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What is DLP?

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Anonymous
May 8, 2004 11:48:11 PM

Archived from groups: alt.video.digital-tv (More info?)

In what way, if any, this DLP different or better than digital and hdtv?

More about : dlp

Anonymous
May 8, 2004 11:48:12 PM

Archived from groups: alt.video.digital-tv (More info?)

"Wishy13764" <wishy13764@aol.com> wrote in message
news:20040508154811.26879.00000742@mb-m19.aol.com...
> In what way, if any, this DLP different or better than digital and hdtv?

Try http://www.dlp.com/#Scene_1 for starters. Click on the little picture
under What is DLP Technology?

DLP is a means to produce the images, regardless of the source, so it needs
to be compared to other display
technologies, such as the CRT, LCD or plasma displays, all of which can
render digital TV, both standard and HD.
Most digital display devices can also make a picture from an analog source;
they convert it to digital internally, but
the best pictures are digital the whole way -- no conversions.
Anonymous
May 9, 2004 4:28:03 PM

Archived from groups: alt.video.digital-tv (More info?)

"Wishy13764" <wishy13764@aol.com> wrote in message
news:20040508154811.26879.00000742@mb-m19.aol.com...
> In what way, if any, this DLP different or better than digital and hdtv?

DLP is a display technology - in just the same way that CRTs, Plasmas,
Liquid Crystal Displays are. It is not something you can compare directly
to "digital" or "HDTV"

HDTV is High Definition Television and describes a higher resolution (i.e.
sharper, clearer etc.) picture than normal NTSC, orPAL (and standard
definition digital) systems. Most modern HDTV systems are also digital, but
not all digital TV systems are high definition.

You can transmit normal standard definition signals over digital (as is the
case with a lot of digital satellite and digital cable systems) Digital
systems have quite a lot of advantages over analogue TV systems, and a few
disadvantages.

DLP systems work by having a small "chip" covered in thousands of tiny
mirrors. Each mirror can be independently moved to reflect light from a
light source, which can then be projected onto a screen. If only one DLP
chip is used then colour is created by spinning a disc with red, green and
blue filters in the light path.

In other words you can use DLP, CRT, LCD, Plasma etc. to watch HDTV or
non-HDTV - and not all DLP,CRT,LCD or Plasma displays are HDTV.
Related resources
Anonymous
May 10, 2004 3:52:28 PM

Archived from groups: alt.video.digital-tv (More info?)

"Stephen Neal" <stephen.neal@nospam.as-directed.com> wrote in message
news:c7l4k4$j2g$1$8300dec7@news.demon.co.uk...
>
> "Wishy13764" <wishy13764@aol.com> wrote in message
> news:20040508154811.26879.00000742@mb-m19.aol.com...
> > In what way, if any, this DLP different or better than digital and hdtv?
>
> DLP is a display technology - in just the same way that CRTs, Plasmas,
> Liquid Crystal Displays are. It is not something you can compare directly
> to "digital" or "HDTV"
>
> HDTV is High Definition Television and describes a higher resolution (i.e.
> sharper, clearer etc.) picture than normal NTSC, orPAL (and standard
> definition digital) systems. Most modern HDTV systems are also digital,
but
> not all digital TV systems are high definition.
>
> You can transmit normal standard definition signals over digital (as is
the
> case with a lot of digital satellite and digital cable systems) Digital
> systems have quite a lot of advantages over analogue TV systems, and a few
> disadvantages.
>
> DLP systems work by having a small "chip" covered in thousands of tiny
> mirrors. Each mirror can be independently moved to reflect light from a
> light source, which can then be projected onto a screen. If only one DLP
> chip is used then colour is created by spinning a disc with red, green and
> blue filters in the light path.
>
> In other words you can use DLP, CRT, LCD, Plasma etc. to watch HDTV or
> non-HDTV - and not all DLP,CRT,LCD or Plasma displays are HDTV.
>
>

Spinning disk? As in Nipkow disk? It's last gasp was thought to be during
color tv development - almost 60 years ago.
Anonymous
May 10, 2004 4:24:24 PM

Archived from groups: alt.video.digital-tv (More info?)

> DLP systems work by having a small "chip" covered in thousands of tiny
> > mirrors. Each mirror can be independently moved to reflect light from a
> > light source, which can then be projected onto a screen. If only one DLP
> > chip is used then colour is created by spinning a disc with red, green
and
> > blue filters in the light path.
>
> Spinning disk? As in Nipkow disk? It's last gasp was thought to be during
> color tv development - almost 60 years ago.
>
>
Shot my mouth off before getting all the facts. Single DLP chip - color
wheel. Not a disk with two lines of holes arranged in a tightening spiral
towards the disk's center.
Anonymous
May 11, 2004 12:14:34 AM

Archived from groups: alt.video.digital-tv (More info?)

Yes...but you weren't too far off anyway.

Single chip DLP projection systems are a compromise. By all rights, there
should be 3 DLP chips...which are used in larger (more $$$) DLP projectors;
however, to save $$$, they use a single chip and a synchronized filter wheel
to produce a full color image. With today's faster, high tech motors,
synchronizing is more accurate and works pretty well; however, there are
still some artifacts and if that motor ever has problems...well, you can
imagine. I haven't seen a single chip DLP that looked as good as the better
CRT projection systems.

"Antwarp" <virihater@large.net> wrote in message
news:c7oabq020g0@enews2.newsguy.com...
> > DLP systems work by having a small "chip" covered in thousands of tiny
> > > mirrors. Each mirror can be independently moved to reflect light from
a
> > > light source, which can then be projected onto a screen. If only one
DLP
> > > chip is used then colour is created by spinning a disc with red, green
> and
> > > blue filters in the light path.
> >
> > Spinning disk? As in Nipkow disk? It's last gasp was thought to be
during
> > color tv development - almost 60 years ago.
> >
> >
> Shot my mouth off before getting all the facts. Single DLP chip - color
> wheel. Not a disk with two lines of holes arranged in a tightening spiral
> towards the disk's center.
>
>
Anonymous
May 11, 2004 3:02:13 AM

Archived from groups: alt.video.digital-tv (More info?)

"Antwarp" <virihater@large.net> wrote in message
news:c7o8g601ud3@enews2.newsguy.com...


< snip >


> Spinning disk? As in Nipkow disk? It's last gasp was thought to be during
> color tv development - almost 60 years ago.

Not quite. The spinning disk is a color wheel for field-sequential color.
It was CBS Labs' system of choice around 1950. NASA used this method for at
least some of the color video cameras that went to the moon. The image
scanning is electronic, so the disk is not modeling the Nipkow method.
Anonymous
May 11, 2004 3:29:28 PM

Archived from groups: alt.video.digital-tv (More info?)

Sal M. Onella wrote:
> "Antwarp" <virihater@large.net> wrote in message
> news:c7o8g601ud3@enews2.newsguy.com...
>
>
> < snip >
>
>
>> Spinning disk? As in Nipkow disk? It's last gasp was thought to be
>> during color tv development - almost 60 years ago.
>
> Not quite. The spinning disk is a color wheel for field-sequential
> color. It was CBS Labs' system of choice around 1950. NASA used this
> method for at least some of the color video cameras that went to the
> moon. The image scanning is electronic, so the disk is not modeling
> the Nipkow method.

Yep - the use of colour sequential scanning on the colour Apollo material is
apparent on fast movement - such as when the top of LEM took off to return
to the orbiting Command Module - the bits of material flying off in all
directions split up into R,G and B bits!

In the UK Wireless World ran an article when PAL UHF colour transmissions
started, detailing how to convert a B&W TV to Colour using a colour
sequential disc. It worked by having a PAL decoder that output just Red,
Green then Blue signals on sequential fields to feed the B&W tube (I think -
not frames) which was synced to a motorised disc. The result was a 16.7fps
colour system (albeit with some motion information up to 50fps but with
colour break up!) Pretty much the same system as CBS promoted for display -
though the transmission system was regular PAL (and 2/3 of the colour
information was thrown away)

I'm not an expert on DLP - but AIUI the colour scan rate is at least 3x the
input signal field rate (the motors in higher end single chip units run at
multiple speeds and have 6 segments to allow a higher field rate without the
motor having to spin as fast as a 3 segment - reducing noise) so that no
colour temporal resolution is chucked away. However colour sequential
presentation does introduce artefacts - with some people finding the
"rainbow" artefacts, which become more obvious if you move, quite
objectionable. Of course this is not a function of DLP technology in
itself - you can use 3 DLP chips (just as you can use 3 CRTs or 3 LCDs)

Steve

Steve
Anonymous
May 11, 2004 10:09:40 PM

Archived from groups: alt.video.digital-tv (More info?)

On Sat, 8 May 2004 15:07:19 -0700, "Sal M. Onella"
<salmonella@food.poisoning.org> wrote:

>
>"Wishy13764" <wishy13764@aol.com> wrote in message
>news:20040508154811.26879.00000742@mb-m19.aol.com...
>> In what way, if any, this DLP different or better than digital and hdtv?
>
>Try http://www.dlp.com/#Scene_1 for starters. Click on the little picture
>under What is DLP Technology?

35 trillion colours in the three-chip cinema system? Assuming that's
an American trillion, I calculate that equates to 45-bit colour (15
bits per chip). What do they do with the 16th?

Charlie

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