Abstract: A standard keypad comprises a rigid support plate having a front face and formed with an array of throughgoing apertures, respective push-buttons projecting at the apertures through the plate past the front face thereof, and a continuous flexible membrane overlying the front face and formed in front of each of the push-buttons with a relatively thick projecting portion. Thus the membrane seals the apertures around the buttons while allowing same to be depressed via the projecting portions. The switch associated with the push-buttons urges the push-buttons and the overlying thick portions forward from the front face. A shield assembly has a rigid shield plate formed with an array of throughgoing apertures aligned with and generally identical to those of the support plate and having a rear face confronting the front face of the support plate and an opposite front face. The projecting portions of the membrane project forward through the apertures of the shield plate past the front face thereof.

Abstract: A directional acoustic transducer includes a plurality of acoustic paths each having first and second ends. The second end of each path terminates in the atmosphere. An electroacoustic device is attached to an acoustic cavity and the acoustic path first ends are coupled to the said acoustic cavity through an acoustic arrangement adapted to produce a predetermined transducer directional response pattern.

Abstract: The charges induced by the light image to be scanned are integrated cyclically. During each integration cycle, the total amplitude of the signal corresponding to said image is calculated. The calculated amplitude is compared with a threshold amplitude value which is a function of a saturation value which is itself fixed by the amplitude of a periodic bias voltage applied to the device. The amplitude of the potential wells created by said bias voltage is modulated as a function of the result of said comparison. The invention is applicable to solid state TV cameras, e.g. for use in low light.

Abstract: A portable, self contained, lightweight cordless phone holder is provided for the user to permit the free use of both hands and have virtual freedom of movement within the range of the unit while at the same time having ready access and use of the cordless phone. The mechanism is a device made of lightweight, malleable metal which permits it to be bent or adjusted to rest on the shoulder of the principle user just below the juncture of the neck and shoulders. The mallable metal permits the principle user to adjust the device for his individual body contours for the most comfortable position while being used.The device is basically of a rectangular configuration shape comprised of two "L" shaped wire components, an obliquely vertical phone support extended vertically from one end of one of the "L" shaped components and adjusting strap attached to the other end of the other "L" shaped component.

Abstract: A system for generating an electrical indication indicative of an image scansion, comprising in combination: image sensing means including a plurality of one-dimensional image sensing arrays arranged in parallel with each other, each of the sensing arrays being for generating an electrical indication indicative of a line scansion of a portion of an image; storage means including a plurality of one-dimensional storage arrays arranged in parallel with each other; and control means for controlling the image sensing means and the storage means, the control means causing the sensing means to successively form, at a selected one of the sensing arrays, composite electrical indications each being composed of a selected plural number of the line scansion indications and causing the storage means to successively store the composite electrical indications formed by the sensing means.

Abstract: A modular transducer mounting arrangement includes a substantially planar support plate. An aperture having an angular bevel is provided in the support plate such that a loudspeaker may be positioned in the bevel to allow sound to exit from the loudspeaker in a manner which is substantially unobstructed acoustically. An adhesive shock absorbing pad is attached to the rear of the support plate for isolating the loudspeaker microphone and support plate from mechanical shock. This creates a free floating and reliable transducer mounting assembly which provides shock isolation and easy serviceability.

Abstract: Low frequency streaking noise which is effected by modulating the black reference with high frequency noise is eliminated from the displayed picture in a television system by switching the signal during the horizontal blanking interval to a noise-free black reference. A CCD or other imagers where a pixel-by-pixel reference is available provide a unique opportunity to eliminate low frequency streaking in the video display. Each pixel of a solid state imager includes a black level reference. In accordance with the invention, a switch circuit is added to a correlated double sampling system used in conjunction with a CCD imager. During the horizontal blanking interval the switch is rendered conductive to substitute a noise-free reference derived from the pixel clamp.

Abstract: An electroacoustic transducer comprises a diaphragm (1), a magnet system (4) and a voice coil (3) arranged on a voice-coil former (2) in an air gap (5) of the magnet system. The movement is transmitted between the voice-coil former and the diaphragm via a lever mechanism comprising n lever devices (6) arranged at an angle relative to each other (n.gtoreq.2). A lever device (6) comprises a lever arm (9) coupled to a fulcrum (11) at the location of a first position (10) on the lever arm, to the voice-coil former (2) at the location of a second position (13), and to the diaphragm (1) at the location of a third position (14). The lever mechanism multiplies the excursion of the voice-coil former by a factor greater than unity. This results in an electroacoustic transducer with a long stroke which provides large excursions of the diaphragm. The lever mechanism may also be employed in other types of transducer, such as piezo-ceramic transducers.

Abstract: A portable television camera comprises a relatively small housing including a solid-state imager for generating image-representative signals, and signal processing circuitry coupled to the imager for generating a video signal from the image representative signals. The noise performance of the solid-state imager is degraded by a temperature rise within the small housing caused by the heat generated from the signal processing circuitry. A thermal isolation is used for dividing the housing into a first part including the solid-state imager and a second part, isolated from the first part, which is associated with the heat generating signal processing circuits.

Abstract: A detachable earmuff has an entrance separation which is normally biased closed and which is resiliently flexibly openable for receiving a headband of a headset for retaining the earmuff in covering relation to a users ear and an earphone held to the users ear by means of the headband. For biasing the entrance separation, overlapping parts of a frame structure extend inwardly from the outer end of the entrance separation. In one embodiment the earmuff frame may comprise a generally flat split plastic ring. In another embodiment the earmuff frame may comprise a resilient wireform which may be constructed in one piece.

Abstract: A plane speaker comprises a frame having an opening; a diaphragm facing said opening and having secured its peripheral edge portion to the frame; an actuating plate attached perpendicularly to the back of said diaphragm; a coil mounted on the surface of said actuating plate; and magnets attached to the frame opposite to each other in relation to said coil.

Abstract: An electronic power control circuit for a hearing aid amplifier. The circuit includes a feedback stage, output stage, and output transducer. The feedback and output stages cooperatively define a current regulator that controls the current of the output stage. A variable resistor is provided for adjusting the maximum signal level that can be applied to the output transducer in the hearing aid. Such adjustment prohibits the output transducer from producing an undesirably loud acoustic output. Adjustment of the variable resistor also simultaneously varies both the quiescent current of the output stage and the hearing aid gain.

Abstract: A hearing-aid has an electronic voltage stabilizing circuit (16) to compensate for change in supply voltage due to battery (18) aging and use. The electret microphone (11) is located within a housing, the voltage stabilizing circuit (16) being located within the same microphone housing, thus requiring no additional space or terminal connections. Preferably, an impedance transformer is provided; the electronic components (31-34) are placed on the same semi-conductor chip as the components (35, 36) of the voltage stabilizing circuit.

Abstract: The moving coil (voice coil) of the loudspeaker is so designed that the loudspeaker will become suitable for automatic production. For this purpose, the moving coil is positioned on a coilform, and as a connecting line extending to the ends of the moving coil there are used flexible ribbon conductors secured to a plastics carrier.

Abstract: A connecting cord has a plug at each end. Either such plug may be plugged into the receptacle of a hearing aid and the other plug may be plugged into an external microphone. The contacts of each plug are connected in a different circuit configuration to the conductors of the cord so that when one plug is plugged into the receptacle, the internal hearing aid microphone is shorted out, and when the other plug is plugged into the receptacle, both microphones operate in parallel. The plug contacts are formed of printed circuit board and each plug has a rocker with a hooked top which engages a slot in the receptacle to prevent the inadvertent movement of the plug out of the receptacle. Other plug internal circuit configurations allow connection of other signalling systems to the hearing aid.

Abstract: An in-canal hearing aid is inserted and worn within the auditory canal of a hard-of-hearing wearer. This hearing aid has a generally-cylindrical body with a resilient stretchable outer layer and an adjustably expandable member therewithin for changing the diameter of the generally cylindrical body without significantly changing the length thereof. Hearing aid amplifying circuitry are contained within the generally cylindrical body. The body is hingedly flexible and a flex circuit connector is used to support the amplifying circuitry. These features permit rounding the curve of the auditory canal when the hearing aid is inserted. The body of the hearing aid can be selectively expanded for a snug, comfortable fit. A touch control permits the wearer to adjust the volume by touching a single control stem extending from the external end of the hearing aid.

Abstract: A protection circuit for limiting the sound pressure level provided by transducer loads, such as headphones, in which there is provided interconnections between the input to the transducer load and the transducer load such that when loudness exceeds a predetermined limit, the connection to the transducer load is opened and the circuit turns off the audio signal to the transducer load and optionally illuminates an LED. After a predetermined time interval, the circuit automatically resets; however, if the sound pressure level has not been reduced below the predetermined limit, the circuit again immediately turns off the audio signal to the transducer load and this is continued until such time as the sound pressure level is reduced below the predetermined limit.

Abstract: This low friction rotatable electrical connector is for use with coiled telephone cords to prevent the cord from becoming twisted and knotted-up. This connector is generally of insulating material formed by a hollow inner cylindrical member telescoped within a hollow outer cylindrical member. A pair of ball bearing members support the outer member on the inner member for rotation about a central longitudinal axis. The inner member has a single longitudinal split in one side for receiving a plurality of continuous conductive rings on the outer surface when the inner member is squeezed, and a first set of flexible insulated conductors extend through the interior of the inner member and then through this split for connection to these rings. A plurality of apertures are formed in the wall of the outer member in alignment with the conductive rings, and these apertures contain spring-biased balls in rolling contact with the rings.

Abstract: An electroacoustic transducer, primarily in the form of a capacitive microphone, for incorporation into a semiconductor substrate. The vibrating element comprises a largely nontensioned diaphragm, such as an epitaxial layer formed on the semiconductor substrate, so as to greatly reduce its mechanical stiffness. The substrate is etched away in the desired area to define the diaphragm and form an acoustic cavity. A continuous array of microscopic holes is formed in the backplate to cut down the lateral flow of air in the gap between capacitor electrodes. Narrow gaps made possible by the hole array allow low voltage diaphragm biasing. In at least one embodiment, the acoustic input can be provided through the air hole array. An acoustic port may be added to alter the frequency response of the device, and a back closure provided to act as a rear acoustic cavity and an EMI shield.

Abstract: A device for controlling an electromechanical transducer such as a proportional electromagnetic valve, in which a pulse signal having a constant period shorter sufficiently than the minimum response time required for the displacement of the plunger of the proportional electromagnetic valve over its predetermined full stroke is applied to the electromagnetic coil of the proportional electromagnetic valve to superpose a very small vibratory stroke component on the stroke of the plunger, and the duty cycle of the pulse signal applied to the electromagnetic coil is varied so as to urge the plunger in directly proportional relation to the variation of the duty cycle without substantially giving rise to mechanical hysteresis in the stroke of the plunger.