Magnetic field sensing CCD device with a slower output sampling rate than the transfer rate yielding an integration

Claim 1

A charge coupled device (CCD) for sensing a magnetic field, said CCD comprising: a. a substrate of semiconductor material for providing a path for the passage of minority carriers therethrough; b. a first layer of dielectric material overlying said substrate; c. source means for injecting a substantially uniform distribution of minority carriers within said substrate; d. first and second output means for collecting the minority carriers directed along said path of said substrate and each providing an output signal indicative of the collected minority carriers; e. a plurality of electrodes disposed along said path of said CCD between said source means and said first and second output means and overlying said first layer of dielectric material for defining underlying portions of said substrate wherein minority carriers are collected; f. means for applying varying potential signals to said electrodes for directing the minority carriers at a first rate from one underlying portion to the next along the path of said substrate, whereby the minority carriers are deflected as they are directed through the substrate in the presence of the magnetic field; g. an input gate electrode disposed upon said first layer of dielectric material intermediate said source means and the first of said plurality of electrodes; h. input signal source means electrically coupled to said input gate electrode for controlling the travel of minority carriers to said plurality of electrodes; i. a sampling electrode disposed upon said first layer of dielectric material intermediate the last of said plurality of electrodes and said first and second output means; j. output signal source means electrically coupled to said sampling electrode for applying sampling signals to said sampling electrode at a second rate, slow with respect to the first rate whereby the minority carriers are permitted to be stored in that region beneath the last of said plurality of electrodes for a relatively long integration period before being sampled by the application of a sampling signal derived from said sampling means; and k. said first and second output means spaced from each other and disposed traverse to the path for collecting the minority carriers as deflected by the magnetic field, the output signals derived at said first and second output means indicating the strength and direction of the magnetic field.

Claim 12

A method of operating a charge coupled device (CCD) to sense a magnetic field, the CCD comprising a semiconductor substrate upon which there is disposed a layer of dielectric material, source means for injecting a substantially uniform distribution of minority carriers into the substrate, first and second output means for collecting the minority carriers directed through the substrate for providing corresponding output signals, a plurality of electrodes disposed overlying said dielectric layer, serially between the source and output means, and a sampling electrode disposed upon the dielectric layer between the plurality of electrodes and the output means, said method comprising the steps of: a. energizing the source means to inject a substantially uniform distribution of minority carriers into said substrate; b. applying potential signals to the electrodes whereby ''''wells'''' of varying depth are formed in the substrate into which the minority carriers are directed and varying the potential signals at a first rate whereby the minority carriers are directed through said substrate toward the first and second output means; c. exposing the charge coupled device to a magnetic field whereby the minority carriers are deflected in accordance with the strength and direction of the magnetic Field; and d. applying a sample signal to the sampling electrode at a second rate sufficiently slow with respect to the first rate to permit deflected minority carriers to be stored beneath the last of the plurality of electrodes before being directed to the output means which provide an integrated output signal therefrom thus increasing the sensitivity of the magnetic sensing CCD.

Claim 13

A method of operating a charge coupled device (CCD) to sense a magnetic field, the CCD comprising a semiconductor substrate upon which there is disposed a layer of dielectric material, source means for injecting a substantially uniform distribution of minority carriers into the substrate, first and second output means for collecting the minority carriers directed through the substrate for providing corresponding output signals, a plurality of electrodes disposed overlying said dielectric layer, serially between the source and output means, and a sampling electrode disposed upon the dielectric layer between the plurality of electrodes and the output means, said method comprising the steps of: a. energizing the source means to inject a substantially uniform distribution of minority carriers into said substrate; b. applying potential signals to the electrodes whereby ''''wells'''' of varying depth are formed in the substrate into which the minority carriers are directed and varying the potential signals at a first rate whereby the minority carriers are directed through said substrate toward the first and second output means; c. exposing the charge coupled device to a magnetic field whereby the minority carriers are deflected in accordance with the strength and direction of the magnetic Field; and d. applying a sample signal to the sampling electrode at a second rate sufficiently slow with respect to the first rate to permit deflected minority carriers to be stored beneath the last of the plurality of electrodes before being directed to the output means which provide an integrated output signal therefrom thus increasing the sensitivity of the magnetic sensing CCD.