Abstract: An improved method and apparatus are disclosed for the reading (or sensing) and decoding of two frequency "bar coded" or transition coded sensible data. The data may take the form of indicia recorded on various media or it may be transmitted on a communications channel. The method and apparatus include means for simultaneously or separately accommodating both variable velocity scan (or distorted reception) conditions and non-uniform bar widths in the coded data or other variations in the spacing of transition signals in the recorded indicia. Frequency variations in transmitted data signals can also be accommodated. Hand held sensor or "wand" scanning of coded tangible indicia-bearing media is facilitated for either optically or magnetically recorded data indicia. Correct interpretion of frequency-distorted transmitted data is also made possible.

Abstract: A FET structure for a magnetic field sensor which operates by achieving very high carrier velocities in the active region of the sensor is disclosed. A Hall output voltage is produced by the sensor in response to a magnetic flux field passing therethrough and, due to the high carrier velocities achieved, a very high sensitivity device is obtained by operating the FET structure in the pinch off mode or depletion mode. The position of the pinched off area of the conductive channel is varied to position the location of maximum carrier velocity in the channel at a desired point relative to an output probe. This position is controlled by the use of a control gate.

Abstract: A semi-conductive magnetic flux sensor is disclosed in which semi-conductive material having a resistance on the order of at least 500 ohms per square is placed in a lateral electric field of at least 500 volts per centimeter. A signal probe or contact located between the two lateral field contacts produces an output voltage when the sensor is subjected to magnetic fields having at least some component perpendicular to the plane of the three contacts. The device is highly sensitive and yields approximately one order of magnitude higher signal output than conventional Hall type semi-conductive magnetic sensors.

Abstract: A general method for reading or decoding the self-clocking encoded data content of digital data bits, which may be recorded on magnetic or optical media or received on a communication channel in an encoded electrical signal form, is described. The method is useful for decoding all self-clocking codes where signals in the form of optic, magnetic, or electric signal variations are presented to a decoding apparatus for the extraction of data content therefrom. The technique utilizes a standard reference length, or alternatively, a set of transitions placed outside of each series of coded data bits or characters to provide a reference length, and then predicts, for the known type of code format, each possible location for each next valid data pulse or signal transition.

Abstract: An improved method and apparatus are disclosed for the reading (or sensing) and decoding of two frequency "bar coded" or transition coded sensible data. The data may take the form of indicia recorded on various media or it may be transmitted on a communications channel. The method and apparatus include means for simultaneously or separately accommodating both variable velocity scan (or distorted reception) conditions and non-uniform bar widths in the coded data or other variations in the spacing of transition signals in the recorded indicia. Frequency variations in transmitted data signals can also be accommodated. Hand held sensor or "wand" scanning of coded tangible indicia-bearing media is facilitated for either optically or magnetically recorded data indicia. Correct interpretation of frequency-distorted transmitted data is also made possible.

Abstract: An improved method and apparatus are disclosed for the reading (or sensing) and decoding of two frequency "bar coded" or transition coded sensible data. The data may take the form of indicia recorded on various media or it may be transmitted on a communications channel. The method and apparatus include means for simultaneously or separately accommodating both variable velocity scan (or distorted reception) conditions and non-uniform bar widths in the coded data or other variations in the spacing of transition signals in the recorded indicia. Frequency variations in transmitted data signals can also be accommodated. Hand held sensor or "wand" scanning of coded tangible indicia-bearing media is facilitated for either optically or magnetically recorded data indicia. Correct interpretation of frequency-distorted transmitted data is also made possible.

Abstract: An improved method and apparatus are disclosed for the reading (or sensing) and decoding of two frequency "bar coded" or transition coded sensible data. The data may take the form of indicia recorded on various media or it may be transmitted on a communications channel. The method and apparatus include means for simultaneously or separately accommodating both variable velocity scan (or distorted reception) conditions and non-uniform bar widths in the coded data or other variations in the spacing of transition signals in the recorded indicia. Frequency variations in transmitted data signals can also be accommodated. Hand held sensor or "wand" scanning of coded tangible indicia-bearing media is facilitated for either optically or magnetically recorded data indicia. Correct interpretation of frequency-distorted transmitted data is also made possible.