Patent ID: 7186982

Claim:
A method for calibrating a plurality of individual light sensor elements of a linear sensor array of a scanner, wherein output values of odd-numbered elements are carried by a first output channel and output values of even-numbered elements are carried by a second output channel, comprising: calculating a relative gain (Stored Gain) for each element from a scan of a light calibration strip area of substantial uniformity; obtaining output values of the elements from a scan of a light calibration strip area of unknown uniformity; calculating an average of the obtained output values of the odd-numbered elements (Odd Light Average) and an average of the obtained output values of the even-numbered elements (Even Light Average) from the scan of the light calibration strip area of unknown uniformity; calculating a low pass gain for each element from the obtained output values of the elements from the scan of the light calibration strip area of unknown uniformity; calculating an adjusted gain for each even-numbered element and each odd-numbered element, the adjusted gain for each even-numbered element being equal to its Stored Gain, and the adjusted gain for each odd-numbered element being equal to its Stored Gain times the Even Light Average divided by the Odd Light Average; and calculating a final gain for each element, the final gain being equal to its adjusted gain times its low pass gain.