Abstract: A laser scanner system for producing and projecting a multi-line scanning pattern into a space in which a bar code is to be brought. The system includes plural modular laser scanners, each producing a line scan pattern, but mounted with respect to one another so that the pattern of each scanner is projected into the space to conjoin to form the multi-line pattern. Each module is arranged to receive light reflected off the object to convert that light into electrical output signals indicative of the bars and spaces of the code. The system also include means for decoding the output signals and for providing the decoded signals to some peripheral device, e.g., an electronic cash register or computer. In one embodiment the scanner is located adjacent a conveyor carrying bar coded items to form an automated check-out counter.

Abstract: In an optical detection system a plurality of photodiode detectors are placed in an enclosure. The enclosure has an aperature through which is directed a light beam to be analyzed. To eliminate the effect which ambient light entering the aperture would have on the detector signals, each of the detectors are arranged to be at equal distances from the aperture so that they all have the same acceptance cone angle for the light entering the aperture. Thus the ratio of signal to ambient light in the portion of the light beam reaching each detector is the same and the d.c. component of the signal produced by the detector can be easily removed in the signal conditioning electronics. The equal spacing of the detectors from the aperture is achieved in accordance with the invention by using beam splitters in the path of the beam to deflect portions of the beam to detectors which are offset from the base axis.

Abstract: A reference beam type optical laser Doppler velocimeter for emitting two or more probe beams to an object to be measured at a predetermined angle to multi-dimensionally measure a velocity and/or a displacement vector of the object due to Doppler shifts of beams reflected by the object. This velocimeter includes a frequency shifting means for dividing a laser beam from a single light source into two or more beams, and shifting optical frequencies of the beams each by a predetermined shift amount, a photodetecting means for receiving the reflected and reference beams to obtain a detection current, and a bandpass filter for causing the detection current to pass therethrough to obtain a required signal.

Abstract: Each photosensitive dot of the photosensitive matrix disclosed is formed by one capacitor and two diodes. The capacitor is connected between a row conductor and a common floating node. A photodiode is connected between the floating node and a reference voltage source which biases it in reverse. A small-sized reading diode, hence one with low capacitance, is connected between the floating node and a column conductor. This structure enables the making of a matrix having a reduced column capacitance. It therefore enables a more efficient transfer of charges from the photodiodes to the reading circuit connected at the end of a column.

Abstract: Apparatus for determining the effective surface roughness of polished optical samples, by measuring the total integrated scattering, only operates for non-light-transmissive samples. For a transmissive sample, the invention adds a light trap behind the sample for transmitted light, and a diaphragm in front of the sample. The rear surface of the diaphragm is provided with a non-reflective wafing which traps secondary light reflected or scattered by the inside rear surface of the sample.

Abstract: The disclosure concerns photosensitive matrices, and especially those using NIPIN or PINIP type phototransistors made of amorphous silicon. To prevent problems of remanence, due to the collecting of holes in the base after an illumination stage, it is proposed to follow the step for reading the illumination signal by a remanence erasure step in which the phototransistor is made conductive in forward or reverse bias, so as to inject, into the base, electrons which will eliminate the holes by recombination. Switching on by reverse bias proves to be more efficient than switiching on by forward bias. The invention is applicable notably to a matrix structure of rows and columns of photosensitive sites in which each site is formed by a NIPIN transistor made of amorphous silicon in series with a reading diode that may be put into reverse conduction.

Abstract: A photographic printer is provided with a film strip receiving means including an elongated film strip receiving slot. A transport means is activated by a film strip detection means when the leading end of a film strip is inserted into the slot to move the film strip into the slot. The detection means also detects the presence of the trailing end of the film strip if the film strip is not totally contained by the slot. If a trailing end is not detected, a door is closed to light seal the entrance to the slot. If a trailing end is detected, the door is not closed to prevent damage to the film strip.

Abstract: The invention relates to a circuit for a light-sensitive element (1), for example an infrared diode. The anode (a) of the light-sensitive element is coupled to a point of constant potential (earth). The cathode (c) of the light-sensitive element (1) is coupled to the collector of a pnp transistor (7) and, via a resistor (3), to the base of this transistor. The emitter of the transistor is coupled to a second point (6) of constant potential (+). The base is also coupled to this point (6) via a series arrangement of a resistor (5) and a capacitor (4). The desired sensitivity of the circuit is maintained even in the case of a high background light level.

Abstract: In the compound rotary encoder of this invention, an absolute signal representing the upper m bits of a rotation angle signal, and an icreametal signal used for detecting the lower bits of the rotation angle signal are detected to obtain more detailed rotation angle information. Moreover, the rotation angle obtained by counting the increamental signal closely matches that obtained from the absolute signal, assuring the detection of the rotation angle with high resolution and precision. Since a rotating disk has only m bits of absolute code pattern, the rotary encoder can be small. This permits the absolute code pattern to have greater diametrical width so that a large output of the absolute signal can be stably obtained. On the other hand, the number of rotations can be obtained by counting and compensating a standard position signals. Since the rotary disk has the patterns both for detecting the standard position signal and for detecting the rotation angle, this too allows the rotary encoder to be small.

Abstract: An adaptive optics system is disclosed which has a phase detector to detect phase distortions acquired by an input beam, and a separate phase adjustor which predistorts a transmission beam so that it is restored to its proper phase during transmission back through the same medium travelled by the input beam. The phase adjustor consists of a liquid crystal mechanism with an area substantially greater than that of the phase detector, thereby permitting high power operation. Liquid crystal pixels in the phase adjustor have dual transistor signal storage circuits which apply operating signals to the pixels without significant decay or flicker. The phase adjustor can be constructed in either a reflective or transmissive mode. Two phase adjustors may be placed in series to enhance response time and/or process an unpolarized beam. A data processor interfaces between the phase detector and phase adjustor.

Abstract: In a diffraction type optical displacement encoder using a diffractive light source and having a main scale grating and an index scale grating, a light-receiving element receives two rays satisfying a relationship concerning the lengths of light paths at the rays between the light source and the index scale grating, and the width of the light receiving element, wherein the difference between the path length of each ray is approximately equal to an integral multiple of the square of the pitch of the main scale grating divided by the wavelength of the light source, and the width of the light receiving element, measured as the distance between the impingement points of the two rays at the index scale, is integrally related to the difference in ray path lengths and the angle of the impinging rays due to an offsetting of the light-receiving element.

Abstract: A method and apparatus for measuring strain of an object is provided. The object to be measured is provided with a diffraction grating which is illuminated with radiation including at least two frequencies to produce an interference pattern. At least a portion of the interference pattern corresponding to at least one of the frequencies is detected and analyzed to determine strain. In some embodiments, the frequency of a portion of the diffraction pattern is detected, for example, by a human eye and the detected frequency compared with known frequencies to determine strain. In other embodiments, the relative angular position of portions of the pattern corresponding to different frequencies is detected. Since the relative angular position and intensity is affected by strain but not by certain rigid body rotations, strain measurement free of body rotation error may be made.

Abstract: Wireless remote-control system with motion-dependent controls for electronic apparatus and, in particular, for entertainment-electronics apparatus, has a remote-control transmitter, a remote-control receiver contained in the electronic apparatus, at least one radiation source contained in the remote-control transmitter or the electronic apparatus, at least two radiation detectors contained in the electronic apparatus or the remote-control transmitter, and means associated with the radiation detectors for deriving electric signals from the motion of the remote-control transmitter and the remote-control receiver or the electronic apparatus relative to each other.

Abstract: Web-like planar structures 10 are tested by means of a light source 11 which directs a light beam 4 onto a rotating mirror wheel 5. The light beam is projected onto the web 10 to be tested via a stationary folding mirror 1 which is centered above the web to be tested. The folding mirror 1 is composed of at least two mirror surfaces 2, which form an obtuse angle .alpha. to each other. The light beam 4 coming from the polygonal surface 14 of the mirror wheel 5 covers successively all mirror surfaces 2 of the folding mirror 1 during the rotation of the mirror wheel 5. The number of scannings of the web-like planar structures 10 per polygonal surface 14 is increased, corresponding to the number of mirror surfaces 2.

Abstract: A multiple-point temperature sensor, with optic fibers, uses the effect of variation in the birefringence in a birefringent optic fiber as a function of temperature. This sensor has a plane polarized, wide spectrum source coupled to a monomode optic fiber for preservation of polarization, along one of the neutral axes, with weak coupling points distributed along this fiber. A polarizer at 45.degree. to the neutral axes of the fiber is placed at the output of this sensing fiber. The output radiation is analyzed by spectroscopy, for example in a Michelson interferometer, capable of being swept, associated with a detector. The interferometer shifts needed to detect the extreme values of the transmission function are measurements of temperature deviations.

Abstract: This invention presents both a method and device capable of accurately measuring fixed lengths of moving strand or yarn as it is pulled from an essentially continuous source of supply and wound onto a take-up reel by an appropriately powered winding mechanism. In its preferred embodiment, the invention is used to measure lengths of fiberglass strand unwound from forming packages and onto rotating bobbins carried on a twist frame. As its principal component, the invention utilizes a lightweight, low inertia measuring rim supported on a layer of pressurized gas, such as air, so that frictionless rotation of the rim about a stationary hub is thereby made possible. Moving strand is maintained in continuous contact with the rim thereby causing it to rotate. The number of rotations is counted by electrical means and multiplied by the circumference of the rim whereby the length of strand advanced over the rim and onto the rotating bobbin is calculated.