Is kydex a good screen surface for a perf screen?, what thickness

 http://www.diamondman.com/29400.gif 10 % hole
http://www.diamondman.com/29500.gif 8.1% hole
http://www.diamondman.com/29100.gif 9.1% hole



These squared array perforations guarantee the possibility of matching the screen array to the pixel array with unprecedented precision so that on each corner of a pixel there is a hole . For contrast enhancement and to transmit the required 5 channels of sound.


I told you so , it can be done.




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The Artist formerly known as PANARAMAX.....

KBK:


You may end up making paint money after all.


With a 60 by 159 inch screen there would be 1025 holes 1/16 horizontally

by 769 holes Vertically. I know that is 2.65. I like BenHur.


No the reason for the screen aspect ratio is for using a dlp xga with an off the shelf cinema adapter which is 2x . 2x in video yields 2.65 while in film it is 2.35. The compromise should be a 2.5 ratio screen , but that is a different subject.


The first prototype will have to be flat.


I have a body shop with a paint room around the block .


Assumming they can provide this plastic inexpensively I could then have it painted with your dlp finish.


Figuring out the hole spacing for a horisontally curved screen is going to be a *****. It may be nearly impossible for a perfect match because of the pincushion variances.

Further info:

Peter,


Thank you for your interest in Diamond Manufacturing Company - Perforated

Metal Specialists. Per your request, we are sending you some samples. Due to

the fact that the samples we do have available are run-offs of previous

jobs, we are sending the closest we have on hand to what you have specified.


As for the type of perforation and the layout you are asking about, we

request that a drawing (preferably done in CAD) be sent to ensure we clearly

understand what it is you are looking for. As for sheet size, the can be

supplied up to 250" long by 60" wide depending on the perf pattern. For

information on perforated sheet options and tolerances, check out the

following page on our site http://www.diamondman.com/prod.htm.


In addition, we suggest referring to the following page on our web site for

some insight on designing perforated products http://www.diamondman.com/proc.htm. The lower level pages under the section

entitled "factors affecting cost, quality, and delivery" should provide some

direction and clear up some potential questions. NOTE: If this is a small

quantity requirement (ex. under 15 sheets), you may want to consider using

standard size perf sheets stocked by our sister company Perforated Metals

Plus ( www.perf-plus.com ). Stocked sheets cost considerably less than custom

made product.


I hope this is of help. If I can be of further assistance, please feel free

to contact me.


There are some real power buy potentials here.



LUCA: Hello neighboor!


Since DILA has contrast enhancement buit into the matrix.


IE the non active pixel area is black versus DLP's White non active area.


The perforations on my IMAGE ENHANCING DILA SCREEN would be narrow vertical slits that would coincide with the actual pixel elevation alternating every other pixel, on the vertical domain i would skip vertical slits evry two rows and then add horizontal slits that actually matched the pixel width in a repeating pattern of horisontal slits.


Those that help the contrast on DILA? NO, Does it depixelate? NO.


But is the only possible acousticqally transparent screen usable for Flcd and dila. You could put the speakers behind a screen 60" high by 141" wide using a standard 35mm cinemascope adapter, and the screen would look just like a non perforated screen.


These guys can pretty much perforate anything you send them a CAD drawing on.

Hey looks like my Mass Production classes are going to come in handy! In small quantities water perforation is likely less expensive than injection molding. The high initial cost of injection molding comes from the machining of the mold, there is no such cost associated with computer controlled water perforation.


Using plastics for a screen is a brilliant idea! I wonder how the paint will affect the perforations...It would definitely have to be painted and you might need a rough finish for better paint adhesion.


Anyways Kydex would seem like the best option of the plastics they offer on that page, mostly because of its excellent formability when heated. Acrylic and PVC are both thermoplasts so you should be able to heat them and form them. With proper support you could have a Torus CCS-type screen with no elaborate vacuum system! WOW! The hard part would be heating and custom forming such a large surface...


Regards,


Kam Fung

Thanks Kung Fu:


A Torus ray trace design would be ideal. And part of the plan, of course. In fact I have E mailed Don Stewart to colaborate on this.


This is an excerpt of my preliminary design request notes:


"I am looking to place 769 vertical perfs and 1025 horizontal perfs on a 60 x 150 kydex, flat white and degreased to the bone. The holes to be no greater than 1/16 spaced in rows and columns that forms miniature rectangles of a horizontal proportion


60 inches divided by 769 equals. .078 inches. This would be the vertical spacing in between the vertical holes center to center. So the columns would have 769 holes with centers to center (of hole ) dimension of .078.VERTICAL


For the horizontal rows :


150 inches (screen width) divided by 1025 (Holes) is = .147 Horizontal spacing center to center.


This is the preliminary calculation.


Is that possible on a sheet of 3/8 , 5/16?


I need a ball park figure for a prototype.


By matching the pattern array of the pixel to the perforations I will have invented the projection screen of the future."


The above is for a 2.5 aspect ratio screen (the half of 2.65 and 2.35)

This is required to maintain maximum pixel count when fudging an xga projector's image when using a Cinemascope 2x Film anamorphic lens.


Basically overscanning vertically by 1.5 % and squeezing horizontally by 1.5%.



Pf course these calculations are wrong because of the slight pincushion associated with the TORUS the holes would have to be ray traced considring both radi of the parabollic screen.

Quote:
This is where my original comments on 'vacuum based' - plastic bag molding systems comes back into play, for the manufacture of the FORMING MOLDS, for the heat curing of the shape, into the plactic. You should be able to use the inflated bag, on a square box, that has a shaping of theouter four pieces, that will automaticlly infer the proper shape to an inflated bag..


Using the proper high grade materials for the inflated bag, and usig HOT AIR, in an agitated way, will cause the 'inner plastic screen, to form to the desired shape, due to the fact that it will press hardest upon the parts of the bag that are not conforming to the desired shape. The heat transfer will be the greatest at this point, thus the plastic will heat up most there,and become pliable, and then bend to th underlyng hard mold shape.


parhaps, all that is needed is the blown up, shaped bag, with agitated heated air flow, and the screen plastic dropped straight on it, above it. Pressure works against gravity, and btween the two, the desired shape is created,and the bag is then filled with cooler air, thus solidifying the screen into the impressed shape.



There is no reason, why this should not work PERFECTLY, ater a few trial runs have been made.


The biggest problem, is the mathematical transfer of the curvature desired WITHIN THE SCREEN, to the CURVED, FLAT sides of the 'pressurized-air-bag-mold'. THe desired pressure is reached to describe the flatness of the inner part for the problems associated thru the use of CRT's, and the multiple seating positions.


The math is straightforward, and it only has to be done once. The mold can be experimentally manufactured on a small scale in a few hours, using some cardboard, some tape, a garbage bage, and a vaccuum's reverse flow (air exit) to prove the validity of the 'hot-air-bag' molding approach.


For those with a sense of humor, it can be noted that all that is needed, is a blow-hard, a garbage bag and some duct tape... and a box to put the mess in.


For those of you who are having a hard time visualizing exactly what I am getting at, recall the appearance of a pressurized, inflated dome tent building, like a indoor tennis court, or a indoor soccer field. You drop the pre-perfoated flat, rectangular screen material on top, and let the heated air in the 'tent' do it's job, along with gravity, then substitute with cold air in the tent for hardening.


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---Place Signature Here---


[This message has been edited by KBK (edited 10-04-2000).]

I can't believe that we may actually make the contrast enhancing, pixel fitted, compound curved screen for DLP a reality. Next DILA, because of its higher pixel count is a lot more work.


I intend to patent my idea but, I would like Stewart to maybe produce it.


He who has the necessary triginometric and ray tracing skills that

feels like it can fine tune the perforation formulas adjusted for anamorphic and pincushion ,can co-own the patent. Jeff S already seems to have an idea about the formula for the flat screen.


KBK and Kung Fu you can have a piece of co ownership too if you help me.

KBK,


I don't believe plastic bag molding will work...I'm molding small scale acrylic products in my mass production class, and I can tell you that hot air will not provide enough heat to make acrylic pliable. The oven we use to heat our plastic before we form it is around 350 F. The plastic bag you use as the form would melt before the screen would soften. Also there is the problem of shrinkage when you mold plastic, the plastic may buckle if not secured properly. A proper solid mold would need to be made and some method of heating the plastic uniformly (if possible) would need to be developed.


Also are perforations necessarily the right answer to contrast enhancement if one is already custom painting the screen? Perhaps some kind of overlay with holes punched in it could serve as a template for a coat of matte black paint? The location of the perforations would be uncertain if the plastic was heated and molded.


What is really interesting to me is the possibility of a cheap torus screen without the vacuum, but unless someone has a great idea about how to form large sheets of plastic into a curved surface we may be SOL. If the degree of curvature is not too much the idea is probably workable, you run into more problems the more you try and change the shape of the basic sheet.


Oh, and to answer you question about thickness...there is no way to know without experimentation. As thin as possible, while still being able to support itself would be optimum. Thinner sheets would be easier to form. With a proper support structure 1/16" might even be realistic (and it is also much more pliable).


As for the problem of ray-tracing the screen it doesn't seem impossible if the gain characteristics of the screen are known. Just a matter of optimizing the angle of view from each extreme seating point to the extreme points of the screen (i.e. the corners). That would give you the direction of a normal vector drawn at the corner of the screen from which you could derive the curvature of the screen. Unfortunately I've been away from math too long to be really comfortable with these calculations. It could be pretty simple if you had a simple raytracing program...


Also, anyone have any ideas about what a curved plastic screen would do the the acoustics of your room and the speakers behind the screen. Plastic is definitely not as "acoustically-transparent" as a normal screen.


Regards,


Kam Fung

Interesting discussion.


>>I intend to patent my idea but, I would like Stewart to maybe produce it.<<


You'd best stop talking about it in public; may have already blown any ability to patent it! These discussions might also have inadvertently created multiple co-inventors. If serious, ecommend you talk immediately to qualified IP (intellectual property) attorney.


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Stew

The search for excellence is unending . . .

Thanks Stew. I very much appreciate advice on IP matters from someone from

your state. 10 years ago Miami and Seattle where equivalent sized cities with equivalent Net Worth's Per Capital. In 10 years, well....what a difference. I believe IP is the reason. Don't you? Miami is the most IP oblivious city in the US.


At the moment I do not have the time or resources to go patent. My attormey is bussy with a breach of contract case with a "Celebrity", and I can't ask him.


Interestingly enough, the case is basically over rights to publication to a cutting edge a/v system design. Everything was clearly documented with having the design rights, the rights to publish etc. etc.


The athlete's career floundered and he just did not have time. In discussing the case my attorney said he would win it as a breach of contract, without even mentioning "IP" rights. So the legal atmosphere in this region suppresses any progress in that area. Isn't that bad for the State? Now back to the screen:


If I get around to it, and we find that someone patented the concept, maybe? Maybe? It can be traced to the forum. In that case I would ask the help of the forum, to round up a posse, go rent KU-KLUX-KLAN costumes and burn the guys house down.


So the pure VIDEOPHILE cannot place economic interests in the way of mankind's progress... Next post.


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The Artist formerly known as PANARAMAX.....

OK, different idea and good progress:



I can purchase the already concave plastic 1/4 inch with the screen laminate on or off. In 2.35 aspect ratio , 8 foot wide.Close enough to a 30,000 torus in shape.


It is a monocoque shell, actually it is the frontal component of an existing screen that cannot be cut down to 2.35 due to the bulkier design rib design of a support that was designed for 3x4 but can be cut down to 16 x 9.


Let's work with that shell as our base. Do not worry about the back support, I'll let my 11 and 9 year old figure that one out.It will be rigidly in place.


Is laser perforation possible? If done in a freezer the hole dimension should be controllable right? The laser can be digitally controlled, right?


I found this:
http://www.bhlaser.com/


I know stewart experimented with lasers with uneven results. But we are 1/4 inch here.......




[This message has been edited by CINERAMAX (edited 10-07-2000).]




Kung FU:



"Also are perforations necessarily the right answer to contrast enhancement if one is already custom painting the screen? Perhaps some kind of overlay with holes punched in it could serve as a template for a coat of matte black paint?


We think alike.. But if you get a machine to precisely perforate the laminate, with a hole on each corner of the pixel. And then you would need a second perforation process on the black monocoque shell i think , that if lucky enough to align the overlay to the speaker perfs that ther could be noticeable surface uneveness.


I then say that sitting the monocoque black shell in a craddle that laser perf can work. At the lasershop we set up a projector VH-10Q with an isco lens to project a 21 x 9 image, (this is an inexpensive way to develop now for future 16 by 9 DLP and PURELY KUNG FU'S IDEA ).


Let the guys measure and perfect the formula at the laser shop.


They then ship the monocoque to our assembly line for painting.


Having flat black absorbency behind the perfs will help reflections.


Also by having most of the sound coming out of the parabola, and having an absorbent material all around the speakers within the screen the reflectivity of the curve, specially on a 2.35 aspect ratio would be negligible.



Also, anyone have any ideas about what a curved plastic screen would do the the acoustics of your room and the speakers behind the screen. Plastic is definitely not as "acoustically-transparent" as a normal screen.