Abstract: A method and apparatus are provided wherein there is associated with each value of a measurement of a parameter such as pressure, for transmission through an electromagnetic coupling device, a time duration or period which is a function of the measured value. A first, start signal of relatively short duration is transmitted and thereafter, at the end of a period which is a function of the parameter, a second, ending signal of relatively short duration is transmitted. A receiving device which is responsive to said signals, measures the elapsed time between them, i.e., measures the length of the intervening period, and converts this measurement into a measure of the parameter.

Abstract: An encoder for a wheel comprises a linear Hall-effect sensor and magnet mounted on a non-ferrous metal shaft. A ferrous metal ring having a toothed structure extending inward such that each tooth ends at a point on a spiral curve is molded into the printwheel encircling the shaft. The Hall-effect sensor output provides a determined output when each tooth is positioned over the sensor to enable an absolute position determination while the signal drop off between the teeth as the wheel is moved allows for counting the steps between settings for relative encoding and redundancy.

Abstract: A joystick controller apparatus comprises a lever mounted for pivotal motion in at least two directions, a guide defining a preselected shift pattern for the lever, and an indicating arrangement for producing a digital logic representation of the position of the lever relative to the shift pattern. The indicating arrangement comprises energy actuated members positioned at predetermined locations relative to the shift pattern, energy producing members positioned in registry with the energy actuated members for normally actuating the same and shield members interposed between the energy producing members and energy actuated members and movable in response to movement of the lever into positions for respectively permitting and preventing actuation of the energy actuated members by the energy producing members in a predetermined fashion such that said energy actuated members collectively form a representation of the location of the lever relative to the shift pattern.

Abstract: A keyboard with capacitive keys is operable through a thick dielectric wall which may be integral therewith. The keyboard may be installed inside an agency or store and coupled to a micro-informatic system providing audiovisual information selected at the request of a passer-by on the street operating the keyboard through a thick shop window. The keyboard includes a base panel (1) made of insulating material provided with Cnm electrodes integrated into the panel. with a free running oscillator being associated with each electrode key. A method of scanning the keyboard is provided.

Abstract: A remote oil tank display apparatus is set forth in combination with an oil tank for the indication of oil tank volume. The sending unit is encased in a hermetically sealed container to prevent oil fume propagation throughout an area. A combination digital and light emitting diode display is set forth and is remotely positioned relative to the oil tank to enable individuals of diminished physical capacity to receive and display information of oil volume remaining in an oil tank. Further, an audio means may be selectively employed in concert with the visual displays to assist individuals of diminished hearing capacity.

Abstract: A decodable alphanumeric membrane switchcore (12, 12a, 12b,100) of at least 36 key cells (55,122) including spaced circuits (16,17;105,115) having row and column traces (20-34, 40-47,51;106,116) and key cell elements (37,38,49;80;107,117) printed with ink having a resisitivity of at least about 10 ohms per square per 0.001" of ink thickness and having at least one path defined by a row trace, column trace and a key cell that has a resistance greater than 10,000 ohms.

Abstract: A membrane capacitive keyboard of the type including a first flexible dielectric sheet and a second dielectric sheet having electrically conductive patterns thereon which form an array of capacitors and connecting matrices of drive and sense conductors. The patterns on the sheets include a first array of capacitor plates on an inner surface of the first sheet and a second array of capacitor plates on the outer surface of the second sheet. A third array of electrically floating capacitor plates is formed by a third pattern on the inner surface of the second sheet. The sense conductors are capacitively coupled to ground through coupling capacitor plates connected to the sense conductors and a common capacitor plate overlaying the coupling capacitor plates.

Abstract: A key-depression data input device for detecting a depressed key in a plurality of keys arranged in a key matrix, the device including phantom key detection unit for detecting an occurrence of phantom key state, andkey release checking circuit for checking a released key among depressed keys, the releasing of the released key causing a cancellation of the phantom key state. Code data corresponding to the depressed keys being generated and delivered when the key release checking circuit detects that the released key is the key satisfying a predetermined depression-release sequence condition and an error warning being delivered when the key release checking circuit detects that the released key is not the key satisfying the predetermined depression-release sequence condition.

Abstract: A keyboard and keyboard system for use in an electronic device having a plurality of keys. A matrix of keys in rows and columns with each key being defined by an intersection of a row and column wire is used. Either the rows or columns function as initial inputs and the other of the rows or columns function as an initial driver. After a key press, the initial input is changed to a secondary driver and all initial drivers are changed to secondary inputs. The secondary inputs are then read to detect which key has been pressed and the row and the column are connected at the appropriate intersection representing the key which has been pressed. The keyboard system decodes each intersection to define the representation of each key and the representation is communicated to the associated electronic device. A method for detecting input from a keyboard is also disclosed.

Abstract: A keyboard switch assembly includes a thin, flexible, glass top layer forming a membrane. Disposed on an inner surface of the glass membrane is a first conductive layer forming an electrode. Disposed beneath the first conductive layer is an insulating layer or spacer having an aperture therein that defines a switch contact area. Beneath the spacer a rigid portion of the keyboard switch assembly is provided. The rigid portion of the keyboard switch assembly includes a rigid substrate with a conductive coating formed thereon to provide a second conductive layer or electrode disposed beneath the spacer. A flexible polymer layer may further be disposed between the rigid substrate and the second conductive layer to reduce point contact degradation in the keyboard switch assembly. Decorative paint layers may be formed on the inner surface of the glass membrane between the glass membrane and the first conductive layer.

Abstract: An electromagnetic transducer utilizes flat permanently magnetized plates made of magnetically hard ceramic materials having thicknesses substantially less than the dimensions across the faces thereof. Electric signals may be applied through a coil adjacent one of the faces to cause a changing flux on the opposite face. This changing flux then may be utilized to produce electric outputs in an output coil or to drive a resiliently mounted magnet or shorted turn speaker coil. Conversely, changes may be induced in magnetic flux through the plate which are picked up by a coil on the other side of the plate and converted to electric signals which in turn may be applied to a suitable utilization device.

Abstract: There are provided a method and an apparatus for absolute position detection, in which position detection is performed with high accuracy by interpolation between feedback pulses generated as an object of position detection moves, and the power-on command displacement can be calculated with high accuracy, the method and the apparatus entailing only small electric power consumption. A stored value in an absolute counter (2), which is indicative of an approximate absolute position of an object of position detection, is updated each time a feedback pulse is generated from a feedback pulse generating circuit (1), and is retentively stored in the counter even after the power is turned off. As the object of position detection moves, moreover, the count value of interpolation pulses, generated during the time interval which elapses from the instant that the power is turned on again until the first one of the feedback pulses is generated, is temporarily stored in a correction counter (5).

Abstract: A keyboard for data entry or control purposes includes a plurality of sets of two or more keys arranged for receving the tips of the finger of a hand of an operator, the keys of each set have such a small superfical touch area and are clustered together so as to be substantially comprehended and selectively operated by a single finger tip of an operator. Additional keys having their superficial touch area spaced from but sufficiently close to the superficial touch area of a set of the sets may be provided to be conveniently operable by a finger tip of user operating the keys of the adjacent set. In a preferred embodiment of the invention, the superficial touch area of each key takes the form of a roller and each set of keys is made up of two keys. In some embodiments, the relative spacing between sets of keys or between keys may be adjustable.

Abstract: A circuit arrangement is described for automatically monitoring several analog electric signals and for maintaining predetermined ranges of tolerances by successive comparison with reference values. Error alarm signals are produced and stored, dependent upon the comparison and timed (synchronized) simultaneously with the connection of the respective signals to be monitored to a comparator (20). Access is provided to a reference value storage (30) from which reference signals assigned to each single signal and ranges of tolerances defining reference values are timed and led to the comparator (20). The respective outlet (output) signal of the comparator (20) for producing similar error alarm signals to be stored is logically linked with an evaluating signals (ZB 0) indicating which of the two reference values lies at any time on the comparator (20).

Abstract: A matrix keyboard system for producing key codes in response to the actuation of key switches. The keyboard system includes ghost key condition detection. In the keyboard system, a group of parallel drive lines and a group of orthogonal parallel sense lines form a matrix, with a key switch being associated with each of the intersection points on the matrix. The drive lines are sequentially activated, and the actuation of a key switch along an activated drive line results in the coupling of a drive signal to the associated sense line. A ghost key condition arises when three of the four corners of a notional rectangle in the matrix contain an actuated key switch. The ghost key condition detector senses the presence of drive signals not only on the sense lines but also on the drive lines, with a ghost key condition being identified if a drive signal is sensed on two or more sense lines and two or more drive lines simultaneously.

Abstract: A loudspeaker device comprises an input circuit for obtaining an input signal to be sounded by a loudspeaker as a digital signal, a phase correction circuit for correcting the digital signal in phase, a loudspeaker drive circuit for producing a loudspeaker drive signal in accordance with the digital signal which has been phase-corrected by the phase correction circuit, and loudspeakers driven by the loudspeaker drive signal. The phase correction circuit consists of a digital filter capable of determining sound pressure-frequency characteristics and frequency-phase characteristics independently from each other. By determining the two characteristics in such a manner that, for example, the sound pressure-frequency characteristics will become flat and the phase-frequency characteristics will become linear, naturalness in hearing can be improved.

Abstract: New loudspeaker driver configurations comprise positioning the high frequency driver between symmetrically located lower frequency drivers and providing in combination electrical or acoustical delay to the high frequency driver relative to the lower frequency drivers. The lower frequency drivers are located above and below at equal distances from the high frequency driver or, with more than two lower frequency drivers, symmetrically about the high frequency driver. The sound pressure level and phase response is substantially equivalent to co-axial drivers including suitable high frequency electric delay circuitry operating at similar power levels. The delay for the high frequency driver is electrical or electrical in combination with a geometrical delay. With a stereo pair of loudspeakers the high frequency driver may be offset from the vertical between the above and below low frequency drivers in an outboard direction of the stereo pair.

Abstract: A matrix-scanning optical keyboard comprising a logical matrix of optical paths between light inlets (3) and outlets (2) with keys disposed on each optical path connecting an inlet to an outlet in such a manner that depressing a key causes a change which can be detected by a scanning driver circuit connected to the light inlets and outlets in order to respond to changes affecting each inlet-to-outlet (3-to-2) coupling by periodically injecting an interrogation signal into each inlet in turn and by inspecting each outlet for the presence of possible changes. The keyboard is capable, for a given emission level, of increasing the sensitivity of the driver circuit to light arriving at the outlets.

Abstract: A combustible gas sensor with a calibration test adaptor. A standard combustible gas sensor attached to a transmitter in transmitter housing has a body portion attached thereto which is adapted to receive and slowly distribute test gas in the vicinity of the combustible gas sensor. A flexible bladder fastened to the main body portion receives the test gas, inflates, and slowly releases the test gas through a sintered stainless steel plug mounted in one end of the flexible bladder.

Abstract: The portable terminal keyboard includes silicone rubber mixed with phosphorescent material used on the external exposed surface of the keyboard and conventional silicone rubber used for the moving parts, so that it is luminous for a certain duration by being irradiated for a while with a light source, thereby facilitating the user's entry operation and also enhancing the durability of the keyboard. The keyboard has its key mat made of a magnetic material so that it is attached by magnetism to the main frane, thereby faciliting replacement with a different key mat. The magnetic key mat structure allows the single access attachment and eliminates such conventional fixtures as lugs, whereby the key mat can be replaced more easily even in darkness and the lugs or the like are not present to be damaged as would be otherwise caused by frequent key mat replacement.