Auto-zeroing linear analog to digital converter apparatus and method

Claim 1

A method of generating reaction effect data in the form of offset-error free digital transmission data derived by directing a beam of radiant energy through a plurality of cuvettes containing reaction samples, the cuvettes being partially transparent, the method comprising: A. scanning the cuvettes seriatium with the beam during cuvette sample intervals by passing the beam through the cuvettes containing reaction samples and directing the light transmitted therethrough to a sensor; B. blocking the beam from passing to the sensor during at least one dark sample interval occurring other than during cuvette sample intervals; C. generating from said sensor representative analog cuvette and dark transmittance signals representing, respectively, the quantity of light from said beam striking said sensor during said cuvette sample interval and during said at least one dark sample interval; D. converting said representative analog cuvette and dark transmittance signals to digital cuvette and dark transmittance signals, said digital cuvette transmittance signals including an offset-error value and said digital dark transmittance signal representing the offset-error value; and E. using the digital dark transmittance signal that represent the offset-error value to eliminate the offset-error value included in the digital cuvette transmittance signals.

Claim 2

A method of generating reaction effect data in the form of offset-error free digital transmission data derived by directing a beam of radiant energy through a plurality of cuvettes containing reaction samples, the cuvettes being partially transparent, the method comprising: A. scanning the cuvettes seriatium with the beam during cuvette sample intervals by passing the beam through the cuvettes containing reaction samples and directing the light transmitted therethrough to a sensor; B. blocking the beam from passing to the sensor during at least one dark sample interval occurring other than during cuvette sample intervals; C. generating from said sensor representative analog cuvette and dark transmittance signals representing, respectively, the quantity of light from said beam striking said sensor during said cuvette sample interval and during said at least one dark sample interval; D. converting said representative analog cuvette and dark transmittance signals to digital cuvette and dark transmittance signals, said digital cuvette transmittance signals including an offset-error value and said digital dark transmittance signal representing the offset-error value; and E. using the digital dark transmittance signal that represent the offset-error value to eliminate the offset-error value included in the digital cuvette transmittance signals.

Claim 8

A method of producing, from a beam of radiant energy having certain time varying quantities of radiant energy, offset-error free digital beam signals where the signal values represent said certain quantities, said beam being directed onto and striking a sensor, said sensor converting said quantities of radiant energy into representative amplitude analog beam signals, said analog beam signals being converted to digital beam signals in an analog to digital converter that introduces offset-error values, the method comprising: A. blocking said beam from striking said sensor during at least one dark sample interval; B. producing from said sensor an analog dark interval signal during said dark sample interval; C. converting in said analog to digital converter said analog dark interval signal to a digital dark interval signal that represents the offset error value of said sensor and converter; and D. using said digital dark interval signal to eliminate the offset-error value that otherwise would be included in said digital beam signal.

Claim 9

A method of producing, from a beam of radiant energy having certain time varying quantities of radiant energy, offset-error free digital beam signals where the signal values represent said certain quantities, said beam being directed onto and striking a sensor, said sensor converting said quantities of radiant energy into representative amplitude analog beam signals, said analog beam signals being converted to digital beam signals in an analog to digital converter that introduces offset-error values, the method comprising: A. blocking said beam from striking said sensor during at least one dark sample interval; B. producing from said sensor an analog dark interval signal during said dark sample interval; C. converting in said analog to digital converter said analog dark interval signal to a digital dark interval signal that represents the offset error value of said sensor and converter; and D. using said digital dark interval signal to eliminate the offset-error value that otherwise would be included in said digital beam signal.

Claim 14

A method of producing offset-error free digital output signals from radiant energy input information to a sensor which introduces offset errors, in an analog to digital converter that also introduces offset-errors, the method comprising: A. blocking said input information from a radiant energy sensor during a dark sample interval when said sensor generates an analog dark interval signal containing said offset errors input to said converter; B. producing a digital dark interval output signal during said dark sample interval, said dark interval output signal representing the offset-error of said sensor and said analog to digital converter; and C. using said digital dark interval output signal to digitally eliminate the offset-error of said sensor and said analog to digital converter that otherwise would be introduced into said digital output signals.

Claim 15

A method of producing offset-error free digital output signals from radiant energy input information to a sensor which introduces offset errors, in an analog to digital converter that also introduces offset-errors, the method comprising: A. blocking said input information from a radiant energy sensor during a dark sample interval when said sensor generates an analog dark interval signal containing said offset errors input to said converter; B. producing a digital dark interval output signal during said dark sample interval, said dark interval output signal representing the offset-error of said sensor and said analog to digital converter; and C. using said digital dark interval output signal to digitally eliminate the offset-error of said sensor and said analog to digital converter that otherwise would be introduced into said digital output signals.

Claim 20

An apparatus for generating reaction effect data in the form of offset-error free transmission data derived by directing a beam of radiant energy through a plurality of cuvettes containing reaction samples, the cuvettes being partially transparent, the apparatus comprising: A. rotor means for scanning the cuvettes seriatim with said beam and directing the unabsorbed radiant energy that is transmitted through each cuvette and its reaction sample during cuvette sample intervals onto the face of sensor means; B. blocking means for blocking the beam from the face of said sensor means during dark sample intervals occurring between cuvette sample intervals; C. said sensor means for sensing the quantity of radiant energy striking its face and generating representative analog cuvette transmittance signals during said cuvette sample intervals and at least one analog dark transmittance signal during one of said dark sample intervals; D. analog to digital converter means for converting said analog cuvette and dark transmittance signals from said sensor means to digital cuvette and dark transmittance signals, said converter means introducing offset-errors into said digital signals; and E. control means for eliminating the off-set error in said digital cuvette transmittance signal with said digital dark transmittance signal.

Claim 21

An apparatus for generating reaction effect data in the form of offset-error free transmission data derived by directing a beam of radiant energy through a plurality of cuvettes containing reaction samples, the cuvettes being partially transparent, the apparatus comprising: A. rotor means for scanning the cuvettes seriatim with said beam and directing the unabsorbed radiant energy that is transmitted through each cuvette and its reaction sample during cuvette sample intervals onto the face of sensor means; B. blocking means for blocking the beam from the face of said sensor means during dark sample intervals occurring between cuvette sample intervals; C. said sensor means for sensing the quantity of radiant energy striking its face and generating representative analog cuvette transmittance signals during said cuvette sample intervals and at least one analog dark transmittance signal during one of said dark sample intervals; D. analog to digital converter means for converting said analog cuvette and dark transmittance signals from said sensor means to digital cuvette and dark transmittance signals, said converter means introducing offset-errors into said digital signals; and E. control means for eliminating the off-set error in said digital cuvette transmittance signal with said digital dark transmittance signal.

Claim 24

A system for producing offset-error free output signals including analog to digital converter means producing digital output signals but introducing offset errors from radiant energy input information to a sensor which also introduces offset errors, the system comprising: A. radiant energy sensor means for sensing said input information to generate an analog light interval signal input to said analog to digital converter means during a light interval, and for generating at least one analog dark signal input to said analog to digital converter during a dark interval when said input information is blocked from said sensor means; B. means for blocking said input information from said sensor means during said dark interval; C. said analog to digital converter means including means for converting said analog light interval signal to a digital output signal and for converting said analog dark signal to a digital dark output signal containing said errors in digital form; and D. control means for eliminating said offset-errors in said digital output signal using said digital dark output signal.

Claim 25

A system for producing offset-error free output signals including analog to digital converter means producing digital output signals but introducing offset errors from radiant energy input information to a sensor which also introduces offset errors, the system comprising: A. radiant energy sensor means for sensing said input information to generate an analog light interval signal input to said analog to digital converter means during a light interval, and for generating at least one analog dark signal input to said analog to digital converter during a dark interval when said input information is blocked from said sensor means; B. means for blocking said input information from said sensor means during said dark interval; C. said analog to digital converter means including means for converting said analog light interval signal to a digital output signal and for converting said analog dark signal to a digital dark output signal containing said errors in digital form; and D. control means for eliminating said offset-errors in said digital output signal using said digital dark output signal.