Τεχνολογιες panel LCD-TFT
TN + film
The inexpensive 'TN (twisted nematic) + film' display is the most common consumer display type. The pixel response time on modern TN panels is sufficiently fast to avoid the shadow-trail and ghosting artifacts of earlier production. The fast response time has been emphasised in advertising TN displays, although in most cases this number does not reflect performance across the entire range of possible color transitions. Response times were quoted for an ISO standard black-to-white transition and did not reflect the speed of much more common transitions from one shade of grey to another. More recent use of RTC (Response Time Compensation – Overdrive) technologies has allowed manufacturers to significantly reduce grey-to-grey (G2G) transitions, without significantly improving the ISO response time. Response times are now quoted in G2G figures, with 4ms and 2ms now being commonplace for TN Film based models. The good response time and low cost has led to the dominance of TN in the consumer market.
IPS
IPS (in-plane switching) was developed by Hitachi in 1996 to improve on the poor viewing angles and color reproduction of TN panels. Most panels also support true 8-bit per channel color. These improvements came at the cost of a slower response time, initially about 50ms. IPS panels were also extremely expensive. A partial list of LCDs that utilize IPS can be found at PcHardwareHelp.
IPS has since been superseded by S-IPS (Super-IPS, Hitachi in 1998), which has all the benefits of IPS technology with the addition of improved pixel refresh timing. Though color reproduction approaches that of CRTs, the dynamic range is lower. S-IPS technology is widely used in panel sizes of 20" and above. LG and Philips remain one of the main manufacturers of S-IPS based panels.
Evolution of IPS liquid crystal
AS-IPS – Advanced Super IPS, also developed by Hitachi in 2002, improves substantially on the contrast ratio of traditional S-IPS panels to the point where they are second only to some S-PVAs.
A-TW-IPS – Advanced True White IPS, developed by LG.Philips LCD for NEC, is a custom S-IPS panel with a TW (True White) color filter to make white look more natural and to increase color gamut. This is used in professional/photography LCDs.
H-IPS – Released in late 2006, an evolution of the IPS panel which improves upon its predecessor, the S-IPS panel.
MVA
MVA (multi-domain vertical alignment) was originally developed in 1998 by Fujitsu as a compromise between TN and IPS. It achieved pixel response which was fast for its time, wide viewing angles, and high contrast at the cost of brightness and color reproduction. Modern MVA panels can offer wide viewing angles (second only to S-IPS technology), good black depth, good color reproduction and depth, and fast response times due to the use of RTC technologies. There are several "next-generation" technologies based on MVA, including AU Optronics' P-MVA and A-MVA, as well as Chi Mei Optoelectronics' S-MVA.
Analysts predicted that MVA would dominate the mainstream market, but the cheaper and slightly faster TN overtook it. MVA's pixel response times rise dramatically with small changes in brightness. Cheaper MVA panels can use dithering and FRC.
PVA
PVA (patterned vertical alignment) and S-PVA (super patterned vertical alignment) are alternative versions of MVA technology offered by Samsung. Developed independently, they offer similar features to MVA, but with higher contrast ratios of up to 3000:1. Less expensive PVA panels often use dithering and FRC, while S-PVA panels all use at least 8-bit color and do not use color simulation methods. Some newer S-PVA panels offered by Eizo offer 10-bit color internally, which enables gamma and other corrections with reduced banding. PVA and S-PVA offer good black depth and wide viewing angles and S-PVA also offers fast response times using modern RTC technologies.
Πηγη: http://en.wikipedia.org/wiki/TFT_LCD
Πως λειτουργουν οι TFT-LCD...
http://solutions.3m.com/wps/portal/3M/en_US/Vikuiti1/BrandProducts/secondary/optics101/
TN + film
The inexpensive 'TN (twisted nematic) + film' display is the most common consumer display type. The pixel response time on modern TN panels is sufficiently fast to avoid the shadow-trail and ghosting artifacts of earlier production. The fast response time has been emphasised in advertising TN displays, although in most cases this number does not reflect performance across the entire range of possible color transitions. Response times were quoted for an ISO standard black-to-white transition and did not reflect the speed of much more common transitions from one shade of grey to another. More recent use of RTC (Response Time Compensation – Overdrive) technologies has allowed manufacturers to significantly reduce grey-to-grey (G2G) transitions, without significantly improving the ISO response time. Response times are now quoted in G2G figures, with 4ms and 2ms now being commonplace for TN Film based models. The good response time and low cost has led to the dominance of TN in the consumer market.
IPS
IPS (in-plane switching) was developed by Hitachi in 1996 to improve on the poor viewing angles and color reproduction of TN panels. Most panels also support true 8-bit per channel color. These improvements came at the cost of a slower response time, initially about 50ms. IPS panels were also extremely expensive. A partial list of LCDs that utilize IPS can be found at PcHardwareHelp.
IPS has since been superseded by S-IPS (Super-IPS, Hitachi in 1998), which has all the benefits of IPS technology with the addition of improved pixel refresh timing. Though color reproduction approaches that of CRTs, the dynamic range is lower. S-IPS technology is widely used in panel sizes of 20" and above. LG and Philips remain one of the main manufacturers of S-IPS based panels.
Evolution of IPS liquid crystal
AS-IPS – Advanced Super IPS, also developed by Hitachi in 2002, improves substantially on the contrast ratio of traditional S-IPS panels to the point where they are second only to some S-PVAs.
A-TW-IPS – Advanced True White IPS, developed by LG.Philips LCD for NEC, is a custom S-IPS panel with a TW (True White) color filter to make white look more natural and to increase color gamut. This is used in professional/photography LCDs.
H-IPS – Released in late 2006, an evolution of the IPS panel which improves upon its predecessor, the S-IPS panel.
MVA
MVA (multi-domain vertical alignment) was originally developed in 1998 by Fujitsu as a compromise between TN and IPS. It achieved pixel response which was fast for its time, wide viewing angles, and high contrast at the cost of brightness and color reproduction. Modern MVA panels can offer wide viewing angles (second only to S-IPS technology), good black depth, good color reproduction and depth, and fast response times due to the use of RTC technologies. There are several "next-generation" technologies based on MVA, including AU Optronics' P-MVA and A-MVA, as well as Chi Mei Optoelectronics' S-MVA.
Analysts predicted that MVA would dominate the mainstream market, but the cheaper and slightly faster TN overtook it. MVA's pixel response times rise dramatically with small changes in brightness. Cheaper MVA panels can use dithering and FRC.
PVA
PVA (patterned vertical alignment) and S-PVA (super patterned vertical alignment) are alternative versions of MVA technology offered by Samsung. Developed independently, they offer similar features to MVA, but with higher contrast ratios of up to 3000:1. Less expensive PVA panels often use dithering and FRC, while S-PVA panels all use at least 8-bit color and do not use color simulation methods. Some newer S-PVA panels offered by Eizo offer 10-bit color internally, which enables gamma and other corrections with reduced banding. PVA and S-PVA offer good black depth and wide viewing angles and S-PVA also offers fast response times using modern RTC technologies.
Πηγη: http://en.wikipedia.org/wiki/TFT_LCD
Πως λειτουργουν οι TFT-LCD...
http://solutions.3m.com/wps/portal/3M/en_US/Vikuiti1/BrandProducts/secondary/optics101/