David W Lederer

US Patent:

39744884, Aug 10, 1976

Filed:

Mar 14, 1975

Appl. No.:

5/558296

Inventors:

David B. Lederer - Rochester NY

Assignee:

Detection Systems, Inc. - Fairport NY

International Classification:

G08B 1300

US Classification:

340214

Abstract:

A switch incorporated in a photoelectric intruder detection system provides a simple means for testing the system for a predetermined margin of safety from false alarm producing sources. Upon actuation of the switch, the sensitivity of the system is reduced by a predetermined factor, such factor representing a predesired margin of safety from false alarms. During installation of the system, the switch is actuated to reduce system sensitivity. Upon positioning the system components to provide a desired catch capability, the switch is deactuated, thereby increasing the system sensitivity to a level which provides a margin of safety equal to or greater than the amount of gain reduction effected by the switch.

US Patent:

D2930897, Dec 8, 1987

Filed:

Feb 1, 1985

Appl. No.:

6/697159

Inventors:

David B. Lederer - Rochester NY

Assignee:

Detection Systems, Inc. - Fairport NY

US Classification:

D10106

US Patent:

49202685, Apr 24, 1990

Filed:

Jan 31, 1989

Appl. No.:

7/304025

Inventors:

Robert E. Walters - Webster NY
David B. Lederer - Rochester NY

Assignee:

Detection Systems, Inc. - Fairport NY

International Classification:

G01J 508

US Classification:

250353

Abstract:

A passive infrared detection system includes a reflective optical system comprising a focusing element (e. g. an elliptical or parabolic reflector) having an apparent focal length dependent upon the displacement of incident rays from the optical axis of such element, and a plurality of planar reflectors arranged at different angles with respect to such optical axis to provide the detection system with a plurality of different zones of detection, each having a different maximum detection range associated with it. According to the invention, the planar reflectors are arranged with respect to the focusing element so that each planar reflector cooperates with a different portion of the focusing element to project onto an IR detector located at the focus of such focusing element a relatively constant size image of a given target located at the maximum detection range associated with that planar reflector. Such an optical system provides the detection system with more uniform sensitivity from one zone of detection to another.

US Patent:

D2617404, Nov 10, 1981

Filed:

Nov 5, 1979

Appl. No.:

6/091107

Inventors:

David B. Lederer - Rochester NY

Assignee:

Detection Systems, Inc. - Fairport NY

International Classification:

D1005

US Classification:

D10106

US Patent:

57215294, Feb 24, 1998

Filed:

Aug 1, 1996

Appl. No.:

8/691153

Inventors:

Burton Warner Vane - Fairport NY
David Bush Lederer - Sodus Point NY

Assignee:

Detection Systems, Inc. - Fairport NY

International Classification:

G08B 2900

US Classification:

340515

Abstract:

A smoke detector is provided with testing apparatus for determining if its sensitivity is within a predetermined acceptable range. The testing apparatus stores in the detector a range representing acceptable sensitivities. When a test is initiated the resulting test output is compared to the sensitivity range, or its representation, and a warning signal is provided when the output is not acceptable. According to one feature, the stored representations of the acceptable range include a maximum acceptable value and a minimum acceptable value, and the warning signal indicates when the output is above the maximum or below the minimum. According to other features, the output signal is periodic at one frequency when above the maximum and at another frequency when below the minimum. The test is initiated by a magnetic reed switch and the results are immediately apparent. Each smoke detector is calibrated on an individual basis that accounts for its particular electrical response, and the calibration information is retained in the detector wherever it goes after installation.

US Patent:

46894861, Aug 25, 1987

Filed:

Nov 29, 1985

Appl. No.:

6/802683

Inventors:

David B. Lederer - Rochester NY

Assignee:

Detection Systems, Inc. - Fairport NY

International Classification:

G01J 100

US Classification:

250338

Abstract:

A folded modular optical system adapted for use, for example, in a passive infrared intruder detection device for directing radiation from a plurality of discrete fields of view onto a radiation-sensitive detector comprises an elongated rectangularly-shaped spherical reflector and a multifaceted reflective element. The latter comprises a plurality of elongated, generally parallel, planar reflectors which serve to direct radiation onto different portions of the spherical reflector. To minimize the effects of spherical aberration, the planar reflectors are arranged so that the portions of the spherical reflector which they irradiate are substantially perpendicular to the longer dimension of the rectangularly-shaped spherical reflector. Preferably, each of the planar reflectors is canted relative to the others so that its field of view is substantially co-planar with those of the other planar reflectors. It is also preferred that the planar reflectors vary in size and, hence, light-gathering power as a function of the intended range of protection they provide.

US Patent:

41737172, Nov 6, 1979

Filed:

Jan 27, 1978

Appl. No.:

5/872885

Inventors:

David B. Lederer - Rochester NY

Assignee:

Detection Systems Inc. - Fairport NY

International Classification:

H01J 502

US Classification:

250239

Abstract:

An optical assembly comprising a spherically shaped optical module. A flexure member cooperates with a portion of a supporting housing to support the module for rotation in two mutually perpendicular planes. The assembly is particularly useful in photoelectric beam systems commonly known as "electric eyes".

US Patent:

42246083, Sep 23, 1980

Filed:

Nov 13, 1978

Appl. No.:

5/960464

Inventors:

David B. Lederer - Rochester NY

Assignee:

Detection Systems, Inc. - Fairport NY

International Classification:

G08B 1318

US Classification:

340556

Abstract:

A single terminal detection system of the beam variety is provided with polarizing filters to sense "near-field" problems. One filter polarizes radiation reflected back to the transceiver component and a second filter, positioned within the transceiver, polarizes radiation before it is incident upon one of two radiation detectors. Circuitry, operatively coupled to the detectors, actuates an alarm in the event either an alarm condition or a near-field problem exists.