Abstract: An apparatus for collecting and integrating radiation is disclosed. In embodiments, the apparatus comprises a shell configured to at least partially surround a sample container having a liquid sample contained therein. The liquid sample can comprise one or more liquids. The shell includes one or more inner surfaces with suitable reflectance for causing radiation that is at least one of scattered, reflected, diffracted, refracted, or radiated from one or more particles within the liquid sample to be redirected within the shell until the radiation is received by a detector.

Abstract: A low cost, self-stirring container is disclosed. In embodiments of this disclosure, the container has one or more protuberances extending from a bottom, a top, a sidewall, and/or an end cap of the container. In use, the one or more protuberances cause a liquid or mixture of liquids within the container to be stirred when the container is rotated about a longitudinal axis (e.g., central axis) of the container. In some embodiments, a rotary actuator (e.g., motor or servo) is coupled with the container or coupled to a holder securing the container. The rotary actuator repeatedly rotates the container N degrees in a first direction and M degrees in a second (e.g., opposite) direction, thereby imparting an oscillatory motion that causes the liquid or liquids within the container (and any particles contained therein) to be continually disrupted and mixed or stirred within the container.

Abstract: A low cost, compact, opto-mechanical system for particle analysis is disclosed. In embodiments of this disclosure, the system includes: a holder configured to rigidly secure a container that contains a liquid sample; an actuator configured to repetitively rotate the holder N degrees in a first direction and M degrees in a second direction different from the first direction, wherein N and M are real numbers greater than zero; a radiation source configured to generate a beam of radiation, the radiation source being rigidly attached to the holder; and a detector configured to receive radiation that is at least one of scattered, reflected, diffracted, refracted, or radiated from one or more particles within the liquid sample in response to the beam of radiation being incident upon the one or more particles.

Abstract: An integrating optical collector with a diffusely reflective interior surface and with at least one wavelength selective absorptive filter located therein in a position that nearly bisects the interior of the collector. The filters are highly transmissive in a first wavelength band corresponding to an emission band of a storage phosphor, but highly absorptive in a second wavelength band corresponding to a stimulation band of the phosphor. The filter's wavelength selective properties and nearly bisecting position in the collector minimizes re-illumination of a phosphor at the stimulation wavelength, while permitting efficient radiation collection and detection at the emission wavelengths. A cylindrical collector with two parallel lengthwise slits permitting passage of the scan beam to the phosphor surface is preferred. Two filter plates on opposite sides of the slit may be used, which can either be parallel to each other and to the slits or oriented at an angle with respect to each other.

Abstract: An absorption spectroscopy device for determining the concentration of a gas (such as oxygen) in a sample cell includes a neutral density absorber or a quarter wave plate. Laser radiation from a laser diode passes through the neutral density absorber or the quarter wave plate, then passes through the sample cell, and then is incident upon a detector. In some embodiments, the laser diode is driven with a drive current having a stepped periodic waveform.

Abstract: The absorption of laser radiation by a gas (such as oxygen and/or carbon dioxide) in human breath is detected on-airway by generating laser radiation using a laser diode, passing the laser radiation through a volume containing human breath multiple times, and detecting the laser radiation which is not absorbed by gases in the volume. To reduce the amount of energy required to control the laser diode, a laser diode is selected which generates laser radiation having a wavelength which is reasonably close to the wavelength of an absorption line of a desired gas when the laser diode is at or near normal body temperature. By passing the laser radiation through the sample gas multiple times, a longer path through the sample gas is provided for absorption thereby allowing the concentration of a gas having weak absorption lines (such as oxygen) to be determined using on-airway absorption detection.

Abstract: A laser diode/lens assembly wherein a lens (or multi-lens assembly) is immovably adhered to a housing of a laser diode package. The laser diode package may be a metal can style package having a substantially transparent window portion through which laser radiation is emitted when a laser diode inside the housing is supplied with current. The lens may be immovably fixed to an outer surface of this window so that a central axis of a beam of laser radiation emerging from the lens has a desired spatial relationship with a reference surface of the housing. An adhesive such as an epoxy adhesive which is cured under exposure to ultraviolet radiation may be used to freeze the lens in place to the window when the lens is correctly positioned. In accordance with some embodiments of the present invention, a lens is positioned in three dimensions (X, Y and Z) and then fixed in three dimensional space with respect to a laser diode housing.

Abstract: A spectroscopy device comprises a laser diode/lens assembly driven by a periodic stepped laser diode drive current. Each period of the stepped laser diode drive current has a plurality of constant current intervals: a left baseline interval, a left skirt interval, a peak interval, a right skirt interval, and a right baseline interval. The left and right skirt constant current intervals are used to lock the laser radiation emitted during the peak interval onto a preselected absorption line. The left and right skirt intervals are also used to obtain a value indicative of line width. The peak interval is used to obtain a value indicative of peak absorbance. Multiplying the peak and line width values together yields a value indicative of a gas concentration which is substantially independent of foreign gas line-broadening effects.

Abstract: A spectroscopy device comprises a laser diode/lens assembly driven by a periodic stepped laser diode drive current. Each period of the stepped laser diode drive current has a plurality of constant current intervals: a left baseline interval, a left skirt interval, a peak interval, a right skirt interval, and a right baseline interval. The left and right skirt constant current intervals are used to lock the laser radiation emitted from the laser diode onto a preselected absorption line. The left and right baseline constant current intervals are used to subtract baseline absorption measurements from peak constant current interval absorption measurements. A high frequency common mode noise rejection circuit rejects noise common to a monitor radiation detector and a radiation detector which detects radiation passing through a sample cell. A serial line locking cell is provided to allow locking when little or no absorbing material is present in the sample cell.

Abstract: In a printhead for electrostatic printers, the styli of the printhead are formed on a monolithic substrate, such as a printed circuit board. Each stylus has its own driver circuit incorporated into one or more integrated circuit die which are mounted directly on the monolithic substrate, and electrically connected to traces formed on the printed circuit board. The styli are the ends of the traces as formed on the edge of the substrate. The integrated circuit die are connected to the traces by wire bonding or TAB bonding. The printhead is implemented in monoscan, biscan, triscan, and various other configurations.

Abstract: A laser beam profiler having a movable member on which is mounted a means adapted to be moved through a laser beam for measuring the profile of the laser beam. The profiler comprises an interferometer which uses a multimode diode laser to generate a reference laser beam and a distance measuring laser beam. A retro-reflector is rigidly attached to the movable member and varies the path length of the distance measuring laser beam as the movable member is moved. A photodetector responsive to the reference laser beam and the distance measuring laser beam as said movable member is moved provides a frequency modulated output signal, said output signal having an envelope, the amplitude of which varies as a function of .DELTA.l, where .DELTA.l is the difference in the path lengths of said reference and said distance measuring laser beams, said interferometer, including said movable member, being so arranged that the amplitude of said envelope of said output signal is maximum when .DELTA.l is zero.

Abstract: Each of the plurality of styli contained in an electrostatic print head and used for placing an electrostatic charge on a dielectric coated medium has a rectangular cross section. The thickness of the cross section is selected such that the difference between the lowest voltage on the stylus at which the amount of electrical charge deposited on the dielectric medium for any increase in voltage on the stylus increases substantially in a linear fashion and the lowest voltage on the stylus at which an unwanted background image is formed on the medium is selected to have a value equal to or less than a selected number. In one embodiment this thickness is selected to minimize this difference. In another embodiment this thickness is selected to ensure that the electrostatic print head performs for some minimum lifetime.

Abstract: In a printhead for an electrostatic printer, the printhead styli are formed on a monolithic substrate, such as a printed circuit board material. Each stylus has its own driver circuit incorporated into one or more integrated circuit die which are mounted directly on the monolithic substrate, and electrically connected to traces formed on the printed circuit board. The styli are the ends of the traces as formed on the edge of the substrate. The integrated circuit die are connected to the traces by wire bonding or TAB bonding. The printhead is implemented in monoscan, biscan, triscan, and various other configurations. To fabricate the printhead, the printed circuit board material is ground to a precise thickness and conductive traces are photolithographically etched in copper foil laminated thereto. Using adhesives, the printhead is laminated together including supporting side plates, and in some embodiments multiple substrates, which are laminated together directed or by spacers therebetween.

Abstract: A plurality of hues of color or shades of grey are obtained on a print medium using an electrostatic printer by varying either or both the voltage applied to each styli in the print head and the time of application of such voltage.

Abstract: A registration system is provided for maintaining accurate correspondence between an image on a moving substrate and the action of an operating element with respect to the substrate. A comparison optical device is mounted such that the timing marks pass in correspondence with the comparison optical device when the substrate is moving. A detector senses the intensity of radiation reflected from the substrate through the comparison optical device and generates a firing signal based on the reflected radiation intensity. The firing signal is provided to the operating element to activate it in correspondence to the passage of the timing marks.

Abstract: A system for activating an operating element with respect to a moving substrate comprises a tracking line formed on the substrate, the tracking line having an activation mark formed therein which reflects light of an intensity which is distinguishable from that reflected from the remainder of the tracking line. A photosensor is mounted in relation to the tracking line to sense the intensity of light reflected from the tracking line when the substrate is moving. The photosensor generates an output signal indicative of the passage of the activation mark with respect to the photosensor. The output signal is utilized to activate the operating element.

Abstract: An electrostatic printing apparatus is disclosed having an improved optical scanner. The optical scanner is capable of directing a beam of radiation about a circular target zone. The scanner includes hollow shafted rotor having focusing and deflecting elements, rigidly mounted therein. The scanner can be readily adjusted to eliminate any timing errors.

Abstract: An encoding disk including a multiplicity of linear gratings placed accurately on the disk to diffract a light beam to a fixed point in space accurately does so independently of the centering of the disk on its axis of rotation.

Abstract: A structure for focusing, collimating or diverging the light beam from a solid state laser diode comprises means non-symmetrically mounted between the structure for holding the lens system and the means for holding the laser diode thereby to allow the laser diode to be adjusted in position relative to the lens system along the optical axis of the lens system. Surprisingly, the non-symmetrical mounting of the adjusting means relative to the optical axis of the lens system does not cause any substantial transverse movement of the laser diode relative to the optical axis of the lens system. In one embodiment, the adjusting means comprises a screw rotatably mounted such that one end of the screw is rotatably screwed into with the structure holding the lens system and the other end of the screw is in rotatable contact the structure holding the laser diode.

Abstract: An optical laser scanning system includes a hologram spinner disc (32) having diffraction grating facets (33) around its periphery. The spinner is susceptible to wobble and translational movement of the facets with respect to a plane perpendicular to the disc axis (35). Corrective means (37) in the form of a ray converging element (37) are provided to collect parallel diffracted rays from the facets in translated positions of wobble and converge such rays to a spacial spot scan (38) on an imaging surface (40). By orienting the spinner such that the diffracted light beam makes a 90.degree. angle with the incident light beam and then providing a parabolic cylinder to direct and focus the diffracted light beam on the imaging surface, the effects of both translational and angular wobble on the image formed are eliminated.