Variable ELVDD Calibration for AMOLED Brightness Discontinuities

The patent divides the variable ELVDD range into multiple discrete step levels (e.g., ELVDD_1 to ELVDD_4), with each step calibrated independently. By segmenting the voltage range and applying separate calibration codes to each segment, the system maintains smooth brightness transitions while preserving the ability to achieve high luminance levels. This segmentation approach prevents interpolation errors by ensuring each voltage step is precisely calibrated rather than relying on continuous interpolation between widely spaced voltage levels.

The patent implements dynamic ELVDD adjustment where the electroluminescence voltage is adaptively changed based on the required brightness level. At low brightness levels, a lower ELVDD step is used to minimize power consumption, while at high brightness levels, a higher ELVDD step is activated to provide sufficient luminance capability. This dynamic voltage scaling allows the display to optimize power consumption across different operating conditions while maintaining the ability to achieve high brightness when needed.

The patent performs calibration at multiple ELVDD voltage levels rather than a single fixed voltage. Separate calibration codes are generated for each ELVDD step (e.g., first calibration code for first ELVDD step, second calibration code for second ELVDD step). This multi-level calibration approach maintains high calibration accuracy at each specific voltage level while providing adaptability across the full range of brightness levels through the use of multiple calibrated voltage steps.