Abstract: In a cordless, electro-magnetic digitizing system having a drive circuit outputting a square wave drive signal of known initial polarity to a transducer coil in a cursor to oscillate the transducer coil and cause a magnetic field output therefrom which is detected in an associated tablet, a method of operation and associated apparatus for determining the phase of a response signal induced by the magnetic field from the response signal itself.

Abstract: A telephone privacy protector for connection to a common exchange line and each one of at least two telephone operated devices sharing a line includes a voice connecting circuit for connection between a respective telephone line operated device and the line. There is a control deice connected to the circuit having an on and off state wherein the control device in the on state permits the voice connecting circuit to operate. There are means for turing the control device on when the respective telephone line operated device goes off hook provided that no other telephone line operated device sharing the line is off hook. There are means for providing a residual charge to the control device in order to reactivate same after the respective telephone line operated device is placed momentarily on hook and then returned to an off hook state while any other telephone line operated device connected to the line is off hook.

Abstract: One or more lines of a communication terminal are monitored to determine blocked calls by detecting times of incoming calls. A signal corresponding to the pattern of incoming calls is generated from the detected times. After detection of the starting time of an all lines are busy state, an estimate of blocked calls is formed from the incoming call pattern signal and the detected start of the all lines are busy state.

Abstract: A digitizer tablet providing hysteresis compensation in which the X and Y coordinates of a pointing device are measured at different times. In order to enable the tablet to report X and Y coordinates that when displayed will more accurately reflect the pointing device movements, a correction algorithm, built, for example, into the controlling software, estimates and reports what the first measured coordinate would have been, measured when the second coordinate is measured, based upon the calculated velocity and acceleration of the pointing device. A similar technique can be used to correct the reported value of the second coordinate. In a preferred embodiment, constant coefficients of a linear equation having as variables three consecutive coordinate values or three consecutive preprocessed coordinate values are predetermined and used in the correction algorithm. The preferred embodiment integrates the velocity and acceleration hysteresis compensation into a three point recursive noise filter.

Abstract: A handwriting capture device which employs a highly sensitive digitizer to accurately capture signature information entered using a writing force greater than or equal to a predetermined writing force. The handwriting capture device includes a housing having a top surface, a resistive membrane digitizer mounted in the top surface and having a low pattern density, a layer of urethane rubber for frictionally holding the receipt in place, circuitry for processing digitizer information, a clamp for retaining a receipt in place over the digitizer during movement of the device, and circuitry for sensing the presence of the receipt and for activating data capture by the digitizer when the receipt is positioned under the clamp. In the preferred embodiment, the clamp also serves to minimize finger contact with the digitizer.

Abstract: An intercom system for a door and inside stations has a speech function for two-way communication with hands-free operation. The intercom system includes a two-wire connecting lead between the door station and each inside station to transmit a conversation current and an operating current. The intercom system includes a bridge circuit for suppressing feedback, a bipole circuit to decouple conversation currents from a power supply, a calling circuit for calling on the two-wire connecting lead and using a call current of opposite plurality with respect to the operating current, and a short-circuit circuit in each inside station for short-circuiting the corresponding two-wire connecting lead when the corresponding door opening button is actuated.

Abstract: A position resolving system is described incorporating a cordless pointing instrument such as a pen having an oscillator and battery supply therein. Electromagnetic radiations from the pen are directed onto a tablet grid having a plurality of grid loops therein. When the pen is in contact with the tablet, signals of maximum amplitude are radiated; when the pen is raised out of contact with the tablet, signal radiation is maintained but at a decreased amplitude for a predetermined time and then reduced to zero. Each loop is formed of parallel conductors joined at one end thereof by an end conductor; each loop is placed adjacent corresponding loops in the X and in the Y directions. The electromagnetic radiations are non-coherently amplitude detected to select the grid loop in the X direction and the grid loop in the Y direction having the maximum amplitudes thereon.

Abstract: An apparatus and method for digitizer sampled point validation which compares charge and discharge voltages across a capacitive element within the digitizer or a filter coupled between the digitizer and an analog-to-digital convertor to accept or reject the point. The method of the present invention detects excessive contact resistance, typically caused by insufficient actuation force. The method alternately charges and discharges the digitizer sampling circuitry to positive and negative voltage rails prior to readings. The sampling circuitry includes the layer in use, and the wire connections, all of which provide resistance and capacitance affecting the time constants for charging and discharging. The sampling circuitry also includes the filter in use, when so installed. High contact resistance due to excessive contact resistance prevents adequate charging and discharging of the sampling circuitry to the position voltage of the point and results in unequal values for the two readings.

Abstract: A testing system for digital transmission lines with a metallic loopback and direct current bypass for use with regenerative repeaters. The Bell telephone network typically includes transmit and receive lines interconnected to a central office. Regenerative repeaters positioned along the lines detect signals and regenerate new signals. The present invention includes a controller, loopback line, and bypass. The loopback line interconnects the transmit and receive lines upon receiving a test activation signal from the controller. The bypass allows direct current to pass through to the rest of the line during a test. Accordingly, when a test of the telephone lines is to be performed, lines will allow the test signal to loop back to the source of origin, but will block the loopback of DC power signals. Moreover, DC power is supplied to the rest of the transmission line, in the same manner as when the testing procedure is not occurring.

Abstract: A handwriting capture device which employs an insertable form interface over a digitizer to minimize or eliminate the need for a display. The form may include a menu corresponding to a repetitive task, a keypad, or a place for a signature. The form may be removable as a receipt, work order, invoice, or other document. The handwriting capture device also includes a housing having a top surface and a recess within the top surface, a frame for holding the form in the recess in the top surface, and circuitry for processing information entered into the digitizer. A display of minimal size may be added when the form is permanent and reusable to display signature and user prompts.

Abstract: Disclosed is a key telephone system provided with a key service unit (KSU) 1 having a central control unit 6, and a digital key telephone set (DKT) 10 having a local control unit 13 for communications of control data with the central control unit 6. First and second add-on modules (ADMs) 24 and 34 for communications of control data with the central control unit 6 are optionally connectable to the DKT 10. When control data (up-data) are transmitted from the local control unit 13 of the DKT 10 to the KSU 1, a disable signal is given from the DKT 10 to the first ADM 24 to disable up-data from being transmitted from the first ADM 24. At this time, the first ADM 24 also outputs a disable signal to the second ADM 34 to disable up-data from being transmitted from the second ADM 34. At any selected time when no up-data are transmitted from the DKT 10, an enable signal is given from the DKT 10 to the first ADM 24.

Abstract: Method for use in developing, testing, debugging, and/or troubleshooting a call progress monitoring (CPM) detection system which is utilized, for example, by a voice messaging system (VMS). One embodiment of the present invention which is utilized in conjunction with a VMS includes the steps of: (a) monitoring at least one voice channel of the VMS to obtain CPM tones and having a CPM Detection system associated with the VMS perform an analysis of the CPM tones, the output of which analysis is referred to as CPM Trace Variables; (b) storing the CPM tones and the CPM Trace Variables for the at least one voice channel, which stored CPM tones and CPM Trace Variables are referred to as a CPM Trace file; (c) obtaining a first voice channel; and (d) feeding the voice portion of the CPM Trace file to a second voice channel for playing it to the first voice channel.

Abstract: A microprocessor-controlled coin telephone station includes apparatus that enables it to provide dialed telecommunications service and accept payment therefor--which is its primary function. The coin telephone station further includes apparatus for automatically dialing predetermined telephone numbers, automatically answering incoming telephone calls, and apparatus for monitoring conditions associated with its primary function in order to be a participating member of a hierarchal reporting network--which is its secondary function. In order to carry out the secondary function, the coin telephone station stores operating instructions which cause it to operate as either a Master or a Slave station within the hierarchal network.

Abstract: A telephone system comprises a multi-channel transmission apparatus for connecting a subscriber line to a telephone exchanger, where the transmission apparatus comprises: a subscriber interface for interfacing said subscriber line; a detecting circuit in the subscriber interface for detecting a change in a voltage on the subscriber line; and a discriminating circuit for discriminating whether the change detected by the detecting circuit is continuous or intermittent, upon discriminating the detected change in voltage as intermittent the discriminating circuit outputs a first alarm signal. The discriminating circuit may be formed of a software counter which counts a number of the intermittent signals for a predetermined period. The software counter does not require a bulky and expensive components, such as a 60 Hz filter. If the counted number is larger than a predetermined number the signal is determined to be intermittent.

Abstract: A portable telephone of a type to which a plurality of subscriber numbers are registered comprises an air timer for measuring a calling period of time from start of calling and end of calling and a memory device for saving and integrating results of measuring by the air timer for each subscriber number. The portable telephone also includes a last call timer, a user timer and a system timer. The memory device includes a RAM. In the RAM, memory areas for the last call timer, user timer and system timer are provided for respective subscriber numbers. As a telephone communication is finished, a calling period of time measured by the air timer is saved in the last memory area to which the subscriber number just used is assigned and this calling period of time is also added up into the user timer memory area and/or system timer memory area for the just used subscriber number.

Abstract: A contact sensor comprises a first sheet of flexible material and second sheet. The first sheet is capable of being energized to establish an electrical potential thereon. The second sheet can be energized to establish an electrical potential in juxtaposition with the first sheet. The two sheets are formed of materials that tend to stick together. To keep the sheets apart, a plurality of substantially uniform discrete insulating islands are used. By the use of a non-square insulating island spacing pattern with the island spacing satisfying rigorous criteria, the two sheets can be prevented from sticking together without unduly increasing the amount of force required to activate the device. The sensor is particularly useful as a transparent touchscreen.

Abstract: Shielding materials used in electromagnetic digitizers which are packaged in a notebook computer environment. Shielding materials with sufficiently high magnetic permeability to increase the magnetic signal detected by the digitizer sensor grid can be used in such an environment, and can be placed in direct contact with the sensor grid. Aluminum or copper shields can also be placed in direct contact with the sensor grid to provide the requisite shielding. A combination of conductive and ferrite material can also be used as the conductive base material provides for shielding and a layer of ferrite material increases the magnetic signal and prevents signal attenuation by the conductor.

Abstract: A public pay telephone station constructed to accept user carried media which may be in the form of CD disks which are capable of storing a variety of data or information for interacting with the public telephone station. The station is provided with a display screen and control switches. Interaction is provided between the database in the user disk and distributed databases in the telecommunications network. The system provides sophisticated services based upon the massive data storage capacity of the CD disk used in conjunction with a microprocessor and memory in the telephone station as combined with the virtually limitless distributed storage data and capabilities of the telephone network.

Abstract: A digitizing system includes a tablet and a cordless pointing device including a plurality of data grid conductors in the tablet and a plurality of clock grid conductors in the tablet, all receiving a magnetic field signal transmitted by the pointing device. A data channel circuit includes a differential amplifier and demodulating and filtering circuitry coupled to an output of the differential amplifier, having a clock input. An A/D converter has an input coupled to an output of the demodulating and filtering circuitry. Multiplexing circuitry selectively couples various grid conductor signals to the data channel circuit. A clock recovery circuit responsive to the clock grid conductors includes a phase-locked-loop circuit that generates a recovered clock signal which is synchronous with the magnetic field signal and is used as a reference for demodulating the phase and amplitude of signals multiplexed from the data grid conductors to the data channel circuit.

Abstract: Disclosed is a telephone line testing device comprising: clip leads for connecting the device to "ring," "tip" and external ground lines of the telephone line to be tested. Terminal pads make "ring" and "tip" connections to a craft telephone and a first testing circuit connectable to receive DC signals from the "ring" and the "tip" lines to provide electrical signals indicative of the magnitude of direct current available from the lines. Another testing circuit is connectable to receive AC signals from the "ring" and the "tip" lines to provide electrical signals indicative of the signal loss of the lines. A third testing circuit is connectable to receive AC signals selectably either from the "tip" and the "ring" connections or from the "tip" and the external ground connections comprising a filter and amplifier to receive and treat the AC signals and to apply the treated signals to the input of the second testing circuit.