ROBERT GEORGE KNOLLENBERG
Pilots at Canon Vw Rd, Boulder, CO

4571079, Feb 18, 1986

Dec 29, 1983

6/566863

Robert G. Knollenberg - Boulder CO

Particle Measuring Systems, Inc. - Boulder CO

G01N 1502, G01N 2100

356336

An aerosol sampling device and method are disclosed having improved sample flow characteristics. Sample flowing through an inlet nozzle is heated prior to discharge from the nozzle toward a measurement area to maintain sample flow more nearly laminar by compensating for the adiabatic cooling that occurs due to acceleration of flow through the nozzle. In addition, heating of the sample flow prevents condensation which can result with ambient air having a relative humidity of fifty percent. An optical particle measuring apparatus is shown having a generator for providing a laser beam, the path of which is through a measurement area, and an inlet nozzle through which aerosol sample is injected into the measurement area, after heating in accordance with this invention, to allow operation of the laser at a relatively high Q by reducing non-laminar flow characteristics.

4798465, Jan 17, 1989

Apr 14, 1986

6/851477

Robert G. Knollenberg - Boulder CO

Particle Measuring Systems, Inc. - Boulder CO

G01N 1502, G01N 2100

356336

A detection device is disclosed for determining particle size from particle effected light scattering in a sensing region receiving the particles in a gas carrier, such as air, and a laser beam to illuminate the sensing region. Background light from molecular scattering is reduced to a level that enables light scattered by particles having a size of at least as low as about 0. 1 micron to be sensed in a high background of molecular scattering such as, for example, where molecular scattering can exceed the 0. 1 micron particle's scattering by one hundred times. High molecular scattering is generated whenever the gas volume being viewed is large as is required for high flow rates, high molecular density (high pressures), or large gas molecules. This high sensitivity at high molecular scattering background is achieved through use of a linear array of detectors positioned, with respect to an imaging system, so that each detector monitors a different portion of the sensing region and provides an electrical output signal indicative of sensed particle presence within that portion monitored. The output signals from the detectors are parallel processed and coupled to a converter which provides an output indicative of the particles sensed in the entire sensing region.

4011459, Mar 8, 1977

Dec 5, 1975

5/638015

Robert George Knollenberg - Boulder CO
Robert E. Luehr - Boulder CO

Particle Measuring Systems, Inc. - Boulder CO

G01N 2126, H01J 3912

250576

Method and apparatus for establishing a valid sample volume in a beam of radiation, wherein a sample stream is introduced substantially transversely to the radiation beam, an optical system is configured to produce images on first and second image planes, the two planes preferably being perpendicular to one another and established by means of a beam splitter, first and second photosensors being positioned in the image planes, the first photosensor having greater optical and an electronic gain and a masked portion, and the second photosensor being either unmasked or having masked portions corresponding generally to the unmasked portions of the first photosensor, the first photosensor being connected to comparator means and the second photosensor also being connected to the comparator means which accepts data only when the signal from second photosensor is of a greater magnitude than the signal from the first photosensor, whereby images on the photosensors from points outside the selected sample volume will be oriented with a sufficient portion of the image on the unmasked section of the first photosensor to produce a signal greater than that produced by the second photosensor thus rejecting data from that event.

4594715, Jun 10, 1986

Nov 17, 1983

6/552689

Robert G. Knollenberg - Boulder CO

Particle Measuring Systems, Inc. - Boulder CO

H01S 310

372 32

A laser having a stabilized external passive cavity is disclosed, with stabilization being effected by modulation of an external mirror positioned along the laser axis. The laser system includes first, second and third spaced mirrors with the second mirror being an output coupler positioned between the first and third mirrors so that an active cavity is defined between the first and second mirrors and a passive cavity is defined between the second and third mirrors. The active cavity feeds, or pumps, the passive cavity which is stabilized by modulation of the third mirror by movement along the laser axis by linear oscillation to Doppler shift the reflected waves within the passive cavity and thereby produce frequencies that do not interfere with the stable modes of the active cavity. By stabilization of the passive cavity, advantages of an intercavity laser device can be realized without incurring the practical disadvantages of such devices, and results in a laser device that is particularly well suited for particle size measurement.

4636075, Jan 13, 1987

Aug 22, 1984

6/643665

Robert G. Knollenberg - Boulder CO

Particle Measuring Systems, Inc. - Boulder CO

G01N 1514

356336

Particle measurement is disclosed utilizing orthogonally polarized components of a laser beam. A laser beam is split into orthogonally polarized components and at least one of the components is thereafter beam shaped to have a modified dimension. The components are then recombined and focused to provide a beam combination that is directed through a particle containing volume where scattering of the components occurs by the particles. With the components superimposed upon one another, a localized volume is created with one beam being contracted to a smaller volume than the other beam with the illumination intensity ratios thereat being either greater or less than unity depending upon the optics selected. Particle scattering events are observed within the localized volume in order to define those particles transitting through its central uniform intensity region (sample volume) independent of viewing circumstance by comparing scattered intensity ratios of the orthogonally polarized beam components using a polarizing analyzer and a pair of detectors. The scattering intensities measured of those particles transitting through the preferred sample volume are retained as valid size measurements.

5459569, Oct 17, 1995

Apr 21, 1993

8/051055

Scott C. Knollenberg - Boulder CO
Robert G. Knollenberg - Boulder CO

Particle Measuring Systems, Inc. - Boulder CO

G01N 2100, G01N 2105

356338

A modular particle detecting device is disclosed for nonintrusive in-situ detection of particles passing through a sensing region. The device is particularly useful for microcontamination control in semiconductor processing environments, and includes, as separate components, a viewing unit and a sensing unit. The viewing unit has a detecting window and heated illuminating and discharge windows for condensation control. A fluid passage connectable to a flow line enables particle-carrying fluid to pass through a sensing region within the passage. The sensing unit has illuminating circuitry for providing light through the illuminating window to the sensing region, and has detecting circuitry to receive, through the detecting window, light scattered at the sensing region to thereby detect particles in fluid then at the sensing region without physical intrusion of the sensing unit into the sensing region. The sensing unit is mounted on the viewing unit when operationally positioned, and is readily removable to allow servicing and/or alternate use without interupting fluid flow through a flow line having the viewing unit connected therewith.

5493123, Feb 20, 1996

Apr 28, 1994

8/234402

Robert G. Knollenberg - Boulder CO
Vaughn C. Hoxie - Longmont CO
Clinton E. Utter - Aurora CO

Particle Measuring Systems, Inc. - Boulder CO

G01N 2147, G01N 2188

250372

System and method are disclosed for inspecting objects, such as sheets of flat panel glass, to detect flaws or contamination at a surface. The surface to be inspected is illuminated with 253. 7 nm ultraviolet (UV) radiation to assure detection of defects only at the front surface subjected to the radiation. UV radiation reaching the front surface is scattered by defects at the front surface, and scattered UV radiation is collected by a UV dark field imaging system and directed by the imaging system to a detecting unit, preferably including a charge coupled device (CCD). The detecting unit senses UV radiation scattered at the surface due to defects within a selected size range and provides an output to a processing unit providing an output indicative of the defects sensed within the selected size range. The illumination system preferably illuminates the entire surface to be inspected, an enclosed dark field chamber having shielding houses the illuminating source and radiation collecting system, an anti-reflecting UV coating is preferably used, as is a bandpass filter, and the detecting unit is preferably cooled, accompanied by heating of the imaging system. The system is capable of detecting defects at least as small as five microns using a ten second sampling period.

4728190, Mar 1, 1988

Oct 15, 1985

6/787602

Robert G. Knollenberg - Boulder CO

Particle Measuring Systems, Inc. - Boulder CO

G01N 2100

356336

A device and method are disclosed for optically detecting particles in a fluid. A fluid passage with transparent walls defining a monitoring volume, or region, is provided, and particles in the fluid are optically detected by directing a laser beam through the fluid in the monitoring region and collecting light scattered by the particles. A capillary is utilized as the fluid passage, and reflections from the walls of the capillary are effectively precluded. The laser beam is directed through the capillary by means of a window at the entrance side and a lens at the collecting side with the air-glass interfaces being outside the depth of view of particle monitoring within the monitoring region. As a result of this arrangement, the amount of scattered light is greatly reduced and a more uniform light signal is achieved which results in better size resolution of particles than has heretofore been achieved.

5282151, Jan 25, 1994

Feb 28, 1991

7/662441

Robert G. Knollenberg - Boulder CO

Particle Measuring Systems, Inc. - Boulder CO

G01N 1502

364555

Submicron diameter particle detection utilizing a high density array is disclosed. The high density array, such as a charge coupled device, is utilized to detect light scattered at a sensing region by particles illuminated by a light source, such as a laser source. Charge storage is utilized to buffer each data frame transferred from the high density array and the multiple serial outputs are processed by parallel processing that includes threshold detection and analog-to-digital converting. A micro-computer and associated digital storage receives the digital outputs and provides outputs indicative of submicron particle sizing. Further improvement in minimum detectable particle sizing of particles carried by a fluid is realized by use of beam shaping optics to shape the illumination beam passed through the sensing region to form either an astigmatic (highly elliptical) beam cross-section, with the fluid being directed towards the imaging system orthogonal to the object plane, or a circular beam cross-section with the flow directed parallel to object plane, and with the focal point of the beam being substantially centrally positioned within the sensing region in either case.

4740988, Apr 26, 1988

Nov 12, 1986

6/929497

Robert G. Knollenberg - Boulder CO
Ramin Lalezari - Denver CO
Kenneth R. Sample - Longmont CO

Particle Measuring Systems, Inc. - Boulder CO

H01S 303

372 99

A laser device is disclosed having mirror heating to enhance performance of the device by minimizing induced light absorption to thereby improve mirror quality. The mirrors of a laser device are commonly made of a substrate having a coating thereon formed by alternating layers of high and low refractive index materials, normally classified as refractory oxide materials, which materials are susceptible to formation therein of color centers, such as formation of F-centers when exposed to ultraviolet light, which color centers reduce mirror quality due to induced light absorption losses. By heating the mirror, the F-centers are substantially eliminated to thereby improve mirror quality and enhance the longevity of the laser device.