Many people spend an increasing amount of time in front of computer screens equipped with light-emitting diodes (LED) with a short wavelength (blue range). Thus we investigated the repercussions on melatonin (a marker of the circadian clock), alertness, and cognitive performance levels in 13 young male volunteers under controlled laboratory conditions in a balanced crossover design. A 5-h evening exposure to a white LED-backlit screen with more than twice as much 464 nm light emission {irradiance of 0,241 Watt/(steradian × m(2)) [W/(sr × m(2))], 2.1 × 10(13) photons/(cm(2) × s), in the wavelength range of 454 and 474 nm} than a white non-LED-backlit screen [irradiance of 0,099 W/(sr × m(2)), 0.7 × 10(13) photons/(cm(2) × s), in the wavelength range of 454 and 474 nm] elicited a significant suppression of the evening rise in endogenous melatonin and subjective as well as objective sleepiness, as indexed by a reduced incidence of slow eye movements and EEG low-frequency activity (1-7 Hz) in frontal brain regions. Concomitantly, sustained attention, as determined by the GO/NOGO task; working memory/attention, as assessed by "explicit timing"; and declarative memory performance in a word-learning paradigm were significantly enhanced in the LED-backlit screen compared with the non-LED condition. Screen quality and visual comfort were rated the same in both screen conditions, whereas the non-LED screen tended to be considered brighter. Our data indicate that the spectral profile of light emitted by computer screens impacts on circadian physiology, alertness, and cognitive performance levels. The challenge will be to design a computer screen with a spectral profile that can be individually programmed to add timed, essential light information to the circadian system in humans.

In commodity LC flat-panel displays, the traditional CCFL backlight is being replaced more and more by LEDs. The typical spectrum of LED-lit displays shows a significantly higher amount of blue light in the range around 464 nm. Blue light in this wavelength area suppresses the melatonin level in humans and thus effects the biological clock. Our hypothesis was that the amount of blue light reaching the human eye from a LED-backlit display is sufficient to have a significant effect on the biological clock. The results of clinical user studies comparing the effects of LED- vs. CCFL-backlit displays on humans, resulting from the emitted amount of 464-nm light, will be presented. It was found that the LED-backlit display causes significant suppression of melatonin, which effects the biological clock of the test persons, indicating the necessity for displays with a controllable 464-nm emission. A technical concept for a display with such functionality will be presented

The new S‐Class introduced a newly developed 3D instrument cluster display as one of its highlights. The display enables real depth perception without the need for glasses and without compromising visual quality. This paper describes the requirements, system design and technical realization of a fully position‐adaptive autostereoscopic display.

We have realized a full color 4‐inch quarter‐VGA amorphous‐Silicon AMLCD with pixel electrodes made of random carbon nanotube (CNT) networks instead of ITO. The CNTs are deposited from suspension by spray‐coating. with this work we demonstrate the applicability of CNT pixel electrodes in a standard AMLCD process.

Immersive visualization environments have generally been built on single user stereoscopic displays. We have extended these systems to multi-view systems that provide perspectively correct stereoscopic image pairs for up to six users. As a result, groups of users can explore a shared 3D virtual environment from all perspectives and discuss it using barehanded gestures. From all displayed images, each user should perceive only one dedicated image per eye. All additional views must be filtered. Consequently, the noise level for each user increases with the number of displayed views. Keeping the image crosstalk under the threshold of human perception is a necessity for this type of visualization system. To separate the images we have used a hybrid approach which combines active shuttering and passive polarization filtering. In projection-based view systems brightness and crosstalk are one of the major issues which have to be handled as the noise increases and the signal br ightness decreases with the increase of views. To evaluate different technical approaches for optimization and also to compare these systems with existing single user 3D systems, we have extended the crosstalk measurement approach by Weissman and Woods to our projection-based specific multi-view case where the eye separation is carried out with polarization filters and the user separation with time sequential shutter elements. Our contribution is a method for defining and measuring crosstalk for projection-based multi-view systems