Claims
- 1. An electrographic writing head for recording information on a recording medium comprising:
- a planar substrate having first and second surfaces;
- an array of writing nibs disposed on said first and second surfaces of said substrate, each nib for depositing an electrostatic charge on said recording medium;
- at least one shielding means provided internally in said substrate for preventing electrical interaction between the array of writing nibs on the first surface of said substrate from the array of writing nibs on the second surface;
- a plurality of thick film resistor means formed on said first and second surfaces of said substrate, each resistor means coupled to a corresponding writing nib of said array of writing nibs for substantially reducing discharge current of stray capacitances;
- a plurality of switch means for selectively charging a corresponding writing nib when said switch is in a first state, each switch means coupled with a corresponding one of said thick film resistor means;
- a plurality of high impedance, thick film pull-up resistors formed on said first and second surfaces of said substrate, each pull-up resistor coupled between a high voltage line and a corresponding one of said plurality of said switch means for controlling a charging current applied to each writing nib.
- 2. An improved electrographic writing head according to claim 1 wherein said writing nibs have a thickness of at least 40 microns.
- 3. An improved electrographic writing head according to claim 1 wherein said substrate is a printed circuit board or the like.
- 4. An improved electrographic writing head according to claim 1 wherein said substrate is a glass epoxy material.
- 5. An improved electrographic writing head according to claim 1 wherein said at least one shielding means comprises a continuous plane of conducting material disposed parallel to the plane of said substrate and separating said first and second arrays of writing nibs.
- 6. An electrographic writing head according to claim 1 wherein a plurality of shielding means are disposed internally in said substrate and wherein at least one of said plurality of shielding means is disposed as close as possible to at least one of said first and second arrays of writing nibs.
- 7. An electrographic writing head according to claim 1 wherein said shielding means includes a planar grid of conductive material disposed within the body of said be substrate and parallel to plane of the substrate.
RELATED APPLICATIONS
This application is a continuation in part of co-pending application Ser. No. 410,594, filed Sept. 21, 1989, entitled, Integrated Thick Film Electrostatic Writing Head, and assigned to the same assignee as the present invention.
US Referenced Citations (9)
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
410594 |
Sep 1989 |
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