Originally Posted by garciab
I understand why the connection to heat is made, but consider that this failure has hit pretty much every OEM that used the DMD chips within a certain time frame.
Did it effect the premium DLP projector manufactures. The likes of Projectiondesign, Runco, Barco, Christie? And if it did were their larger more expensive projectors effected.
Originally Posted by garciab
Also consider that there are many previous generations of tv's/projectors using older DLP chips that are still not exhibiting this issue. So either the newer generation of DMD chips required vastly improved cooling to remain troublefree, and all OEM's dropped the ball on their thermal designs.
DMD DLP chips have become higher resolution and smaller in size so higher mirror density on the chip, they are also driven faster as in the number of times the mirrors tilt per second or what have you. The black coatings have also been improved a bit so more light absorbant. So I would guess that modern smaller higher resolution faster driven chips need to get rid of more heat. And obviously a smaller chip size means the light is focussed on a smaller object the chip so more heat.
But I expect the vast majority of failures are down to projector manufactures not faulty TI chips.
Consumer projectors are often very compact so the lamp is close to everything else and there is not much space for large fans inside or for air flow cooling. Noise is also seen as an issue with quieter better which means fans may also be releatively slow speed. Due to lack of space what space there is might be easily reduced by dust, and fans may also wear out over time and get slower.
Depending on design of the lamp housing the lamp reflector maybe not very efficient so resulting in more heat and might not be adequately cooled. Lamps are now often modulated to the color wheel segments and dymanic so they are at times overdriven so running hotter. The IR UV filter in some consumer projectors looks to be part of the projector not part of each lamp housing, IR UV filters deteriorate over time so letting more through the light path and causing more heat further down the light path. IR UV filters on some designs also appears to not be tilted so it is not deflecting the heat away from the light path.
The colorwheel maybe more light efficient due to clear segment or brilliant color segments which also means it will result in more light through the light path and so possibly more heat further down the light path.
The light integrator rod on most consumer projectors is a mirrored tunnel which is less efficent and generates far more heat than a glass rod light integrator. And over time may degrade so generating more heat.
On many consumer projectors the DMD DLP chip illumination has overspill around the chip which is absorbed so more heat. The light box in many consumer projectors is also very small so the heat from the light dump for the DLP chip offstate is close to the DLP and the lens may also be very close to the chip, and often a mirror or two, so again more heat. Overtime depending on what it is made of the light dump and other black areas may get bleached and so relfect light back onto the chip, that might also add to heat.
Consumer projectors are also cheap so possibly cheap components or less strnigent quality control in manufacture.
Consumer projectors often come with a manufacture warranty which is less than 5 years let alone 100,000hrs. So they may not be built to last and some of the things not built to last might adverserly affect DMD DLP chip life expectancy.