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LCoS technical info

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Anonymous
June 9, 2005 9:38:01 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

According to a tech article I read,


"LCOS' calling card is ultrahigh resolution. A typical high-resolution LCOS
panel comprises 1080 pixels x 1920 pixels, making it the first fixed-pixel
imaging system capable of faithfully reproducing every detail in a 1080-line
image (LCD and plasma HD panels typically "scale," or interpolate, 1080-line
images in order to display them in the panels' 1024 actual lines).
Additionally, among current technologies, LCOS is uniquely capable of
upconverting a 1080-line interlaced image (1080i) for true progressive-scan
display (1080p). Visible pixelization (known as "screen-door effect") is
virtually eliminated at normal viewing distances with LCOS, because the cell
structure of the panels features very little space between the individual
pixels. And because the light passes through the liquid crystals twice on
its way to the projection lens (once between lamp and mirror, and once more
when reflected back toward the projection lens), LCOS improves upon the
traditionally marginal contrast performance of LCD displays, while sharing
LCD's imperviousness to burn-in."

Is this accurate?

So, LCoS is *supposed* to be able to have a higher native resolution than
plasma or DLP, yielding a sharper picture, but I don't think they are
actually building LCoS units that good yet. Of course, plasma has its own
advantages and I'm sure many people will still prefer it.

How long will it take LCoS to reach its display potential? Think it'll be
about three to five years?

More about : lcos technical info

June 10, 2005 12:04:49 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

"Adam Corolla" <nospam@nospam03550265902.com> wrote in message
news:VbGdndsUg7lUWTXfRVn-oA@giganews.com...
> According to a tech article I read,
>
> "LCOS' calling card is ultrahigh resolution. A typical high-resolution
> LCOS panel comprises 1080 pixels x 1920 pixels, making it the first
> fixed-pixel imaging system capable of faithfully reproducing every detail
> in a 1080-line image (LCD and plasma HD panels typically "scale," or
> interpolate, 1080-line images in order to display them in the panels' 1024
> actual lines). Additionally, among current technologies, LCOS is uniquely
> capable of upconverting a 1080-line interlaced image (1080i) for true
> progressive-scan display (1080p). Visible pixelization (known as
> "screen-door effect") is virtually eliminated at normal viewing distances
> with LCOS, because the cell structure of the panels features very little
> space between the individual pixels. And because the light passes through
> the liquid crystals twice on its way to the projection lens (once between
> lamp and mirror, and once more when reflected back toward the projection
> lens), LCOS improves upon the traditionally marginal contrast performance
> of LCD displays, while sharing LCD's imperviousness to burn-in."
>
> Is this accurate?
> So, LCoS is *supposed* to be able to have a higher native resolution than
> plasma or DLP, yielding a sharper picture, but I don't think they are
> actually building LCoS units that good yet. Of course, plasma has its own
> advantages and I'm sure many people will still prefer it.
>
> How long will it take LCoS to reach its display potential? Think it'll be
> about three to five years?


In front projectors, 1080p LCoS models have been available for about a year
now, one is the beautiful Sony Qualia, the other is a JVC. I believe Toshiba
also has one.

I bought my first LCoS front projector [JVC G-11] in 1998.
1365x1024. The HDTV picture quality is still mind-blowing.

Anyway, talking about rear projectors as you are, have you read the rave
reviews of the new Sony Qualia 1080p rear projector, I think LCoS is already
reaching it's potential.

"And because the light passes through the liquid crystals twice...".
I don't think the light ever passes through the LCoS panels, rather it's
always reflected off of them.
Anonymous
June 10, 2005 7:55:13 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

David wrote:
> "Adam Corolla" <nospam@nospam03550265902.com> wrote in message
> news:VbGdndsUg7lUWTXfRVn-oA@giganews.com...
>
>>According to a tech article I read,
>>
>>"LCOS' calling card is ultrahigh resolution. A typical high-resolution
>>LCOS panel comprises 1080 pixels x 1920 pixels, making it the first
>>fixed-pixel imaging system capable of faithfully reproducing every detail
>>in a 1080-line image (LCD and plasma HD panels typically "scale," or
>>interpolate, 1080-line images in order to display them in the panels' 1024
>>actual lines). Additionally, among current technologies, LCOS is uniquely
>>capable of upconverting a 1080-line interlaced image (1080i) for true
>>progressive-scan display (1080p). Visible pixelization (known as
>>"screen-door effect") is virtually eliminated at normal viewing distances
>>with LCOS, because the cell structure of the panels features very little
>>space between the individual pixels. And because the light passes through
>>the liquid crystals twice on its way to the projection lens (once between
>>lamp and mirror, and once more when reflected back toward the projection
>>lens), LCOS improves upon the traditionally marginal contrast performance
>>of LCD displays, while sharing LCD's imperviousness to burn-in."
>>
>>Is this accurate?
>>So, LCoS is *supposed* to be able to have a higher native resolution than
>>plasma or DLP, yielding a sharper picture, but I don't think they are
>>actually building LCoS units that good yet. Of course, plasma has its own
>>advantages and I'm sure many people will still prefer it.
>>
>>How long will it take LCoS to reach its display potential? Think it'll be
>>about three to five years?
>
>
>
> In front projectors, 1080p LCoS models have been available for about a year
> now, one is the beautiful Sony Qualia, the other is a JVC. I believe Toshiba
> also has one.
>
> I bought my first LCoS front projector [JVC G-11] in 1998.
> 1365x1024. The HDTV picture quality is still mind-blowing.
>
> Anyway, talking about rear projectors as you are, have you read the rave
> reviews of the new Sony Qualia 1080p rear projector, I think LCoS is already
> reaching it's potential.
>
> "And because the light passes through the liquid crystals twice...".
> I don't think the light ever passes through the LCoS panels, rather it's
> always reflected off of them.
>
>
I was about to say the same thing about SXRD but don't have to. I will
just agree with this post. SXRD is close to full potential for LcOS and
stunning either as front or rear projection.

Bob Miller
Related resources
Anonymous
June 10, 2005 2:40:23 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

"David" <davey@home.net> wrote in message
news:beSdnbF-fr2BRDXfRVn-qw@comcast.com...

> "Adam Corolla" <nospam@nospam03550265902.com> wrote in message
> news:VbGdndsUg7lUWTXfRVn-oA@giganews.com...
>>[quoting an article] "And because the light passes through the liquid
>>crystals twice...".

> I don't think the light ever passes through the LCoS panels, rather it's
> always reflected off of them.

If I remember correctly, the LCD material sits on a reflective mirror
surface. Light from the projector lamp passes through the LCD material,
reflects off of the mirror surface, then passes back through the LCD
material, heading to the screen.

Because in the LCOS design light reflects off of a mirror surface, it is
similar to DLP. Because it employs LCD material, is has some of the
characteristic of LCD displays. Some people say that LCOS takes advantage
of the best of both technologies: DLP and LCD.

Neil
Salem, MA USA
June 11, 2005 8:12:51 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

In article <GKGdnYxEI9X8OzTfRVn-gA@comcast.com> "Neil - Salem, MA USA" <Neil@Salem.Massachusetts.USA> writes:
>"David" <davey@home.net> wrote in message
>news:beSdnbF-fr2BRDXfRVn-qw@comcast.com...
>
>> "Adam Corolla" <nospam@nospam03550265902.com> wrote in message
>> news:VbGdndsUg7lUWTXfRVn-oA@giganews.com...
>>>[quoting an article] "And because the light passes through the liquid
>>>crystals twice...".
>
>> I don't think the light ever passes through the LCoS panels, rather it's
>> always reflected off of them.
>
>If I remember correctly, the LCD material sits on a reflective mirror
>surface. Light from the projector lamp passes through the LCD material,
>reflects off of the mirror surface, then passes back through the LCD
>material, heading to the screen.
>
>Because in the LCOS design light reflects off of a mirror surface, it is
>similar to DLP. Because it employs LCD material, is has some of the
>characteristic of LCD displays. Some people say that LCOS takes advantage
>of the best of both technologies: DLP and LCD.


If this is the case, what happens for dark areas of the picture? The LCoS material
turns dark, and blocks the light, by absorbing it?

This seems unlikely, since for a dark image, the rather small LCoS device would be
absorbing all the light energy that would have gone to the screen, resulting it it
heating up rather substantially. Excess heat is clearly not in the best interests
of liquid crystal lifetime.


Also, if the light is reflected back, the light is likely to come out through a
*different* pixel in the LCoS device, since you cannot run it in and out at a
90 degree angle to the LCoS device -- the reflection from the mirror would be reflected
back to the bulb, and not to the screen. Thus, you must:

\ /
\ /
---------
.

To make this sort of work, the mirror would have to be incredibly thin, with
the reflecting surface very close to the LCoS device, and it still would have
some light coming back out the wrong pixel.


The feature of the DLP is that the surface reflects light from the pixels all
the time -- either to the screen, or to a light dump with a heat sink.


Alan
June 11, 2005 12:12:55 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

"Neil - Salem, MA USA" <Neil@Salem.Massachusetts.USA> wrote in message
news:GKGdnYxEI9X8OzTfRVn-gA@comcast.com...
> "David" <davey@home.net> wrote in message
> news:beSdnbF-fr2BRDXfRVn-qw@comcast.com...
>
>> "Adam Corolla" <nospam@nospam03550265902.com> wrote in message
>> news:VbGdndsUg7lUWTXfRVn-oA@giganews.com...
>>>[quoting an article] "And because the light passes through the liquid
>>>crystals twice...".
>
>> I don't think the light ever passes through the LCoS panels, rather it's
>> always reflected off of them.
>
> If I remember correctly, the LCD material sits on a reflective mirror
> surface. Light from the projector lamp passes through the LCD material,
> reflects off of the mirror surface, then passes back through the LCD
> material, heading to the screen.
>
> Because in the LCOS design light reflects off of a mirror surface, it is
> similar to DLP. Because it employs LCD material, is has some of the
> characteristic of LCD displays. Some people say that LCOS takes advantage
> of the best of both technologies: DLP and LCD.
>
> Neil
> Salem, MA USA

Well I guess the LCD is one layer of the LCOS device.. you're right, the
light does go through that in both directions. The mirror is referred to as
the "reflective electrode". Anyway, here's a diagram at the JVC site:

http://pro.jvc.com/pro/attributes/PRESENT/desc/structur...

This page has cool flash diagrams of how the different types work:

http://optics.unaxis.com/en/LCOS_3_538.asp
Anonymous
June 11, 2005 12:44:02 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

"Alan" <nospam@w6yx.stanford.edu> wrote in message
news:D 8doc3$2m7$1@news.Stanford.EDU...
> In article <GKGdnYxEI9X8OzTfRVn-gA@comcast.com> "Neil - Salem, MA USA"
> <Neil@Salem.Massachusetts.USA> writes:
>>"David" <davey@home.net> wrote in message
>>news:beSdnbF-fr2BRDXfRVn-qw@comcast.com...
>>
>>> "Adam Corolla" <nospam@nospam03550265902.com> wrote in message
>>> news:VbGdndsUg7lUWTXfRVn-oA@giganews.com...
>>>>[quoting an article] "And because the light passes through the liquid
>>>>crystals twice...".
>>
>>> I don't think the light ever passes through the LCoS panels, rather it's
>>> always reflected off of them.
>>
>>If I remember correctly, the LCD material sits on a reflective mirror
>>surface. Light from the projector lamp passes through the LCD material,
>>reflects off of the mirror surface, then passes back through the LCD
>>material, heading to the screen.
>>
>>Because in the LCOS design light reflects off of a mirror surface, it is
>>similar to DLP. Because it employs LCD material, is has some of the
>>characteristic of LCD displays. Some people say that LCOS takes advantage
>>of the best of both technologies: DLP and LCD.
>
>
> If this is the case, what happens for dark areas of the picture? The
> LCoS material
> turns dark, and blocks the light, by absorbing it?
>
> This seems unlikely, since for a dark image, the rather small LCoS device
> would be
> absorbing all the light energy that would have gone to the screen,
> resulting it it
> heating up rather substantially. Excess heat is clearly not in the best
> interests
> of liquid crystal lifetime.
>
>
> Also, if the light is reflected back, the light is likely to come out
> through a
> *different* pixel in the LCoS device, since you cannot run it in and out
> at a
> 90 degree angle to the LCoS device -- the reflection from the mirror would
> be reflected
> back to the bulb, and not to the screen. Thus, you must:
>
> \ /
> \ /
> ---------
> .
>
> To make this sort of work, the mirror would have to be incredibly thin,
> with
> the reflecting surface very close to the LCoS device, and it still would
> have
> some light coming back out the wrong pixel.
>
>
> The feature of the DLP is that the surface reflects light from the pixels
> all
> the time -- either to the screen, or to a light dump with a heat sink.
>
>
> Alan

Check out: http://www.projectorcentral.com/lcos.htm?print=1

"LCOS combines these two ideas. It is a reflective technology that uses
liquid crystals instead of individual mirrors. In LCOS, liquid crystals are
applied to a reflective mirror substrate. As the liquid crystals open and
close, the light is either reflected from the mirror below, or blocked. This
modulates the light and creates the image."
June 12, 2005 10:49:55 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

In article <3padnQYM1fgIQTffRVn-pg@comcast.com> "Neil - Salem, MA USA" <Neil@Salem.Massachusetts.USA> writes:
>"Alan" <nospam@w6yx.stanford.edu> wrote in message
>> To make this sort of work, the mirror would have to be incredibly thin, with
>> the reflecting surface very close to the LCoS device, and it still would have
>> some light coming back out the wrong pixel.
>>
>
>Check out: http://www.projectorcentral.com/lcos.htm?print=1
>
>"LCOS combines these two ideas. It is a reflective technology that uses
>liquid crystals instead of individual mirrors. In LCOS, liquid crystals are
>applied to a reflective mirror substrate. As the liquid crystals open and
>close, the light is either reflected from the mirror below, or blocked. This
>modulates the light and creates the image."

Frightening. The references, given here clearly indicate that the LCoS
absorbs the light energy for dark areas -- which means it has to become
rather hot from all that energy on a small device.

I wonder how long these things last before the heat starts to get to them.

(A previous poster gave this good link to the structure of the device:
http://pro.jvc.com/pro/attributes/PRESENT/desc/structur...


Alan
Anonymous
June 13, 2005 9:18:39 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

"Bob Miller" <robmx@earthlink.net> wrote in message
news:Ba8qe.1727$hK3.1274@newsread3.news.pas.earthlink.net...
> David wrote:
>> "Adam Corolla" <nospam@nospam03550265902.com> wrote in message
>> news:VbGdndsUg7lUWTXfRVn-oA@giganews.com...
>>
>>>According to a tech article I read,
>>>
>>>"LCOS' calling card is ultrahigh resolution. A typical high-resolution
>>>LCOS panel comprises 1080 pixels x 1920 pixels, making it the first
>>>fixed-pixel imaging system capable of faithfully reproducing every detail
>>>in a 1080-line image (LCD and plasma HD panels typically "scale," or
>>>interpolate, 1080-line images in order to display them in the panels'
>>>1024 actual lines). Additionally, among current technologies, LCOS is
>>>uniquely capable of upconverting a 1080-line interlaced image (1080i) for
>>>true progressive-scan display (1080p). Visible pixelization (known as
>>>"screen-door effect") is virtually eliminated at normal viewing distances
>>>with LCOS, because the cell structure of the panels features very little
>>>space between the individual pixels. And because the light passes through
>>>the liquid crystals twice on its way to the projection lens (once between
>>>lamp and mirror, and once more when reflected back toward the projection
>>>lens), LCOS improves upon the traditionally marginal contrast performance
>>>of LCD displays, while sharing LCD's imperviousness to burn-in."
>>>
>>>Is this accurate?
>>>So, LCoS is *supposed* to be able to have a higher native resolution than
>>>plasma or DLP, yielding a sharper picture, but I don't think they are
>>>actually building LCoS units that good yet. Of course, plasma has its
>>>own advantages and I'm sure many people will still prefer it.
>>>
>>>How long will it take LCoS to reach its display potential? Think it'll
>>>be about three to five years?
>>
>>
>>
>> In front projectors, 1080p LCoS models have been available for about a
>> year now, one is the beautiful Sony Qualia, the other is a JVC. I believe
>> Toshiba also has one.
>>
>> I bought my first LCoS front projector [JVC G-11] in 1998.
>> 1365x1024. The HDTV picture quality is still mind-blowing.
>>
>> Anyway, talking about rear projectors as you are, have you read the rave
>> reviews of the new Sony Qualia 1080p rear projector, I think LCoS is
>> already reaching it's potential.
>>
>> "And because the light passes through the liquid crystals twice...".
>> I don't think the light ever passes through the LCoS panels, rather it's
>> always reflected off of them.
> I was about to say the same thing about SXRD but don't have to. I will
> just agree with this post. SXRD is close to full potential for LcOS and
> stunning either as front or rear projection.
>
> Bob Miller

Bob, what is SXRD?
Anonymous
June 13, 2005 9:25:24 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

"Alan" <nospam@w6yx.stanford.edu> wrote in message
news:D 8gluj$9oo$1@news.Stanford.EDU...
> In article <3padnQYM1fgIQTffRVn-pg@comcast.com> "Neil - Salem, MA USA"
> <Neil@Salem.Massachusetts.USA> writes:
>>"Alan" <nospam@w6yx.stanford.edu> wrote in message
>>> To make this sort of work, the mirror would have to be incredibly thin,
>>> with
>>> the reflecting surface very close to the LCoS device, and it still would
>>> have
>>> some light coming back out the wrong pixel.
>>>
>>
>>Check out: http://www.projectorcentral.com/lcos.htm?print=1
>>
>>"LCOS combines these two ideas. It is a reflective technology that uses
>>liquid crystals instead of individual mirrors. In LCOS, liquid crystals
>>are
>>applied to a reflective mirror substrate. As the liquid crystals open and
>>close, the light is either reflected from the mirror below, or blocked.
>>This
>>modulates the light and creates the image."
>
> Frightening. The references, given here clearly indicate that the LCoS
> absorbs the light energy for dark areas -- which means it has to become
> rather hot from all that energy on a small device.
>
> I wonder how long these things last before the heat starts to get to
> them.

Agreed, that's an intense amount of heat for such a small area. They
probably have a massive copper heat sink & fan or perhaps even a passive
water cooling system, in addition to a fan blowing directly on the LCD
screen...
Anonymous
June 13, 2005 9:38:36 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

"David" <davey@home.net> wrote in message
news:beSdnbF-fr2BRDXfRVn-qw@comcast.com...
> "Adam Corolla" <nospam@nospam03550265902.com> wrote in message
> news:VbGdndsUg7lUWTXfRVn-oA@giganews.com...
>> According to a tech article I read,

>
> Anyway, talking about rear projectors as you are, have you read the rave
> reviews of the new Sony Qualia 1080p rear projector, I think LCoS is
> already reaching it's potential.

Interesting! I tried to get pricing on one of these at the web sites of
Best Buy, Circuit City and Ultimate Electronics, but none of them carry it
apparently. I even tried Sears. I checked Sony's web site and the only one
they list is a 70-incher, and there's no way that's going to be anywhere
near my budget range.

I guess I'll have to wait until they become more popular and much of the R&D
is paid off...
!