-emitting element is connected to a gate of a transistor for correction, and when a predetermined potential Ps is set to a value calculated by deducting a threshold voltage Vth of the transistor for correction from a terminal potential Pi of the light-emitting element with respect to a drive current, the drive circuit sets a source potential of the transistor for correction to the predetermined potential Ps to thereby generate a voltage corresponding to an impedance of the light-emitting element as a source-to-drain current of the transistor for correction.

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