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Discussion Starter · #1 ·
 http://www.jvcdig.com/papers/SPIEDef...y03-04RevD.pdf


What do you get from this white paper. I do not quite understand what that rotating disc shutter is about, do you?


It is always fun with new white papers from JVC. I only hope the next one is about lasers!
 

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Here's the most interesting thing I see in that article:
Quote:
Given that the current offering of light valve projectors is motivated by the presentation and now the entertainment (e-cinema) markets, high brightness is a driving parameter. High brightness is also important to simulation, but it is not as important as high resolution. Human vision is highly adaptable to brightness conditions. (Brightness as low a 0.1 ft-lamberts has been used as full daylight in some flight simulators.)
0.1 ft-lamberts! Where does SMPTE get off telling us we need at least 12 ft-L! And where does Tryg get off telling us we need 30 ft-L! :)


Seriously, I wonder what it is about the specific operating conditions that lets 0.1 ft-L faithfully represent daylight in a simulation?
 

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Mattias,


The purpose of the shutter is to sharply define the duty cycle of each pixel on the screen and cause the apparent synchronous update of all pixel on the screen at once.


Think of it in terms of a square wave that has a somewhat fast rise time and a slower decay time...mechanically take a snapshot of the wave once it has reached it's peak and before decay begins and the result is a very sharply defined on/off pulse at the same rate but at a much shorter duration than the underlying pulse.


This totally eliminates smear associated with the decay time common in LC systems but has the effect of reducing brightness due to shortened "on" time. Additionally, the shutter timing can be set in such a way as all pixels can be refreshed before the shutter "on" state occurs...giving a full-panel synchronous refresh capability.


I hope that helps...
 

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Tom that is the most detail you have ever given, and i thought you where just a sales guy.
 

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One other question does this improve the on/off contrast for a Lcos panel?
 

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Quote:


(Brightness as low a 0.1 ft-lamberts has been used as full daylight in some flight simulators.)
On a 92" wide 2.0 gain screen I calculate that this would require under 4 lumens.


So, basically they had close to the same white level as Tryg has for black level. Sort of a night and day difference there.


--Darin
 

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0.1 ft-lamberts? Is this per pixel, hehe?
 

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Jon,


I am a sales guy with an engineering background...the realm in which I work on a day to day basis requires a pretty substantial level of technical expertise in all areas of imaging...from acquisition/creation to display.


Cheers,
 

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Discussion Starter · #9 ·
tstites

Many thanks for your answer. From memory the paper said that it took 8ms to update a line of pixels. Does this mean that with d-ila it takes about 8ms to complete a refresh of each frame? I guess that the hold charachteristics of the pixels lets you wait until all pixels are refreshed and then display them at once.

What would be gained if this were to be implemented for video projectors?


everybody

Perhaps it would be interesting to learn how long it takes sxrd panels to refresh a frame. This is likely the only big difference between d-ila and sxrd. sxrd seems to be faster, 5ms vs 12ms, but has a lower fill factor.
 
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