Return to the archive index

Re: (hardware,hmd)help me,is this correct,Kopin cheap mono320 complete hmd unit

From:
Date: Mon, 2 Jul 2001 01:08:36 +0000

Edward Keyes wrote:

> RS170 is just a fancy term for "black and white NTSC", i.e. ordinary
> television signals.  The effective resolution of TV is about 320x480
> interlaced, or 320x240 at 60Hz, so it's already the right size for
> the QVGA display chips.  Without dealing with color, the driving is
> a lot simpler too, so you can do it very low-power.

Interesting. My PCM-5822 has onboard Chrontel scan converter that 
outputs NTSC or PAL composite video. Do you think that could be 
attached directly to the RS170?

> Depending on your video board, getting this sort of signal might
> be easy or hard.  For instance, on the ipEngine I was able to
> program in the video controller to output the appropriate timings
> for NTSC, and then all you need is a simple op-amp and a few
> resistors to get a monochrome composite signal.  Add a video DAC
> if you want grayscale too.

Assuming that I already have NTSC (color) signal, can any of this
be avoided? 

The above are actually moot questions for me because I'm not 
interested in anything less than 640x480 resolution. I have used
the SVGATextMode "living in text world" and I don't like it. I 
need to have x-windows at VGA resolution. I'm thinking though that
there might be a good trade-off in going with greyscale VGA instead
of color SVGA. Look at the power consumption of Cy-Visor and Sony
PLM-S700, and also the size of driver hardware. If I can reduce 
power down to 200mW by going monochrome, that's a trade-off that 
I'm willing to make. Sounds like the hardware required is also 
simpler/smaller than field sequential color. I'd like to attempt
to do what you did for a VGA mono microdisplay. Any ideas on 
which display part might be good for this?

> Heh heh.  The general pattern is that successfully interfacing to
> a Kopin chip from scratch takes about 3 months and 6 board revisions.
> And for some reason (presently under debugging), our driver board
> only works with older MicroOptical displays, not the ones they're
> currently shipping.  They are *picky* chips.

That's really discouraging. I'll go back to what I said, the industry
needs some interface standards for these microdisplays. Wouldn't it 
be nice if one flexible controller could support different displays 
via software configuration ...

> >BTW Steve, quantity one of RS170 is $500, so you might as well
> >just buy an M1.
> 
> Or a LitEye-B.  Worse optics, but much smaller and lower power.

Is that the one that is $500? 
I think the prices on Micro-Optical and M2 are way too inflated. 
The kopin parts are cheap. The driver hardware is not all that 
expensive either. So people are paying $3k just for optics???
I know these companies are just trying to make a business, but 
they are pricing themselves out of the market. Perhaps the govt
is willing to pay that much, but it will never reach consumers
at that kind of price. If Micro-Optical had color VGA for $1000
they could sell them like hotcakes.

  -- Doug

--
Subscription/unsubscription/info requests: send e-mail with subject of
"subscribe", "unsubscribe", or "info" to 
Wear-Hard Mailing List Archive (searchable): http://wearables.blu.org
please, Please, *PLEASE* don't subscribe through a forward/false domain

+Previous Message in Thread | Next Message in Thread

From Wear-Hard Mailing list Archive (WH)
Maintained by R. Paul McCarty

Archive created with babymail