Patently Apple’s Jack Purcher reports the US Patent & Trademark Office has published a patent application from Apple revealing possible changes in the iPad 3′s backlighting system. It has been reported that Apple is likely to modify LED back-lighting for next-generation iPads. The patent application may show an insight into what these modifications might be.
While the patent discusses the use of one or two OLED backlighting units in a future iPad, other devices adopting multiple OLED backlights could also include the Cinema Display, MacBook Air and, as some hope, an HDTV. At this point the focus seems to be on the iPad.
LCD devices generally include a light source, as liquid crystal materials themselves do not emit light. A typical light source, also referred to as a backlight, may include light sources along one or more edges which emit light into light guide panels (LGPs) which guide the light across the display area. To increase the uniformity and brightness over the display area, a typical LCD device may also include brightness enhancement film (BEF) layers which reflect and enhance the light. However, such efforts to increase uniformity and/or brightness may also increase the thickness and complexity of the backlight and the LCD device. Furthermore, the different films and parts of an LCD having a LED backlight may be susceptible to contamination.
Referring to Apples solution, Purcher also states:
“Apple’s patent generally relates to a liquid crystal display (LCD) device having an organic light emitting diode (OLED) backlight. In one embodiment, an OLED backlight may include one or more OLED pixels disposed between two glass substrates. The OLED backlight may be optically bonded to the back of an LCD, which may prevent contamination between the LCD and the OLED backlight and increase the mechanical rigidity of the display device. Further, the OLED backlight may also be electrically connected with light modulating portions of the LCD, such that information transmitted to selected pixels of the LCD active matrix may also be transmitted to areas of the OLED backlight electrically connected to the selected LCD pixels. For example, grayscale information transmitted to selected LCD pixels may also be received by corresponding areas of the OLED backlight.”
The article continues that using OLED backlighting may be coming to Apple’s Cinema Display, MacBooks and iOS devices such as the iPhone and iPad.