Active Matrix Pressure Sensor Block Scanning for Low Power
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing 2-dimensional pressure detecting apparatuses with active matrix type pressure sensing elements face high power consumption even when no pressure input is applied, particularly in battery-driven devices, due to continuous operation of control and detecting circuits.
Innovation Solution
The apparatus includes a 2-dimensional array of sensing cells with first and second driving signal lines, where the first driving circuit sequentially drives the first signal lines when pressure changes are sensed, and the second driving circuit concurrently drives the second signal lines when no pressure change is detected, allowing for reduced power consumption in standby mode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If active matrix type pressure sensing elements are driven using shift register and control circuits to measure 2-dimensional pressure distribution, then measurement precision and detection capability are improved, but power consumption increases significantly due to continuous operation of control and detecting circuits
Solution Approach 1:
The sensing cell array is divided into multiple blocks, with each block independently controllable through block selection signals. This segmentation allows only the necessary blocks to be activated for measurement, reducing overall power consumption while maintaining measurement precision for the active regions.
Solution Approach 2:
The patent implements periodic scanning of sensing blocks using block selection signals that activate different blocks at different time intervals. During non-measurement periods, blocks are deactivated to reduce power consumption, while measurement periods maintain full operational capability for accurate pressure distribution detection.
2Reliability
If control circuits and detecting circuits operate continuously to measure pressure changes over time, then detection reliability is improved, but power consumption in no-pressure input state increases
Solution Approach 1:
The system dynamically adjusts its operational state by switching between active measurement mode and standby mode. Block selection signals enable or disable specific sensing blocks based on whether pressure changes are detected, allowing the system to maintain detection reliability when needed while minimizing power consumption during stable conditions.
Solution Approach 2:
The patent employs feedback mechanisms where detection results from previous measurement cycles inform the activation of block selection signals for subsequent cycles. When no pressure changes are detected, the feedback signal keeps blocks deactivated; when changes are detected, blocks are reactivated for continued monitoring, thus maintaining reliability while reducing standby power consumption.
3Measurement precision
If all sensing cells are continuously scanned to ensure no pressure change is missed, then detection completeness is improved, but power consumption and processing load increase
Solution Approach 1:
By dividing the sensing cell array into multiple independently controllable blocks, the system can selectively activate only the blocks that contain pressure changes. This reduces the complexity of continuous full-array scanning while maintaining detection completeness for active regions through targeted block-by-block measurement.
Data Source
AI summary
A pressure detecting includes a plurality of sensing cells arranged a plurality of rows and columns, each of the plurality of sensing cells including a pressure sensing element and a selection transistor. First driving signal lines are disposed in the rows, and the first driving signal lines are connected to the selection transistors of a first portion of the plurality of sensing cells in a respective row. Second driving signal lines are disposed in a portion of the plurality of rows, and the second driving signal lines are connected to the selection transistors of a second portion of the plurality of sensing cells in a respective row. First and second driving circuits are respectively connected to the first driving signal lines the second driving signal lines.