Optics and Photonics Essential Technologies for Our Nation (2013) / Chapter Skim
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10 Displays
10 Displays
Pages 260-274
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From page 260... ...
The 1998 National Research Council report Harnessing Light: Optical Science and Engineering for the 21st Century1 mentioned 10.4-inch LCD displays and postulated the potential for 40-inch plasma displays. Today, LCD displays are ubiquitous.
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From page 261... ...
. To create flexible displays, however, it is necessary to develop flexible substrate materials and processes that exhibit chemical resistance, thermal stability, and endurance of high temperatures and pressures during fabrication.
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From page 262... ...
Additional trends for display products include thinner and lower-power-consumption displays. Several countries are beginning to impose restrictions on the total power consumption of display units, forcing manufacturers to come up with better designs, especially for lighting, which consumes approximately 25 to 40 percent of the total display unit power.9 On the notebook computer side, where low power consumption is a major consideration, LED lighting is the dominant technology.
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From page 263... ...
Improvements in LCDs resulted in wider applications and led to the displacement of competing technologies, including CRTs in traditional television sets. There has been at least some market interest in extending LCDs to three dimensional displays, exploiting polarization in a different way.13 In one tech nique, a polarizer on the glasses worn by the viewer matches the orientation of the polarized output of the display.
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From page 264... ...
The result would be more pure colors and a broader color gamut. Touch Displays Of the several kinds of touch technologies, three are most prevalent: resistive, in which a touching object presses down and causes two separated layers to connect to each other at that point; optical, in which a touching object appears as a shadow, and cameras can locate and measure the size of the object; and capacitive, in which an electrically conducting finger touching a screen results in a distortion of the screen's electrostatic field and a change in capacitance.
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From page 265... ...
Reprinted with permission. FIGURE 10.2 Improved color gamut with quantum dots.
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From page 266... ...
However, as a result of Apple's introducing its first iPhone, which incorporated projected capacitive multi-touch, considerable new interest in this technology has been generated. In projected capacitive touch, the display area is divided into a grid of unit cells of roughly 5 mm × 5 mm each, the size commonly selected for the typical size of a fingertip.16 The most common implementation of projected capacitive touch involves a touch sensor array bonded directly behind a cover glass.
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From page 267... ...
That makes OLEDs potentially useful in ap plications in which they will be subjected to rough handling, such as in cell phones or other consumer electronics. Furthermore, in the case of completely flexible substrates, the displays could be used in applications in which no other display currently can be contemplated, such as being integral with an article of clothing.
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From page 268... ...
Moreover, plastic substrates and printable semiconductors are now available to help to create flexible back planes. Other key technologies are needed for future flexible LCDs or OLEDs, such as the use of stable and heat-resistant organic materials and low temperature printing.
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From page 269... ...
DLP projectors incorporating RGB LEDs have high image quality and low power consumption, but they have lower resolution than LCoS projectors. Laser scanning also has low power consumption, but laser speckle noise affects image quality.
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From page 270... ...
data, this stage is trivial inasmuch as the data may already be stored as three-dimensional voxels, and each voxel might already have the color and shading information. Later, the fringe generation stage computes a large two-dimensional holographic fringe based on the result of the computer graphic stage.
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From page 271... ...
Nature 468:80-83. FIGURE 10.4 Holographic optical modulation using a typical high-resolution spatial-light modulator (SLM)
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From page 272... ...
The same holds true in the production of touch sensors; Taiwan holds a slightly stronger position than the others. The segment of the touch-display technologies in which the United States leads is the touch controller circuits, in whose production the major firms are Atmel,34 Broadcom,35 and Synaptics.36 In the United States, Corning is producing large sheets of the high-quality glass needed for the display panels (color filter and thin-film transistors)
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From page 273... ...
Recommendation: U.S. private companies and the Department of Defense should ensure a leadership role by funding R&D related to new materials for flexible, low power, holographic and three-dimensional display technologies.
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