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Freitag, 09 Oktober 2009 |
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Flat multitouch LCD monitor which only uses light emitting diodes as optical sensor elements. The sensor resolution is 48 × 32 LEDs. Instead of the high number of LEDs the power consumption is about 3W at a frame rate of 10 Hz.
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This work was developed in collaboration with
1 Abstract
This thesis is about the development of a multitouch sensor for LCD displays. The sensor is placed behind a LCD panel and extends it with multitouch capabilities. The sensor only uses light emitting diodes which are used bidirectionally, that means that the LEDs are used for emitting as well as for sensing light. The LEDs are multiplexed in that way that every LED is used as emitter and sensor, so the effective sensor resolution is equal to the number of used LEDs. The sensor is organized as 48 × 32 matrix, that’s 1536 LEDs in total. Despite of the large number of LEDs, the sensor only consumes 3 W at a frame rate of 10 Hz. Furthermore the sensor is designed to be scalable to almost any screen size.
2 Realized System
- Modular Master-Slave-System
- Master saves sensor and calibration data
- Slave module contains entire electronic for 16x16 LEDs
- Master and Slave modules communicate via cascaded SPI
- Additional ARM7 microcontroller for data exchange between Master and PC via USB
- Modules can be tiled hirozontally and vertically without gaps
- Any number of Slave modules possible without changes on the hardware
3 Dimension
- 6 Modules with je 16x16 LEDs (=1536 LEDs)
- Organized in 3x2grid
- LED distance 7mm
- Total area 336x224mm (~16" diagonal)
4 Documents
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Last Updated ( Freitag, 09 Oktober 2009 )
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Multitouch LCD 
