Display Device Channel Gain Offset Calibration
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Solution Overview
Problem
Existing display devices face challenges in accurately calibrating channel deviations due to variations in current measurements across data lines, leading to inconsistent calibration values and potential deviations in light-emitting device performance.
Innovation Solution
A display device with grouped data lines and channels, each equipped with an amplifier and ADC, uses a controller to calibrate gain and offset deviations by setting input voltages to specific thresholds and calculating slope ratios to determine accurate calibration values, minimizing channel variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If multiple channels are used to sense current flowing to data lines, then measurement coverage is improved, but channel deviations cause measurement precision to deteriorate
Solution Approach 1:
The patent applies parameter changes by measuring code values at multiple different input voltage levels (first voltage level, second voltage level, and third voltage level) rather than a single level. This enables calculation of slopes representing channel characteristics, which are then used to identify and correct channel deviations through comparative analysis against reference slopes.
2Loss of time
If calibration is performed based on single code value measurement, then calibration speed is improved, but calibration precision deteriorates due to channel variations
Solution Approach 1:
The patent implements partial action by performing calibration at multiple discrete voltage levels (first, second, and third levels) rather than continuous measurement. This selective multi-level approach provides sufficient data to calculate slopes and identify channel deviations without requiring exhaustive measurement across all possible voltage values, thus balancing calibration time and accuracy.
3Measurement precision
If gain and offset calibration are performed separately, then calibration precision is improved, but device complexity increases
Solution Approach 1:
The patent merges gain calibration and offset calibration into a unified process. By measuring code values at multiple voltage levels and calculating slopes, the system simultaneously determines both gain characteristics (from slope magnitude) and offset characteristics (from intercept analysis). The controller performs both calibrations in an integrated manner using the same set of measurements, reducing overall process complexity while maintaining precision.
Data Source
AI summary
A display device includes: a plurality of pixels; a plurality of data lines coupled to the pixels and grouped into a plurality of groups; a plurality of channels corresponding to the plurality of groups, each of the channels being configured to sense a current flowing to a data line of a corresponding group from among the data lines to output a code value; and a controller configured to calibrate a deviation of a gain and an offset of the channels based on the code value of each of the channels.