Illumination detection method for LED printbars
AssigneeXerox Corporation
InventorPatrick Y. Maeda
Life of this patent
Estimating the term…
Abstract
A system to monitor light emitting diodes (LEDs) in a printbar is described. The system integrates photodetectors into a printer or into the printbar itself such that as the printbar ages, the photodetectors can detect the decrease in intensity of the LEDs in the printbar and recalibrate driver circuits providing power to each LED. The recalibrated power output of each driver circuit compensates for nonuniformities in the LEDS that result from uneven aging of the LEDs.
Claims19
A method of calibrating a printbar in a printer comprising the operations of:
- utilizing a printbar to output an image;
- receiving a signal to recalibrate the printbar;
- and
- detecting at a photodetector integrated into said printer, the output of a Light emitting diode on the printbar and adjusting a current provided to the Light emitting diode until the intensity of light detected by the photodetector matches a reference intensity determined during assembly of the printbar.
A method of calibrating a printbar in a printer comprising the operations of:
- utilizing a printbar to output an image;
- receiving a signal to recalibrate the printbar;
- detecting at a photodetector integrated into said printer, the output of a group of light emitting diodes on the printbar and adjusting a current provided to the group of Light emitting diodes until the intensity of light detected by the photodetector matches a reference intensity determined during assembly of the printbar.
A method of calibrating a printbar in a printer comprising the operations of:
- switching on one light emitting diode and switching all other light emitting diodes off;
- detecting using a detector the output of the one light emitting diode;
- comparing the detected output of the detector with a stored value, the stored value corresponding to a previous output of the detector measured during assembly of the printbar;
- and
- adjusting the power supplied to the one light emitting diode until the output of the detector matches the stored value.
A method of calibrating a printbar in a printer comprising the operations of:
- switching on a group of light emitting diodes and switching all other light emitting diodes off;
- detecting using a detector the output of the group of light emitting diodes;
- comparing the detected output of the detector with a stored value, the stored value corresponding to a previous output of the detector measured during assembly of the printbar;
- and
- adjusting the power supplied to the group of light emitting diodes until the output of the detector matches the stored value.
Dependencies are inferred from the claim text.