Many people have mentioned that you can use peltiers to cool the sensor below room temperture, This is probably the most cost effective way to do it, but since this is/., there's another really cool way to do spot cooling. If your lab has a clean source of compressed air, check out exair.com. These things are called vortex tubes, and can create incredible temperature deltas, that are ideal for spot cooling, provided that you can supply the amount of air it requires. I've been told that it's actually relatively quiet given how much air it consumes, but i have no personal experience with them. just make sure you keep the exhaust end away from anything you don't want to melt. I woulda used it to make coffee while cooling my processor, but not everyone can afford a pump and a tank that can maintain that kind of airflow at 100 PSIG. Oh, one other thing... have you considered the potential issues w/ cooling the chip to those temperatures? I'd imagine condensation would kill your image quality, and depending on how well the boards are made, the solder joints may develop stress fractures. I remember using cold spray to cool PCB's to make sure there aren't any cold solder joints on PCB's we test. Oh yea, you could also use cold spray instead of the votex tube, but something about that stream of hot exhaust seems strangely apealing.
Finally, someone else that doesn't associate response times w/ refresh rates. The response times for black->white or white->black transitions are based on whether the pixels are designed as default on or default off. LCDs operate by changing the polarization of the light shining through it so whether a the transistor lets light through when it's off or not determines which way the transistions will be slower another effect of this is that one configuration will give you truer whites, and the other will give you truer blacks
Color calibration on an LCD is so poor because the digital to analog converters (yes, they do exist, those bit values do have to be converted to a brightness level somehow) are actually fixed. Any given input will always produce the same analog level of how bright that pixel is. The brightness of an lcd panel is controlled by the backlight, but the contrast is controlled by software, while the software may exist within the monitor, and not on your desktop, it is interpolated. I suspect the SWAP compliant monitors have colormapping curves of the DAC that have been calibrated, thus perform well, but I have no experience with SWAP. The bottom line is, currently, the only displays in the consumer maybe pro market that are flexible enough to be calibrated are CRTs
Yes, that is right, so many sites claim that lcds have different refresh rates, it's not true, every lcd refreshes at 60 Hz. What differs from lcd to lcd is the response time of a pixel, which is how long it takes for a pixel to turn on or off, as a frame of refrence, i believe the response time of CRT's are on the order of 4 ms while a typical TFT LCD is around 25 ms. If you're old enough to remember the DSTN panels, those things had a response time of close to 125 ms. If you read the datasheets on the raw lcd panels, it'll usually state the response times. I haven't looked at them for a couple of years so TFT response times may have gotten better
A few things most people don't know about DVI
on
DVI Flat Panels?
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Any idea why monitors with DVI support are more (it's digital, so in theory, it should cost less, because there's no need for a analog to digital conversion)?"
Yes, it stays digital, but not necessarily in the same format. Cheap older LCD's use TTL, current cheap LCD's use LVDS, and the more expensive ones use RSDS. Most of these different signal formats require different scalar chips to interpolate the image to fill the screen, how much each scalar chips costs is up to the manufacturer. Some use discrete converters to convert the format. So there are differences in being a digital signal. RS232 is serial, so is USB, but you're can't plug one into the other w/o some sort of adaptor, it's the same way w/ digital signals for the panels. Of course, "digital is better" so the market will pay more for it.
Not really sure about what you're referring to as update times. All LCD flat panels refresh at 60 Hz regardless of how fast you set your refresh rates to. There may be differences in the latency between the video card drawing the image and the screen displaying the image, this usually shouldn't trail by more than a frame, but usually on the order of milliseconds.
For those of you that don't know.. there ARE competing standards for Flat panel displays. DVI which is backed by intel, and proprietary.. and OpenLDI, which is the standard that is currently used in notebooks. OpenLDI consumes much less power and is capable of driving much higher resolutions. (yes there is such a thing as bandwidth when it comes to displays).. but anyway.. by the end of december, there will be a new crop of lcd displays these are 24" UXGAW displays w/ a resolution of 2048x1536. So far, these panels use OpenLDI.. ok.. I'm biased.. I used to work for a company that supports OpenLDI, but if anybody would care about proprietary standards I'd think the linux community would be the one to support the open standard. Too bad not enough consumers even know there's such a battle going on. Most geeks only care about rambus and ddr sdram. btw currently.. those 24" panels alone (like buying just a crt tube) costs around $5k
I've got 1 of these 2 way pagers using skytel.. let's you send and recieve email plus all the other services skytel offers.. it's got an IR port for those of you w/ palms that have them... there's software that'll let you use palms and laptops to use it as an email gateway.. the plus is it's the size of a normal flex pager w/ a decent battery life (1 1/2 months) as opposed to the old monster of a 2 way pager i used to carry around w/ a 2 week battery life
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Many people have mentioned that you can use peltiers to cool the sensor below room temperture, This is probably the most cost effective way to do it, but since this is /., there's another really cool way to do spot cooling. If your lab has a clean source of compressed air, check out exair.com. These things are called vortex tubes, and can create incredible temperature deltas, that are ideal for spot cooling, provided that you can supply the amount of air it requires. I've been told that it's actually relatively quiet given how much air it consumes, but i have no personal experience with them. just make sure you keep the exhaust end away from anything you don't want to melt. I woulda used it to make coffee while cooling my processor, but not everyone can afford a pump and a tank that can maintain that kind of airflow at 100 PSIG. Oh, one other thing... have you considered the potential issues w/ cooling the chip to those temperatures? I'd imagine condensation would kill your image quality, and depending on how well the boards are made, the solder joints may develop stress fractures. I remember using cold spray to cool PCB's to make sure there aren't any cold solder joints on PCB's we test. Oh yea, you could also use cold spray instead of the votex tube, but something about that stream of hot exhaust seems strangely apealing.
Finally, someone else that doesn't associate response times w/ refresh rates. The response times for black->white or white->black transitions are based on whether the pixels are designed as default on or default off. LCDs operate by changing the polarization of the light shining through it so whether a the transistor lets light through when it's off or not determines which way the transistions will be slower another effect of this is that one configuration will give you truer whites, and the other will give you truer blacks
Color calibration on an LCD is so poor because the digital to analog converters (yes, they do exist, those bit values do have to be converted to a brightness level somehow) are actually fixed. Any given input will always produce the same analog level of how bright that pixel is. The brightness of an lcd panel is controlled by the backlight, but the contrast is controlled by software, while the software may exist within the monitor, and not on your desktop, it is interpolated. I suspect the SWAP compliant monitors have colormapping curves of the DAC that have been calibrated, thus perform well, but I have no experience with SWAP. The bottom line is, currently, the only displays in the consumer maybe pro market that are flexible enough to be calibrated are CRTs
Yes, that is right, so many sites claim that lcds have different refresh rates, it's not true, every lcd refreshes at 60 Hz. What differs from lcd to lcd is the response time of a pixel, which is how long it takes for a pixel to turn on or off, as a frame of refrence, i believe the response time of CRT's are on the order of 4 ms while a typical TFT LCD is around 25 ms. If you're old enough to remember the DSTN panels, those things had a response time of close to 125 ms. If you read the datasheets on the raw lcd panels, it'll usually state the response times. I haven't looked at them for a couple of years so TFT response times may have gotten better
Any idea why monitors with DVI support are more (it's digital, so in theory, it should cost less, because there's no need for a analog to digital conversion)?"
Yes, it stays digital, but not necessarily in the same format. Cheap older LCD's use TTL, current cheap LCD's use LVDS, and the more expensive ones use RSDS. Most of these different signal formats require different scalar chips to interpolate the image to fill the screen, how much each scalar chips costs is up to the manufacturer. Some use discrete converters to convert the format. So there are differences in being a digital signal. RS232 is serial, so is USB, but you're can't plug one into the other w/o some sort of adaptor, it's the same way w/ digital signals for the panels. Of course, "digital is better" so the market will pay more for it.
Not really sure about what you're referring to as update times. All LCD flat panels refresh at 60 Hz regardless of how fast you set your refresh rates to. There may be differences in the latency between the video card drawing the image and the screen displaying the image, this usually shouldn't trail by more than a frame, but usually on the order of milliseconds.
For those of you that don't know.. there ARE competing standards for Flat panel displays. DVI which is backed by intel, and proprietary.. and OpenLDI, which is the standard that is currently used in notebooks. OpenLDI consumes much less power and is capable of driving much higher resolutions. (yes there is such a thing as bandwidth when it comes to displays).. but anyway.. by the end of december, there will be a new crop of lcd displays these are 24" UXGAW displays w/ a resolution of 2048x1536. So far, these panels use OpenLDI.. ok.. I'm biased.. I used to work for a company that supports OpenLDI, but if anybody would care about proprietary standards I'd think the linux community would be the one to support the open standard. Too bad not enough consumers even know there's such a battle going on. Most geeks only care about rambus and ddr sdram. btw currently.. those 24" panels alone (like buying just a crt tube) costs around $5k
I've got 1 of these 2 way pagers using skytel.. let's you send and recieve email plus all the other services skytel offers.. it's got an IR port for those of you w/ palms that have them... there's software that'll let you use palms and laptops to use it as an email gateway.. the plus is it's the size of a normal flex pager w/ a decent battery life (1 1/2 months) as opposed to the old monster of a 2 way pager i used to carry around w/ a 2 week battery life