Technical question about Hitachi CRT RP HDTV

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

In article <41928baf$0$120$65c69314@mercury.nildram.net> "hg" <hg@gh.hg> writes:
>I notice in the specs it says 1280 Horizontal TV lines of resolution. What
>is this referring to? The X axis or the Y axis? Does this mean that its max
>resolution is only in reality 1280x1080 or does this mean that it can
>display more TV lines than the 1080i spec allows?

I suspect that it means that the people who write their web site specs don't
really understand the specifications.

Alan

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

> A TV line is a measure of resolution for an analog display. It is
> defined as a distinct pel along a horizontal line that is a scan line.
> If an analog TV can display 640 black pels alternating with 640 white
pels:
>
> BWBWBWBWBW ... BWBWBWBW
>
> Then it can claim a resolution of 1280 TV lines. In printing and
> photography lines are defined to be a BW pair, so the same physical
> resolution would be called 640 lines.
>
> 1280 TV lines of resolution == 1280 pixels along a scan line.
>
> 1280x720 is the resolution of 720p. It could be stated as:
>
> 1280 TV lines x 720 scan lines.
>
> Matthew
>

Good answer but how does this explain in the same spec where it mentions
1280 TV lines does it also state that the TV can "display more than 90% of
the 1080 HD signal"?
Link -
http://www.hitachi.us/tv/resource/ [...] 51S500.pdf

Hmm, I just checked one of the older models (F series) and in the spec the
above statement has been changed to "display more than 90% of the _vertical_
1080i signal"

So, I was hoping that this TV would display most of the 1920x 1080i signal
but now it turns out it's actually not much better resolution 'real estate'
than a 1280x720 DLP.
I know someone will jump in and say current tranmissions are in fact a
maximum of 1440 horizontal pixels. I'd still like to have a TV can display
true 1920x1080i though.

One way to dispel my doubts. Can anyone who owns a Hitachi CRT RP HDTV set
tell me when connected to a PC and the res is set to 1080i are the
individual pixels visible on the screen when examined closely?
Non-scientific test I'm sure but this is one way of finding out what the TV
is actually capable of.

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

hg wrote:
> I know someone will jump in and say current tranmissions are in fact a
> maximum of 1440 horizontal pixels. I'd still like to have a TV can display
> true 1920x1080i though.

There are very few HD TVs on the market right now that can display the
full 1920x1080 resolution. The RP CRTs are 1080i but as you have noted
from the spec for the Hitachi, the horizontal axis is no more than 1280
lines of effective resolution.

If you want true 1920x1080 your choices are limited to fixed pixel
displays. The new direct view Sharp 45" 1920x1080p LCD started shipping
a month or more ago and is now showing up at Best Buys. It also lists
for a cool 8 grand USD. Samsung has a new 46" LCD out, but the Sharp is
getting much more positive comments. Early next year the 70" Sony SXRD
based RPTV which is 1920x1080 is due to hit the market at $10K list and
the xHD3 DLP sets should be coming out next spring. By this time next
year, we should have a number of 1920x1080 sets on the market but likely
only at the high $ end.

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

666 wrote:
> On Thu, 11 Nov 2004 16:35:16 -0500, Alan Figgatt
> <afiggatt@comcast.net> wrote:
>> There are very few HD TVs on the market right now that can display the
>>full 1920x1080 resolution. The RP CRTs are 1080i but as you have noted
>
>>from the spec for the Hitachi, the horizontal axis is no more than 1280
>
>>lines of effective resolution.
>>
>> If you want true 1920x1080 your choices are limited to fixed pixel
>>displays. The new direct view Sharp 45" 1920x1080p LCD started shipping
>>a month or more ago and is now showing up at Best Buys. It also lists
>>for a cool 8 grand USD. Samsung has a new 46" LCD out, but the Sharp is
>>getting much more positive comments. Early next year the 70" Sony SXRD
>>based RPTV which is 1920x1080 is due to hit the market at $10K list and
>>the xHD3 DLP sets should be coming out next spring. By this time next
>>year, we should have a number of 1920x1080 sets on the market but likely
>>only at the high $ end.
>
>
>
> My computer's Mitsubishi DP930 19" monitor does 1920x1080
>
> bargain prices too

Yes, there are a lot of computer desktop monitors and laptops which
can get to 1080 vertical. Not as many widescreen which get to 1920
horizontal, but they are becoming more common. I am writing this on a
Samsung 213T LCD which is 1600x1200. But these are computer monitors,
not large screen TVs with high refresh rates, scalers, and tuners. I am
surprised that we don't have more LCD TVs with 1920x1080 resolution, but
I expect the need to get to 24 bit color with brighter screens and
higher refresh rate have kept the < 40" LCD flat panel TVs to 1366x768
or lower resolution.

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

Jeff Rife wrote:
> Matthew L. Martin (nothere@notnow.never) wrote in alt.tv.tech.hdtv:
>
>>A TV line is a measure of resolution for an analog display. It is
>>defined as a distinct pel along a horizontal line that is a scan line.
>>If an analog TV can display 640 black pels alternating with 640 white pels:
>>
>>BWBWBWBWBW ... BWBWBWBW
>>
>>Then it can claim a resolution of 1280 TV lines. In printing and
>>photography lines are defined to be a BW pair, so the same physical
>>resolution would be called 640 lines.
>>
>>1280 TV lines of resolution == 1280 pixels along a scan line.
>
>
> Exactly right except for this last line. TV lines of resolution are "per
> screen height", so they are adjusted for the aspect ratio. A 16:9 set
> with 1280 TV lines of resolution can display 2275 "pixels" along one scan
> line.

Excepting, of course, that the FTC has yet to make a rule that defines
anything.

> To be able to achieve full 1080i display, you only need 1080 TV lines of
> resolution...720p requires 720 TV lines of resolution.
>
> The nice this is that this spec works for *any* shape display, and that's
> why it is supposed to be adjusted per screen height. Unfortunately, some
> manufacturers do not do this in their specs.
>

Ask the FTC to fix that problem. Of course that might take another
election before they care.

Matthew

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