Abstract: An electro-optical instrument means for measuring the relative angle of roll about an optical axis extending between a sending unit and a receiving unit. The measurement is independent of relative displacements in pitch and yaw within the dimensional limits of the apparatus. The sending unit comprises a pair of light sources behind respective apertures in a mask and differently modulated. The apertures are imaged onto a divided photodetector on the receiving unit. Each half of the detector receives modulated light from both sources. The differently-modulated photocurrents are separated electrically, and the roll angle computed from the ratios of the separated components. These ratios are unaffected by relative displacements of the two units in pitch and yaw.

Abstract: An improved apparatus for automatic focusing of a lens system, including a space dissector (17) for analyzing the space frequency components of the image planes close to the ideal focus plane, and devices (53, 57) for detecting the position of the plane at which the maximum of space frequencies occurs, close to the ideal focus plane. An electronic device is provided for obtaining a suitable signal from said space dissector (17), to provide an adjustment control signal actuating a servo-control unit controlling the lens focusing, and for thus leading to the image plane having the maximum of high frequency components being placed in coincidence with the ideal focus plane.

Abstract: A sensing device for obtaining optical density or light scattering measurements or other, in a turbulent liquid comprising a light source and a facing sensor located within a housing. The housing is provided with orifices through which liquid flows into the housing for measurement. The liquid entering the housing is slowed by passage through the orifice, and the bubbles of the liquid rise to the upper region of the housing, out of the measurement region, e.g. out of the line of the sight between the light source and the sensor.

Abstract: An image intensifier with an internal power supply that produces 20,000-25,000 Hz. noise in the output screen voltage is provided with an additional power supply coupled to the output screen through an R-C filter which removes that noise. The additional power supply produces the screen voltage at a current that is a large multiple of the current produced by the output screen voltage of the internal power supply, so that the screen voltage from the additional power supply prevails over the screen voltage from the internal power supply. The additional power supply is regulated by an optical coupler which responds to the light input level to the image intensifier, as follows: at light inputs above about 5.times.10.sup.

Abstract: A method and apparatus for directly converting an analog photodiode signal to digital form using a switched capacitor successive approximation A/D converter. The charge extracted from a video line during a predetermined time interval by a photodiode is compared with charges successively injected onto the video line by a plurality of capacitors of decreasing capacitance value having a reference voltage sequentially impressed thereon. The voltage on the video line is compared with a threshold voltage for each of the capacitors, and the capacitor is returned to its previous state if it is found to have injected sufficient charge to increase the voltage on the video line to above the threshold voltage. The states of the capacitors at the conclusion of the process is a digital representation of the light intensity at the photodiode.

Abstract: A directly detectable image sensor applicable to an image reader of a facsimile and others includes two glass substrate members which are bonded to each other, and an array of miniature lenses arranged at the interface between the two substrate members and each having a different refractive index from the substrate members. Sensor elements and electrodes are provided on one major surface of a sensor substrate which is made up of the two glass substrate members, a document being laid closely on the other major surface of the sensor substrate. Light is propagated through the sensor substrate from the sensor elements and electrodes side to reach the document, while a reflection from the document is focused onto the sensor elements by the miniature lenses.

Abstract: A light measuring circuit, consisting of an amplifying circuit amplifying the output of a photoelectric conversion element, is arranged to detect the occurrence of a low frequency component in the output of the photoelectric conversion element that comes to exceed a given level and, upon detection of that, to bypass the output of the photoelectric conversion element to prevent the output of the amplifying circuit from being saturated by a DC light (external or ambient light).

Abstract: An optical sensing circuit useful for detecting the end of a moving tape in a tape transport includes a light source and a light sensor which are closely spaced across a gap. The radiation output of the light source is modulated at a selected frequency which is determined by the operating frequency of a frequency detector. In the absence of a light obstruction, such as passage of the tape in the optical path between the light source and the light sensor, the modulated output from the light source is detected by the sensor. The processed signal from the sensor, which is characterized by the modulation frequency, is applied to the frequency detector. The detector recognizes only those signals having the modulated frequency, and does not respond to signals of different frequencies, which may result from impingement of other radiation than that from the light source on the photosensor.

Abstract: An external mirror is positioned relative to the output mirror of a laser to form a Fabry-Perot cavity. The light transmitted by this Fabry-Perot cavity is compared to a reference value in order to develop an error signal which in turn is used to adjust the transmission characteristics of the Fabry-Perot cavity. In the embodiment constructed a beam splitter is positioned to deflect light coupled out of the Fabry-Perot cavity to an optical detector. The output of this detector is compared to a reference voltage in a difference amplifier which generates an electrical error signal. The electrical error signal is coupled to a piezoelectric translator which is attached to the external mirror and is capable of moving that mirror in a way so as to change the transmission characteristics of the Fabry-Perot cavity. Specific embodiments using a dye laser and a soliton laser are also disclosed.

Abstract: A system for calibrating a raster input scanning device for detecting an image on a preselected surface, including a linear photoelectric sensor array comprising a plurality of discrete photosensitive elements arranged along a first axis, for sensing and generating electrical representations of an image on a surface; a carriage assembly movable along a second axis, transverse to said first axis; and supporting a sensor detectable target image for movement along the second axis. The sensor detectable target image includes an alignment feature for use during alignment operations. A drive system moves the carriage assembly carrying the target image from a starting position along said second axis, and the distance traveled by the carriage assembly from said starting point until the alignment feature on said target image is sensed is measured. A y-axis comparator compares the measured distance with a y-axis reference to determine an y-axis offset value which is stored in a y-axis memory as an y-axis offset value.

Abstract: In an optical pattern follower, of the rotating scanning type, in which co-ordinated drive signals are produced by sampling two co-ordinate sinusoids, an adjustable kerf off-set is provided by selectably delaying the sampling pulse.

Abstract: An optoelectronic transducer is proposed which includes a PIN diode (2) that delivers a current that is proportional to a light signal that is received. The diode is connected to the input of an inverting amplifier (4) that delivers a voltage signal v.sub.s. A negative feedback means of the transfer impedance type (6) is connected across the inverting amplifier. The transducer further includes a stabilizing means (8) for the amplifier gain and a temperature drift compensating means (10) for compensating for the drift in amplifier temperature. The stabilizing means (8) includes a detector (26, 28, 32) for the high peak of the signal v.sub.s, and the temperature drift compensating means (10) includes a filter means (38) for producing the means value v.sub.m of the signal v.sub.s, and a comparator (40) that receives the signals v.sub.s and v.sub.m and delivers a signal that reproduces the interference of the light signal that has been received.

Abstract: An optical detector is provided. The optical detector provides automatic zeroing of a logarithmic ration function in applications such as absorption meters, fluorometers and other chromatographic techniques.

Abstract: Apparatus and method are disclosed for transmitting modulated, collimated light and receiving reflected light that is used in providing a three-dimensional display of a field being viewed. The apparatus includes a pair of counter-rotating optical wedges in both the transmitter and receiver sections of the apparatus. An elevation mirror communicates with both the light transmitted to and the light reflected by objects in the field of view. The counter-rotating wedges and the elevation mirror cooperate to provide a raster scan of the field of view using the transmitted light beam. The reflected light communicates with further optical and electronic hardware for subsequent filtering and processing. Each of the four optical wedges is rotated using a secondary gear, with each secondary gear on the transmitter section being aligned with a secondary gear on the receiver section of the apparatus. Each of the aligned secondary gears is driven by the same primary gear.

Abstract: An image evaluation apparatus for quantitative and qualitative evaluation of an optical image generated by an x-ray imaging system of the type including an x-ray source, an image intensifier tube for converting received x-ray radiation to optical images to be recorded photographically and/or electronically. The evaluation apparatus comprises an image projection device in the form of a cylindrical housing having a lens mounted in one end and a light diffuser mounted in a second end. The lens is of the type having a focal point at infinity such that all of the light passing through the lens is substantially parallel. The evaluation apparatus is mounted to the x-ray imaging system in a position normally occupied by one of the recording or display apparatus so as to be in a position for receiving light generated by the optical image on the image intensifier tube. The received light is focused onto the diffuser and its intensity is measured using a light photometer.

Abstract: A defect inspection apparatus for bottles made of transparent material in which a light source is located under a bottle made of transparent material and to be inspected for irradiating a bottom of the bottle, a photoelectric conversion sensor is installed above the mouth of the bottle for receiving such a light that enters the bottle from its bottom, passes through the inside of the sidewall of the bottle and then is emitted upwards from the mouth of the bottle and, an electric processor is provided for electrically processing the responsive electrical signal from the photoelectric conversion sensor to thereby inspect defects of the bottle.