An Apple patent (number 20130021567) for “undulating electrodes for improved viewing angles and color shift on LCD displays” has appeared at the U.S. Patent & Trademark Office. It shows that Apple continues to work on ways to improve the screens on its OS X and iOS devices — and, who knows, perhaps the long-rumored “iTV.”
The invention provides for a variety of multi-domain pixel configurations that may be implemented in the unit pixels of an LCD display device, such as a fringe field switching LCD display panel. An LCD display device utilizing one or more of the presently disclosed techniques disclosed herein may exhibit improved display properties, such as viewing angle, color shift, and transmittance properties, relative to those exhibited by conventional multi-domain designs.
Here’s Apple’s background on the invention: “Liquid crystal displays (LCDs) are commonly used as screens or displays for a wide variety of electronic devices, including such consumer electronics as televisions, computers, and handheld devices (e.g., cellular telephones, audio and video players, gaming systems, and so forth). Such LCD devices typically provide a flat display in a relatively thin package that is suitable for use in a variety of electronic goods.
“In addition, such LCD devices typically use less power than comparable display technologies, making them suitable for use in battery powered devices or in other contexts were it is desirable to minimize power usage. LCD devices typically include a plurality of unit pixels arranged in a matrix. The unit pixels may be driven by scanning line and data line circuitry to display an image that may be perceived by a user.
“Conventional unit pixels of fringe-field switching (FFS) LCD display panels may utilize multi-domain or single-domain configurations and may typically include strip-shaped or finger-shaped pixel electrodes. The pixel electrodes are generally controlled by transistors to create electrical fields that allow at least a portion of a light source to pass through a liquid crystal material within the pixels. In conventional single-domain pixel configurations, pixel electrodes are generally arranged parallel to one another such that all the pixel electrodes within the LCD panel are oriented in the same direction.
“This generally results in the electrical fields generated within a single-domain unit pixel being in the same direction throughout the unit pixel, thereby providing a higher light transmittance rate compared to that of multi-domain pixel configurations. However, conventional single-domain pixel configurations generally offer poorer viewing angles and color shift properties compared to multi-domain configurations.
“In conventional multi-domain pixel configurations, pixel electrodes within each unit pixel may be oriented in more than one direction. In this manner, the overall viewing angle and color shift properties of the LCD panel may be improved. However, disclinations may result in light-transmissive portions of multi-domain unit pixels due to the differing directions of electrical fields generated within each unit pixel. Such disinclinations are particularly problematic in that they may block a portion of the light transmitted through the pixels, thus reducing the overall transmittance rate of the LCD panel.”
The inventors are Mingxia Gu, Ming Xu, Cheng Chen, John Z. Zhong, Shih Chang Chang and Shawn Robert Gettemy.