Suppression of banding due to vibration in imager with LED array
AssigneeXerox Corporation
InventorsMohammad H. Rahnavard, Mehrdad Zomorrodi
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Abstract
A method for banding suppression due to vibration in an imager utilizing a light emitting diode (LED) array is disclosed. By characterizing the LED array and knowing the amplitude and frequency of the signal due to vibration which causes the banding, the LEDs' driving currents are modulated in reverse direction corresponding to the banding signal to suppress the banding.
Claims20
A method for suppressing banding due to vibration in an imager utilizing a light emitting diode (LED) array, comprising the steps of:
- selectively discharging an imaging means including a light emitting diode array for producing a light beam and scanning means for repeatedly scanning said light beam in parallel and adjacent linear scan lines across an electrophotographic medium, said imaging means further including beam modulation means for modulating light emitting diodes' driving currents in a direction opposite to the driving current of a light emitting diode, such that the driving currents correspond to a banding signal to suppress said banding.
A system for suppressing banding due to vibration in an imager utilizing a light emitting diode (LED) array, comprising:
- imaging means including a light emitting diode array for producing a light beam and scanning means for repeatedly scanning said light beam in parallel and adjacent linear scan lines across an electrophotographic medium, said imaging means further including beam modulation means for modulating light emitting diodes' driving currents in a direction opposite to the driving current of a light emitting diode, such that the driving currents correspond to a banding signal to suppress said banding.
A method for suppressing banding due to vibration in an imager utilizing a light emitting diode (LED) array, comprising the steps of:
- selectively discharging an imaging means including a light emitting diode array for producing a light beam and scanning means for repeatedly scanning said light beam in parallel and adjacent linear scan lines across an electrophotographic medium, said imaging means further including beam modulation means for modulating light emitting diodes' driving currents in a direction opposite to the driving current of a light emitting diode, such that the driving currents correspond to a banding signal to suppress said banding wherein modulating said driving current of each light emitting diode is defined by −(1/k) mcos(2παt) and using a frequency modulation rectangular irradiance distribution, H1(x), of amplitude H0 and width W modulated in time with a simple harmonic, H2(t), with amplitude m and temporal frequency α;
- wherein k is the slope of a curve representing an optical output power of a light emitting diode with respect to a drive current, m is a vibration velocity modulation, α is a temporal frequency and t is time.
Dependencies are inferred from the claim text.