William J Doherty

US Patent:

20020121683, Sep 5, 2002

Filed:

Feb 26, 2002

Appl. No.:

10/085164

Inventors:

Stephen Kelly - Melrose MA, US
Kenneth Philpot - Nashua NH, US
Henricus Giesen - Didam, NL
William Doherty - Bedford MA, US

International Classification:

H01L023/495
H01L023/36

US Classification:

257/675000, 257/712000, 257/713000, 257/787000, 438/123000, 438/124000, 438/122000, 257/100000

Abstract:

An semiconductor device package () with improved thermal properties that limits unwanted parasitics and provides a more consistent distribution of parasitics from one device to another. The package of the present invention () is extremely compact and uses, in one embodiment, a minimal length of bond wires (and ) between the terminals (and ) and the attached device (). The path length of the package () is reduced so as to represent only some fraction of a wavelength relative to the terminals (and ) of the package (). By reducing the length of the bond wires (and ) and selecting the appropriate dielectric constant of the encapsulant (), the invention provides a package () with a unique hexagonal structure that limits the effects of parasitics and provides good thermal dissipation. In a second and third embodiment of the present invention, the semiconductor device package () is useful in optoelectronic devices such light emitting diodes with an anode () and a cathode (). The use of the novel design in this implementation also improves thermal properties and limits unwanted parasitics.

US Patent:

42064562, Jun 3, 1980

Filed:

Jan 12, 1978

Appl. No.:

5/868841

Inventors:

William J. Malinowski - Pembroke MA
William F. Doherty - Halifax MA

Assignee:

Chloride Incorporated - Tampa FL

International Classification:

G08B 1710
G01J 132
G01N 2126

US Classification:

340630

Abstract:

A photo-electric smoke detector operating on the reflected light principle which has a rate detector for detecting the rate of increase of smoke concentration. When the rate exceeds a predetermined value, the rate detector causes the intensity of the smoke detector light source to increase, thereby increasing the sensitivity of the detector. In one embodiment of the invention, after the intensity of the light has been increased by the rate detector, it is maintained at the higher intensity for a predetermined time, even if the rate of increase of smoke concentration falls below the predetermined value.

US Patent:

41444582, Mar 13, 1979

Filed:

Nov 29, 1977

Appl. No.:

5/855623

Inventors:

William F. Doherty - Halifax MA

Assignee:

Chloride Incorporated - Tampa FL

International Classification:

G01N 2126

US Classification:

250574

Abstract:

A smoke detector of the photo-electric type having a photo-responsive device viewing a volume illuminated by a light beam, in which a test member is provided for being temporarily positioned in the light beam so that one side of said member is exposed to the light and the other side is in the view of the photo-responsive device. The test member has an area near the forward edge which is thin in relation to the thickness of the rest of the test member. In one embodiment of the invention this area is thin enough to be translucent, so that the translucent area illuminated by the beam simulates a predetermined percentage of smoke in the beam with a high degree of accuracy, since the transmission characteristics of the translucent area can be consistently maintained within production tolerances, and the exact position of the translucent area in the light beam for the smoke simulation is not critical. In another embodiment of the invention, the thin area may or may not be translucent, and a small hole is provided therein extending completely through the thin area to pass a predetermined amount of light from one side of the thin area to the other.

US Patent:

39887251, Oct 26, 1976

Filed:

Dec 12, 1973

Appl. No.:

5/423934

Inventors:

William F. Doherty - Halifax MA

Assignee:

Pyrotector, Incorporated - Hingham MA

International Classification:

G08B 1712

US Classification:

340228R

Abstract:

A detector system particularly adapted for use in installation where the supply voltage is subject to wide variations comprises a detector which produces a voltage in response to a condition to be detected, a supervisory circuit, and an alarm actuator, in which the voltage signal produced by the detector when the predetermined condition exists, varies in proportion to line voltage, the alarm actuating means produces an alarm when the input signal rises to a predetermined percentage of the line voltage, and the supervisory circuit applies to the signal lead a supervisory voltage which also varies in proportion to the variation of line voltage.