James G Kerr

US Patent:

59233460, Jul 13, 1999

Filed:

Oct 23, 1995

Appl. No.:

8/551907

Inventors:

Ross Neal Mills - Boulder CO
James Elwood Kerr - Boulder CO

Assignee:

imaging Technology international - Boulder CO

International Classification:

B41J 2065
B41J 2205

US Classification:

347 11

Abstract:

In an electrostatic ink jet printer, all nozzles of a printhead are spaced generally the same distance from a moving paper print substrate. Three voltage levels are selectively applied to each nozzle of the printhead. As the paper moves past the printhead, a bias voltage Vb is applied to all nozzles which have a static protruding meniscus which shape is determined by a balance between the internal pressure, surface tension, and bias voltage. When the paper arrives at a print row, nonprinting nozzles have a shadow voltage pulse Vs, the "shadow pulse," applied thereto, and printing nozzles have a higher magnitude print pulse Vp applied thereto. The magnitude of the shadow pulse Vs causes an additional excursion of the ink meniscus to form at each non-printing nozzle. The higher magnitude of print pulse Vp causes an ink filament to move from a printing nozzle to the paper. The time duration of each print pulse is varied in accordance with an ink density parameter up to a range that is determined by the duration of the shadow pulse.

US Patent:

40126498, Mar 15, 1977

Filed:

Oct 9, 1975

Appl. No.:

5/621110

Inventors:

John C. Cook - Dallas TX
James D. Kerr - Allen TX

Assignee:

Teledyne Industries, Inc. - Dallas TX

International Classification:

H01L 4104

US Classification:

310 83

Abstract:

A detector structure and array to be buried in a solid medium either singly or plurally at spaced intervals to detect intrusions such as footsteps upon the surface under which the detectors are buried. Each detector comprises a cup having a diaphragm at one end and a closure at the other end, piezoelectric transducer disc means in the cup and bonded to the diaphragm, the diaphragm being large enough in diameter to achieve good coupling to the medium in which it is buried, especially if it is a particulate medium such as ground soil. A cable joins the cup units, and sealing means are provided for the cup and cable entrance to seal against entry of moisture. Successive detector units may be coupled to the cable with reversed polarities to cancel out frontal disturbances such as seismic events.