Low cost trim-gap-conductivity TC sensor
AssigneeXerox Corporation
InventorsMark J. Hirsch, John F. Knapp, William H. Wayman, Thomas W. Pike
Life of this patent
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Abstract
A toner maintenance system for an electrophotographic developer unit, including a sump for storing a quantity of developer material comprised of carrier and toner material; a first member for transporting a mixture of developer material and toner particles from the sump, the first member having a voltage applied thereto; a metering blade, positioned closely adjacent to the first member to maintain the compressed pile height of the developer material on first member at a desired level; and a sensor device for measuring the current between the first member and the metering blade, and generating a signal indicative thereof.
Claims12
A toner maintenance system for an electrophotographic developer unit, comprising:
- a sump for storing a quantity of developer material comprised of carrier and toner material;
- a first member for transporting a mixture of developer material and toner particles from said sump, said first member having a voltage applied thereto;
- a metering blade, positioned closely adjacent to said first member to maintain the compressed pile height of the developer material on first member at a desired level, and maintained at a voltage different from said first member by means of a suitable electric circuit;
- and
- a sensor device for measuring the current between said first member and said metering blade, and generating a signal indicative thereof.
An electrophotographic printing machine having a toner maintenance device in which a toner image is developed on a photoreceptive member, having a toner maintenance device, comprising:
- a sump for storing a quantity of developer material comprised of carrier and toner material;
- a first member for transporting a mixture of developer material and toner particles from said sump, said first member having a voltage applied thereto;
- a metering blade, positioned closely adjacent to said first member to maintain the compressed pile height of the developer material on first member at a desired level, and maintained at a voltage different from said first member by means of a suitable electric circuit;
- and
- a sensor device for measuring the current between said first member and said metering blade, and generating a signal indicative thereof.
A method of maintaining the toner level in a developer housing comprising:
- applying a voltage to a developer carrying member;
- measuring the current between the developer carrying member and a metering blade and generating a signal indicative thereof;
- and
- calculating the toner concentration as a function of the generated signal.
Dependencies are inferred from the claim text.