Abstract: An optical displacement sensor is disclosed for use in robotic applications. The sensor can be used to examine the shape and surface texture of an object. In the embodiment which includes a compressible means of known spring constant, the sensor can be used to measure contract force. The position sensor uses an electro-optical displacement transducer to convert a displacement into an electrical output. The sensor utilizes a phototransistor to measure light emitted by an infrared light emitting diode. The amount of light received from by the phototransistor is varied by the displacement of the contact probe, or shadow rod.

Abstract: An optical switching device comprises a light emitting device, a reflector for reflecting a light emitted by the light emitting device and having a plurality of set states, a reflected light distribution being changed by switching the set state, a pair of photo-sensing devices for sensing a light from the reflector, and a detector for detecting a difference between light amounts sensed by the photo-sensing devices. The set state of the reflector is discriminated based .on the detection output of the detector.

Abstract: A photoelectric switch having a rectifier for converting a received AC voltage to a DC voltage, a transparent cover having a user friendly finger rest surface, means for generating a pulsed infrared beam across the finger rest surface, means responsive to the breaking of the pulsed infrared beam by an operator placing at least one finger on the finger rest surface to actuate a relay to generate an output signal, and means for disabling the actuation of the relay in response to the operator removing his finger from the finger rest surface restoring the continuity of the pulsed infrared beam. The photoelectric switch includes fault protection circuits which disable the relay when the AC voltage is below a predetermined voltage or the ambient infrared background illumination exceeds a predetermined value.

Abstract: The leaf switch of the invention consists of an optical switch mounted on a printed circuit board having electrical conducting means imbedded therein. An opto-interrupter is mounted on an actuator arm that is moved by the player controlled button to close the optical switch and complete the electrical circuit. To complete more than one circuit, a plurality of optical switches are provided with the opto-interrupter mounted on the actuator arm associated with each optical switch. The opto-interrupter is configured such that different ones of the switches are closed depending on how far the player controlled button is depressed.

Abstract: Disclosed is a positioning mechanism of an ophthalmologic apparatus in which the operation property of the conventional mechanical vertical movement mechanism is kept while the feature of the vertical movement by means of electrical driving source or the like is utilized. That is, a positioning mechanism of an ophthalmologic apparatus for making positioning so as to obtain a predetermined height relationship between a subject eye and a measurement system or an inspection system of the ophthalmologic apparatus, comprises: a driving means for moving the measurement system or the inspection system relative to the subject eye; an operation knob to be operated for the operation of vertical movement; a speed detection means for detecting rotating speed of the operation knob; and a control means for non-linearly controlling the quantity of driving of the driving means relative to the rotation of the rotary knob on the basis of the result of detection of the speed detection means.

Abstract: An optical rotary control device (10) is provided comprising a light source (12) and at least one light receptor (14) linearly spaced, creating a planar axis with the light source (12). A rotatable light director (16) is provided which includes means for directing light from the light source (12) to at least one optical aperture (22) in the light director (16). The optical aperture (22) refracts the directed light from the light director (16) to the light receptor (14). The optical rotary control (10) device further comprises an isolator portion (20) having recesses (24) for receiving and separating the light source (12) and light receptor (14). The means for directing light may include a cut out section (18) in one end of the light director (16 ).

Abstract: An improved sheet detecting rotary switch activator is disclosed. The switch is modified by mounting the switch for rotation at a hub member which pivots about a fixed point. The hub member has teeth with a helical surface which mate with fixed surfaces having helical top surfaces. When the switch is rotated from a first position by passage of a paper sheet, energy is stored in the spring connected to the hub member. Upon release of the spring, energy by movement of the paper path switch contact arm moves the hub member from a position where the mating helical surfaces overlying are in contact to the output contact position. The return is a "soft" stop due to the dissipation of the release force of the spring in a direction generally normal to the helical surfaces of the mating teeth.

Abstract: A photosensor controller is described comprising sensor units 17-0 to 17-7, 18-0 to 18-7, 19-0 to 19-7 and a circuit 16 driving light emitting diodes by a method of time division. Each sensor unit comprises pairs of an LED and a photodiode. After the driving circuit 16 turn on the proceeding LED, if turns off the next LED for a period corresponding to the delay time constant of a detected signal from a photodiode which corresponds to "OFF", making a completely to "0" in this off period of turning off, even in case of waveform rounding. Following this, the next LED is turned on.

Abstract: A control knob assembly primarily for use with devices utilizing flat panel display technology, each assembly having means for manipulating the electronic apparatus by using remote sensing capability to transfer control knob input into a control signal. The assembly is mounted on a bezel, affixed to the front side of the flat panel display and cooperates in conjunction with a plurality of photodiode devices located near the back side of the flat panel display. Photodiodes are located with respect to knob location so as to be able to detect knob adjustment by monitoring a reflected signal that is alternatively disrupted by knob adjustment. The photodiode devices may be infra-red light emitting diode as are well known in the prior art. Circuitry to the photodiode device is used to transmit detected knob adjustment to the appropriate device control circuitry.

Abstract: An access security system employs a non-duplicatable key made from an optically transmissive material having gradient refractive index and diffusive properties which provide the material with a non-duplicatable quality. The system provides a high level of security comparable to many biometric systems and is well suited for use in the prevention of unauthorized access to high security areas.

Abstract: To detect a faulty operation in a non-contact switch, a pulse signal is applied to the light emitting element of non-contact switch. The thus input pulse signal is compared with an output signal generated by a light receiving element of the non-contact switch. The faulty operation of the non-contact switch is discriminated in accordance with the thus compared input and output signals. Also to detect a faulty operation of the non-contact switch, a switch assembly includes a main push-button and an auxiliary push-button concentrically located over and within the main push-button. When the main push-button operates properly, the blocking members associated with the main push-button and the auxiliary push-button are displaced together. On the other hand, when the main push-button malfunctions, the light blocking member of the auxiliary push-button blocks the passage of light within the non-contact switch. Thus, an erroneous operation resulting from jamming of the main push-button is prevented.

Abstract: A keyboard mounted in connection with a circuit board (2) includes a light source (3). A key (1) of the keyboard comprises a key cap (4) and a body part (5) located between the key cap (4) and the circuit board (2). The body part (5) diffusively transmits light. The light source (3) is arranged to conduct light into the body part (5) and to illuminate the key (1). A photoelectric member (6) is mounted on the circuit board (2) under the key (1) and at a distance from the light source (3). There is further arranged a light barrier (7) in connection with the circuit board (2) or with which key (1), the barrier is arranged to shield the photoelectric member (6) from the light of the light source (3) coming from the body part (5) when the key is depressed. The decrease in light provides an electric change (1) in the photoelectric member (6) indicating a depression of the key.

Abstract: The present invention provides a joy stick mechanism having a simplified structure in which a size reduction of the apparatus can be attained, there is little possibility of breaking of electric wires, and switching can be surely realized. To this end, the joy stick mechanism is arranged in such a manner that it includes an optical system such as a slit lamp laser delivery system or a fundus camera and the optical system can be moved fore and aft, and right and left by operating a joy stick, the mechanism being provided with switch button device located at a top portion of the joy stick bar, a movable shaft which can move in an axial direction of the joy stick bar by the movement of the switch button device, a detection device for detecting the movement of the shaft, and a control device for generating a trigger signal of photographing, coagulating and so forth on the basis of the detected result.

Abstract: A method for electronically scanning a photodiode array that is sequentially illuminated by individual light beams by way of a shutter mechanism that has opening and closing transition times during which each light beam is only partially projected onto the array. An integrating light projected on the respective photodiodes of the photodiode array by each light beam over a predetermined period of time beginning after the opening transition time when the shutter mechanism is fully open and ending prior to initiation of the closing transition time while the shutter mechanism is still fully open and producing electrical signals corresponding to the light integrated by the respective photodiodes over the predetermined period of time and storing the electrical signals for subsequent use.

Abstract: A new, inexpensive and unobtrusive opto-electronic sensor which requires no manual adjustments after installation under the keys of the piano keyboard. Post-installation manual adjustments are unnecessary because a method embodied in a computer program and performed by a microprocessor digitally adjusts the operating ranges of the keys. After electronic adjustment, the opto-electronic sensors are scanned and sampled according to another portion of the method to determine the current key position and velocity. The key position and the velocity determined by the method are then transmitted in a MIDI compatible data stream.

Abstract: A position detecting apparatus in the form of a sphere movable about three mutually orthogonal axes and employing optical encoding such as gray scale encoding and detector so positioned that motion about any of the three orthogonal axes is detected by one and only one of the detector.

Abstract: An interlock system for a machine cover including an optical sensor providing a cover open signal, a housing secured to the cover and defining a hollow cavity communicating with the optical path with the cover closed, a reflector fixed to one end of the cavity to reflect light to the sensor with the cover closed, a wall forming part of the housing and disposed in an interference relationship with the optical path for blocking light with the cover open, the length of the optical path with the cover open being less than the length of the optical path with the cover closed, and circuitry to trigger the optical sensor to provide light pulses at a predetermined frequency.

Abstract: In a push-to-release latch connected to a door/lid revolving about an axis of rotation of a cabinet between open, closed and unlatched, and closed and latched positions wherein the closed and unlatched and closed and latched positions are rotationally displaced from one another, apparatus for determining the status of the latch without sensing the latch. A reflector is carried by the door/lid or the cabinet and a non-contacting optical sensor carried by the other for directing a beam of light from an emitter, for receiving the beam of light as reflected by the reflector, and for outputting an electrical signal at an output thereof as a function of reflected light. The reflector and the non-contacting optical sensor are positioned such that the beam of light strikes the reflector to be reflected thereby when the door/lid is in a closed and latched position and the beam of light does not strike the reflector to be reflected thereby when the door/lid is in a closed and unlatched position.

Abstract: An optical type position detecting device comprising a light source, and a light-receiving element for detecting a light beam emitted by the light source, a region on the light-receiving element whereon the light beam is incident having parallel boundaries, the boundaries extending in directions substantially corresponding to directions of relative displacement of the region and the light-receiving element, the relative displacement accompanying a displacement of a body. The relative displacement can be detected by detecting a change in area of the region using the light-receiving element. A magnitude of displacement of the body is proportional to a change in output of the light-receiving element since, irrespective of where the displacement of the body begins from, a contstant width of the region is maintained along a direction perpendicular with respect to the direction of the relative displacement.

Abstract: A photoelectric switch is sealed against the infiltration of contaminants, for example, oil mist within a combustion-powered tool comprising a switch. In a housing structure sealed by an O-ring when assembled, two photoelectric devices define a line of sight therebetween. A plunger is biased to an inoperative position, in which a shutter portion thereof blocks the line of sight. In an operative position, the shutter portion unblocks the line of sight. The plunger has a stem portion sealed by another O-ring. Where electrical leads from the devices extend through apertures defined within the back member, the apertures are sealed by solder used to connect leads to copper layers, which may be screen-printed upon an outer surface of the back member. A cap mounted upon the back member covers the contacts and admits electrical wires soldered to the layers.

Abstract: A structure for providing an N by N optical switch includes input and output structures disposed on either side of a planar electronic shutter array. Each of the input and output structures, which respectively provide optical signal splitting and combining, is realized by the stacking of N molded optical elements. Each element is formed of a plurality of molded materials with one providing an optical waveguide and the other providing a supporting structure for such waveguides. Advantageously, both the input and output structures utilize the same molded optical element and are fabricated in an identical manner. After such fabrication, the one structure to be designated as the output structure is rotated 90 degrees with respect to the input structure prior to abutment against the planar electronic shutter array.

Abstract: A device for establishing the initial distance between the surface of a grinding tool and the surface of a workpiece to be ground. A combination of an active and a passive sensing element rigidly connected at a known distance is positioned between the workpiece and the grinding tool. The workpiece is brought into contact with the passive sensing element and both the workpiece and sensing elements are moved toward the grinding tool while maintaining contact. The active sensing element senses the grinding tool when the distance between the tool and the workpiece is equal to the distance between the active and passive sensing elements. When this occurs, the active sensing element provides a signal and therefore the distance at which the grinding wheel will meet the workpiece can be calculated. A fixed abutment is also provided so that absolute measurements of the dimensions of the workpiece or grinding tool can be obtained.

Abstract: A switch (10) comprises a rotary part (12, 14, 16 and 18) and a bracket (24) for supporting the rotary part. The rotary part comprises a knob (12), a shaft (14), attached to, or formed on, the knob, a detent cam (16) attached to, or formed on, the shaft, and a light director (18), attached to the shaft, for directing light from an external light source to a light receiver when the switch is in a first position and for directing light from the light source away from the light receiver when the switch is in a second position. The bracket comprises a detent spring (17) for making contact with the detent cam to provide operating positions for the switch.

Abstract: A broadcast receiver is disclosed which is powered by a solar cell in combination with a rechargeable battery mounted within a waterproof housing which is adapted for attachment to a lounge chair used for suntanning. The control of power, tuning and volume functions is accomplished using photodetectors mounted within and adjacent transparent areas of the housing. User operated shutters mounted external to the housing shield selective photodetectors from ambient light. A separate data entry shutter is used to enable memory circuits which store control signals corresponding to the shielded photodetectors. The stored control signals are used to control the operating functions of the receiver. Audio signals are inductively coupled through the housing to external headphones.

Abstract: An optoelectronic position-sensitive detector (PSD) is disposed within a protective housing. An operator is movably mounted to the housing to be mechanically displaced by an object whose position is being sensed. A light projector within the housing is moved in response to operator movement to move a narrow light beam along a surface of the PSD corresponding to the position of the operator. A control system receives signals from the two output terminals of the PSD, compares and processes the same and produces a single analog signal indicative of the position of the object. The operator may be axially reciprocally movable or rotatable, and may have direct or indirect coupling with the light projector.

Abstract: Optoelectronic positioning tap circuit arrangements of the type in which a beam from a light source irradiates two adjacently arranged diodes connected at their cathode ends and further including an element that is perpendicularly movable with respect to the beam path to partially shade the beam and supply a signal proportional to the difference between the diode currents, such signal characterizing the position of the shading element in the light beam. Sensitivity is increased by utilizing both diode currents to achieve a deflection-proportional output signal by short-circuit current meansurement. Existing current sum points are decoupled as each of the (three) terminals of the series diode circuit is connected to a single current/voltage converter stage. The current sum is directly detected at the input of the voltage converter stage that is connected to the (coupled) cathodes to control the operating point of the light source.

Abstract: An electronic device which optically determines the relative position of a joystick using one or more sets of light emitters and light detectors. This device simulates the closing and opening of electromechanical switches without any physical contact with the joystick control shaft. Light beams are selectively blocked or allowed to shine on the opposing photo-detector of a set by movement of the joystick. When the photo-detector receives sufficient light a logic high is lowered to a logic low allowing more current to flow through it, thus simulating the closure of a mechanical switch. From the "open" or "closed" states of the photo-detectors, the displacement of the control shaft may be determined. The sensitivity may be easily changed, or the controller changed between a 4-way and 8-way controller by altering the outer diameter of the control shaft, such as by an interchangeable bushing.

Abstract: A travel sensor for measuring mechanical quantities of motion, in particular for determining the brake pedal position, comprising a transmission unit axially slidable in a housing and comprising a measuring apparatus for generating an electric signal representative of the travel of the transmission unit. The transmission unit is formed of two mechanical transmissions elements (12, 13 and 3, 6, respectively) corresponding with each other and effecting a reduction of the introduced quantity of motions that the test signal is tapped by a reduced test travel. This provides a travel sensor of particularly short dimensions which permits to use of Hall-effect sensors.

Abstract: Circuit breakers can be used to replace fuses in plant comprising centrifuge machines driven by small three-phase electric motors. The circuit breakers incorporate three bi-metal strips which bend due to the heat produced by current flow. Loss of current in one phase results in unequal bending of these trips. In one arrangement, a light-emitting diode 5 fitted to a first strip 2 produced light to pass through an aperture 8 in a plate 7 on the second strip 3 to fall on a photo-sensitive detector 6 on the third strip 4. Any unequal bending causes the light to be cut-off and the resulting signal can be used to trip the circuit breaker. In some cases the strips are the strips in the circuit breaker.

Abstract: This invention provides an optical micro-switch, and a method of mass-producing such optical micro-switches. The optical micro-switch comprises a first housing half containing electronic circuitry which generates light and a second housing half containing electronic circuitry which senses light, the electronic circuitry is separated by a plunger with an aperture and a slide with two apertures. The plunger and slide are positioned in the light transmission path between the light-emitting circuitry and the light sensing circuitry. The optical micro-switch has an input prong, output prong, and a ground prong. The slide can be moved into either of two different positions which configures the switch as a normally open switch or a normally closed switch. In mass-producing these optical micro-switches, a continuous tape lead frame is provided. This continuous tape lead frame contains duplicate sets of frame portions for the first housing half and a second housing half of each optical micro-switch produced.

Abstract: A non-contacting rotary type mode switch for a magnetic tape recording device such as VCR, in which a plurality of reflector pieces are arranged on tracks of a plurality of concentric circles respectively on the rear surface of a mode switch gear, and a plurality of opto-reflection sensor units composed of a light emitter and light receiver for discriminating the presence or absence of the reflector pieces, arranged on the top surface of a switch body, so that the rotational mode of said cam gear, i.e. running state, such as play, review, normal or reverse speed winding, stop and the like can be read out. Since the non-contacting type system utilizing the reflector pieces and opto-reflection sensor units are employed instead of the conventional contacting type, various disadvantages such as mechanical abrasion, deformation, leakage of lubricating oil, and electric discharging are eliminated, and also the system can be miniaturized.

Abstract: An apparatus and method is disclosed for centering a pattern wheel of a modular optical shaft encoder and setting a predetermined gap distance between the pattern wheel and a mask and photodetector. The apparatus is built in to the encoder and facilitates aligning and gapping of the pattern wheel with respect to the mask and photodetector during installation of the encoder about a rotatable shaft. The apparatus consists of a slidable linear cam which cooperatively engages a centering collar to urge the collar against a pattern wheel, the pattern wheel is in turn urged into a predetermined position. The collar is retractable from contact with the pattern wheel after the pattern wheel is mounted in position on the rotatable shaft to allow rotation of the wheel and the shaft.

Abstract: An optically-addressed liquid crystal light valve comprises a transparent insulating substrate having either one-dimensional or two-dimensional arrays of optical switching elements thereon which can perform switching with an incident light, another opposing transparent substrate having transparent electrodes and a liquid crystal sandwiched therebetween. Each of the light switching elements comprises a photo-detector circuit and a thin-film-transistor (TFT) drive circuit. The photo-detector circuit comprises a serially connected photodiode and a passive element such as capacitor or resistor. The TFT drive circuit receives as input the voltage produced from the photo-detector circuit, while the output voltage from the TFT drive circuit is applied to one pixel electrode for the liquid crystal.

Abstract: A hybrid switch includes a snap-action switching portion having a butterfly-type mechanism and a solid-state switching portion formed within a single, compact housing. The solid-state switching portion is formed of an electro-electronic device consisting of a light-emitting diode and a phototransistor. Alternatively, the solid-state switching portion is formed of a bipolar transistor.

Abstract: An adaptive optics system and method for providing wavefront aberration compensation with both phase reversal and amplitude preservation. Two operational modes, namely, a transmission mode and a compensated imaging mode, are available. Two spatial light modulators, preferably liquid crystal light valves (LCLVs) are operatively connected in tandem. Each LCLV has an associated feedback loop. One LCLV acts upon the phase aberrations in an input aberrated beam and the other LCLV acts upon the amplitude information in the aberrated beam. Alternative embodiments are also disclosed.

Abstract: A new optical theft deterrent device wherein a ray from a light source is divided by a beam splitter mounted on a key into a plurality of light beams which are detected by photosensors to determine authorized use of the key only when predetermined one or ones of the photosensors produce electrical outputs. The beam splitter serves to uniformly divide the ray from the light source into the light beams and also to accurately guide these beams toward the photosensors. The key may be utilized to mechanically and electrically unlock a locking device. The new system may preferably be applied to a steering column shaft locking device to prevent theft of an automotive vehicle on which the system is equipped.

Abstract: A video imaging device permits a first teleconference participant to transport information contained on copy material to a second teleconference participant for display in a portion of a video image viewed by the second teleconference participant. The video imaging device automatically reconfigures itself to transmit information contained on transparent, translucent, or opaque copy material.

Abstract: A key input apparatus includes a light beam source, a plurality of input keys operable for varying the color of a light beam or intercepting a group or groups of light beams, an optical detector for detecting variations in the color of the light beam or interception of the group or groups of light beams, and a circuit for identifying operated keys based on outputs of the optical detector.

Abstract: An optically activated keyboard having key members, each with a key pad having illuminated symbols at the keypad surface and for contact with the finger of the operator. A plunger is secured to the key pad for operating a device to indicate which key has been depressed. In one embodiment of the present invention, the plunger is formed of light transmitting material to transmit light from the interior of the keyboard to the key pad. The key pad has a light transmissive portion with a symbol thereon which is illuminated by the light passing through the plunger to provide the desired illuminated symbol. As a second embodiment, the symbol can be disposed in the light conducting plunger or therebeneath whereby the light entering the transparent key pad is in the shape of the desired symbol in either a negative or a positive representation thereof to project the desired symbol from the key pad.

Abstract: A high hat cymbals device is automatically actuated to hold the cymbals locked in place. The presence or absence of the drummer's foot on or above the foot pedal for actuating the high hat is sensed, and the cymbals held together if the drummer's foot is not sensed. Sensing is accomplished utilizing an infrared LED or other source of light, preferably one that is pulsed and frequency modulated, and a photodiode or other light sensing device. The signal from the photodiode is filtered and amplified and ultimately operates a solenoid to either allow normal operation of the high hat, or move the high hat cymbals together. The light source and sensor are mounted on the bottom of the foot pedal and cooperate with an opening in the foot pedal so that the light is reflected to the photodiode if the drummer's foot is present on or above the foot pedal, but passes through the opening if it is not.

Abstract: The flooring apparatus for pool or the like comprises an elevating floor formed almost identically with an opening area of a pool or the like, an elevator for moving the elevating floor vertically, and a means for holding the elevating floor at a desired level position, the elevating floor can be set securely and solidly at a desired level position on a small power by sealing the elevating floor hermetically with air for a buoyancy coming almost zero underwater, further one pool can be used for multiple purpose of adults' use, children's use, infants' use and others, thus providing a flooring apparatus for pool or the like which is simple in construction and moderate in cost.

Abstract: A contactless switch comprising a moveable body assembly including a plunger and a lens carrier received in a casing axially slidable manner between a light emitting element and a light receiving element which are also disposed along and on the axial line of the casing. Thus, the radial dimension of the switch can be reduced, and a compact design is made possible. Additionally, the actuating stroke of the moveable body assembly can be made large without increasing the dimensions of the switch. In particular, since a switch output can be produced from a signal processing circuit when the amount of the light received by the light receiving element has reached a certain predetermined level, the point of activation of the switch can be accurately defined by adjusting a reference level for the level of the light received by the light receiving element, and this adjustment can be easily carried out.

Abstract: A new, inexpensive and unobtrusive opto-electronic sensor which requires no manual adjustments after installation under the keys of the piano keyboard. Post-installation manual adjustments are unnecessary because a method embodied in a computer program and performed by a microprocessor digitally adjusts the operating ranges of the keys. After electronic adjustment, the opto-electronic sensors are scanned and sampled according to another portion of the method to determine the current key position and velocity. The key position and the velocity determined by the method are then transmitted in a MIDI compatible data stream.

Abstract: An opto-electrical joystick switch having a hollow cylindrical (20) housing with a collared top (26) and a separated bottom (28). A resilient joystick shaft (36) is rigidly mounted onto the housing bottom and penetrates through an opening at the top of the collar. A pair of printed circuit boards (46) and (50) are juxtapositioned within the housing, each having at least four light emitting diodes (48) and opposed light sensing photodiodes (52) in communication with each other through a light beam. A light blocking commutator disc (54) is disposed upon the shaft between the boards such that when the shaft is manually forced in a given direction, the light is interrupted from the diodes. An external or optional internal power source energizes the diodes and provides a basis for an electronic circuit that processes a signal created by the blocked diodes when the 8-position switch is displaced from its neutral position.

Abstract: An optical-mechanical rotation sensing mechanism for a web-roll rotatably mounted within a cartridge comprises a flange on the web-roll, activating means on the flange, and an optical sensor, outside the cartridge, including a beam of light for sensing incremental rotation of the flange and web-roll. A movable flag on the cartridge exterior actuates the optical sensor in response to movement of the flag between a first position, in which the light beam is interrupted, and a second position in which the light beam is uninterrupted. A coupling means, including a light-shield hood, couples the flange activating means to the flag for moving the flag between its first and second positions.

Abstract: In at least one of a plurality of shutter vanes forming a shutter there are provided a plurality of openings adapted to detect the movement of the shutter vanes. A photointerrupter is turned on and off by the openings when the shutter vanes move. An output voltage of the photointerrupter is compared with a reference voltage by a comparator. A series combination of a switch, which is turned on and off by the output voltage of the comparator, and a resistor is connected between the output of the photointerrupter and ground. The output signal of the comparator is delayed. The delayed version and the output signal of the comparator are exclusive ORed to produce a train of pulses corresponding to the openings as the shutter vanes move. A drive and control section is responsive to the count of the pulses to control the operation of the shutter.

Abstract: An optical encoder having a concentric cylindrically disposed reticle and moving unit with each having alternating transparent and opaque regions. A light emitter is located in each of two windows on one side of the recticle and moving unit while a light sensor is located on the other. The spacing of transparent and opaque regions in the reticle relative to that in the moving unit is such that when the transparent regions in one window are aligned those in the other unit are sufficiently non-aligned to produce quadrature and enable detection of both motion and direction of motion.

Abstract: A limit switch having a fixed casing, an actuating part moveably support by the casing, and a pair of contact sets which are adapted to be activated by the movement of the actuating part, one for producing a normal switch output and the other for producing a stroke signal which serves as data for evaluating the appropriateness of the stroke of the actuating part. The other contact set may produce a signal when the actuating part has moved a certain distance more than the minimum stroke for activating the first contact set. Thus, the output from the second contact set ensures a certain stroke margin of the actuating part. Further, the second contact set may produce another stroke signal when the actuating part has been displaced close to the maximum permissible stroke of the actuating part so that an excessive stroke of the actuating part may be detected. The contact set may be purely mechanical or may also be a combination of a mechanical switch and a photoelectric switch.

Abstract: A manually operable switch apparatus for a machine having at least one mode of operation actuated by a control circuit includes a spaced pair of switches which are simultaneously manually operable without the application of exertive contact by an operator. Preferably, each switch includes an infrared emitter spaced from an infrared receiver, and a single or double pole, double throw relay actuated when the beam between the emitter and receivers are broken, so as to cause actuation of an alternative mode of machine operation. The use of switches which do not require exertive contact obviates the injury to wrist and finger tendons experienced by machine operators when conventional palm buttons are employed on machines requiring repetitive operator manipulations.

Abstract: An optically activated keyboard provides inputs to a digital computer or the like. The keyboard includes a key housing having formed therein a wave guide matrix of intersecting columns and rows with light emitting diodes (LED's) installed in one end of each column and photo transistors installed in one end of each row. A plurality of keys are mounted at the top surface of the housing, each key having a plunger which projects through a corresponding aperture in the housing, when the key is depressed. The intersections of the columns and rows are located directly beneath the apertures so that when a key is depressed, its plunger intrudes into the volume at the intersection. Each plunger, in concert with the wave guide intersection, forms a light polarizing system. In the preferred embodiment, each plunger has a reflecting face that is angled to reflect light from the LED in the corresponding column into the corresponding row, finally impinging against the appropriate photo transistor.