Clairvoyante

Use of PenTile RGBW™ technology can benefit many types of display technology with minimal disruption to fabrication processes, including amorphous silicon, Low Temperature Polysilicon, and Organic Light-Emitting Diode.

It can be applied with success to transmissive, transflective, wide-viewing-angle, 3-D, and wide-temperature range displays. In addition, its highly efficient software algorithms can be implemented at different points in the display system-driver chip, bridge chip, or DSP–providing system engineers with a high degree of design flexibility.

Amorphous Silicon (a-Si)

PenTile RGBW™ designs enable existing amorphous silicon plants to create higher resolution panels that are not economical to manufacture without moving to a newer-generation fab or an LTPS process. Older fabs can now manufacture higher-resolution panels using PenTile RGBW™ technology because the greater efficiency of PenTile RGBW™ displays reduces the subpixel density required. Design rules can be relaxed, which in turn improves yield. This is particularly significant as new fabs are increasingly configured for larger glass sizes, and older fabs are re-tooled for production of smaller, high-resolution mobile displays. Because the introduction of PenTile RGBW™ into a-Si plants does not require difficult process changes, improvements can be realized for the next-generation fabs as well.

Low Temperature Polysilicon (LTPS)

Compared to most a-Si processes, the use of LTPS alone brings superior aperture ratios and higher brightness to high-resolution displays. However, even further improvements can be realized by coupling PenTile RGBW™ designs with LTPS technology, which enables the industry's most transmissive high-resolution displays, improving the performance of even the most advanced LTPS technology and reaching performance levels not attainable by any other method.

Combining PenTile RGBW™ technology with LTPS can double white brightness with no power increase, due to the improved aperture ratio of the larger PenTile® subpixels and the utilization of white (clear color filter) subpixels. As an example, the table below compares two 2.8-inch LTPS prototype panels manufactured by AUO, with and without PenTile RGBW™ technology. Both panels are VGA resolution (287 dpi), have identical design rules and achieve 175 cd/m2 (nits) of brightness with a 69% NTSC ratio:

	RGB Stripe	PenTile RGBW™
Transmittance	5.2%	10.5%
Contrast	300	350
Source Drivers	1,440	960
Gate Drivers	640	640
Backlight Power	475 mW	233 mW

The AUO panel built using PenTile RGBW™ has twice the transmittance, and at the same time improved contrast. The number of source drivers is decreased from 1,440 to 960-lowering clock frequency, power consumption, and cost. Note that alternatively, the PenTile RGBW™ panel could be driven with a backlight power of 475 mW to double the brightness.

Organic Light Emitting Diode (OLED)

OLEDs offer the benefits of an extraordinarily thin display with quick video response, a 180-degree viewing cone, and power consumed only where the display is activated. There are two types of OLEDs: those utilizing white emitters and color filters, and the much more common type which are direct-emitting.

Lifetimes of OLEDs are a function of current density, so scaling to higher resolution is a challenge, as current density becomes an issue. A PenTile layout optimized for OLED technology can eliminate one-third of the subpixels which can significantly reduce current density, improving the lifetime of higher resolution OLEDs while also increasing brightness. Clairvoyante has solutions to improve the performance of both types of OLEDs. PenTile RGBW™ technology is fully applicable to OLEDs with white emitters. For direct-emitting OLEDs, Clairvoyante has developed an optimized PenTile RGB layout.