Abstract: A method of monitoring the deflocculation of particles in a suspension, which particles, when deflocculated, are such that they can become aligned in an applied field, comprises applying a beam of radiation to a region of the suspension, applying a field to the region and detecting a change, if any, in radiation scattering properties of said region due to the aligning of deflocculated particles if any, of the suspension in the field, the method comprising applying such a field to such a region of a first sample of suspension whose degree of deflocculatin is desired to be monitored and applying such a field to such a region of a second sample of suspension, whose particles are known to be substantially fully deflocculated, detecting the change in radiation scattering properties of each region due to the field to produce a respective output indication, and comparing the indications to produce an indication related to the degree of deflocculation of the particles in the first suspension.

Abstract: The specification discloses apparatus and methodology for calibrating optical-response tissue-examination apparatus of the type having an optical probe with at least one light-sending terminal portion adapted for introducing light into a test subject and a terminal portion for receiving resulting light from such subject. The calibration apparatus includes a body having outer walls which enclose an internal area and define an inlet aperture and an outlet aperture adapted to receive the terminal portions of the optical probe in a manner to substantially preclude entry or exit of ambient light. Means are included within said body for conveying inlet light from the test probe along a tortuous path communicating with the outlet aperture.

Abstract: A system for determining the position of an object in which a moving periodic pattern is projected onto the object. A sensor on the object generates a sensor signal related to the periodic pattern. A reference signal is generated relating to the position of the moving periodic pattern. The sensor signal and the reference signal are compared to determine the position of the object. The pattern may be generated by projecting light through two gratings which are separated and have the same pattern. Errors created by instability or nonisotropy can be corrected employing a third grating having a different pattern and generating a correction value related to the difference between the position of the object determined employing the pattern generated by the two gratings and the pattern generated by the third grating. The moving nature of the pattern may be created by employing a fixed projector and a moving mirror.

Abstract: A medium including particles to be analyzed is contained in a cell through which excitation rays are passed. The excitation rays are focused and have a predetermined wave form. A period in time of the excitation rays is set substantially equal to and preferably longer than the attenuation time of an acoustic pulse which is generated when the excitation rays are absorbed in the particle and when the particle release heat. The acoustic pulse is used to analyze particle size and number of particles.

Abstract: A Moire system for linear measurement of an unknown distance defined by two surfaces, a collimated light source, a first grating between light source and the surfaces, a second grating positioned to receive collimated light from the surfaces after the light has reached the surfaces from the first grating, the first and second gratings being rotated relative to each other by a small angle .theta., a screen located after the second grating for receiving Moire patterns caused by the first and second gratings, and a mechanism for shifting the patterns as a function of the unknown distance whereby measurements of the amount of shifting is determinative of the unknown distance.

Abstract: A method and apparatus for calculating the equivalent blackbody color temperature of incandescent lamps. A lamp analyzer having photosensors which detect the red and blue components of lamp radiation and convert the components to analog currents. The currents pass through a multiplex system and are converted into a signal with voltages proportional to the photosensor currents. A signal conditioner circuit removes switching transients, damped oscillations and cell noise from the circuit, and an automatic gain controller system insures linearity in the signal. The ratio of the blue component of the signal to the red component is then determined by a ratio computer, producing an output which is linearized and scaled by a translator to display the corresponding color temperature of the lamp in Kelvins.

Abstract: A method whereby the circuit pattern on a photographic mask or a reticle used in the manufacture of semiconductor devices is inspected for defects by an image processing technique. In this inspection method, the pattern of the mask is printed on a photosensitive member prepared by forming an opaque or semitransparent photosensitive layer on a transparent substrate and an image of the printed pattern formed on the photosensitive member is inspected by the image processing technique.

Abstract: A method and apparatus for determining the luster of a surface as a numerical value. The apparatus projects light from a light source through a light diffusing layer and through a layer of semitransparent material having thereon groups of parallel lines for projecting the lines onto the surface of a sample the luster of which is to be determined. The lines projected onto the surface are viewed with the eyes and the degree of distortion among the lines in the respective groups, which occurs due to the various conditions of the surface which affect the luster thereof, and to which has previously been assigned a numerical value, is determined, the numerical value of the thus determined degree of distortion for one group of figures being for the degree of gloss of the surface and the numerical value of the thus determined degree of distortion for another group being for the degree of clarity of the surface.

Abstract: An alignment device for aligning a reticle and a wafer with the aid of a projection lens system for projecting an integrated circuit pattern of the reticle onto the wafer, wherein a light beam from the wafer is passed throught the projection lens and is directed by way of an objective lens to a spatial filter to detect a positional relation between the reticle and the wafer. According to the position of an optical axis of the objective lens relative to an optical axis of the projection lens and according to the telecentricity of the projection lens, the spatial filter is displaced relative to the optical axis of the objective lens, whereby a particular component of the light beam from the wafer is positively extracted out, without being affected against by displacement of the objective lens for the alignment operation.

Abstract: The surface texture of a moving transparent film is determined by applying a beam of collimated electromagnetic radiation at an angle of incidence sufficient to produce detectable backscattered radiation; collecting the backscattered electromagnetic radiation while avoiding specularly reflected radiation; and evaluating the intensity of the collected radiation for two components, a first component corresponding to the haze percent of the film and arising from the scattering of the collimated electromagnetic radiation by microscopic and submicroscopic features of the film surfaces, and a second component produced by the scattering of the collimated electromagnetic radiation by macroscopic surface blemishes, gouges and gel-like particles on each surface of the transparent film.

Abstract: The measuring device is used for determining a relative position between a first item and a second item or the image thereof. The items are displaceable or rotatable relative to one another. The first item has a code carrier, which is arranged along a path. The code carrier is provided with a code pattern at right angles to the path. The second item has a code reader oriented on the code carrier path. A computer is connected downstream of the code reader and has means for quantifying the signal supplied by the code reader and for comparing with a stored code image of the code carrier, as well as for calculating the relative position from the comparison result. This measure permits automatic reading of the position, accompanied by a very high measuring accuracy. The measured result can be digitally displayed and, if required, can be directly stored on a data carrier and/or can be further processed in a computer.

Abstract: A method and apparatus for the on-line determination of the bonding strength of a plural layer laminate having at least one outer layer transparent to electromagnetic radiation, said method comprising: directing a collimated beam of electromagnetic radiation onto the substantially flat surface of said laminate at an incident angle substantially greater than a normal to the surface of said laminate; measuring the reflected intensity of said electromagnetic radiation at two substantially different diffuse reflectance angles; converting said reflected intensity to an intensity ratio by dividing the greater intensity value by the lesser intensity value to obtain a value which is proportional to the adhesion of the laminate based upon a pre-determined relationship of the bonding strength of said laminate and the value of said intensity ratio.

Abstract: Printed webs leaving a printing press at speeds above 500 feet per minute are inspected with precision across the full width of the web by a stroboscope method and apparatus. Each repetitive image or design imprinted on the high speed web is rendered stationary relative to the eyes of a viewer at a web inspection station by bright short flashes of light emitted by an elongated xenon flash tube or tubes spanning the web transversely of its path of movement. Filtered light flashes are triggered by an improved strobe circuit which is synchronized with the press at all times and permits an inspector to produce from one to six equally spaced images per press cylinder revolution. Additionally, the system can be used in either an image lock mode for side-by-side comparison with a standard or in a controlled pan or scroll mode to allow optimal inspection of entire impression sequences. Also, when desirable, both sides of the web can be inspected by utilizing a second flash tube configuration located behind the web.

Abstract: A photoelectric length or angle measuring system for measuring the relative position of two objects includes a graduation of a scale which is scanned by a scanning plate of a scanning unit. The scanning unit includes an illuminating unit for the illumination of the graduations of the scale and the scanning plate. In this illuminating unit there is arranged a light emitting diode on a surface of a carrier. For the improvement of the light radiating characteristics of the illuminating unit, reflections in the direction of the graduations of the scale and the scanning unit of light beams emerging laterally from the light emitting diode are avoided by properly configuring the surface of the carrier. In alternate embodiments, this surface of the carrier consists of a light absorbing material, is covered by a light absorbing material, or is provided with a dimension along the measuring direction no greater than that of the light emitting diode.

Abstract: An oximeter for measuring oxygen saturation in arterial blood includes a light source for projecting light to a body member to be measured, a light responsive circuit for receiving the light which has transmitted through said body member and for generating at least first, second and third signals at three different wavelengths, and a calculator for calculating at least first SaO.sub.2 data using first and second signals and second SaO.sub.2 data using first and third signals. It is detected whether or not a difference between the first and second SaO.sub.2 data is within a predetermined level. When the difference is within the predetermined level, it is assumed that the first and/or second SaO.sub.2 data are valid, but if not, they are assumed as invalid.

Abstract: A system for characterizing miniature optical sources such as laser diodes is disclosed. In its most convenient form the system includes an optical system for collecting a wide angle beam and collimating the beam into substantially parallel rays. In the substantially parallel beam, equal area angular portions of the wide angle beam should correspond to equal areas in the parallel beam. Optical sensors are utilized to generate signals indicative of the intensity of the parallel optical beam. Digital processing is included to calculate the characteristics of the optical beam from the intensity samples of the parallel beam. In one embodiment, a reflecting plane is positioned between the source and the optical system so that Lloyd's fringes are produced in a measurement plane.

Abstract: A plurality of sample beam wavefronts derived from selected portions of a wide-aperture outgoing optical beam wavefront enter an entrance pupil (11) located adjacent a focal surface (12) on which the sample beams are individually focussed. A relay lens system (13) transmits the sample beams to a beam splitter (14), which divides each of the sample beams into an undeviated component and a diviated component. The undeviated components of the various sample beams image the entrance pupil (11) on a first scanning mirror (15), and the deviated components image the entrance pupil (11) on a second scanning mirror (16). The focal surface (12) is reimaged by the relay lens system (13) onto focal planes (17 and 18), respectively, so that the foci of the individual sample beams appear as spots on the focal planes (17 and 18).

Abstract: An optical displacement sensor comprises a light source 2 coupled to an optical fiber 1 the end 5 of which is directed onto a reflector 3 the displacement of which is to be measured. A lens 4 of appropriate focal length is positioned between the end of the optical fiber and reflector 3 to focus the light emitted from fiber 1 onto reflector 3 so that the amount of light reflected back is a function of the position of reflector 3. A signal detector 6 is also coupled to fiber 1 to detect and measure the light reflected back from reflector 3. Additionally a further light source 8 optical fiber 7 and detector 10 are provided with the end 9 of fiber 7 positioned at the focus of lens 4 so that the light reflected back to detector 10 is independent of the position of reflector 3. The ratio of the measurements from the two detectors gives the position of the reflector 3 with compensation for the effects of the deterioration of its reflectance.

Abstract: A method of determining the displacement of a fiber optic sensor from a target in which a first lens is spaced from the target at a first distance an a second lens is spaced from said target at a second distance which provides the greatest intensity response at said first distance and thereafter spacing said first lens from said second lens to provide symmetrical slope values of response.

Abstract: A microtiter plate reader is disclosed which allows visual examination of the contents of the wells of a microtiter plate having an array of wells. The microtiter plate reader includes supporting means for supporting the microtiter plate with the wells opening generally upwardly and a light emitting surface is adapted to extend under a microtiter plate so held. Regions of reduced light emission on the light emitting surface are arranged in an array corresponding in relative position to a selected portion of the array of microtiter plate wells. Locator means are provided for locating the microtiter plate with respect to the array of regions of reduced light emission to allow selective alignment of the wells with the dark regions, providing a dark background to the bottom of the wells which are then illuminated indirectly. The wells can be illuminated directly when the dark regions are out of alignment with the wells.