[BRAND
SPECIFIC][TOSHIBA][MISC]
540P Upconversion in 2001-2002 Toshibas
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June 2003 Report (540p Fixed!)
| July 2002 Report | January 2002 (Original Report)
The saga with the 540P up-conversion on 2001-2002 model year Toshiba RPTV's and what
all the fuss is about. Pictures tell the story and I will use test patterns to first
illustrate what is the problem with this 540P up-conversion that Toshiba has implemented
this year.
The two sets used for the demonstration purposes are a fully calibrated 47"
Panasonic PT-47WX51C (without protective screen) and a 65" Toshiba 65HX81 on the
showroom floor which I had just finished fully calibrating … although I did not take
the protective screen off. This simply means a few more reflections where the Toshiba is
concerned.
I start off by using the AVIA test disc and the resolution chart 200 TVL for this
demonstration.
This is the 6.75 MHz pattern as displayed by the Panasonic. Note that the lines in the
"oval" pattern are very distinct. The set has very good high resolution detail
and will show the maximum detail that the DVD has to offer. 6.75 Mhz is equivalent to 540
horizontal lines per picture height. (80 lines per 1 Mhz.)
Next up is the same shot for the Toshiba 65" set.
Here is the same "6.75 MHz oval" as seen on the Toshiba. Note the reflections
off the "anti-glare" screen. Please note that the fine vertical lines you seen
in the oval are actually the lenticular ribbing of the lenticular screen and are not a
part of the image. You can see the real lines on the edges of the oval and how they appear
… and then are pretty much blotched out. It varies a bit between TV sets and on some,
you see hints of the lines that should be there. So the high resolution detail from your
DVD's gets filtered out or masked by the TV. Not so good.
Now we move onto the 4.18 MHz pattern on the same resolution chart. For those keeping
track, this is the 334 lines of resolution range…NTSC over the air transmission
limit. This is the image from the 47" Panasonic. The diagonal lines are clean and the
oval is fairly devoid of artifacts. There is no reflection as the reflective screen has
been restacked.
The next image is the same 4.18 MHz pattern, but from the Toshiba 65". It is easy
to differentiate the two sets due to the "anti-glare" screen. Notice anything
interesting here? What are those horizontal bands of interference doing there in the
diagonal lines?
Now I move back a bit a present a cut off screen shot of the 16:9 resolution
chart from AVIA. The upper right corner circle is the 3.58 MHz circle representing about
290 lines of horizontal resolution. The horizontal bands are still there. In the top left,
you have the 3.0 MHz circle representing 240 lines.
Bottom line, I sincerely hope that Toshiba is aware of this problem and that the next
generation of RPTV's will have overcome this very noticeable deficiency/flaw in the way
they do the 540P up-conversion.
Regards
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