LED Uniformity Compensation/Grey Scale
 

LED uniformity compensation is accomplished using Pulse Width Modulation (PWM) or Amplitude Modulation (AM) or a combination of both.

When grey scale is needed the uniformity correction and grey scale are merged.

Optotek's custom IC, the OTL-444A, is designed to provide 4 bit pulse width control and can also be used for amplitude modulation.


PWM
AM