Abstract: An apparatus for measuring the reflectivity of a product for use in optical sorting machines that is tolerant of background and product trajectory variations. The apparatus computes the percent of the viewing frame filled by the product at any instant as well as the reflectivity of the background when no product is present. The reflectivity at selected wavelengths from selected perspectives is computed for a product as the product passes a viewing frame by correcting for frame fill and background factors. Given an estimate of product velocity, product size may also be estimated.

Abstract: Method for the measurement of the difference in the optical properties dependent on the light direction of two samples (1,2), in which method one or several sources of light (3 to 6) as well as one light detector (7) are used. According to the invention, both of the samples (1, 2) are illuminated simultaneously and from both samples (1, 2) the light is passed simultaneously to the light detector (7). The lights to be measured from the samples (1, 2) have different directions in relation to the sample. The directions of the lights to be measured from the samples (1, 2) are alternated with each other at an appropriate frequency, such as a frequency within the range of 1 c/s to 10,000 c/s. The AC signal given by the light detector (7) is used as a measure of the difference in some optical property dependent on the direction of light between the samples, such as, e.g.

Abstract: In order to obtain an objective measurement of paint gloss on a flat or slightly curved surface, a distinctness of image instrument is provided having a light source for projecting a light beam onto the test surface, a detector responsive to reflected light from the surface, an aperture at the detector, a chopper near the light source and a lens for imaging the chopper blade on the plane of the aperture so that the sharpness of the image depends upon the reflective quality of the test surface. The rate of change of the detector output signal is large for a high glass surface while the rate of change is low for a low gloss surface. For use of the instrument on curved as well as flat surfaces the chopper is provided with a plurality of blades spaced at different distances from the light source.

Abstract: In a reflectance measuring instrument, an integrating sphere is provided to illuminate the sample of which the reflectance is to be measured. A first fiber optic cable is provided to receive a light beam reflected by the sample and a second fiber optic cable is positioned to receive a light beam reflected from the wall of the integrating sphere. The transmitting ends of the fiber optic cables are mounted in a pivoted plate to selectively position the transmitting ends to emit light into the entrance slit of a monochromator.

Abstract: A method and apparatus for automatically monitoring the amount of batch material floating on an irradiant pool of melt in a glass melting furnace is disclosed. A video camera is positioned so as to view the surface of the batch and melt mixture through a window formed in a wall of the furnace tank. The video signal is digitized by a computer into a plurality of pixel signals. The pixel signals can be utilized to generate a histogram relating the number of digitized pixel signals to a relative light intensity scale. The generated histogram will be bimodal, with one peak centering around a lower scale value corresponding to the darker batch pixels and the other peak centering around a higher scale value corresponding to the lighter melt pixels. A suitable threshold, such as the minimum point between the two peaks, can be selected to separate the two peaks.

Abstract: A storage rack entry vehicle for transporting loads in a warehousing system includes infrared radiation source and detector units which determine the relative position of the vehicle and load. The optical axes of the source and detector are parallel and closely-spaced. When infrared radiation from the source is scattered by the load (or a pallet carrying the load), some of the radiation is reflected back to the detector along a path substantially parallel to the optical axes. The maximum range of detection is controlled by adjusting the gain of an amplifier which forms part of the detector.

Abstract: A photometer comprising a light source, a rotating plate provided with a plurality of filter means having different wave lengths, a reference plate and a sample means, said rotating plate disposed between said light source and said reference plate and sample means, and a half-mirror and a reflection plate located between said light source and said rotating plate, said half-mirror and reflection plate being disposed so as to form a first light passage adapted to extend to the reference plate, and a second light passage adapted to extend to the sample means, whereby alternate radiation through one of said filter means against the reference plate and the sample means is made by the rotation of said rotary plate.

Abstract: An analysis instrument for measuring the quantity of a constituent present in a sample of a material comprises a housing having a sample receptacle mounted therein to receive a sample of the material. A filter assembly is mounted in the housing including a plurality of filter elements for passing a corresponding plurality of predetermined frequencies of radiant energy. A motor is provided for selectively providing relative movement between the sample receptacle and filter assembly so as to place individual ones of the filter elements into registry with the sample receptacle. A radiant energy source is mounted within the housing to direct radiant energy onto the surface of the sample through selected ones of the filter elements as each moves into registry therewith, to provide reflected radiant energy at the predetermined frequency of each of the selected filter elements. A sensor is mounted to receive the reflected radiant energy and provide electrical signals corresponding thereto.

Abstract: A device for establishing the magnitude of irregularities at a surface includes a laser directing a beam of light, obliquely towards said surface, a photodetector mounted so as to catch a beam of light reflected from an irregularity at said surface, and a diffraction grating mounted in the path of a beam, mirror-image reflected from said surface and movable in relation thereto. The photodetector is provided with means for measuring the frequency and the amplitude of the time-dependent photocurrent caused by the interaction between the beam reflected from the irregularity and a further beam deflected by the diffraction grating from the mirror-image reflected beam.In a modified version the device may be used for measuring flow velocity, the laser and the photodetector being mounted to opposite sides of a flow path defined by transparent walls.

Abstract: a retroluminometer for measuring retroreflectivity of signs or markings at their actual point of use comprises (1) a source of alternating light; (2) optical means for both directing the alternating light onto a sign or marking that is to be tested and for transmitting light retroreflected by the sign or marking onto a panel within the retroluminometer; (3) a matrix of light-transmitting means arranged on the face of the panel; (4) photosensing means optically connected to the light-transmitting means and adjustable to sense and measure the light from different ones of the light-transmitting means, thereby measuring retroreflection at different angles of deviation from the axis of the light beam incident on the sign or marking; and (5) electric circuitry for presenting the photosensed light as a visually-readable measurement.