Bell Telephone Laboratories

Hans George Mattes

John M Geary

Gabor P Torok

Gerald S Soloway

George W Schramm

John William Wesner, Jr

Fritz E Froehlich

William E Baker

Victor Scott Borison

Daniel Edward Oates

Colonel Blake McDowell, Iii

The present key telephone system comprises cordless telephone stations (FIGS. 6 and 7) which communicate over a line-of-sight transmission end link (276 or 277). The system further comprises a central controller (101) for switching communications between the cordless stations and to the message network. The central controller does not provide any station to transmission channel concentration. Concentration occurs in the bidding by a cordless station for access to a channel provided by the line-of-sight transmission end link. A particular number of transmission channels are provided by the line-of-sight end link which are bid for by any practical number of cordless stations. Subsystem controllers (104) are provided in a large cordless key telephone system. The subsystem controller reformats data for transmission between the central controller (101) and a cordless station. A unique code identifies a cordless station so that the allocation of a new channel to a cordless station may occur automatically when a cordless station is detected within the boundaries of a new subsystem.

Cordless telephone system

A rate adaptive magnetic card writer records data on a card having a magnetizable surface while the card is moved by hand through a slot on the card writer. The rate of movement of the card is determined and then used in adjusting the writing of the data such that it occurs at a rate generally consistent with the speed of the card. The written data is thereby reasonably dispersed on the card and can be read by a variable speed card reader.

Rate adaptive writer for a card having a magnetizable surface

Analog readout devices are disclosed which utilize domain wall motion in a film of ferroelectric material to produce an electrical signal having a desired waveform. Disclosed devices comprise electrodes disposed on facing sides of the film, at least one electrode being patterned in correspondence with the desired waveform. Readout from devices may be direct or as the difference between two signals produced by domain wall motion. In the latter case, constant-width pairs of electrodes may be used in combination with a feedback circuit to ensure constant-velocity ferroelectric wall motion.

Ferroelectric analog device

A reader for optically encoded information such as a credit card having an embossed data track includes an array of radiant energy transmitting elements and a single detector element formed on a planar chip. The chip is seated in a recessed area formed in a unitary lens assembly which includes a first integral lens array for focusing energy from each of the transmitting elements at particular points on the credit card, and a second integral lens array for focusing energy reflected from each of the points on the card onto the detector. Circuitry is provided to sequentially energize the transmitting elements, so that the focusing points, which preferably form a line transverse to the data track, are scanned. Signals from the detector element are processed by establishing a continuously variable threshold level derived as a function of the peak amount of reflected energy and by comparing the detector element output with the thresold value at several time intervals within the scanning period. The entire data track is read by repeating the scanning cycle as the credit card or other record medium is moved relative to the lens assembly.

Apparatus for reading optical codes

An automatic visual ring indicator for telephone station sets which includes a mechanical indicator element viewable through a window in the telephone housing. The indicator element assumes its on position in response to the ringing action of the telephone. The off position of the indicator element is resumed in response to switchhook motion as in removal of the telephone handset.

Visual ring indicator

A graphical input terminal includes a pair of resistive sheets separated by an air gap. An energizing voltage is alternately applied to each sheet while an output voltage representative of the position of contact between the sheets caused by the pressure of a stylus, is derived from the nonenergized sheet. A circuit for indicating stylus up/stylus down status without undue interference from capacitively induced voltages is also provided.

Graphical input terminal

A business transaction terminal for a credit authorization system or the like includes a microprocessor for receiving data from a magnetic card reader and a keyboard, automatically processing such data and transmitting it to a central data base for authorization of a proposed business transaction. The terminal receives back a response from the central data base which directs subsequent actions by the terminal user. Options are provided for receiving the response in a number of ways such as audible response, visual indicators and numeric displays. Options also permit the terminal to be operated in a hands free mode.

Growing community of inventors

Ocean Township, NJ, United States of America

Hans George Mattes