Miniature IR ChipLED
Jul 2011OSRAM Opto Semiconductors Inc.Request Info
SUNNYVALE, Calif., July 26, 2011 — The ChipLED SFH 4053 from Osram Opto Semiconductors provides high output for superlow-profile optical touch screens and is suitable for use in small- and medium-size touch displays.
Touch screens demand infrared components that are superlow-profile and extremely powerful. The infrared emitter combines tiny dimensions with high efficiency, making it suitable for low-profile all-in-one computer, tablet PC and laptop displays, and it is small enough to be easily integrated into smartphones.
Optical touch screens are available in a wide variety of designs, but they share a common principle in that the touch of a finger will either cast a shadow or reflect light. In basic versions, an array of infrared emitters and detectors creates a grid of vertical and horizontal beams. The components are housed in a low-profile frame, known as the bezel, measuring 0.5 to 1 mm in depth around the screen. The ChipLED SFH 4053 measures 0.5 × 1 mm and is 0.45 mm high.
The high light output is important for camera-based touch screens. Such a display setup requires considerably fewer IR emitters than the traditional version, but the emitters must have high output because they flood the display with infrared light from two corners. Next to the IR emitters are camera chips that detect a change in the signal when a pen or finger touches the display.
Because of proprietary thin-film chip technology, the LED provides 35-mW output from an operating current of 70 mA. In pulse mode, it can achieve as much as 260 mW from 700 mA. It provides enough light to make it easy and cost-effective to expand camera-based touch screen systems to larger diagonal sizes.
The ChipLED is available with lens types from ±40° to ±10° and with different chip technologies, including thin film and nanostack.
It can be used in multitouch displays, and icons can not only be selected and moved, but also zoomed.