24 Oct 2006
Cell phones, monitors and televisions could all benefit from a switchable display that offers 2D or 3D viewing.
An LED-based display that supports integral imaging could bring a choice of 2D or 3D viewing to cell phones, monitors and televisions say researchers in South Korea. The system can be electrically converted between 3D and 2D modes by using different combinations of LEDs without any mechanical movement. (Optics Letters 31 2852)
According to the group from Seoul National University (SNU), the ability to switch between 2D and 3D images is critical if its device is to penetrate the highly competitive display market.
The display consists of two sets of interleaved white LEDs, a 35 x 35 matrix of spherical micro-lenses and a spatial light modulator (SLM). One set of LEDs is aligned with a diffuser to provide backlighting for the SLM and offers 2D viewing much like a conventional LCD.
In 3D mode, the display's microlenses focus light from the second set of LEDs into an array of point sources that illuminate elements of the SLM. Driven by image processing software, these elemental views combine to give an autostereoscopic display. Unlike lenticular-based systems, the SNU set-up is said to offer both horizontal and vertical parallaxes within a viewing angle.
Although pleased with its progress so far, the South Korean team accepts that there is still work to do. "High-power, miniature light sources, each smaller than 100 microns, would help to improve 3D image quality," Byoungho Lee of SNU's Optical Engineering and Quantum Electronics Lab told optics.org. "We considered using LED array chips, but they generated too much heat."
Lee says that the 2D-3D display will be used initially in mobile phones and then, as the technology develops, in large panel displays such as monitors and televisions.