RPO Digital Waveguide Touch (DWT) technology is an optical touch system developed based on the traditional IR system concept. This system uses 1 to 2 low-cost LEDs to provide a controllable light source (in fact, an infrared light plane) from two adjacent oblique sides, and then use aggregation on the other two adjacent oblique sides. The objective optical waveguide is used to introduce light into a discrete 10m pipe into a small light sensor matrix.
This technology improved by traditional IR touch effectively solves all the shortcomings of traditional technology. These shortcomings will be discussed below.
Shenzhen optical touch because the optoelectronic devices (LED and sensor) are no longer placed on the oblique side of the display; compared with the traditional optical touch system, the impact of the height and width of the oblique surface on the touch system is reduced. RPO demonstrated a touch system with only 2mm outside the display area, and the side height from the screen protector (lens) to the inner surface of the device housing is only 0.5mm.
DWT has only 1~2 LEDs and 1 light sensor chip, so the cost is much lower; because the optical signal at the receiving end enters the separate light guide and is detected by the independent pixels of the light sensor matrix, it has a "digital nature", so its The resolution is much higher. Therefore, pen detection and handwriting input recognition are possible.
The development of filters and porosity makes ambient light no longer a problem because of the small optical waveguide as the receiving pipe. The key to making this technology possible is RPO's improved low-cost photolithographic printed polymer optical waveguides. The company uses LCD-like processing tools to deposit wet films, direct lithography patterns to process films, and solvent improvements. It sounds simple, but the process of improving polymer materials and the production of high-strength, high-resolution light guides took many years. In addition, the optical system design used by this RPO is very complex, but it is simple, cheap and easy to integrate in the physical system.
RPO demonstrated this system at DisplayWeek2007, which was used for multi-touch on PDA devices at that time. DWT is now used in high-end user products. In theory, this system can be used for displays of any size, but RPO is initially geared toward small and medium-sized consumer electronics and car displays.
Tag: Shenzhen Light Touch