Sensor Panel Duty-Cycle Control for Display EMI Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing display devices face electromagnetic interference (EMI) issues due to the use of driving signals for sensors and display signals, which deteriorate display quality and reduce sensing sensitivity, and it is challenging to find additional suitable frequency bands to mitigate this interference.
Innovation Solution
A sensor device with a sensor panel and driver that uses reference signals with multiple duty cycles to receive sensing signals, applying shield signals with the same waveform and phase to adjacent sensors, and alternating duty cycles for odd and even rows to minimize EMI without changing frequency bands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If driving signals are supplied to sensors in the display device, then sensing function is enabled, but electromagnetic interference occurs that deteriorates display quality and reduces sensing sensitivity
Solution Approach 1:
The sensor panel is divided into multiple sensing regions (first sensing region and second sensing region) that are driven by different driving signals with different duty cycles. This segmentation allows simultaneous operation of multiple sensors while reducing electromagnetic interference through frequency diversity.
Solution Approach 2:
Different duty cycles are applied to driving signals supplied to different sensing regions. The first driving signal has a first duty cycle and the second driving signal has a second duty cycle, creating periodic variations that reduce electromagnetic interference while maintaining continuous sensing capability.
2Object-affected harmful factors
If frequency band of driving signal is changed to avoid electromagnetic interference, then EMI is reduced, but available frequency bands are limited and difficult to find additional suitable bands
Solution Approach 1:
Instead of changing the frequency band, the invention changes the duty cycle parameter of the driving signals. By varying the duty cycle while maintaining the same frequency band, electromagnetic interference is reduced without requiring additional frequency spectrum resources.
Data Source
AI summary
A sensor device includes: a sensor panel including sensors arranged in a matrix, and sensor lines electrically connected to the sensors on a one-to-one basis; and a sensor driver configured to receive, using a reference signal having at least two or more duty cycles, sensing signals from the sensors through the sensor lines.