Question about collimated display systems.

[Matt Olieman]

Just in case you've not found this site and want more info on concave mirrors and optics..

http://www.physicsclassroom.com/class/refln/u13l3d.cfm

Your instincts are probably correct, no manufacturer is going to supply details, trade secrets, and proprietary data to a voice on the phone no matter how sincere, honest, and trustworthy the caller may be. Afraid we're on our own here. OTOH there are some very bright, intelligent, and creative folks in the hobby side of simming as well as those on these forums.

Plus we're not going for FAA Level D certification. Close enough works for me

Good link JW. There lies the problem, the technological, know how and the resources for R&D. We can have all the information regarding how it's done, but when it comes down to the bottom line....... it's nearly impossible for one person to take on this task and I'm just talking about the mylar mirror. The overhead rear projection screen is in itself a major or almost impossible undertaking, if you really think about it. Between the two of them, there is no room for imperfection.

I've researched this for over 15 years, I've tried all sorts of mirror setups, I've studied actual mirrors on a level D sim. I've got rolls of Mylar, different thicknesses and qualities. Even to stretch mylar on a flat surface is a feat itself. Try to find an imperfect piece of mylar.... wow, the frustrations.

If some one can find a way of making this happen, this person will be THE hero of our hobby.

Matt Olieman

[Mike.Powell]

There were a series of reports funded by government money all with the appealing title, "Wide Angle Multiviewer Infinity Display Design". So far I've run across abstracts for 3 different reports with this name. They appear to be have been distributed in micro fiche format to a few university libraries. None of the libraries will send micro fiche out as an inter-library loan. It is possible to buy hard copies from the NTIS for $48 to $60 each. Not being able to preview them, I'm reluctant to spend the money, especially because there is no guarantee that the print-on-demand from old micro fiche will be of readable quality. There is also the issue of just exactly what the reports contain. The abstracts sound appealing, but there is no indication of the level of detail or its usefulness.

I've considered driving to UC Davis California to visit the library as the catalog says they have two of the reports, but I haven't gotten there yet.

If any of you gentlemen are located near a good university engineering library, you might check to see if these reports are available there. They might be full of gold plated hand waving, or they might be real gold mines for this project.

[castle]

Hi Mike,

Were Rhinehart and Shaffer some of the authors of these reports? Any more info such as fiche numbers.

JW

[Mike.Powell]

Hi Mike,

Were Rhinehart and Shaffer some of the authors of these reports? Any more info such as fiche numbers.

JW

Here's what I've got so far:

Wide-Angle, Multiviewer Infinity Display Design by L.W. Shaffer, J.A. Waldelich; Air Force Human Resources Laboratory, Advanced Systems Division, [1977] NTIS product code# ADA053679, Library call: DOC D 301.45/27:77-67 mf11 [@ UCDavis Shields Library]


Wide-Angle, Multiviewer Infinity Display Design by Robert M Rhinehart; Air Force Human Resources Laboratory, Advanced Systems Division, [1977] NTIS product code# ADA051158, Library call: DOC D 301.45/27:77-71 mf11 [@ UCDavis Shields Library]



Wide-Angle, Multiviewer Infinity Display Design by Ian Whyte, A.W. Zepf; Brooks Sir Force Base, TX. : Air Force Human Resources Laboratory, Air Force System Command, [1982] NTIS product code# ADA116308 , Library call: D301.45/27:81-27/V.1-2 [@ New Mexico State Library] Series: AFHRL-TR ; 81-27 (I-II)

NTIS is the US Department of Commerce National Technical Information Service www.ntis.gov


Doing a Google search on the title turns up various links, but no real content. There's even an entry in Google book scan, but no preview.

[Mike.Powell]

I found these abstracts listed in the bibliography of the AF Human Resources Lab. http://www.icodap.org/papers/AFHRL/index.html

Whyte, I., & Zepf, A.W. Wide-angle, multiviewer , infinity display system. AFHRL-TR-81-27(I), ADA116 308. Williams AFB, AZ: Operations Training Division, June 1982. Project ILIR, Contract F3361S-79-C-0002, American Airlines. NTIS. This study examined the design specification for a wide angle infinity display system with minimal distortion, convergence, dipvergence, and collimation errors for use on wide-body-aircraft simulators. The report includes a recommended final design specification; a survey of potential fabrication technologies for projector, screen and large mirrors; an approach to fabrication of a large display system; and finally, assembly and alignment techniques of mirror segments for a large display. (Note: Dipvergence refers to vertical movement of eyes up and down as opposed to side to side. (94 pages)

Shaffer, L.W ., & Waidelich, J.A. Wide-angle, multiviewer infinity display design . AFHRL,-TR-77-67, AD-A051 158 . Wright-[Patterson AFB, OH : Advanced Systems Division, September 1977 .Project 6114, Contract F33615-76-C-0064, General Electric Company. NTIS. There has long been aneed in aircraft simulation for a wide angle visual display that will accommodate the entire crew of a large aircraft type such as a bomber or tanker. This study is concerned with the approach and design of a wide angle display for multiple crew members in large aircraft simulators . The study traces the development of a concept from existing simulation methods. Throughout its 180° by GO° field of view which accommodates pilot, copilot, and instructor pilot the final design meets most of the requirements of the original specification . Because of its relatively large optical components the fabrication of the display will be of a developmental nature itself . (116 pp.)

Rhinehart, R.M. Wide-angle, maaltiviewer infinity display design . AFHRL-TR-77-71, AD-A053 679. Wright-Patterson AFB, OH: Advanced Systems Division, December 1977 . Project 6114, Contract F33615-76-G0052, McDonnell Douglas Electronics Company. NTIS. A research design study was undertaken to define an extended field of view (60° x 180°) infinity image display, suitable for multiviewer use on wide-bodied aircraft simulators. Mosaicking of single channel units, both reflective and refractive was investigated, along with extended field, off'-axis reflective systems. Major emphasis was placed on the investigation of extended field of view, off-axis reflective systems. Various figured screen and mirror combinations, ranging from spherical to high order aspherics, were designed and evaluated. Two specific designs were selected, optimized and evaluated over an extended viewing volume. (78 pp.)

[Mike.Powell]

I found the Whyte & Zepf report for sale in pdf from NTIS. I bought and downloaded it. It is interesting in, shall we say, a historical way. It does not mention film mirrors at all. The optical design reflects very early approaches to the cross-cockpit design goal.

My thought is that information in recent patents is both more detailed and more useful.

[castle]

Thanks, Mike

I would put my money on the 1982 study. If the abstract is accurate, the phrase "approach to fabrication" might provide some insight. While they all are a bit dated. might still be a good starting point.

You can download an electronic copy of the 1982 Project ILIR study for $15 from NTIS. Catch is that file is reproduced from "best digital master available", that could mean an optical scan of an old micro-fiche. Think I'll give then call tomorrow....

JW

[castle]

He, he, guess I won't call them.

[mikesblack]

Mike,

Thank you very much for all of this as well as your insights.

[mikesblack]

Matt,
Can you say from your experiences what the most demanding element you found was? Sounds like there are a bunch, but at any point did you think there was possibility you might have been close to getting it.
It sounds like you have encountered too many obstacles to feel satisfied continuing or that it may be a further exercise in futility to care to bother with it all. After all, this is supposed to be fun.
That said, I should think that your many years of exhaustive and frustrating experience trying to build this has led to many valuable insights that could be of tremendous value. I wonder if you think that a collaborative undertaking by this community and most especially with your rich experiences could be what it takes to make this at all plausible.
At the end of the day, the technology is there and it is a physically reality practically speaking. I would be most grateful for your insight and experience, so long as you come to find it worth your time to do so. With that and the input of diversity of this interested crowd, who knows, perhaps we'll get there.
Thanks,
Mike