Light-emitting diode arrays with integrated photodetectors formed as a monolithic device and methods and apparatus for using same

摘要

A monolithic device comprises an LED chip array that includes photodetectors formed on the device so that each photodetector is associated with a respective LED for detecting light output of the LED. The locations of the photodetectors and the respective rows of bond pads for the LEDs and photodetectors are such as to facilitate connection to associated current driver circuitry. The device is preferably used on an LED printhead. Methods and apparatus are provided for using the device in recording of images. Printheads using such devices allow for determinations of improper operation of the LEDs either in real time or during other times such as interframe per rods. Thus, LED malfunction may be caught promptly without need to stop production to allow a diagnostic photodetector to traverse over the LEDs.