On Apr 25, 2010, at 11:26 AM, Laurence wrote: > > > ==> What is the difference between the above screen and Flexview? I've seen > Flexview and IPS oft mentiond. What's the advantage, is that daylight > readable? > --- >
Hopefully the following isn't too long and boring ... IPS = in-plane switching It is a method of constructing LCD display panels. Good characteristics are fairly low amount of color shift when viewing from off axis, both horizontal and vertical. They also don't change as much in brightness with angle. They are more expensive and, in many cases, they are slower so not quite so good for gamers. IPS panels are used for high quality, color sensitive displays (my 30" desk monitor at work is IPS based). HP's so-called DreamColor desk monitor is IPS based (list price was originally about $2K for a 24-inch 1920x1200 display but it does 10-bit per pixel color). Flexview is an IBM marketing term for a reasonable quality IPS screen used in certain older high-end ThinkPads. For example, my T43p has a 15" 1600x1200 pixel Flexview display. It is now old so somewhat dim (never was that bright) but it has good color off axis. Virtually NO notebook/laptop monitor is daylight readable unless it is specifically built for that (see certain Panasonic Toughbooks and the Dell ATG). A typical sunlight readable display has a brightness of about 1000 nits where most notebooks are 150 to 250 when on AC power and less when on battery. Also most sunlight readable displays have exceptionally good anti-reflective coatings on the display. Some may also "optically bond" any cover to the actual LCD unit to minimize reflections from the back side of the cover and front side of the LCD. Typical glass (think glossy screens) reflect about 4.5% of the incident light from each surface. So you get a 9% or so reflected signal from cover and another reflected signal from the actual LCD. These add up to be brighter than the image generated by the LCD. The LCD transmits some part of the light generated by the backlight (typically cold cathode florescent or LED on some newer displays) but that is typically much less bright than the reflected signal from the sun, sky, lit buildings, etc. The sunlight readable displays typically have 4 to 6 times the brightness (think less battery life) of a normal notebook and a very much better antireflective coating (think expensive and maybe hard to clean and easily scratched). On those special displays, the transmitted signal is still visible with a reasonable signal-to-noise ratio in the presence of the signal reflected from the sunlit scene. Even with a sunlight readable display, the contrast will not be very good compared to what you would see in a dim or dark room but it is usable. I haven't checked recently but a long time back sunlight readable avionic displays for aircraft had brightness of about 2000 nits with a 0.25% reflection from the front. That is an extremely good antireflective coating and a VERY bright display. It has to be dimmed at night. It also had a significant heat sink on the back of the display to get rid of heat from the very bright backlight - not exactly useful for a notebook as the display itself was at least 2" thick. A typical "good" wide-band antireflective coating for consumer level devices might be about 1% or less over most of the visible spectrum. The glossy screens typically do not have an anti-reflection coating so they work best in dim environments or where you can adjust the viewing angle so that any specular (think mirror) reflection reaching your eye is from a dark part of the environment. Stuart _______________________________________________ Thinkpad mailing list [email protected] http://stderr.org/cgi-bin/mailman/listinfo/thinkpad
