Abstract: An optical instrument is provided which comprises emitter means which emit radiation into an elongated emission space and sensor means responsive to radiation directed towards them from any point of an elongated sensing space whereby to generate tone signals, the emission and sensing spaces being in only partial overlapping relationship, preferably as a result of their having different axes of symmetry, the instrument further comprising means for decoding the tone signals and transmitting the same to an interface to a device to be controlled by the instrument. Said controlled device is preferably chosen from among devices for producing musical tones and devices for producing optical images. The tone signal generating means preferably constitute a number of units, each unit corresponding to a tone and the several units being arranged in a line which preferably defines a closed floor space.

Abstract: A detection apparatus for monitoring specified safety eyewear being worn by persons who are either passing into or are located in the designated area which requires that a person in the area be wearing the specified safety eyewear. The detection apparatus includes an infrared reflector which is located on the specified eyewear, an infrared transmitter for transmitting a beam of infrared radiation towards the person, an infrared receiver which receives reflected radiation from the infrared reflector on the safety eyewear being worn by the person and an alarm which is normally inactive and which remains inactive as long as infrared radiation from the transmitter is reflected back to the infrared receiver from the reflector. The alarm is activated when infrared radiation is transmitted to the person and not reflected to the receiver due to the absence of specified safety eyewear which contains the appropriate infrared reflector.

Abstract: A light curtain system and method of operation which detects the intrusion of objects into a protected zone. The system is characterized in having an inherent self-checking mode of operation by logic circuits which analyze data signals from both the LED light transmitters and phototransistor receiver circuits. A shutdown signal is generated if the logic circuit determines that light is not received in a selected channel at the time that the LED is strobing light exclusively for that channel. The system further provides a relatively simple and inexpensive method of selecting and amplifying the LED transmitters and PT receivers. In the circuit each PT acts as a switch which selects itself, and a single amplifier is employed for a plurality of the channels. The circuit further provides for the concatenation of groups of amplifier/PT circuits into a longer chain using a single diode.

Abstract: An autocollimation light curtain comprises a light source which directs a light beam onto a scanning device which scans the light beam so that it is continuously displaced parallel to itself, thus forming a light curtain which is directed through a monitoring region. A reflector is provided at the end of the monitoring region and is subdivided in the scanning direction into a plurality of fields of two types which alternate with each other. Light reflected at the reflector is directed back to a light receiving system comprising first and second photodetectors. The two types of fields of the reflector have characteristics which influence the spectral range and/or the state of polarization of the incident light. In the light receiving arrangement one photoreceiver is filtered so that it receives only light reflected from the one type of field, but not light from the other type of field, whereas the other photoreceiver responds to all the light reflected back from the reflector.

Abstract: A reflection type photoelectric switch including a light emitting member for emitting a substantially single light beam having first and second different wavelengths, a reflector for reflecting the emitted light beam at different reflection rates with respect to the first and second and wavelengths, a light receiving member for sensing rays at the first and second wavelengths, and means for analyzing outputs generated from the light receiving member receiving the reflected light beam at the first and second wavelengths to generate an output representing the existence of an object to be detected by the photoelectric switch.

Abstract: A wired mail delivery indicator having a physical construction which forces any size of mail across a groove (20). Slope on the left vertical wall of mailbox (10), slope of panel (14), and force of gravity cause mail to block light beam. The light beam is generated by a photodiode emitter (22) and detected by a photo detector (24). Mailbox and electronic circuitry (26) contains photodiode emitter (22), photo detector (24), current limiting resistor (42), and current amplifier transistors (46 and 48). House end electronic circuitry (28) contains power transformer (32), diode rectifier (34), and current sensor (38, 40, and 36). House/mailbox connecting wire (18) carries power and mail delivery information with two wires.

Abstract: An extremely reliable, easily portable perimeter alarm system. It is comprised of a light beam controlled radio transmitter and personal warning devices capable of individually warning preoccupied highway workers of the imminent danger present when an errant vehicle violates the established perimeter of a work site. This warning will allow the workers to take evasive action and potentially avoid injury and/or death. It is also the object of this invention to allow for an extremely reliable, easily portable perimeter penetration alarm system that can be utilized in other appropriate settings by security guards, military personnel, etc., and which would provide for confidential notification to such personnel that a temporarily established portable perimeter line had been violated.

Abstract: A station is provided with an external industrial container-shaped shell having a window therein for admitting the passage of a monitoring beam therethrough. The preferably infrared beam is initiated by a beam transmitter having a lens aimed at a corresponding beam receiver in a second station, the stations being adapted for employment in pairs. Interruption of the beam by either an intruder passing between the pair of stations or tampering with a barrel causes a signal to be transmitted to a remote alarm. The housing is designed to be inconspicuous so that an intruder will not locate the station and thereby avoid detection.

Abstract: A proximity detector in which a sensor unit (10) senses reflected energy received from a predetermined volume or zone and generates an electrical signal representative of the received energy. Circuit means process the received signals to control the operation of apparatus such as automatic doors. One aspect of the invention is concerned with the sensor unit in which transmitters (14) are located in a housing with a receiver (15). The housing has a filter (7) through which infrared radiation can be transmitted and received. Mask areas on the filter define the zone into which radiation can be transmitted and from which it can be received. The filter is interchangeable so that zones of different sizes and dimensions can be provided. Another aspect is concerned with novel signal processing circuitry and a further aspect is concerned with an ultrasonic system wherein a multiplier is used to process the received signals.

Abstract: An observation apparatus comprises a transparent keeping cage having cylindrical outer and inner walls defining an annular keeping space therebetween, a group of circumferential position detectors, a group of standing action detectors, a group of inner peripheral position detectors, a group of outer peripheral position detectors, and a data processing unit for processing detection signals produced by the detectors to determine the actions of an experimental animal through the analysis of the detection signals produced by the detectors. The detectors of each group are arranged on a circle at equal angular arrangement. Four detectors each belonging to one of the four groups of detectors are arranged in a set on the same radius and driven simultanelously or sequentially, and the sets of the detectors are driven sequentially one at a time to avoid interference between the detectors. The data processing unit is simple and compact in construction and has amplifiers for each set of the detectors.

Abstract: A method of scanning intrusion detection which is capable of monitoring a large volume of either interior or exterior space from a single relatively inexpensive unit. This method of intrusion detection comprises the steps of scanning a beam of infrared radiation about a field of view and receiving the radiation of the beam reflected from the field of view, generating a signal indicative of the distance from the device at which the beam has been reflected for each of a plurality of azimuthal sectors of the field of view, storing a plurality of reference signals which are indicative of the distance of reflection of the beam from each azimuthal sector of the field of view during a reference time period, comparing the signals from a selected time period with the reference signals, and generating an output signal if one of the signals is different from the respective reference signal.

Abstract: A scanning intrusion detection device is capable of monitoring a large volume of either interior or exterior space from a single relatively inexpensive unit. This intrusion detection device comprises a radiation emitter arranged to scan a beam of infrared radiation about a field of view and means for receiving the radiation of the beam reflected from the field of view. The receiver is arranged to generate a signal indicative of the distance from the device at which the beam has been reflected for each of a plurality of azimuthal sectors of the field of view during a selected time period. A ram is also provided for storing a plurality of reference signals which are indicative of the distance of reflection of the beam from each azimuthal sector of the field of view during a reference time period. The signals from a selected time period are compared with the reference signals and an output signal is generated if one of the signals is different from the respective reference signal.

Abstract: A portable optical alarm system for area protection containing at least one light-emitting transmitter and a receiver sensing the emitted light is disclosed. The transmitters and receivers of the system form a chain in such a manner that the receiver sensing the light-impulses of the first transmitter is always connected electrically to the following transmitter and the last receiver of the system is connected electrically to the intervening organ and partly to the first transmitter of the system, or the first transmitter of the system is formed as a free-running unit. Transmitters and receivers can be arranged in an optical mutual arrangement where they are arranged in a casing containing the transmitter circuit and the associated battery along with the receiver circuit and the battery belonging thereto.

Abstract: A photoelectric intrusion detector for detecting the interruption by an intruder of a monitoring beam of optical radiation such as an infrared radiation includes circuitry for preventing the generation of a false alarm when the optical beam is attenuated during its propagation through space due to fog or the like. This false alarm preventing circuitry is designed so that when the attenuation of a beam of optical radiation during its propagation through space is increased due to the occurrence of fog in cloudy weather, the occurrence of a false alarm due to the attenuation of the pulsed light in cloudy weather is prevented by decreasing a comparator reference value to follow the decrease in the level of a light receiving signal, correcting the gain of AGC amplification to maintain constant the level of a received light signal or correcting the level of a received light signal which follows a received light initial value.

Abstract: A photoelectric alignment indicator that includes two indicators (10) and (11) and a photoelectric receiver (2) is disclosed. A housing (3) houses the indicators (10) and (11) and the photoelectric receiver (2). One indicator (10), formed by a collimating lens (10b) and LED (10a), is mounted adjacent to the photodetector (9) of the photoelectric receiver (2) and transmits visible energy (12) into substantially the same field as the field of view of the photodetector collimating lens (9b). The second indicator (11) is mounted on the rear surface (8) of the photoelectric receiver housing (3), opposite the receiver photodetector (9) and emits visible energy (12) viewable from the end of the photoelectric receiver (2) remote from the transmitter (1). Alignment of the photoelectric transmitter (1) with the photoelectric receiver (2) allows the light (13) from the light source (15) of the photoelectric transmitter (1) to illuminate the receiver photodetector (9), energizing the indicators (10) and (11).

Abstract: A Precinct Protection System includes a laser source of light which is applied at the input to a bundle of light transmissive fibers. The fibers are gathered in a cable in loops of varying lengths so that the fibers enter and exit the cable at one and the same end. The cable is placed along a line adjoining or surrounding the precincts to be protected. An intruder traversing the line or protected perimeter will disturb one or more of the fiber optic loops of the cable. The circumstance and locality of the disturbance produced by the intruder are indicated on an analog or digital display.

Abstract: An infrared light emitter forms a beam of infrared (IR) light directed onto a set of mirrors or reflecting surfaces arranged to form a closed path about a swimming pool and spaced above the pool deck a sufficient amount so as to be intercepted by anyone who might walk through it. After the reflected beam has traversed the closed path about the pool, it then impinges upon a light detector. An electric circuit provides a continuous alarm which can either be sound or visual upon beam interruption and which must be manually reset before it becomes inactive. The monitoring system may be actuated so the operative state by a handheld radio frequency transmitter. Electrical power for the system can be a rechargeable battery which is recharged by a solar array mounted directly onto a part of the system obviating the need for interconnecting cable wiring.

Abstract: Livestock entering a border zone along a vehicle roadway are deterred by devices triggered into operation simultaneously with a remote alarm by interruption of photo-electric beams at ends of the zone from which the animals enter or exit. The deterring apparatus is reset to prevent operation in response to travel of a vehicle through the zone and is temporarily disabled by selective switch actuation.

Abstract: A monitoring device comprises a transmitter and a receiver for transmitting and receiving, respectively, a signal in a medium to be monitored. During a cycle of m sampling periods n sampling values are taken of the signal received during each sampling period. After completion of each cycle a series of n means sampling values is determined by determining a mean value from the m sampling values taken at corresponding instants in the sampling periods. This series forms an actual pattern word which is sub-divided into sub-pattern words, each sub-pattern word being combined with a corresponding sub-pattern word from a reference pattern word in order to form a combination word. The combination word is translated into a code number which is selected from a predetermined series of code numbers. The code number assigned characterizes the time shift of the actual sub-pattern word with respect to the reference pattern word.

Abstract: An intrusion detection device which comprises a radiation emitter arranged to project a beam of infrared radiation toward a field of view and means for receiving the radiation of the beam reflected from the field of view. The receiving means is arranged to generated a signal indicative of the distance from the device at which the beam has between reflected by the field of view during a selected time period. Means is also provided for storing a reference signal which is indicative of the distance of reflection of the beam from the field of view during a reference time period. Further means is provided for comparing a signal from a selected time period with the reference signal and for generating an output signal if the signal differs from the reference signal in a preselected manner.

Abstract: An apparatus and method for detecting disturbance in a protected area or perimeter by scanning the area or perimeter with a rotating beam of radiating energy, such as light, infrared, ultraviolet and the like, and counting the number of pulses at the output of a detector or sensor upon impingement on the detector or sensor of the beam reflected by each one of a plurality of reflectors disposed in the protected area or perimeter. Upon turning on the apparatus, a first pulse count corresponding to each complete revolution of the beam is stored as a pulse reference number for a "normal" state in the protected area or perimeter. In operation, the number of pulses for each revolution of the beam is continuously counted and compared to the stored reference number and an alarm is triggered as soon as the stored reference number and the counted number are unequal.

Abstract: A locking cable for use in an antitheft device adapted to give warning in response to a change in a photo signal transmitted through an optical fiber longitudinally extending through the locking cable. The locking cable comprises a core portion including the optical fiber, a reinforcing layer concentrically disposed around the core portion and including at least one electric conductor and a plurality of reinforcing members, and a flexible hollow protective member as an outermost layer covering the electric conductor and reinforcing members in contact with the protective member. If required, a further reinforcing layer may be interposed between the core portion and the first-mentioned reinforcing member, which includes a plurality of second reinforcing members. A holder holding an end of the optical fiber and a photoelectric element in face-to-face relation to each other is axially movably arranged within a plug connected to an end of the locking cable.

Abstract: A detector for sensing or measuring objects passing a measurement path (5) has a detection element (6), the output signal of which is a function of objects discovered in the measurement path. The output signal is fed to an amplifier and filter circuit (7-9), the output of which is connected to two parallel integration cirucits (11, 12). The integration circuits have time constant (.tau..sub.SH, .tau..sub.L) of different magnitudes, and their output signals are fed to a comparator (13) for obtaining an operative signal indicating the presence of an object in the measurement path, this signal being unresponsive to long-duration fluctuations in the detector's operating conditions, e.g., dirtying of the detection element. The detector includes a dirtiness alarm with the threshold response adjustable to a long-time-constant integrator output.

Abstract: A security device for monitoring unmanned vehicles within an area, the device comprising at least two oppositely directed light barriers associated with the area. Each light barrier includes a light emitter, a reflector, and a light receiver. The light barriers are disposed such that their light-beams are interrupted by the vehicles entering the area. Reflectors are arranged laterally on authorized vehicles, thereby making them undetectable by the security device. Another embodiment uses the light barriers attacted to the vehicle such that unauthorized objects will cause the vehicle to stop.

Abstract: The apparatus is utilized to detect disturbance created in an opening by objects even when the objects do not move so that they cannot be detected by a motion detector. The apparatus includes a transmitter-receiver apparatus provided at the opening comprising a plurality of arrays, each of which comprises a receiver and a plurality of transmitters. Because divergent beams are emitted by the transmitters, which preferably consist of infrared-emitting diodes, the transmitters and the associated receiver can be arranged to define a triangle in space so that the space of the opening can be completely covered by a plurality of transmitter-receiver arrays. By means of a cyclic signal sequence it is ensured that a signal which has been transmitted is checked in the receiver whether it belongs to the correct transmitter.

Abstract: A hinge construction having radiative emitter and detector concealed within the body of the hinge's knuckles so as to be in communication with each other when the hinge leaves, and therefore the door, are in a closed position. This communication is permitted through an opening in a notched collar which is juxtaposed between the emitter and detector elements, the notch being aligned with the emitter and detector when the hinge is closed. The opening of the hinge leaves rotates the collar to misalign the collar notch with the emitter and detector elements, thereby causing an electronics circuit module to form a change of state signal which may then be reported to an external monitoring or alarm system. Closing the hinge leaves to realign the notch with the emitter and detector elements will result in the sensing means being reset.

Abstract: The present invention provides a method and apparatus for counting the number of occurrences that a mobile unit comes within range of a stationary unit. The invention is useful in counting the number of laps which a runner or swimmer completes through a course. In one aspect, the present invention includes a timer which, in cooperation with the information generated by the lap counter, produces information corresponding to the lap time, average minutes per mile and other such data. In a preferred embodiment, a stationary transmitter emits an infrared signal to create a zone of detection which triggers a receiving unit attached to the runner or swimmer each time the runner or swimmer passes through the zone of detection.

Abstract: A semaphore for use in a detection system for a high voltage device and for signalling a predetermined state of the device. The semaphore comprises a housing supporting therein a retroreflector element. The housing has an aperture and the retroreflector has a reflective surface supported in a alignment with the aperture. The housing is mounted in close proximity to the device. A linkage is associated with the housing and the device and is actuated upon the occurrence of a predetermined condition whereby to expose the reflective surface in the housing for the reflection of signals through the apertures. A remote scanning device continuously generates infrared signals in the direction of the aperture and detects reflective signals from the reflective surface.

Abstract: Arrangements for detecting the presence of an opaque object in an area, such as a person in a robotic work cell. Multiple light sources, light reflecting surfaces, light boxes with hole patterns or fiber optic light sources are spaced around the perimeter of the area and imaged by a camera. The change of the camera signal from its normal condition is used to interrupt power to safeguard personnel and/or machinery.

Abstract: A reflection light barrier with a measuring light emitter which emits light nto a space to be monitored, and with a measuring light receiver which receives light reflected from an object present in the space to be monitored. The reflection light barrier, also referred to as light sensor, according to this invention is characterized in that at least one further light receiver is provided which receives the light of the measuring light emitter without reflection, and at least one further light emitter is provided which emits light in a test cycle that is received without reflection by the measuring light receiver. Improper operating conditions can be recognized and indicated thereby.

Abstract: An improved optical fiber monitoring system using a light-emitting diode which is controlled by a module 12 having an oscillator 40, a first JK trigger 42, two univibrators 44, 46 and a second JK trigger 48 with an output stage 43 being connected to one or the other of the two outputs of the first trigger. A synchronization selector 50 is also a part of the module and has four inputs connected to the four output of the two JK triggers and to an output supplying one of the four signals which are received. The photoreceiver is connected to a synchronous detector module which uses the signal supplied by the selector 50 as a synchronization signal. The system also utilizes a inhibit circuit 83 and the control system incorporates a means for detecting the possible failure of the light emitting diode 10 with the controlling means inhibiting the input 83.

Abstract: A light barrier system having a two-terminal network that is connected in series with a precision resistor. In normal operation, in this two-terminal system, two different potential drops occur, according to whether the light path between the light-emitting and the light-receiving elements of the light barrier arrangement is interrupted or not. Correspondingly, one input of a monitoring circuit is located at two different levels. In the event of a breakage of the supply lines or a short circuit of the light barrier system, the input is located at an extremely high or extremely low level.

Abstract: In a light sensor with a housing (19) the light transmitter (17, 20) and the light receiver (12, 15) are arranged alongside one another. The received light beam (11) is deflected behind the front receiving lens (12) onto a photoelectric converter arrangement (15) via a deflecting mirror (14) which is pivotable about a transverse axis (13) and it is possible to change the sensing distance by pivoting the deflecting mirror (14).

Abstract: An automatic faucet control including a radiation emitter directing radiation into the area of a sink where hands are to be washed and a detector positioned to receive radiation reflected from the hands to activate the water supply. The flow of water terminates when the hands are removed.

Abstract: In this system for the securing of rooms, one or more transmitting elements emit suitably modulated light pulses into given regions or sectors which are produced by specially shaped optical components and/or by a special alignment of the transmitting elements and/or by the application of absorbent layers to an infrared filter which is located in front of the transmitting elements and receiving elements. One or more receiving elements receive the incident radiation. Changes in the radiation field with respect to intensity and/or speed of change of the intensity and/or phase are processed in subsequent evaluation logic circuitry. The room security system can also be combined into a larger unit with common evaluation logic.

Abstract: A photodetection type coordinate input device includes a frame having a substantially rectangular opening formed in the center, a light-emitting element array composed of a plurality of light-emitting elements disposed along each of the two sides of the opening of the frame, a light-receiving element array composed of a plurality of light-receiving elements disposed along each of the two sides which respectively oppose the first two sides, and a filter provided in a part or the whole area of the opening and adapted to transmit desired light alone. The opening of the frame is disposed in front of a display to form a plurality of optical paths by pairs of light-emitting and -receiving elements, respectively, in front of the display screen of the display, and a position at which optical paths are blocked is detected to specify a coordinate position on the display screen, thereby inputting the coordinate position.

Abstract: An area-security system comprises a transmitting/receiving strip arranged along one side of an area to be secured and a reflection strip arranged along the other side. The transmitting/receiving strip is divided into transmitting regions and receiving regions, the transmitting regions consisting of a plurality of transmitting elements which are arranged alongside of each other and which are combined in at least two groups, and the receiving regions also consisting of a plurality of receiving elements which are arranged alongside of each other and are also combined in at least two groups. Modulated light from the transmitting elements strikes the receiving regions after being reflected by the reflection strip. A control circuit determines association of different groups of receiving elements with the individual groups of transmitting elements. A multi-channel evaluation, under the synchronizing control of a control circuit, evaluates the signals on the basis of various factors.

Abstract: An optical motion sensor comprises first and second light emitting diodes that emit complementary pulsed beams of infrared energy within a sensing region. A photodiode sums the energies to produce a proportional sensing signal. An amplifier AC coupled to the photodiode blocks the constant portion of the sensing signal and passes a time varying signal portion produced by motion of an object to a sampling circuit. The sampling circuit samples the sensing signal synchronous with emission of the first pulsed beam and converts the time varying signal to a proportional detection signal. An integrator coupled to the sampling circuit responds to a detection signal by modulating the intensity of the second pulsed beam to null the earlier time varying portion of the sensing signal. The motion sensor can be configured as a presence sensor by changing the time constant of the integrator.

Abstract: A light projecting and receiving unit for use in a human body detecting apparatus having a light projecting section consisting of at least one set of concave mirrors and a plurality of light projecting elements, and a light receiving section consisting of at least one set of concave mirrors and a plurality of light receiving elements. The light projecting section and the light receiving section are formed on one side surface of a generally rectangular unit body, and the unit body is divided longitudinally into one and the other sides by a partition wall located at the longitudinal central part of the unit body and projecting vertically therefrom as an integral part thereof. Further, each of the split concave mirror sets consists of a combination of a plurality of concave mirrors oriented in different directions and arranged sequentially in the longitudinal direction of the unit body so as to have a common or the same focus.

Abstract: A method for sensing a human body has the steps of projecting infra-red rays from a projector, receiving infra-red rays reflected from a background and a human body by a photo-sensor, deriving a difference between a reflection amount from the background and that from the human body on the basis of an output from the photo-sensor by the action of first and second integrator circuits, and outputting a human body sense signal from a response circuit when the difference in the reflection amount is held at a predetermined period of time. The first integrator circuit has a relatively small time constant, while the second integrator circuit has a relatively large time constant.

Abstract: An optical coordinate input device comprises a plurality of light emitting elements arranged so that their optical axes intersect mutually, a plurality of light receiving elements arranged so as to receive the light signals of the light emitting elements, a drive circuit for turning on/off the light emitting elements on the basis of a drive signal to cause them to provide the light signals, a first switching circuit for switching the output given from the drive circuit to among the light emitting elements, a second switching circuit for switching the signals given from the light receiving elements in correspondence with the light emitting element lighting, and a waveform shaping circuit for regulating the signal given from the second switching circuit to a certain voltage level on the basis of the drive signal.

Abstract: A control device for valves and the like, including at least one control switch (13) which is inserted in at least one optical conductor (18,118), and is connected to the valve actuating means in such a manner that it will be automatically actuated (i.e. opened or closed) upon the actuation (i.e. opening or closing) of the valve, thus interrupting the respective conductor (18,118) or re-establishing its continuity. The conductor (18,118) is comprised in a warning and/or control circuit, and the opening or the closing of said switch (13) generates a signal which may be utilized, for example, to detect and/or to record the actuation of the valve and/or to activate a television inspection system. The control switch (13) is formed by a connector for optical fibre and comprises two complementary and co-axial connector members (14,15) one of which (14) is stationary and the other of which (15) is movable axially and is urged towards one of its end positions (i.e.

Abstract: A system for automatically controlling lighting fixtures, appliances, an alarm, or the like in a room or enclosure has a pair of sensors installed in association with each entryway leading into a room. The sensors are triggered when a person passes through the entryway and send a signal to a logic circuit which is mounted in operative association with the sensors. The logic circuit distinguishes between entry or exit of persons from the room on the basis that in each entryway or door one of the two sensors is triggered first in case of entry, and the other one of the two sensors is triggered first in case of exit. The signals signalling entry are counted and stored in a first counting register separately from the signals signalling exit of persons from the room which are counted in a second counting register. The status of the first counting register storing the number of entries is continuously compared in a comparator circuit to the status of the second counting register storing the number of exits.

Abstract: A coordinates detector comprises a plurality of pairs of light emitting and receiving elements arranged such that in an X direction pairs of light emitting and receiving elements are located in parallel and in a Y direction pairs of light emitting and receiving elements are located in parallel on an orthogonal coordinates plane. The pairs of light emitting and receiving elements are sequentially, simultaneously and separately enabled and a two-dimensional designation position is detected from the detection output of the light receiving element and a signal for selecting the pair of light emitting and receiving elements.

Abstract: An alarm system for a swimming pool or the like whereby small inexperienced children or animals are detected prior to entering the pool or after an unauthorized entry into the water of the pool. The invention comprises the use of a height sensing apparatus employing fibre optics and a logic circuit whereby an interruption of a pair of different elevations of light paths is accepted and the alarm remains silent and the interruption of the lowest light path only is reflected sounding an alarm. The invention further comprises the use of fibre optics and a movement sensor connected to the optics. Any impact on the water surface of the pool causes the sensor to change the state of the light transmission therethrough by transmitting or interrupting light transmission. This change of normal state activates the alarm. The invention still further comprises a wireless means for detecting a person in the pool water or a man overboard from a ship or the like and sounding an alarm.

Abstract: Seat switches for detecting the presence and absence of an occupant in the seat of a vehicle are commonly used on industrial and commercial vehicles. It is desirable that the control signal produced by such seat switches be responsive only to the presence and absence of the vehicle occupant, and be relatively simple, rugged, and inexpensive. The instant invention includes an emitting device for directing a source of coded radiant energy across a vehicle seat, and a detecting device for receiving radiant energy, including a portion of the coded radiant energy in response to the seat being vacant. The detecting device produces an electrical signal in response to the received radiant energy. An electrical circuit produces a control signal only in response to the detecting device receiving the coded radiant energy.

Abstract: An object detecting apparatus has a plurality of light emitters which are sequentially actuated for projecting sequential light beams. A first structure is provided for receiving beams not reflected off any external body. A second structure is provided for receiving any part of the light beams reflected from an object in the area. A reference phase signal corresponding to the projected light beams is generated. A detection phase signal corresponding to the received reflected beam is also generated. The light emitters corresponding to the reflected light beams are continuously activated. The detection area is restricted by inhibition of output from an alarm phase difference discriminating circuit to a circuit when a difference between the reference and detection phases is not within a predetermined range. Consequently, the detection area can be restricted to a desired range, and the alarm circuit can be retained non-operative unless the object remains continuously in the area.

Abstract: A processor-controlled light screen system comprises spaced-apart Master and Slave units each having a plurality of light transmitters and light receivers. Each transmitter in the Master unit or Slave unit is adapted to provide a light beam carrying a respective binary coded signal to a corresponding receiver in the unit to enable the two otherwise independent units to interactively communicate with one another. The Master and Slave units respectively include a Master processor and a Slave processor, each programmed to sequentially actuate the transmitters and receivers in their respective units in pairs. Operation is initiated by the Master processor program which causes the transmitter of the first actuated transmitter-receiver pair of the Master unit to send its respective coded signal.

Abstract: A pulsed LED photoelectric control apparatus operates in both the proximity mode and the retro-reflective mode. Field stop elements are manually inserted for operation in the retro-reflective mode and are quickly and readily removed for operation in the proximity mode in order to enable the same photo-electric control apparatus to be utilized in both modes.

Abstract: A workmen protecting safety light for roof perimeter edge protection includes a pair of invisible light beam units, one bearing a light beam source and the other being a light beam receiver/control, and a relay box together with audio warning and signalling apparatus. Supporting structure includes a base support frame, a sub-base, tripod support, vertically and horizontally adjustable support pipes and clamping structures. All the foregoing are combined to provide an easily, quickly and accurately installed perimeter safety light protection device. A plurality of specially sized and marked pipes, support brackets for the light units, and specific adjusting/clamping structures are all important features of the invention. Preferably, the units are supplied in kit form and, therefore, suitable containers are provided for holding same in compact, easily shippable and stored form, ready for quick and easy assembly at a job site.