EP0265290A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Electrostatic discharge protection network for large area transducer arrays
Assignee: Xerox Corp
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Filing: 1987-10-26
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Granted: —
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Expires: 2007-10-26
Abstract
Abstract An electrostatic discharge protection network for large area transducer arrays (32) 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 (10) having a resistive path (30) 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 an electrostatic discharge.
Inventors
- 👤 Hsing Chien Tuan
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 08:14
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: 11
Claim 1
Independent Claim
105 words
An electrostatic discharge protection network for a large area transducer array (32), said array including a substrate (34) on which is formed a plurality of transducer elements (36) and a thin film addressing circuit (10) associated with each transducer element for changing the state of said transducer element, each of said addressing circuits including at least one thin film transistor, characterised in that said protection network includes resistor means (30, or 46, or 70) connected to said addressing circuits for providing current leakage paths to substantially equalize the potential on the elements of said array during an electrostatic discharge to any element of said array.
Claim 2
Dependent Claim
105 words
An electrostatic discharge protection network for a large area transducer array (32), said array including a substrate (34) on which is formed a plurality of transducer elements (36) and a thin film addressing circuit (10) associated with each transducer element for changing the state of said transducer element, each of said addressing circuits including at least one thin film transistor, characterised in that said protection network includes resistor means (30, or 46, or 70) connected to said addressing circuits for providing current leakage paths to substantially equalize the potential on the elements of said array during an electrostatic discharge to any element of said array.
Claim 3
Dependent Claim
80 words
The electrostatic discharge protection network for a large area transducer array as defined in claim 1 including a plurality of input contact pads (38) connected to said addressing circuit for receiving signals from an external driver circuit, said resistor means (46) being connected to each of said input contact pads, and the value of said resistor means being at least an order of magnitude greater than the output impedance of said external driver circuit connected to said input contact pads.
Claim 4
Dependent Claim
124 words
The electrostatic discharge protection network for a large area transducer array as defined in claim 1 wherein each of said thin film transistors (10) includes a source terminal electrode (24) and a drain terminal electrode (26) spaced from one another and contiguous to a semiconductor layer (18), and a gate electrode (14) spaced from said semiconductor layer by a gate dielectric layer (16) and located so as to control the current flow from said source terminal electrode to said drain terminal electrode, through said semiconductor layer, wherein said resistor means is connected so as to equalize the potential across all of said gate dielectrics during an electrostatic discharge, and wherein said resistor means does not affect the normal operation of said thin film transistor.
Claim 5
Dependent Claim
42 words
The electrostatic discharge protection network for a large area transducer array as defined in claim 3 wherein said resistor means is connected between each of said gate electrodes and at least one of its associated terminal electrodes of said thin film transistor.
Claim 6
Dependent Claim
42 words
The electrostatic discharge protection network for a large area transducer array as defined in claim 4 wherein said resistor means is connected between said gate electrode and both said source terminal electrode and said drain terminal electrode of said thin film transistor.
Claim 7
Dependent Claim
54 words
The electrostatic discharge protection network for a large area transducer array as defined in claim 3 wherein said array includes a plurality of input contact pads for receiving external signals, connected to said addressing circuit, for controlling the state of said transducer means, and said resistor means connects each of said input contact pads.
Claim 8
Dependent Claim
45 words
The electrostatic discharge protection network for a large area transducer array as defined in claim 6 wherein a stripe of resistive material extends across all of said input contact pads and said resistor means comprises the inter-contact pad portions of said stripe of resistive material.
Claim 9
Dependent Claim
36 words
The electrostatic discharge protection network for a large area transducer array as defined in claim 7 wherein said thin film transistor is made of amorphous silicon and said resistor means is made of n⁺ amorphous silicon.
Claim 10
Dependent Claim
40 words
The electrostatic discharge protection network for a large area transducer array as defined in any one of claims 1 to 8 wherein said transducer elements extend in one dimension and comprise marking electrodes formed along one edge of said substrate.
Claim 11
Dependent Claim
41 words
The electrostatic discharge protection network for a large area transducer array as defined in any one of claims 1 to 8 wherein said transducer elements extend in two dimensions and comprise display electrodes formed orthogonally over the surface of said substrate.
References Cited (Backward Citations)
No citation records indexed.
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