Can one "overclock" a CRT monitor's video input bandwidth? Need slightly higher refresh rate than m

[Ken Moiarty]

My 19" Viewsonic A90's vertical refresh rate peaks out@ 100 Hz for a
resolution of 1024 x 728. For stereo 3-D video viewing purposes, I need it
to display at this resolution at a bare minimum vertical refresh rate of
approximately 120 Hz (though preferabley when I get another monitor, at
about 170 Hz). I could go out and buy another 19" monitor which purports to
be able to achieve the former for only about $250 (CAD) right now; in which
case the current CRT monitor will be gently laid to rest. So since it no
longer matters what happens to my present CRT monitor since I'm going to
replace it anyway, can I ask: Is there any way to over-ride the monitor's
built in refresh rate limitations (e.g. by tweaking some knobs at the back,
or even inside, or by making simple modifications to a component(s) -only of
course with the guidance and asistance of a licensed monitor technician due
to obvious safety reasons)? Aside from the risk of electrocution to those
who'd be foolhardy enough to attempt such an undertaking on their own
without the proper training and qualifications to go inside a monitor, is
it in any way technically feasible, given the right personnel, and done
cautiously and gradually (much like a CPU overclocker takes a high risk
gamble with the investment in his PC) to raise the monitor's refresh rate a
little beyond factory default and (say, if given extra cooling) be able to
keep it there indefinitely?

Sorry if my words above haven't come out quite right. It's late and I'm a
little punchy at the moment.

TIA,
Ken

 

[Mark M]

My 19" Viewsonic A90's vertical refresh rate peaks out@ 100 Hz for a
resolution of 1024 x 728. For stereo 3-D video viewing purposes, I need it
to display at this resolution at a bare minimum vertical refresh rate of
approximately 120 Hz (though preferabley when I get another monitor, at
about 170 Hz). I could go out and buy another 19" monitor which purports to
be able to achieve the former for only about $250 (CAD) right now; in which
case the current CRT monitor will be gently laid to rest. So since it no
longer matters what happens to my present CRT monitor since I'm going to
replace it anyway, can I ask: Is there any way to over-ride the monitor's
built in refresh rate limitations (e.g. by tweaking some knobs at the back,
or even inside, or by making simple modifications to a component(s) -only of
course with the guidance and asistance of a licensed monitor technician due
to obvious safety reasons)? Aside from the risk of electrocution to those
who'd be foolhardy enough to attempt such an undertaking on their own
without the proper training and qualifications to go inside a monitor, is
it in any way technically feasible, given the right personnel, and done
cautiously and gradually (much like a CPU overclocker takes a high risk
gamble with the investment in his PC) to raise the monitor's refresh rate a
little beyond factory default and (say, if given extra cooling) be able to
keep it there indefinitely?

Sorry if my words above haven't come out quite right. It's late and I'm a
little punchy at the moment.

Ken, good quality CRTs are going for next to nothing on eBay and
just about everywhere else. With a little searching (e.g. company
moving/going out of business/etc sales are great for this) you should
be able to knock that $250 down to under$100. Trying to increase
the bandwidth on your existing CRT will cost MUCH more in
component cost and soldering time.

 

[J. Clarke]

My 19" Viewsonic A90's vertical refresh rate peaks out@ 100 Hz for a
resolution of 1024 x 728. For stereo 3-D video viewing purposes, I need
it to display at this resolution at a bare minimum vertical refresh rate
of approximately 120 Hz (though preferabley when I get another monitor, at
about 170 Hz). I could go out and buy another 19" monitor which purports
to be able to achieve the former for only about $250 (CAD) right now; in
which
case the current CRT monitor will be gently laid to rest. So since it no
longer matters what happens to my present CRT monitor since I'm going to
replace it anyway, can I ask: Is there any way to over-ride the monitor's
built in refresh rate limitations (e.g. by tweaking some knobs at the
back, or even inside, or by making simple modifications to a component(s)
-only of course with the guidance and asistance of a licensed monitor
technician due
to obvious safety reasons)? Aside from the risk of electrocution to those
who'd be foolhardy enough to attempt such an undertaking on their own
without the proper training and qualifications to go inside a monitor, is
it in any way technically feasible, given the right personnel, and done
cautiously and gradually (much like a CPU overclocker takes a high risk
gamble with the investment in his PC) to raise the monitor's refresh rate
a little beyond factory default and (say, if given extra cooling) be able
to keep it there indefinitely?

Sorry if my words above haven't come out quite right. It's late and I'm a
little punchy at the moment.

I'm assuming that you have a modern CRT with microprocessor controls that
displays "signal out of range" or words to that effect when it gets a
signal that is beyond its rated capabilities and your intent is to alter
the limit beyond which that signal appears.

To do that you'd have to reprogram the control processor, which means
identifying it, finding the firmware ROM, pulling the program off of it,
disassembling it, analyzing it, and then figuring out how to tweak it to
make the change you want.

This would be weeks or months of work for a professional programmer familiar
with that particular processor's assembly language--coming in cold you're
going to have to learn that before you can do anything, and if you have no
programming experience assembler is generally not the best place to start
learning. You'll also need equipment that costs about the same as a new
monitor to be able to read and reprogram the ROM.

And once you've done that the analog components that actually do the work
are not going to be up to the task of handling that bandwidth--you'll get
any of several kinds of image degradation.

If you are _paying_ somebody to do this then the cost is going to be
enormous. By the time you're done you'll likely have paid enough to get a
containerload of new CRTs.

If you've got a hundred thousand machines out in the field all with the same
monitor and you want to try working up a mod for the monitor rather than
replacing them all then this _might_ be worth trying with the understanding
that there is no guarantee of a successful outcome, but even if the mod
itself is completely successful there opening each monitor and replacing
the ROM is likely to come perilously close to the cost of a new monitor.

For just one monitor, the only justifications I can think of for doing it
are that you want to learn something for your own satisfaction, you just
plain enjoy dinking around with such things, and neither of these is a
sound business reason.

 

[Richard Crowley]

My 19" Viewsonic A90's vertical refresh rate peaks out@ 100 Hz for a
resolution of 1024 x 728. For stereo 3-D video viewing purposes, I
need it to display at this resolution at a bare minimum vertical
refresh rate of approximately 120 Hz (though preferabley when I get
another monitor, at about 170 Hz). I could go out and buy another 19"
monitor which purports to be able to achieve the former for only about
$250 (CAD) right now; in which case the current CRT monitor will be
gently laid to rest. So since it no longer matters what happens to my
present CRT monitor since I'm going to replace it anyway, can I ask:
Is there any way to over-ride the monitor's built in refresh rate
limitations (e.g. by tweaking some knobs at the back, or even inside,
or by making simple modifications to a component(s) -only of course
with the guidance and asistance of a licensed monitor technician due
to obvious safety reasons)? Aside from the risk of electrocution to
those who'd be foolhardy enough to attempt such an undertaking on
their own without the proper training and qualifications to go inside
a monitor, is it in any way technically feasible, given the right
personnel, and done cautiously and gradually (much like a CPU
overclocker takes a high risk gamble with the investment in his PC) to
raise the monitor's refresh rate a little beyond factory default and
(say, if given extra cooling) be able to keep it there indefinitely?

No, there is no practical way to do this without extremely
extensive reworking of the circuit design and components.
This is NOT practical even for people who work on high-
voltage CRT circuits all the time, much less for people like
us who only dabble.

The major limiting factor is the horizontal sweep frequency,
and then the frequency response of the video path. The second
of those factors COULD be modified to get higher frequency-
response, but boosting the horizontal sweep frequency is just
not practical for most people. It very likely would involve
modification or replacement of the two most critical components
in the whole circuit (the deflection yoke and the flyback
transformer).

Richard Crowley in rec.video.desktop
Note that this is not really on-topic for r.v.d which is
chartered for discussion of television editing, which
appears to have nothing to do with your question.
Hopefully, you will get more expert advice from one
of the more on-topic newsgroups.

 

[Michael A. Terrell]

Ken, good quality CRTs are going for next to nothing on eBay and
just about everywhere else. With a little searching (e.g. company
moving/going out of business/etc sales are great for this) you should
be able to knock that $250 down to under$100. Trying to increase
the bandwidth on your existing CRT will cost MUCH more in
component cost and soldering time.

There are literally tons of free, good used monitors out there for
the asking. I picked up seven of them last Thursday at one place. They
were the last items from this year's upgrades. That office maintains a
little over 1000 PCs all over the county, and replaces 200 older working
systems every year, along with some upgrades. I requested 100 complete
computer systems from next years upgrades and was told they would call
me when they started again in the fall.



One of the monitors I picked up is a HP 1130 Professional Monitor
which is a 21" monitor:

Featuring cutting-edge FD Trinitron® technology, the HP p1130 CRT
monitor delivers the ultimate in image quality and user comfort. With
resolutions up to 2048 x 1536 and no image flicker, this monitor is
ideal for graphics-intensive applications including desktop publishing,
design, engineering, software development, image processing, and digital
content creation as well as general office applications such as
spreadsheets and presentations.

(The above excerpt from the HP website file: hpP1130DataSheet.pdf)

BTW: It also has a second video input and front panel switch to use
it with two computers or video cards. I will be using it to write code
on so I can display more information at once.





--
Service to my country? Been there, Done that, and I've got my DD-214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[Gene E. Bloch]

My 19" Viewsonic A90's vertical refresh rate peaks out@ 100 Hz for a
resolution of 1024 x 728. For stereo 3-D video viewing purposes, I need it
to display at this resolution at a bare minimum vertical refresh rate of
approximately 120 Hz (though preferabley when I get another monitor, at about
170 Hz). I could go out and buy another 19" monitor which purports to be
able to achieve the former for only about $250 (CAD) right now; in which case
the current CRT monitor will be gently laid to rest. So since it no longer
matters what happens to my present CRT monitor since I'm going to replace it
anyway, can I ask: Is there any way to over-ride the monitor's built in
refresh rate limitations (e.g. by tweaking some knobs at the back, or even
inside, or by making simple modifications to a component(s) -only of course
with the guidance and asistance of a licensed monitor technician due to
obvious safety reasons)? Aside from the risk of electrocution to those who'd
be foolhardy enough to attempt such an undertaking on their own without the
proper training and qualifications to go inside a monitor, is it in any way
technically feasible, given the right personnel, and done cautiously and
gradually (much like a CPU overclocker takes a high risk gamble with the
investment in his PC) to raise the monitor's refresh rate a little beyond
factory default and (say, if given extra cooling) be able to keep it there
indefinitely?

Sorry if my words above haven't come out quite right. It's late and I'm a
little punchy at the moment.

TIA,
Ken

Another thought: is there a video card that would be able to create the
desired signal?

One might have to hack the video card's firmware as well as the
monitor's.

Sounds like fun to me...well, maybe not.

Just curious -
Gino

 

[Phil Weldon]

'Ken Moiarty' wrote, in part:
| My 19" Viewsonic A90's vertical refresh rate peaks out@ 100 Hz for a
| resolution of 1024 x 728. For stereo 3-D video viewing purposes, I need
it
| to display at this resolution at a bare minimum vertical refresh rate of
| approximately 120 Hz (though preferabley when I get another monitor, at
| about 170 Hz).
..
| Is there any way to over-ride the monitor's built in refresh rate
limitations
| (e.g. by tweaking some knobs at the back, or even inside, or by making
| simple modifications to a component(s) -only of course with the guidance
| andasistance of a licensed monitor technician due to obvious safety
| reasons)?
_____

Your question posted is 'Can one "overclock a CRT monitor's video input
bandwidth?' with the qualification of 'Need slightly higher refresh rate
than by existing CRT allows...'.

First, changing the VERTICAL refresh rate changes the HORIZONTAL rate. The
horizontal rate for 1024 X 728 at 100 Hz vertical refresh is just a bit more
than 728 X 100 = 72,800 Hz; the horizontal rate for 1024 X 728 at 120 Hz
vertical refresh is just a bit more than 728 X 120 = 87,360. The real
limiting factor is the horizontal rate, it is a high power circuit that
drives magnetic coils to sweep the electron beam from side to side. The
same circuit also develops the high voltage (15,000 to 20,000 volts) power
to accelerate the electrons toward the screen.

So it is not just the frequency response of the video amplifiers, which,
except for the final driver stages, run on milliwatts. It is a question of
the horizontal sweep circuits that account for 90% of the power used by a
CRT monitor. It is not a question of cooling, it is not like overclocking a
CPU or display adapter - it is more like trying to drive a Trabant at
autobahn speeds.

You might try 1280 X 720 at 120 Hz; 720 X 120 = 86,400 Hz horizontal sweep
rate, a bit lower than 1024 X 120 Hz. I tried this setting on my Viewsonic
A95f 19" monitor (I had to uncheck the 'Hide modes this monitor cannot
display' box on the 'Monitor' Tab reached clicking on the 'Advanced' button
on the display properties sheet. It works at 1280 X 720 at 120 Hz, though
the screen needs quite a bit of adjustment and the images are not as good as
on the same monitor at 1600 X 1200 at 85 Hz.

You can also run the display card/monitor at a lower vertical resolution say
960 X 600 at 120 Hz; 600 X 120 Hz = 72,000 or 1088 X 612 at 120 Hz; 612 X
120 = 73,440. Both of these resolutions have lower horizontal refresh rates
at 120 Hz than 1024 X 768 at 100 Hz. (Uncheck the box 'Hide modes this
monitor cannot display.

My Viewsonic is protected from unreasonable horizontal rates - at a setting
of 1024 X 768 at 120 Hz no image displays until after the 15 second time out
and the display adapter reverts to the previous good resolution and vertical
refresh rate. I assume your model is also, so give it a try, and let us
know the results.

Phil Weldon


| My 19" Viewsonic A90's vertical refresh rate peaks out@ 100 Hz for a
| resolution of 1024 x 728. For stereo 3-D video viewing purposes, I need
it
| to display at this resolution at a bare minimum vertical refresh rate of
| approximately 120 Hz (though preferabley when I get another monitor, at
| about 170 Hz). I could go out and buy another 19" monitor which purports
to
| be able to achieve the former for only about $250 (CAD) right now; in
which
| case the current CRT monitor will be gently laid to rest. So since it no
| longer matters what happens to my present CRT monitor since I'm going to
| replace it anyway, can I ask: Is there any way to over-ride the monitor's
| built in refresh rate limitations (e.g. by tweaking some knobs at the
back,
| or even inside, or by making simple modifications to a component(s) -only
of
| course with the guidance and asistance of a licensed monitor technician
due
| to obvious safety reasons)? Aside from the risk of electrocution to those
| who'd be foolhardy enough to attempt such an undertaking on their own
| without the proper training and qualifications to go inside a monitor, is
| it in any way technically feasible, given the right personnel, and done
| cautiously and gradually (much like a CPU overclocker takes a high risk
| gamble with the investment in his PC) to raise the monitor's refresh rate
a
| little beyond factory default and (say, if given extra cooling) be able to
| keep it there indefinitely?
|
| Sorry if my words above haven't come out quite right. It's late and I'm a
| little punchy at the moment.
|
| TIA,
| Ken
|
|

 

[Jasen Betts]

Another thought: is there a video card that would be able to create the
desired signal?

I can dial up pretty much any sync rate I could desire from mine

I'm not sure if S3 was the first to come out with programmable clock chips,
(in the early 90s) but now pretty-much all video cards allow the pixel clock
to be varied in reasonably small increments (smaller than 1%), and the
horizontal and vertical clocks are derived from the pixel clock and provide
a further opportunity to fine-tune the sync rates.

One might have to hack the video card's firmware as well as the
monitor's.

SVGATextMode (a neat linux app to tweak video clocks for text mode displays)
can be compiled for dos (with a little work). nothing much else uses the
card's firmware...

Sounds like fun to me...well, maybe not.

Bye.
Jasen

 

[Ken Moiarty]

Well I think I get the gist of the answer to my query: "There's no point".
Based on all (which I didn't know until now) that would be involved, I can
of course only agree.

Thanks all,
Ken

 

[Phil Weldon]

'Ken Moiarty' wrote:
| Well I think I get the gist of the answer to my query: "There's no point".
| Based on all (which I didn't know until now) that would be involved, I can
| of course only agree.
_____

Thanks for replying. Do try one of the modes I suggested and let us know
your results with the Viewsonic A90.

Phil Weldon

| Well I think I get the gist of the answer to my query: "There's no point".
| Based on all (which I didn't know until now) that would be involved, I can
| of course only agree.
|
| Thanks all,
| Ken
|
|

 

[Ken Moiarty]

For resolution 1280 x 1024 my CRT monitor maxes out @ 85 Hz vertical
refresh rate. Any higher refresh rate for this resolution and my monitor
gives me a basically blank screen containing the message "signal out of
range". I wait 15 seconds after that and the setting then returns to what
it was previously. 1280 x 1024 @ 85 Hz used to work just fine for me, until
I had to move out of my rented living accomodations, and into a house that I
actually co-own together with my sister since several years back.
Now, to answer your questions regarding trying the different settings,
first a preamble: In case you hadn't followed the other thread I posted in
this group, I need to explain: This house is located as close as any house
can be legally built to a major (three tower wide) high-voltage powerline
easement. In fact part of the easement spills right into my property. The
60 Hz AC current in these powerlines generates a weak, but significant
oscillating magnetic field which is just strong enough to distort and
disrupt CRT image performance that is not running at the same frequently of
60 Hz. That's is okay for viewing TV video (especially since one obviously
cannot typically change one's TV refresh rate from its factory preset of 60
Hz, even if one wanted to), but is kind of bothersome for the up close
viewing as when using a computer monitor. Thus I actually bought an LCD
monitor to side step this PL interference problem entirely for my daily
computer tasks. Anyway, back to the subject... In an effort to counter the
PL interference, I've experimented by temporarily setting my monitor to
(unacceptably) low resolution settings (e.g. 640 x 480) so as to be able to
achieve and test much higher refresh rates. What I've discovered is that at
refresh rates of around approx. 120 Hz and above, the interference on the
screen diminishes to a level that is barely perceptible.
While there is no CRT interference experienced at the 60 Hz setting, 60
Hz refresh rate is not acceptable for my main purpose here, in which, I'm
aiming be able to view high-quality, high-resolution, stereo 3-D
video --i.e. employing LCD shutter-glasses, etc. (My other purpose is to
use this CRT along side my LCD as a second monitor providing for an extended
Windows desktop.) High-quality, high-resolution, Stereo 3-D video will
actually require refresh rates of something above 120 Hz (e.g. 130 to 144
Hz) at resolutions ranging from 1024 x 768 up to 1280 x 1024. However, the
highest refresh rate I can achieve at a resolution that is the bare minimum
acceptable for my purposes here (i.e. 1024 x 768) is only 100 Hz. (BTW,
further to the above paragraph, 100 Hz provides some, although inadequate,
improvement in noticeable interference compared to the 85 Hz setting.) Of
course 100 Hz is far short of the > 120 Hz refresh rates I'm going to need
here.

Now just to be clear here, I have in fact accepted the fact that in
order to get the kind of "high refresh rate to high resolution" performance
I'm after here I'm simply going to have to buy a good monitor that offers
this capability. In other words, I'm no longer entertaining the
"overclocking of my existing CRT monitor" idea. One monitor model
I'm thinking at the moment of possibly getting is a "22" (20" viewable)
iiyama HM204DT. It's video input bandwidth is 390 MHz. Displays 1280 x 1024
at 133 Hz... MSP: $699 USD. Hoping to find _equivalent_ (of at least as
good, if not better, value) alternative CRT products/models so that I can
at least do some comparison shopping here before taking the plunge. I'm
open to product suggestions from anyone here in this vein...

Ken


PS: Someone, I forget who, suggested that my monitor "resolution to
refresh rate" options were limited perhaps not by the monitor itself, but
by, either, my adapter card or its default settings (which supposedly, I
guess, might not occur to some people to change). This is not the case. I
have explored all the valid settings that my adapter provides. And while
it's hardly a very expensive adapter, according to its specs it is capable
of displaying, for example 1024 x 768 @ 150 Hz. If the monitor could only
keep up, such a setting would basically suffice.
Of course, to find an adapter card capable of displaying the higher
resolution of 1280 x 1024 at such a desired high refresh rate poses no
concern to me in any way, as such high performance adapter cards are, both,
quite affordable, as well as easy to shop for. Still, no use in buying one
of these until I get a CRT monitor that is capable of taking advantage of
the performance parameters which my choice of new adapter card will be
intended to support.

TIA,
Ken

 

[Phil Weldon]

'Ken Moiarty' wrote, in part:
| For resolution 1280 x 1024 my CRT monitor maxes out @ 85 Hz vertical
| refresh rate.

My Viewsonic A95f ALSO maxes out at 85 Hz for 1280 X1024. BUT, it will do
1280 X 720 @ 120 Hz. I suggested you try that resolution and vertical
refresh rate with your Viewsonic A95 as a temporary workaround for 3D.

As for the effect of the high tension lines, without knowing what you see on
your screen, if what you see is a faint rolling bar, I'd have to guess that
it is not the magnetic field of the lines, but the interference induced in
your house AC feed, or even in the house wiring.

Phil Weldon


| For resolution 1280 x 1024 my CRT monitor maxes out @ 85 Hz vertical
| refresh rate. Any higher refresh rate for this resolution and my monitor
| gives me a basically blank screen containing the message "signal out of
| range". I wait 15 seconds after that and the setting then returns to what
| it was previously.

 

[Gene E. Bloch]

Now that you mention stereo...

I have seen reference recently to a new LCD panel design allowing for
viewing stereo directly by what seems to be an analog of the stereo
photos that use a grid of cylindrical lenses in front of a still photo,
where the left and right pictures are successive vertical stripes, and
the grid of lenses directs the appropriate stripe's data to the 'right'
eye.

I forget where I saw it or who was working on it; maybe Samsung.

The bottom line is that maybe this kind of display would have milder
refresh requirements for stereo viewing.

The bad thing is I have no idea if this is already happening or still
being developed.

Gino

PS. The LCD I mention doesn't use lenses, but physical barriers that
prevent one eye from seeing the pixels intended for the other eye.

PPS. I was one of those who mentioned possible limits on the video
card's capabilities. I admit that it was speculation on my pert - sort
of trying to be a messenger of doom and gloom, I guess

On 4/21/2006, Ken Moiarty posted this:

 

[Ken Moiarty]

'Ken Moiarty' wrote, in part:
| For resolution 1280 x 1024 my CRT monitor maxes out @ 85 Hz vertical
| refresh rate.

My Viewsonic A95f ALSO maxes out at 85 Hz for 1280 X1024. BUT, it will do
1280 X 720 @ 120 Hz. I suggested you try that resolution and vertical
refresh rate with your Viewsonic A95 as a temporary workaround for 3D.

Okay, I'm trying the 1280 x 720 @ 120 Hz as we speak. It works. I wasn't
motivated to try it at first as 1280 x 720 resolution is video wide screen
(16:9 aspect ratio) format and as far as I'm aware (at least at this stage
in my pursuit of stereo 3-D video), most (if not all) high-resolution stereo
3-D video content available is from IMAX film productions which match the
video standard (4:3 aspect ratio) screen format.

As for the effect of the high tension lines, without knowing what you see
on
your screen, if what you see is a faint rolling bar,

No, no... Nothing like that.

I'd have to guess that
it is not the magnetic field of the lines, but the interference induced in
your house AC feed, or even in the house wiring.

Well I've explained this to once skeptical others before you, times too
numerous to recount. Let's just say here that if it can't be the
oscillating magnetic field from the power lines -which, by the way, produces
other interesting effects around the house, like bright blue 'star-like'
arcing between the aluminum soffit panels which can be seen any evening
after dark (a soffit grounding * issue I have yet to have repaired)- then
the local city engineers who've seen to it that it be required by law that
the aluminum gutters, the aluminum window frames, the sheet-steel
central-heating ducts, and all other significant metallic surfaces of houses
such as mine (i.e. those being right next to such major powerlines), * must
have special grounding, don't know what they're doing. (Of course, I mean
this remark tongue-in-cheek.)

* {Being that it is oscillating, not unlike that created mechanically by
the rotating permanent-magnet containing armature of a generator, this
magnetic field from the PL is capable of inducing currents in these close
proximity metallic forms. These in turn can pose a fire hazard due to
inevitable charge buildup and the arcing that results in the absence of
effective special-purpose grounding to drain off this charge buildup. Now,
while having described why how this is so, the induction of electrical
current in metal surfaces is _not_ the same process that is responsible for
the oscillating magnetic field's interference with my CRT monitor (which is
actually due to its having a _direct_ influence on the CRT's electron-beam
trajectory, which thereby adds to, or 'contaminates', the otherwise
delicately synchronized and cleanly precise internal control of said beam's
scanning of the phosphor screen), it illustrates just how actually
significant the oscillating magnetic field originating from these powerlines
in fact is, at this close range.}

Ken

 

[Ken Moiarty]

Yes, I've read about this technology. Apparently it has been developed well
enough (as of a while ago already) to produce LCD monitors capable of
displaying full stereo 3-D video without requiring the wearing of
shutter-glasses by the viewer(s). This is done with with the use of these
cylindrical lenses as you describe, which are called if I recall,
"lenticular lenses". Lenticular lenses, if I understand correctly, have
been used with still images for many years now, for example, producing 3-D
or "holographic" images as are common on credit cards, driver's licenses,
Microsoft software security logos, etc...etc... You can actually buy
software that will enable you to print images in such a way that when you
accurately affix the associated special plastic lenticular lens sheet over
top of the printed image, it will then appear in 3-D.) In the case of the
3-D LCD panels, as you describe, lenticular lenses are placed over
corresponding alternating "left field" and "right field" LCD columns. If I
recall the only major hurdle left to overcome has been figuring out how to
market it to the masses so enough people will want to buy it in order that
it can be manufactured on an economy of scale large enough such that it can
be priced just right in order to generate the consumer demand for it to make
it profitable... (A common catch-22 of marketing to consumers many a novel
invention/technology, I would think.)

Ken

 

[J. Clarke]

Yes, I've read about this technology. Apparently it has been developed
well enough (as of a while ago already) to produce LCD monitors capable of
displaying full stereo 3-D video without requiring the wearing of
shutter-glasses by the viewer(s). This is done with with the use of these
cylindrical lenses as you describe, which are called if I recall,
"lenticular lenses". Lenticular lenses, if I understand correctly, have
been used with still images for many years now, for example, producing 3-D
or "holographic" images as are common on credit cards, driver's licenses,
Microsoft software security logos, etc...etc...

Lenticular screens produce a kind of 3d effect but it is different from a
hologram. The images that are used as security features on credit cards
are usually holograms--I'm not sure what Microsoft is using but the
presence of shadows suggests lenticular.

Lenticular screens were around when I was a kid, before the laser had been
invented. Holograms came along later--I made some as a senior physics
project. In the art world the lines between them are not distinct, in the
physics world they are very clear.

 

[Andre Majorel]

"overclocking of my existing CRT monitor" idea. One monitor model
I'm thinking at the moment of possibly getting is a "22" (20" viewable)
iiyama HM204DT. It's video input bandwidth is 390 MHz. Displays 1280 x 1024
at 133 Hz... MSP: $699 USD.

Think carefully before buying an Iiyama 22" CRT monitor. I've
owned the A201HT and the HA202-DT and a colleague has a
something-203-something. All three are somewhat blurry at
1600 x 1200 due to convergence problems. I was unable to correct
this through the OSD.

Their 19" CRT monitors are OK. Their 22" CRT monitors look good
on paper (good specs for the money) but your eyes might not like
them.

hardware.fr recently tested three CRT monitors : the Philips
109B60 (19"), ViewSonic P227FB (21") and Iiyama MA203DT (22").
They found the same thing I did ; the Iiyama is blurry. They
recommended the ViewSonic.

http://www.hardware.fr/articles/613-1/der-der-comparatif-crt.html
http://www.behardware.com/articles/613-1/the-last-crt-survey.html

 

[Jasen Betts]

Yes, I've read about this technology. Apparently it has been developed well
enough (as of a while ago already) to produce LCD monitors capable of
displaying full stereo 3-D video without requiring the wearing of
shutter-glasses by the viewer(s). This is done with with the use of these
cylindrical lenses as you describe, which are called if I recall,
"lenticular lenses". Lenticular lenses, if I understand correctly, have
been used with still images for many years now, for example, producing 3-D
or "holographic" images as are common on credit cards, driver's licenses,
Microsoft software security logos, etc...etc...

No, not those 3d images those are real holograms produced using laser
photography, and mass produced using a photographically etched stamp and a
layer of metal, the images have a prismatic effect producing all the
coulours of the rainbow dependant on viewing angle and lighting conditions..

the 3d images produced using the lenticular grating are fabricated using
specially textured layer of plastic with a specially formatted image printed
using ordinary ink on ordinary paper behind it. they are about 1mm thick.
often the images are cartoon-like drawings and appear with real colours.

You can actually buy
software that will enable you to print images in such a way that when you
accurately affix the associated special plastic lenticular lens sheet over
top of the printed image, it will then appear in 3-D.)

In the case of the

3-D LCD panels, as you describe, lenticular lenses are placed over
corresponding alternating "left field" and "right field" LCD columns.

could a sheet be placed over the front of a regular LCD display.
with 24-bit-per-pixel video each colour bar is individually
addressible (in its own byte) which simplifies the software.
it'd just be a matter of calibration, and apropriate drivers then.

I realise that if the lenticular sheet is integral it reduces those sort of
hassles, but it seems to create a demand an entry level solution might work
better.

Bye.
Jasen

 

[Gene E. Bloch]

Lenticular screens produce a kind of 3d effect but it is different from a
hologram. The images that are used as security features on credit cards
are usually holograms--I'm not sure what Microsoft is using but the
presence of shadows suggests lenticular.

Lenticular screens were around when I was a kid, before the laser had been
invented. Holograms came along later--I made some as a senior physics
project. In the art world the lines between them are not distinct, in the
physics world they are very clear.

Thanks, John, for adding this clarification to the discussion.

I just looked at two MS installation CDs. Their top surfaces are quite
clearly holograms. I don't seem to have any MS stickers on the boxes or
anywhere else I can find them right now, so I can't comment about them.
I recall that they are holograms, but can't verify that.

What I read about the stereo LCD monitors included diagrams showing
that the videos for the two eyes were separated by opaque strip
barriers, not controlled by cylindrical lenses.

BTW, Ken, "lenticular" just means "lens-shaped", although it could just
as easily mean "bean shaped" , since "lens" comes directly from the
Latin word for lentil. The term might have been "lenticular ridges" or
some such... Someone said "lenticular grids" somewhere in this thread,
I think. Sounds good to me.

Gino

Please forgive me if this is a second posting - the original (four
hours ago) seems to have evaporated into cyberspace.
-- Actually, my bad. I just learned something about Follow-up to

alt.comp.hardware.overclocking,rec.video.desktop,sci.electronics.misc,sci.electronics.repair

 

[Richard Crowley]

Gentlemen,
This discussion was NEVER even remotely on-topic for the
rec.video.desktop newsgroup (which is about television editing)
And it has gone far afield from even the original inappropriate topic.

PLEASE remove rec.video.desktop from further postings.
Keep Usenet usenet discussions in their appropriate newsgroups
for everyone's benefit.

Thank you very much.