Source Driver Equalizer Automatic Calibration for Display Devices
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Solution Overview
Problem
The manufacturing efficiency of display devices is low due to the need for user-set external setting pins for equalizers, leading to increased source driver size and manufacturing costs.
Innovation Solution
A source driver with a receiver, data signal generator, equalizer, recovery, and calibrator that automatically sets the equalizer by adjusting frequency gain based on selected option values, using a phase detector, charge pump, voltage control oscillator, differentiator, and controller to optimize signal recovery and reduce manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If an external setting pin is provided for manual equalizer configuration, then the equalizer can be adjusted for different display devices, but the source driver size increases and manufacturing efficiency decreases
Solution Approach 1:
The equalizer automatically configures itself by evaluating multiple option values and selecting the optimal one based on signal recovery performance, eliminating the need for manual user setting while maintaining adaptability to different display devices
Solution Approach 2:
The system pre-evaluates multiple equalizer option values during a calibration period before normal operation, determining the optimal setting in advance so that the equalizer is ready for immediate use without requiring manual configuration during manufacturing
2Adaptability or versatility
If an external setting pin is provided for manual equalizer configuration, then the equalizer can be adjusted for different display devices, but the source driver size increases
Solution Approach 1:
The external setting pin is completely removed from the source driver design. Instead, the system uses internal calibration circuitry that leverages existing components (phase detector, charge pump, VCO) to perform automatic equalizer configuration, thereby reducing the physical footprint of the source driver
3Ease of operation
If manual setting operation through external setting pin is required, then the equalizer can be configured, but manufacturing cost increases
Solution Approach 1:
The equalizer performs self-configuration automatically during a calibration period before normal operation, eliminating the need for manual user setting operations and reducing manufacturing costs by removing external setting pins and associated assembly steps
Solution Approach 2:
The optimal equalizer setting is determined in advance during a calibration period before the display device is put into service, allowing the system to be pre-configured automatically without requiring manual intervention during manufacturing or installation
4Speed
If the data rate of the intra-panel interface is increased, then the transmission speed improves, but signal distortion becomes serious
Solution Approach 1:
The equalizer dynamically adjusts its frequency gain characteristics by selecting from multiple option values based on the actual signal recovery performance, allowing the system to optimize signal integrity at each operating data rate without requiring fixed conservative settings
Solution Approach 2:
The system uses feedback from the phase detector and charge pump that monitor clock signal recovery quality to evaluate different equalizer option values and select the one that provides the best signal integrity for the current transmission conditions
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The automatic setting of the equalizer reduces manufacturing costs and improves manufacturing efficiency by eliminating the need for external setting pins, while ensuring optimal signal recovery and compensation for varying signal transmission rates.
Implementation Method 1
a phase detector which detects a phase difference between the compensated image data and the clock signal
Implementation Method 2
a charge pump which generates a voltage control signal by converting the detected phase difference into a voltage signal
Implementation Method 3
a voltage control oscillator which outputs the clock signal in response to the voltage control signal
Implementation Method 4
a differentiator which outputs a differential value by differentiating the voltage control signal
Data Source
AI summary
A source driver includes an equalizer which outputs compensated image data by adjusting a frequency gain of image data, based on a selected option value among a plurality of option values. A recovery recovers a clock signal corresponding to the compensated image data. A calibrator sequentially provides the plurality of option values to the equalizer, and selects the selected option value among the plurality of option values, based on recovery rates of the clock signal, which respectively correspond to the plurality of option values.