How to Address Touchscreen Performance
Transcription
How to Address Touchscreen Performance
How to Address Touchscreen Performance Copyright © 2012 Synaptics Incorporated. All Rights Reserved. This information and any related goods and services are provided “as is.” Synaptics makes no representations or warranties, expressed or implied. Synaptics providing you information, goods or services does not, by itself, create any express or implied license under any patent, trade mark, trade secret, copyright, mask work right, or any other intellectual property right. … back in the day X Channels Y Channels ? ? Profile ‘projects’ finger signals to X and Y axes The touchpad/touchscreen was one end of a parallel plate capacitor The finger was the other end BUT Subject to fake fingers showing up Poor multi-finger disambiguation Non-linear, lots of jitter Not enough data for advanced user interaction (Pen? Proximity? Glove?) Copyright © 2012 Synaptics Incorporated. All Rights Reserved Page 2 Trans-Capacitive Image Sensing How it works: Grid of electrodes: transmitters in one dimension, receivers in the other Capacitors at overlaps (pixels) Drive waveforms on transmitters, observe signal coupled to receivers Detect variance in capacitance at receiver when conductor (finger) is introduced Transmitters Receivers Copyright © 2012 Synaptics Incorporated. All Rights Reserved Page 3 Trans-capacitive Image Sensing How does the disruption occur? When a finger approaches, some of the field lines from the transmitter will terminate at the finger Fewer field lines at Rx reduction in capacitance Synaptics products work by measuring the reduction in capacitance Copyright © 2012 Synaptics Incorporated. All Rights Reserved Page 4 Trans-capacitive Image Sensing Imaging captures richer image of finger signals – Improved multi-finger disambiguation, can track more fingers – Alleviates fake finger problems Drive Rows – More data enables better performance and functionality Sense Columns Copyright © 2012 Synaptics Incorporated. All Rights Reserved Page 5 How do System-Level Parameters Affect Touch Performance? Lens Sensor Flex What is the material and dielectric constant? What is the thickness? What is the optical quality (e.g. clarity, haze, reflectance)? What is the trace resistance and cross-coupling? How close do traces run to noise sources? How long are the traces? Display What is the material and dielectric constant? What is the thickness? What is the sensor pattern? Is there a shield? How large is the gap between the sensor and the display? What type of display is it? How noisy is it? What is the noise signature? Power What is the power budget? How aggressive are the touch controller sleep modes? Touch Controller Host Software and UI What are the chip resources? How is the analog front end designed? How effective are the fw algorithms? What is the environmental noise? Copyright © 2011 2012 Synaptics Incorporated. All Rights Reserved What is the GUI? Is it designed for touch interactions? What level of touch performance is needed? What gestures are supported? How responsive is the software UI? Page 6 Designing for Touch: More than just a chip δL Cover Lens Glass OCA δOCA PRx δB WTX2 GY Rx/Tx ITO Substrate Glass GH Glass Shield ITO PTx γ Discrete Sensor Stackup (1S1P) δL Rx/Tx ITO VCOM ITO Cover Lens Glass OCA Polarizing Film δP δCF δOCA WRX1 Rx(n-1) Color Filter Glass Finger deforming the sensor Gxx Gx WRX2 PRX GX Rx (n) WE Sensor-on-lens (G2) Tx(m) δL Cover Lens Glass OCA Lens WTX2 GTX δOCA δB PTX Wy Gy Tx(m-1) WE Rx/Tx ITO Substrate Glass PRX/4 Shield ITO PRX/2 Air Gap WRX Discrete Sensor Stackup (1S2P) PET δL Cover Lens Glass Rx ITO PET Core Tx ITO Airgap PRx Display δOCA δc OCA δP Flexing sensor δA PTx δCF GTx Polarizing Film VCOM ITO Color Filter Glass Receiver Width 2-layer PET Sensor Stackup (2S2P) Synaptics’ years of experience in module design as well as a total systems approach has culminated in an unparalleled understanding of sensor design and stackups Sensor Designs are innovated and updated to address total system needs Software tools to enable customers, partners, and the ecosystem, in conjunction with advanced firmware algorithms work with sensor designs for best in class performance Various approaches for different end goals allowing customers to differentiate their products Backed by over 1 billion units shipped Copyright © 2012 Synaptics Incorporated. All Rights Reserved Page 7 Beginning to End Tools for ClearPad design The Synaptics Tool Suite is a beginning to end set of software that compliments the entire Synaptics portfolio and simplifies design for: Faster Time-to-Market Greater flexibility Reduced Total Cost of Ownership Synaptics SafeSense – ClearPad Sensor Simulation Tool Sensor Pattern Generation and Simulation Synaptics Design Studio – ClearPad Development Tool ClearPad bring up, tuning, configuration, exploration, and production test Synaptics TestStudio – ClearPad Production Test Tool Stand alone production test Copyright © 2012 Synaptics Incorporated. All Rights Reserved Page 8 THANK YOU! Copyright © 2012 Synaptics Incorporated. All Rights Reserved. This information and any related goods and services are provided “as is.” Synaptics makes no representations or warranties, expressed or implied. Synaptics providing you information, goods or services does not, by itself, create any express or implied license under any patent, trade mark, trade secret, copyright, mask work right, or any other intellectual property right.