Japanese Color TV set without a tricolor tube

[Charlie]

I think this particular set was discussed here on AK a couple years back. Not quite sure what to use in the search field to locate the thread.

[andy]

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[frenchy]

Originally Posted by andy

This is slightly off topic, but shows that color displays that use a B/W CRT are still around. This JVC professional monitor uses an LCD as sort of a solid state color wheel.

Hmm if you look at their 1st catalog for this set there, it shows the b/w monitor, then the 3 color filters stacked on top of it, with the 2 lcd shutters layered between the filters. I don't get how this works - the filters are all stacked so the light has to go thru ALL of them? How the heck do you just get red, or just blue? (with a wheel, it only has to go thru one color at a time). How do the shutters work, obviously they can't shut light off completely, or just the first shutter would result in no picture. Are the shutters divided into pixels, or is it just a solid pane shutter that goes from clear to black? Can anybody explain how this thing works? thanks...Frenchy

[old_tv_nut]

I suspect the 3 color filters are not plain red,green blue, but are polarized somehow - one LCD then switches transmissions between red and cyan, and the other between blue and yellow.
Red+yellow --> red
cyan+yellow--> green
cyan+blue--> blue
red+blue - not useful - black or nearly so

[andy]

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[frenchy]

Originally Posted by old_tv_nut

I suspect the 3 color filters are not plain red,green blue, but are polarized somehow - one LCD then switches transmissions between red and cyan, and the other between blue and yellow.
Red+yellow --> red
cyan+yellow--> green
cyan+blue--> blue
red+blue - not useful - black or nearly so

But how can you get only cyan+yellow, if red is inline with the other two filters? Dito on the other combinations. Their graphic shows all three filters stacked on top one another in front of the crt face.

[trinescope]

I'm the one who posted about this set a few years back here and on antiqueradios.com. I still have it and it is in working condition, but is missing the knobs, the two woodgrain escutcheons, and the red Mitsubishi light-up logo below the channel selector knob. The picture shown at the top of the thread is a smaller version of the set I have; I guess the "viewing window" was widened a bit soone could view the set slightly off axis. This set uses series-string vacuum tubes; the chassis sits vertically on the right-hand side. The three CRTs have red, green, and blue phosphors; no color filters are used. Like someone just said, it produces a bright picture, and I'll add to that a Technicolor-like vividness to the color. The downside is the small (5-6") picture; but Mitsubishi provided a plastic Fresnel lens to mount in front of the window as a magnifier. The set appears to have been made in 1964 since many parts in the set have a 1964 date code. I doubt these were ever sold in the US in great number as the tricolor CRTs had already existed for years, and the trinescope, at least to me, appears to be a bit Rube Goldberg-ish in comparison.