Shared Analog Front-End Touch and Active Pen Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing display devices face challenges in efficiently performing both touch and active pen sensing with a minimal configuration, particularly in integrating sensor units that can accurately detect user inputs such as touches and active pen interactions without increasing complexity or cost.
Innovation Solution
A sensor device is designed with first and second sensors connected through sensor lines, utilizing a sensor transmitter and receiver with multiple analog front-ends to process touch and active pen sensing signals, including charge amplifiers, band pass filters, mixers, low pass filters, and analog-digital converters, and employing time-divided sensing periods to optimize signal processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If separate sensor configurations are used for touch sensing and active pen sensing, then sensing accuracy is improved, but device complexity increases
Solution Approach 1:
The sensor device uses a unified sensor configuration where the same sensor lines and analog front-ends serve both touch sensing and active pen sensing functions. The sensor transmitter sends driving signals that enable both sensing modes, and the analog front-ends process signals from both touch objects and active pens, eliminating the need for separate sensor configurations while maintaining sensing accuracy for both modes.
Solution Approach 2:
The sensor device employs time-division multiplexing where touch sensing and active pen sensing are performed in different time periods within a frame. The sensor transmitter alternates between sending touch driving signals and active pen driving signals, and the analog front-ends switch between processing touch sensing signals and active pen sensing signals, allowing both functions to share the same hardware resources without interference.
2Adaptability or versatility
If multiple sensor lines and analog front-ends are used, then sensing capability is improved, but manufacturing cost increases
Solution Approach 1:
The sensor device achieves dual sensing capability (touch and active pen) using the same sensor lines and analog front-ends, rather than requiring separate dedicated lines and front-ends for each sensing mode. This universal configuration reduces the total number of components needed, thereby lowering manufacturing costs while maintaining full sensing capability for both touch objects and active pens.
Solution Approach 2:
By implementing time-division multiplexing where the same hardware resources are reused in different time periods, the device reduces component count. The sensor transmitter and analog front-ends are shared between touch sensing and active pen sensing operations, decreasing the overall bill of materials and simplifying the manufacturing process compared to having parallel dedicated channels for each sensing mode.
3Measurement precision
If dedicated hardware is allocated for each sensing mode, then signal processing accuracy is improved, but device complexity increases
Solution Approach 1:
The sensor device uses time-division multiplexing where the same analog front-ends are allocated to different sensing modes in different time periods. During touch sensing periods, the front-ends process touch signals; during active pen sensing periods, they process active pen signals. This periodic allocation allows shared hardware to achieve dedicated-level signal processing accuracy for each mode without requiring separate dedicated hardware channels.
Solution Approach 2:
The sensor device dynamically switches the function of the analog front-ends between touch sensing and active pen sensing based on the current operating period. The hardware configuration is not static but changes over time, with the same physical components adapting their signal processing roles dynamically, thereby achieving accurate signal processing for both modes without the need for static dedicated hardware allocation.
Data Source
AI summary
A sensor device includes: first sensors connected to first sensor lines; second sensors connected to second sensor lines, the second sensors intersecting the first sensors; a sensor transmitter connected to the first sensors through the first sensor lines, the sensor transmitter configured to supply touch driving signals to the first sensors during a touch sensing period; and a sensor receiver connected to the second sensors through the second sensor lines, the sensor receiver configured to receive touch sensing signals from the second sensors during the touch sensing period, wherein the sensor receiver includes a plurality of analog front-ends, and wherein each of the plurality of analog front-ends is connected to at least one of the second sensor lines and at least one of the first sensor lines.