Abstract: In a distance measuring apparatus which performs a distance measuring operation in an active mode and in a passive mode, time serially, on a basis of charging conditions determined for performing the distance measuring operation in one of the active mode or the passive mode, charging conditions to be used in the distance measuring operation in the other mode are determined.

Abstract: A multi-slit spectrometer is combined with a two-dimensional detector array to enable simultaneous spectral analysis of several objects, improving the signal-to-noise ratio of multispectral imagery. The multi-slit spectrometer includes a multi-slit structure defining a plurality of parallel thin slits, and a first lens for directing object light onto the multi-slit structure. A second lens collimates and directs light which has passed through the slits of the multi-slit structure onto a light dispersing element such as a dispersing prism or a diffraction grating. A third lens focuses light which has passed through the light dispersing element onto the two-dimensional detector array at an image plane. A two dimensional detector array of detector elements is placed at the image plane. The slits are separated by a separation distance equal to an integral multiple of the detector width dimension, where the multiple is equal to (N times the number of slits) plus or minus one, where N is an integer.

Abstract: A reference system for an optical wavelength scanner, used for measuring wavelengths of radiation from an optical device. The system utilizes a wavelength reference comprising a fixed fiber Fabry-Perot (FFP) filter in combination with a reference fiber Bragg grating (FBG) having an accurately known reflection wavelength to minimize the effects of drift and non-linearities in the scanner and to allow a simple flexure element to be used to position a dispersive grating. The wavelengths of the reference comb of the fixed FFP are determined by reference to that of the reference FBG. Then, the peaks or notches in the light intensity from the device under test are located with respect to the comb of peaks produced by the reference. In a most simple embodiment two ports are coupled so as to provide their output light to the dispersive element simultaneously and only a single collimating lens is required for collimating light from the output ports.

Abstract: A distance measuring apparatus having skimming function which suppresses electric consumption when a charge storing period is shortened by an electronic shutter function. For this purpose, at an initial setting, an integration period is set to T.sub.1 by ICG pulse and ST pulse, and ON and OFF periods of light emitting diode IRED are set to the same periods. In the ON period, photoelectric conversion is performed on reflected light from a measurement object, and the obtained charge is stored. In the OFF period, a predetermined amount of charge is eliminated by an ICG pulse a, then after the period T.sub.1, the stored charge is transferred to a storage unit on the next stage by an ST pulse b. If an output voltage after several storing operations is higher than a skim judgment voltage, the integration period T.sub.1 is reduced in half, and the ON period of the IRED is shortened.

Abstract: A distance measuring apparatus for a camera includes light-projecting means for projecting a light beam onto an object of distance measurement, and a pair of sensor arrays, each including a plurality of pixels located at respective pixel positions for receiving reflected light of the light beam reflected by the object of distance measurement and outputting a signal corresponding to the amount of reflected light received. The apparatus further includes phase difference detection means for detecting a phase difference between signals output from the pair of sensor arrays, distance measuring means for measuring a distance to the object on the basis of the phase difference, and shortest range discrimination means for discriminating whether the object of distance measurement is in a shortest range, on the basis of levels of maximum values of signals output by said pair of sensor arrays, where the shortest range is a distance or range at which photography can not be performed.

Abstract: A monochromator according to the present invention has an arm 1 rotatably mounted on a rotation shaft 3, and a diffraction grating 6 is fixed to the arm 1. The arm 1 is rotated by a linear motor 9 including a moving part 91 fixed to the arm 1 and a stator part 92 fixed to a base 2. The linear motor 9 is a voice-coil linear motor constructed to allow the arm 1 to rotate reciprocatively around the rotation shaft 3 within a preset angular range. The absolute rotational position of the arm 1 is detected by a rotary encoder 7 including a crossbar 71 fixed to the arm 1 and a encoder block 72 fixed to the base 2. Based on the output signal of the rotary encoder 7, the linear motor 9 is controlled so that the moving part 92 rotates at a fixed angular speed around the rotation axis 3. Thus, the wavelength scanning is carried out at high speed, and sampling of monochromatic light having desired wavelengths is performed accurately.

Abstract: A sensor apparatus which accumulates charges, generated in a sensor array having a plurality of photoelectric conversion elements, in a plurality of accumulation units, and integrates the charges using transfer units having a less number of transfer sections than the number of accumulation units. The plurality of photoelectric conversion elements are grouped into a plurality of groups, a part of the groups is selected, and charges generated by photoelectric conversion elements which belong to the selected group or groups are integrated using the transfer unit.

Abstract: Fourier transform spectrometer using a multielement liquid crystal display. A ferroelectric liquid crystal mask is used as an optical encoder for a solid-state Fourier transform spectrometer. A 1.times.64 element array was striped and used as a 1.times.4 element device. The device intersected dispersed radiation and encoded each spectral component thereof with a carrier signal by applying half-wave potentials to each of the four striped (1.times.16) liquid crystal elements which varied the transmitted amplitude of the light from 0.03% to 28% of full scale. The light was spectrally recombined and imaged onto a photomultiplier and the resulting carrier frequencies (and their amplitudes) detected by Fourier transformation of the time-varying signal. Spectra of colored-glass filters were taken to demonstrate the spectrometer.

Abstract: In a spectroscopic instrument having a spherical grating to disperse incident light into a spectrum, the grating is oscillated on axis to scan the light passing through an exit slit through the spectrum or a portion of the spectrum. The axis of rotation of the grating is shifted to be displaced from tangent to the center of the spherical grating so that the light passing through the exit slit is substantially focused throughout the spectrum scanned by the instrument. The grating is mounted in the holder to shift the center of gravity of the grating and the holder to be on the axis on which the grating is pivoted.

Abstract: A digital image processing system reduces errors in the parameters of a sensor geometry model, through which points in a captured digital image are geolocated to the surface of the earth by means of a `real time` co-registration mechanism that refines the geometry model associated with the working image in a matter of seconds. Using a co-registration mechanism such as that described in the U.S. Pat. No. 5,550,937, the system co-registers the reduced accuracy working digital image with a reference image, geographical spatial locations of respective pixels of which have been previously determined with a high degree of accuracy. The imagery co-registration operator adjusts the respective geometry models associated with its input images, in accordance with differences in cross-correlations of the respectively different spatial resolution versions of the two images, so as to bring the respective images into effective co-registration on image registration surface.

Abstract: In a distance measuring apparatus for measuring the distance to an object on the basis of reflected light obtained as a result of projecting light toward the object, in the case of an active distance measurement operation, the flickering frequency of a light beam projected from a light projection unit (B) toward the object (A) is prolonged within the range in which charges obtained by a signal charge supply unit (C) are not saturated in a circulating shift register (E). When the flickering period is longer than a predetermined period, a distance measurement operation inhibition unit (L) inhibits transition to a passive distance measurement operation.

Abstract: A reflective grating for the optical diffraction of light rays comprises k juxtaposed, grooved, plane sub-gratings, the planes of the sub-gratings being offset in terms of height with respect to one another along the normal to the plane of the reflective surface of the grooves, enabling the difference in optical path of the grating to be reduced to the difference in optical path between the two ends of a sub-grating.

Abstract: For measuring the tread depth of the tyre of a motor vehicle by means of a measuring head containing a laser (67), the laser measuring head is positioned relative to the tyre of the motor vehicle in such a way, that a reference surface or plane adopts a well-defined position with respect to the tyre. The laser beam (66) of the laser (67) is directed through the reference surface (68) at an angle (.alpha.) to the bottom (64) of the tyre tread, whereby a light spot (78) is generated on this bottom (64) of the tyre tread. The position (e) of the light spot (78) is observed by an image resolving sensor (82). Therefrom, a measure (t) of the depth of the tyre tread is gained.

Abstract: A random wavelength access monochromator incorporates a pair of coaxial off-axis parabolic reflectors configured so that the spherical aberrations introduced by the reflectors cancel each other. Light enters through an entrance slit and impinges upon a first off-axis parabolic reflector that collimates the beam and directs it towards a stationary grating. The grating in turn defracts the light and directs it towards a high speed scanning mirror which reflects the defracted light onto a second off-axis parabolic reflector which in turn focuses the beam to an exit slit. Both off-axis parabolic surfaces share the same axis of revolution and the same collimated beam axis. In order to make the apparatus practical, the beam is folded twice so that the exit point is focused away from the internal path of the beam.

Abstract: Disclosed is a distance measuring apparatus for measuring the distance to an object on the basis of reflected light obtained as a result of projecting light onto an object, in which different reliability or contrast discrimination values are set in active and passive distance measurements. When the distance to the object is calculated by performing a correlation calculation on the basis of two received-light images obtained by an active or passive distance measurement, the reliability of the calculated distance and contrast values of the two received-light images are discriminated using the discrimination value.

Abstract: The isotopic composition of a multiatomic isotope-bearing species such as CO.sub.2 in an analyte is measured by maintaining the analyte in a condition such that isotope-bearing species are present in an excited state and directing light at wavelengths corresponding to transition energies of isotope-bearing species with different isotopes. The interaction between the analyte and light at the different wavelengths is monitored, as by monitoring the optogalvanic effect caused by the light of the different wavelengths. The light may be supplied by a laser including the isotope-bearing species. A stable isotope such as .sup.13 C or .sup.18 O can be used as a tracer in a chemical or biological test and detected using the composition-determining method.

Abstract: A distance measuring apparatus in which two, right and left optical systems respectively comprise sensors (5, 6) is disclosed. Sensor output values (35, 36) representing received-light images (31, 32) on the sensors (5, 6) suffer variations due to sensitivity differences between the sensors (5, 6). In order to correct the variations, the minimum values (RD.sub.L, RD.sub.R) of the two sensor output values are normalized to zero level, and thereafter, the smaller maximum value (e.g., S.sub.R) is normalized to the larger maximum value (e.g., S.sub.L). The correlation calculation is made on the basis of the two normalized sensor outputs to calculate the distance to the object to be measured.

Abstract: Light projected by a light projecting portion and reflected by an object is received by two sensor arrays (105, 106). Difference signals between signals respectively added by ring CCDs (113b, 114b) in correspondence with the ON and OFF states of the light projecting portion are calculated, and the distance to the object to be measured is calculated on the basis of the relative values of the positions of the difference signals on the sensor arrays (105, 106). The two sensor arrays (105, 106) form the base length, and the light projecting portion (104) is disposed at a position offset from the base length.

Abstract: An acousto-optic tunable filter (AOTF) has one or more optical wavelength passbands dependent on the frequency or frequencies of a radio frequency signal applied thereto. A radio frequency generator applies the radio frequency signal under computer control of the RF frequency so that the radio frequency signal has one or more preselected frequency components. An input optics system directs incident object or scene light to the AOTF. A first polarizing element passes to the AOTF only image light which is polarized in a first direction. A second polarizing element receives output image light from the AOTF and passes only image light which is polarized in a direction orthogonal to the first direction. The image light passed by the second polarizing element is detected by a camera. An output optics system focusses image light passed by the second polarizer on an image plane of the camera, and an image corresponding to the detected image light is recorded.

Abstract: Analytical apparatus and methods for processing multiple samples simultaneously. Radiation such as laser light desirably including plural wavelengths is directed through multiple samples simultaneously, as by directing a beam of radiation along a single path through all of the samples. Response to each wavelength is monitored by monitoring an induced effect, other than the intensity of the applied radiation itself. Useful signal-to-noise ratios are obtained with low absorption in each sample. One sample desirably is of known composition, and serves as an internal calibration standard.

Abstract: Complex atomic or molecular spectral signatures embedded in interfering background spectra are very rapidly recognized by a spectrometric device that employs precise sweep rate control with signal slope extraction. Very fast optics become feasible. High signal to noise ratios are attained in each of three operational modes. The first, PURGE, is frequently invoked and stores an ambient background pattern in differentiated form. The second, TARGET, stores a signature derived from a target substance placed within the invention's sensing range. The signature retains only signal derivatives that significantly depart from those encountered during PURGE. A SEEK mode employs a similar derivative extraction algorithm, and searches for matches to TARGET signatures stored in a memory bank. During SEEK, pattern correlations to stored targets are sensed, and results displayed.

Abstract: In a distance measuring apparatus, a plurality of line beams transmitted from a light source irradiate objects to form a plurality of images on the objects. Linear light sensors receive the plurality of images and generate a plurality of electric signals corresponding to the quantity of received light. A distance calculator portion carries out a product-sum operation using a predetermined function based on the plurality of electric signals, estimates a function to approximate a location of an image from a result of the product-sum operation, and calculates a distance to the object. Thus, the distance to the object can be measured at high speed and with high precision.

Abstract: The isotopic composition of a multiatomic isotope-bearing species such as CO.sub.2 in an analyte is measured by maintaining the analyte in a condition such that isotope-bearing species are present in an excited state and directing light at wavelengths corresponding to transition energies of isotope-bearing species with different isotopes. The interaction between the analyte and light at the different wavelengths is monitored, as by monitoring the optogalvanic effect caused by the light of the different wavelengths. The light may be supplied by a laser including the isotope-bearing species. A stable isotope such as .sup.13 C or .sup.18 O can be used as a tracer in a chemical or biological test and detected using the composition-determining method.

Abstract: To accurately and easily measure distance even when a photographic subject image has contrast portions inclined at various angles, a shift quantity, between a pair of left and right photographic subject images formed by a pair of left and right optical distance measuring systems having a base length, is detected and then a distance up to the photographic subject is measured.

Abstract: An apparatus that measures the distance to an object by projecting light, receiving reflected light of the projected light through at least two light receiving devices disposed at different positions, and combining information from the two light receiving device to cancel, the influence of a change in the centroid position of the reflected light at the same distance. The apparatus has a signal processor performs a first processing operation for determining the distance to the object by combining information from the two light receiving devices, and a second processing operation for determining the distance to the object using information from only one of the two light receiving devices.

Abstract: An optical apparatus for performing multi-point distance measurement by measuring the distance to an object using a triangulation method and light received from the object, includes first and second light-receiving systems each constituted by a multi-eye lens in which a plurality of elementary lenses are disposed adjacent to each other in a base line direction, and a photoelectric conversion element. The first and second light-receiving systems respectively form images of regions of the object, which correspond to the elementary lenses constituting the multi-eye lenses and are separated from each other, on the photoelectric conversion elements.

Abstract: A distance measuring apparatus includes: a light projecting unit including a light source and a light projecting lens; a distance measuring first photosensor unit disposed at a predetermined baseline length from the light projecting unit and including a first photosensor and a first light receiving lens; and a second photosensor unit disposed in the vicinity of the light projecting unit in a direction perpendicular to the baseline and including a second photosensor and a second light receiving lens. An output of the second photosensor unit is used for correcting an output of the first photosensor unit.

Abstract: An electro-optical system for high speed measuring of the dimensions of a multiplicity of articles having varying part-to-part surface reflectivity comprises impinging a modulated intensity light beam on each individual article, where the intensity of the beam impinged on the article is varied in response to the image signal from a prior beam impingement. The intensities of image signals from all articles are made comparatively uniform, to improve accuracy. Preferably, light intensity is modulated for each individual article at a speed commensurate with less than 0.004 second pass-by intervals by phase shifting a polarized laser light beam using a Pockel Cell type electro-crystallographic device. The system is particularly useful in grinding the tips of blades of gas turbine engine rotors while the blades are mounted in a spinning rotor.

Abstract: An active-type automatic focusing apparatus having an arrangement that a light receiving portion is disposed on each side of a light emitting unit to obtain the distance from a subject in accordance with the output from each light receiving portion. An automatic focusing apparatus of the foregoing type is enabled to have a small size by shortening the distance from either of the light receiving portions disposed on the two sides of the light emitting unit to the light emitting unit than the distance from the other light receiving portion.

Abstract: To dramatically reduce image data processing requirements in spectroscopic imaging systems, an optical filter is alternatingly tuned to a pair of selected passband wavelengths related to an absorption wavelength of a sample under test, such that only light of the two selected wavelengths received from the test sample are recorded as alternating image frames by a CCD optical detector. Successive pairs of consecutive image frames are computer processed, on a corresponding pixel-by-pixel basis, to generate a series of composite image frames that may be displayed in enhanced contrast to permit real time analysis of a sample characteristic of interest.

Abstract: A laser beam profile sensor system for which is capable of accurately determining distances to both close and distant objects, particles, liquid interfaces and the like and of identifying the locations of ice layers on metal surfaces. Basically, the system includes a laser diode for generating a laser beam along a selected path, a receiver spaced from the laser diode for receiving light along a receiver axis, the laser beam and receiver axis intersecting at any desired angle from nearly 0.degree. to nearly 180.degree.. The receiver comprises a linear array of light responsive elements. An optical system is provided for directing light approaching the receiver along the receiver axis to the array. An electronic circuit processes signals from the array elements and produces a display showing the distance to any target lying along the laser beam path that reflects light along the receiver axis.

Abstract: A distance measuring device has an infrared light-emitting diode by which an infrared light is emitted towards a subject, and first and second linear line sensors on which an image corresponding to light reflected from the subject is formed. The first and second linear line sensors are disposed adjacently and in parallel to each other, and offset by an amount corresponding to half of the predetermined A/D converting step. Analog distance data outputted from the linear line sensors are converted to digital distance data using the predetermined A/D converting step, and then, the digital distance data are added together to obtain a subject distance with a high accuracy.

Abstract: An apparatus comprising two light sources, a composite detector, a fixed grating, two independent slits and a mask with a multiplicity of slits analyzes the spectral composition of samples rapidly and accurately and can transmit such information to other locations by modem. A first light source produces a spectrum with broad spectral range, a second light source produces a spectrum with multiple sharp spectral features. The first and second light sources are used to produce a sample spectrum and a reference spectrum respectively. A portion of the light from each of the two sources is used to calibrate the intensity of the instrument at each wavelength measurement. Rapid scanning is achieved by continuous multiplexing of each wavelength of light to the detector using a rotating mask with a multiplicity of slits. Continuous wavelength calibration is achieved by using the reference spectrum to encode a wavelength scale as spectrum is acquired.

Abstract: A distance measuring apparatus includes a first light projecting device for projecting a light to a projection range, and a first light receiving device arranged along a base length direction thereof, for receiving a reflection light of the light projected from the first light projecting device. The first light receiving device has a first position sensor to detect, in accordance with a position of light reception, a distance to an object, the object being located at least within a middle distance. A second light projecting device, provided independent of the first light projecting device, projects a light to substantially the same projection range as the first light projecting device. A second light receiving device, arranged in a direction different from the base length direction of the first light receiving device, receives a reflection light of the light projected from the second light projecting device.

Abstract: Light from a discrete broadband visible and/or infrared light source is collimated and transmitted within an optical path that is open to an ambient environment through a spatial region of interest and is focused to a beam splitter, which splits the transmitted light into different beams and directs the different beams respectively to a pair of narrowband acousto-optical tunable filters (AOTF). One such AOTF is disposed for filtering one split transmitted light beam and is rapidly tuned through a predetermined series of different wavelengths that are characteristic of an energy absorption spectrum for a first given substance, or of a first predetermined set of given substances. The other AOTF is disposed for filtering the other split transmitted light beam and is rapidly tuned through a given substances.

Abstract: An apparatus and method of wavelength detection and parameter sensing uses a variable magnetic field applied to a Faraday effect thin magnetizable film to perform spectral analysis based on detected intensity distribution of diffracted light for known magnetic field strengths. The strength of the applied magnetic field can also be varied by change in a physical parameter relative to a fixed magnet in a magnetic circuit which generates a magnetic field about the grating to produce diffracted wavelengths which correspond to the parameter which influences the magnetic circuit.

Abstract: The isotopic composition of a multiatomic isotope-bearing species such as CO.sub.2 in an analyte is measured by maintaining the analyte in a condition such that isotope-bearing species are present in an excited state and directing light at wavelengths corresponding to transition energies of isotope-bearing species with different isotopes. The interaction between the analyte and light at the different wavelengths is monitored, as by monitoring the optogalvanic effect caused by the light of the different wavelengths. The light may be supplied by a laser including the isotope-bearing species. A stable isotope such as .sup.13 C or .sup.18 O can be used as a tracer in a chemical or biological test and detected using the composition-determining method.

Abstract: An optical frequency multiplex carrier control system which permits high-accuracy, high-speed stabilization control of the frequency of an optical signal. Based on the fact that the time waveform of the output signal from scanning type Fabry-Perot which receives the output optical signal from an optical frequency multiplexer is composed of pulse signals corresponding to an optical frequency standard and spectrum multiplex carriers of the output optical signal, the time intervals between the pulse corresponding to the optical frequency standard and pulses corresponding to the spectra of a scanning signal and each multiplexed carrier are measured by a counter having a high-accuracy clock, and variations in the optical frequency scanning region of the scanning type Fabry-Perot and in each carrier frequency with respect to the optical frequency standard are detected by hardware, with high accuracy, as variations in the pulse intervals, thereby stabilizing the frequencies of the multiplexed optical carriers.

Abstract: An analyzer measures properties of multiple chemical samples, and includes an optical filter element having a long axis and positioned at a location where simultaneous multiple light beams, corresponding to the chemical samples to be measured, form a diffuse light spot elongated along an axis which is substantially aligned with the filter element long axis. The analyzer also includes a light source, filter means incorporating the filter element for transmitting spectrally selected portions of the light beams, sample cell means for exposing each sample to its associated light beam, and detector means for detecting the light beams after modification by the samples and after transmission by the filter. In a preferred embodiment, optical fibers carry the light beams to and from the chemical samples.

Abstract: The present invention is a scanning monochromator for producing a light beam which rapidly and repetitively varies in wavelength. The device is a subtractive double monochromator in which an intermediate slit is moved to effect wavelength scanning; the intermediate slit fitted in a rotating disk positioned at the intermediate focal plane of the monochromator. Two forms of the device are disclosed.

Abstract: In a spectrophotometer having an oscillating grating, an automatic calibration system is provided to ensure that the instrument constants are recomputed before each measurement of an unknown sample. In the system, whenever a reference scan is carried out, a second scan through an absorbance standard is carried out automatically and the data obtained is used to correct the instrument coefficients relating the angular position of the grating to the wavelength. The corrected coefficients are then stored to be used in the measurement of the unknown sample immediately thereafter. For near infrared spectrum measurements, the absorbance standard is a polystyrene plate. For visual measurements, the absorbance standard is a didymium plate. The didymium plate is mounted on the polystyrene plates eclipse a portion of the polystyrene plate.

Abstract: An optical spectrum analyzer is provided with a user selectable sensitivity. Required operating parameters are set in response to user selection of sensitivity to permit measurement of an input light beam at the selected sensitivity. Setting the required parameters includes setting a required gain of a video channel to permit measurement of a specified maximum light signal and to provide the selected sensitivity, setting a required video bandwidth of the video channel to provide the selected sensitivity at the required gain of the video channel and setting a sweep rate to provide the selected sensitivity at the required video bandwidth. When the normal bandwidth of the video channel is not adequate to provide the selected sensitivity, the electrical signal is passed through a digital filter having a filter coefficient set to provide the required video bandwidth. A peak detector is incorporated in the video channel to accurately measure signal amplitudes in a fast scanning condition.

Abstract: A spectrometer using a CCD array in the time-delay integration mode is claimed. The spectrometer comprises a CCD having a plurality of charged-coupled devices disposed along a scan dimension which terminates at an output end of the CCD. Each device produces an electronic charge in response to electromagnetic radiation incident thereon. A monochromator, optically aligned with the CCD, has a diffraction grating which generates a plurality of spectral beams from an external source of electromagnetic radiation. The diffraction grating is movably mounted to sequentially scan the plurality of spectral beams. A control unit, coupled to the monochromator, controls the scanning operation of the diffraction grating and determines a scan rate for the spectral beams. The spectral beams are scanned along the scan dimension of the CCD during the scanning operation.

Abstract: An optical spectrum analyzer includes a surface elastic wave generator for generating in an optical waveguide a surface elastic wave which has a continuously varying frequency and which diffracts and deflects a guided wave as it travels across the path of the guided wave, which guided wave is introduced as a measured light beam into and travels in the optical wave guide. The measured light beam which has been deflected is emitted from the optical waveguide and detected by a light detector. A modulator turns on and off or modulates the surface elastic wave by repeatedly energizing and de-energizing the surface elastic wave generator, the frequency of the modulation being lower than the continuously varying frequency. A filter receives a signal corresponding to the modulation frequency from the modulator and a signal corresponding to the measured light beam from the detector, and extracts a signal component having the same frequency as the modulation frequency from the signal received from the light detector.

Abstract: An optical scanner is provided wherein each waveband, i.e. blue, green and red, is detected during successive revolutions of an analyzing drum. A variable scanning aperture disc selectively transmits a different image portion during each waveband scan so that the image portion detected during each waveband scan is transversely displaced along the axis of the analyzing drum. The transverse distance of optical image portion displacement corresponds to and corrects for the transverse distance travelled by the optical scanning head during one revolution of the analyzing drum. Magnification optics are also provided for, inter alia, adjusting the transverse displacement of the image portions.

Abstract: In a spectrophotometric instrument, a system is provided to correct for distortion caused by rapid scanning of the spectrum. In the instrument, photodetectors detect light energy which is scanned through a spectrum at a rapid rate. An amplifier amplifies the output signal generated by the photodetectors. The output signal of the amplifier is sampled at increments and the samples are converted to digital values. A first derivative is determined from the digital values by subtracting from each value the value from the preceding increment. The first derivative values are multiplied times a constant selected to correct for the distortion and the resulting product values are added to the amplitude digital values to provide a set of corrected values representing the intensity detected by the photodetectors.

Abstract: A scanning spectrometer scans the spread spectrum of sunlight and low level luminescence or fluorescence past a slit to provide the spectrum scanned in the time domain. An image intensifier responsive to the light energy passing through the slit is gated on when Fraunhofer lines are coincident with the slit. A photodetector responsive to the image intensifier detects the intensified total energy within each Fraunhofer line.

Abstract: A dispersion-type spectral element designed for reflecting an incident sample light is rotated by a drive mechaism. The sample light reflected by the element is applied to a sample-light receiving device. The device converts the light into a first signal representing the intensity of the sample light. Reference light consisting of beams having various wavelengths over a broad range is supplied from a reference light source to the spectral element. Further, standard light consisting of one beam of a known wavelength is also supplied from a standard light source to the spectral element. The reference light reflected by the element is applied to a reference-light receiving device. The reference-light receiving device converts the reference light into a second signal representing the intensity of the light. An etalon is located in the optical path between the spectral element and the reference-light receiving device. The standard light reflected by the element is applied to the standard-light receiving device.

Abstract: An optical grating is oscillated at a high rate to scan a narrow wavelength band of light through the spectrum dispersed by the grating. The grating is connected integrally with the rotor of a motor, which is energized to oscillate its rotor between selected limits. The direction of rotation of the motor is controlled by an H drive circuit connected to a coil of the motor. The speed of the motor is controlled by a pulse train applied to the motor coil through the H drive. The pulse train has a duty cycle varying inversely with the motor speed. The duty cycle of the pulse train is controlled by a counter which is connected to count high frequency pulses and which is reset each time the grating rotates through an angular increment. The limits of the oscillation of the grating and the rate of rotation of the grating between the limits are selectively variable.

Abstract: A method of microphotometering individual volume elements of a microscope specimen 10, comprising generating a luminous dot or cursor and progressively illuminating a plurality of part elements in the focal plane 11 of the microscope through the specimen. The mutual position between the specimen and the focal plane is then changed and a plurality of part elements in the focal plane are illuminated. Reflected and/or fluorescent light and transmitted light respectively created by the illumination is collected, detected and stored for generating a three-dimensional image of that part of the specimen composed of the volume elements. Illumination of multiples of part elements is implemented by deflecting the cursor and/or by moving the specimen. The change in the relative mutual position between the specimen and the focal plane of the microscope is effected either by displacing the specimen or the objective.