Touch Screen Controller Chip Timing Control for Brightness Uniformity
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Solution Overview
Problem
In touch screens, the overlap of display and touch circuits leads to uneven brightness due to coupling between data lines and dummy lines, which affects the display's uniformity.
Innovation Solution
A signal control method and controller chip configuration that sequentially switches scan lines and turns on switches to transmit display data, while setting dummy lines to a touch voltage, ensuring proper timing to prevent voltage deviations and maintain uniform brightness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If dummy lines are added above data lines for touch circuit function, then touch detection capability is improved, but voltage coupling between dummy lines and data lines causes uneven brightness
Solution Approach 1:
The patent applies preliminary action by setting dummy lines to touch voltage before touch detection begins, and by turning on switches coupled to dummy lines after other switches are turned on during display. This sequencing prevents voltage coupling from affecting brightness uniformity while maintaining touch detection capability.
Solution Approach 2:
The patent changes the voltage parameter of dummy lines dynamically - setting them to touch voltage during touch stage and to display voltage during display stage. It also changes the switching sequence parameter, turning on switches coupled to dummy lines later than other switches, thereby eliminating voltage coupling effects that cause brightness non-uniformity.
2Productivity
If switches coupled to dummy lines are turned on simultaneously with other switches, then transmission efficiency is improved, but voltage deviation occurs causing display non-uniformity
Solution Approach 1:
The patent applies preliminary action by turning on switches coupled to dummy lines after other switches are turned on. This delayed switching sequence ensures that voltage is stable before these switches close, preventing voltage deviations that would cause display non-uniformity while maintaining efficient data transmission.
Solution Approach 2:
The patent applies preliminary anti-action by deliberately delaying the turn-on timing of switches coupled to dummy lines. This counteracts the potential harmful effect of simultaneous switching by ensuring voltage stability is established first, thereby preventing display non-uniformity while preserving transmission efficiency.
Data Source
AI summary
A signal control method suitable for a touch screen is provided. The signal control method comprises: switching a plurality of scan lines to an enabling voltage level sequentially in a display stage; turning on a plurality of switches sequentially to transmit a plurality of display data to a plurality of data lines when a first scan line of the plurality of scan lines is in an enabled voltage level, wherein a first switch of the plurality of switches is coupled to a first data line of the plurality of data lines, and the first data line corresponds to one of a plurality of dummy lines in a vertical direction, when the first scan line is in the enabled voltage level, the first switch is turned on after other switches are turned on; and setting the plurality of dummy lines to a touch voltage in a touch stage.