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US4803536A Expired / Lapsed US ⏱️ 0.0 years remaining

Electrostatic discharge protection network for large area transducer arrays

Assignee: Xerox Corp
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Filing: 1986-10-24
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Granted: 1989-02-07
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Expires: 2006-10-24
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Abstract

Abstract An electrostatic discharge protection network for large area transducer arrays in which each transducer has associated therewith an addressing circuit for changing the state of the transducer element. Each addressing circuit includes at least one thin film transistor having a resistive path provided between the thin film transistor gate electrode and one or both of the transistor's other two terminal electrodes in order to provide current leakage paths for equalizing the potential between the gate electrode and the other two terminals during electrostatic discharge.

Inventors

  • 👤 Hsing C. Tuan

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 03:14
CPC Classifications
H; H10; H10D; H10D86/00; H03; H03K; H03K19/00; H03K19/003; H03K19/00315; Y; Y10; Y10S; Y10S345/00; Y10S345/904

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 221 words
An electrostatic discharge protection network for a large area transducer array, said array including a substrate on which is formed a plurality of thin film transducer elements and a thin film addressing circuit associated with each transducer element for changing the state of said transducer element, each of said addressing circuits including at least one thin film amorphous silicon transistor having a source terminal electrode and a drain terminal electrode spaced from one another and contiguous to a semiconductor layer, a gate electrode spaced from said semiconductor layer by a gate dielectric layer and located so as to control the current flow from said source terminal electrode to said drain terminal electrode, through said semiconductor layer, and a plurality of input contact pads for receiving external signals, connected to said addressing circuit, for controlling the state of said transducer elements said protection network including a strip of n+ amorphous silicon resistive material extending across all of said input contact pads, and resistor means comprising inter contact pad portions of said stripe of resistive material for providing current leakage paths to equalize the potential across all of said gate dielectrics during an electrostatic discharge and wherein said resistor means as connected to said circuits and functioning to provide current leakage paths does not affect the normal operation of said thin film transistors.
Claim 2
Dependent Claim 221 words
An electrostatic discharge protection network for a large area transducer array, said array including a substrate on which is formed a plurality of thin film transducer elements and a thin film addressing circuit associated with each transducer element for changing the state of said transducer element, each of said addressing circuits including at least one thin film amorphous silicon transistor having a source terminal electrode and a drain terminal electrode spaced from one another and contiguous to a semiconductor layer, a gate electrode spaced from said semiconductor layer by a gate dielectric layer and located so as to control the current flow from said source terminal electrode to said drain terminal electrode, through said semiconductor layer, and a plurality of input contact pads for receiving external signals, connected to said addressing circuit, for controlling the state of said transducer elements said protection network including a strip of n+ amorphous silicon resistive material extending across all of said input contact pads, and resistor means comprising inter contact pad portions of said stripe of resistive material for providing current leakage paths to equalize the potential across all of said gate dielectrics during an electrostatic discharge and wherein said resistor means as connected to said circuits and functioning to provide current leakage paths does not affect the normal operation of said thin film transistors.
Claim 3
Dependent Claim 36 words
The electrostatic discharge protection network for a large area transducer array as defined in claim 1 wherein said transducer elements extend in two directions and comprise display electrodes formed orthogonally over the surface of said substrate.
Claim 4
Dependent Claim 45 words
The electrostatic discharge protection network for a large area transducer array as defined in claim 1 wherein the value of said resistor means is at least an order of magnitude greater than output impedance of an external driver circuit connected to said input contact pads.

References Cited (Backward Citations)

US4070653A Cited
US4332075A Cited
JPS59224172A Cited
US4618873A Cited
JPS6038858A Cited
US4624737A Cited
JPS6188557A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1992-02-07 1992-08-08 1993-02-07 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1996-02-07 1996-08-08 1997-02-07 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2000-02-07 2000-08-08 2001-02-07 $7700.00 Window Closed / Lapsed

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