Touch Display Device Time Division Multi-Pen Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current touch display devices face challenges in efficiently sensing multiple pens simultaneously, leading to increased sensing time and potential distortion of pen position, while also struggling with multiplexing and pen search speed.
Innovation Solution
A touch display device with a touch panel and touch driving circuit that employs time division sensing intervals and different operation frequencies to detect signals from multiple pens, allowing for simultaneous sensing and improved reporting rates, and uses a touch controller to generate synchronization signals for efficient data processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional touch sensing methods are used to detect multiple pens, then the basic touch display function is provided, but the sensing time increases and pen position distortion occurs
Solution Approach 1:
The sensing operation is divided into multiple time division sensing intervals (first, second, third, fourth intervals) within one frame period. Each interval is dedicated to detecting signals from specific pens at different operation frequencies, allowing simultaneous sensing of multiple pens without increasing total sensing time
Solution Approach 2:
The touch driving circuit operates at different operation frequencies (first operation frequency, second operation frequency) in different time intervals. Each pen is assigned a specific operation frequency and detected during its designated time interval, enabling periodic detection of multiple pens with distinct signal characteristics
2Productivity
If multiple pens are sensed simultaneously using conventional methods, then basic touch functionality is maintained, but pen search speed decreases
Solution Approach 1:
The system changes the operation frequency parameter to differentiate between multiple pens. Each pen is assigned a unique operation frequency (first operation frequency for first pen, second operation frequency for second pen), allowing the touch driving circuit to quickly identify and distinguish pens without complex spatial scanning
Solution Approach 2:
The touch driving circuit is designed to perform multiple functions: detecting position, tilt, and additional information of multiple pens simultaneously. The same circuit infrastructure handles various sensing tasks across different time intervals and frequencies, improving productivity without proportionally increasing device complexity
3Speed
If multiplexing is implemented to increase sensing speed, then sensing time is reduced, but position distortion of pens occurs
Solution Approach 1:
The frame period is segmented into distinct time division sensing intervals, with each interval dedicated to detecting specific pens at specific operation frequencies. This segmentation prevents signal interference and position distortion while maintaining high sensing speed through efficient time utilization
Solution Approach 2:
The touch driving circuit acts as an intermediary that manages the detection process by assigning specific time intervals and operation frequencies to different pens. This intermediary control ensures that each pen's signal is detected at its optimal frequency without interference, preserving position accuracy while achieving fast sensing
Data Source
AI summary
A touch display device comprises a touch panel including a plurality of touch electrodes; and a touch driving circuit configured to sense one or more of the plurality of touch electrodes, wherein the touch driving circuit has an operation period including a plurality of touch intervals that includes a first sensing interval and a second sensing interval, and the first sensing interval includes at least a first time division sensing interval and the second sensing interval includes at least a second time division sensing interval, and wherein the touch driving circuit is configured to detect a pen signal output from a first pen through one or more touch electrodes of the plurality of touch electrodes during the first time division sensing interval, and detect a pen signal output from a second pen through one or more touch electrodes of the plurality of touch electrodes during the second time division sensing interval.