Jerome is correct. I quoted a European publication.

Found a Patent that was assigned to JVC by Hughes. This one seems to be more closely aligned to the set under discussion.

http://www.google.com/patents/US3781465

You can get a clearer image at the Us patent office site. go to:
http://patft.uspto.gov/netahtml/PTO/patimg.htm
and enter the number 3781465

old TV nut,

Can't get the viewer to work on my iPad Air. Probably works okay on Windows. If you click on the "download the PDF" on the link I provided, you will get the original document with drawings.

So when you adjust "shutter gains" does the waveform/duty cycle to the liquid crystal cells change, or does the brightness/contrast of the CRT in each color field change?

Who is going to be the first to cut one apart so we can figure out how the JVC color sutter works? :scratch2:
Some questions:

1. 2 or 3 liquid crystal cells in the assembly?
2. RGB or MYC colored filters/cells?
3. External polarized color filters on the liquid crystal cells, or some sort of "colored magic liquid crystal goo" fill in the cells?

jr

I'm not a digital video designer...I just play one on tv...and own one of these things that I keep looking at to figure it out. I need to figure out the difference between a filter and a shutter.

JR...my first use of "RGB shutters" in my text should be more like a "RGB drive" adjustment and needs correcting via Jerome's pix. The RGB should be a filter. His shows two shutters sandwiched in between (probably polarized).

I can see how a 3x modulated RGB tube pushes color through variable density filters but I am missing what the shutters do.

The Hughes patent look similar but only has one polarized shutter.

I have to grab the printout of the block and scan it. Stay tuned.

Well, I may confuse things a bit with a kinda High School science class explanation, but I will take a stab at it:

1. A filter may be as simple as the colored filters used to select a specific portion of a light spectrum, for example a blue filter placed in front of a "white" light source to produce blue illumination.

2. A liquid crystal cell is usually a couple pieces of glass with transparent electrodes (usually tin oxide) arranged in a specific pattern to control the orientation of liquid crystal material that is contained between the two glass pieces, by applying voltage to the electrodes.

3. Color shutters are a combination of LC cells, polarized filters and color polarized filters that can switch the color transmitted by applying voltage to the cell.
Imagine this high school experiment... take 2 pieces of polarized material and observe a "white" light source through the two filters... if you rotate one filter with respect to the other, you will observe a minimum and maximum transmission of light at 90 degrees rotation. If one of the filters is, say blue color polarized material, you will observe a change from white light to blue light as you rotate the filters 90 degrees. Now if instead of mechanically rotating the polarized filters 90 degrees with respect to one another you placed a liquid crystal cell designed to rotate polarized light 90 degrees when voltage is applied to it, you could produce the same optical changes by merely flipping a switch.

jr

Question 1. 3
Question 2. External based on the below comment, however JVC says there are two? polarizers and two shutters? Uncertain here.

From JVC press release: "single electron gun aimed through red light, green light and blue light filters, each separated by a liquid crystal shutter."

Jerome's illustrations were from a JVC brochure.

If you read through the Hughes/JVC Patent, it talks about your other question. It appears that JVC made some enhancements by adding a second polarizer.

The patent has three LC layers. Each one can be made either clear or a primary color (red in one, green in the other, blue in the third) by orienting the liquid crystal dyes perpendicular to the light path (colored) or parallel (clear). I take it that the dye molecules also mainly affect one axis of polarization when they are perpendicular to the light path, so using polarizers makes the color effect stronger.

So, two are clear on any given field and one is a primary (additive) color. This seems to be how the TV works, as the brochure talks about clear states and shows three colors. The brochure also makes the usual illustrator's /printer's mistake of showing the primary images as red and white instead of red and black, etc. This same mistake was made in early illustrations of how the trinoscope worked.

The difference between a filter and a shutter:

Filter states: clear, color (in the patent, the color state is: not transmitting light of two primary colors, but only of one primary color). It is also possible to make filters that would stop one primary color and transmit two, so the three would individually be yellow, cyan, and magenta. Then, to get additive red, green blue, you would have to activate two filters at a time.

Shutter states: clear, black (the color of the color state is black - not transmitting any light of any color).

Got the idea to see what we would see, if I took a slow motion video of the JVC field sequential receiver/monitor with an iPhone 6 plus.

Posted to You Tube. http://youtu.be/GTDpVZWQaFE

You can see the sequential switching going on.

The old trick to seeing the colors is to spread your fingers on one hand and wave them in front of the tube/wheel. You will see the colors.

etype...can you do a high-speed recording? That would record each color for a few frames depending on the speed. Playback would be slo-mo and show each in full.

I believe we did that by accident. I was recording at normal 1080P frame rate, but in slow motion, 240 fps and when the video played back, the first 20 seconds or so was in normal speed, but showed the slow progression from bottom to top of screen of each color, red, green and blue. One color filled the screen and slowly transitioned to the next color. I can post that video if interested.

Great minds accidentally think alike. I think that 20 seconds would show the real progression of RGB across the BW tube. The bottom to top is interesting. Maybe a frame rate collision.

Someone already mentioned the Tektronix NuColor displays. While this thread was sleeping for several months I actually ended up finding one of their standalone models. Give it a modified composite signal and boom, you got color.

http://i11.photobucket.com/albums/a1...d/IMG_8902.jpg

I really gotta take better photos of this thing.

Posted new video with description showing this.
http://youtu.be/sUFFqBhGUgY

...

NU900M

This ebay listing has great pics and a spec sheet.

If OP still has this monitor, I'm curious what its input lag is like, relative to, say, a Trinitron PVM, or even the IDX-5000 Indextron PVM? Mayhaps a test could be conducted with such monitors daisy-chained to all display video from a single composite video source?

The OP is here and still has the monitor in a dubbing rack. I will try to build a comparison in real time via a DA that would feed the monitors. The only other small size set I have might be my KV-5000 via RF. That should be real time. And I will try to add a slo-mo like Marshall just for fun. Stay tuned.

Dave
Didn’t know you had one of these. Congrats. EDIT: Oops, just went further back in this thread and saw your posts.

Here, tech data about the monitor/receiver.
https://visions4netjournal.com/wp-co...c-Sheet-01.pdf

Yep, I bought it a few years ago minus the power supply. An old Gateway PC adaptor now does the DC. The beauty of this, for a field camera op, is that it is so bright in daylight and then the color flickers up on top. It was the perfect 4x3 field monitor in analog glass. As a veteran field cam op I can understand the tuner onboard. A way to show the talent their effort on air in full daylight. And the rest is for us to wonder at.

I keep thinking about if CBS were allowed to compete with RCA back with the debut of color TV which system would prevail today.

Take a guess at the size of a CBS color wheel for a 21" BW tube to be like the 21AXP22 color tube. My Col-R-Tel 10" wheel is 34" across and this is only a 1/4 horse motor. Move grandma back a few feet.

RCA had the right approach. Keep the scan rates the same (well close enough that most users wouldn't have to touch the hold controls), and don't force the system to be mechanical. The opposite of how ATSC was implemented...Screw consumers with working equipment, they're going to have to buy more equipment to keep watching and ATSC 3.0 will eventually be the same ( though if they mandate all new sets after next year have tuners then they can reduce the aggravation 10 years from now).

I mean the RCA system could be implemented mechanically too...The Col-r-Tel was an RCA NTSC modulation standard demodulator and color wheel adapter for monochrome sets (and there was another maker of a similar adapter).

Yes saw that, also Alan DuMont’s demo of a giant color wheel for the 30 inch monochrome set. Mostly hype to disuay folks against the system. TV manufactures did not want to take on RCA for fear of being sued and losing millions. Farnsworth, Philco, Aiken come to mind. CBS made (or had sets made) a few prototypes and a consumer set with self contained color wheels and sets with drums. The 21 inch was the prevailing size for many years, but reflect back on the early projection designs, then modern designs to obtain larger screen sizes. Large cabinets with entertainment centers? Large vertical consoles? Then new tech like the JVC set?