The Long road of cosplay and engineering

peterthethinker

Well-Known Member
Aloha One and all .
With ideas comes learning and exploring.
I would like to pen these musings on paper and put forth some of the crazy Ideas Ive had over the years for cosplay. Most here are gonna be Halo related and current ideas.


Well lets start off. Heads up displays.


Will let's start thinking heads up displays there are two kinds of heads-up displays reflective and transmissive. In the movie you oftentimes see them drawn by a scanning laser onto a visor. The one that Master chief would be wearing is very similar to this. Scanning lasers require; galvanometer scanner and are not easy and are not designed for a higher refresh rate they would be great for static icons but they're not really good for fancy overlays think of a laser light show. Basically that's what's happening.

More commonly is the use of a LCD screen or a cathode ray tube that is imaged upon the eye.

My personal heads-up display uses a reflective curved mirror.
I've also got a headmounted display based on a helmet and a high definition screen this one uses semi natural viewing distances of about 7 cm. This is Ray at the edge of my personal focusing ability with my naked eyes.
I usually wear 2.5 dpt correction glasses magnify the image.
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One of the things you can do is to study the concept of imaging optics and pick the elements according to map. It is rather trivial to do basic ray tracing and figure out exactly where the optical elements including the actual display screen have to go.

If you intend to protect the image onto the inside of a visor there is the curve you have to deal with. And you also have to overcome any ambient light. A photocell tied to the backlight power system or brightness control will allow you to keep a constant contrast on the screen. If you also applies to my transparent heads-up displays. You get a pump out quite a lot of lumens.

Most LCD screens are transmissive at the resolutions that we desire.. Because of this you can swap out the backlight to a brighter one. In the past this meant to you for your ark lamp or a very bright cold cathode display these days it's a simple LED change and unless you're trying to build a projtector out of the small LCD screen you most likely will not need to use a heatsink or any kind of substantial cooling system.

That takes care the optics section. However a good displays useless without items to put on it. VGA is hard to integrate into most heads-up displays as it's an analog protocol and most displays are not .

HDMI is technically just a bunch of paired signals going down a bus. HDMI is a form of LVDS... DVI is the same...

You can also use simple serial and just bang and some bits down a wire..
Displays that play motion are likely going to be something besides serial.

The raspberry pie is a good example of a signal source for a embedded system that takes a headmounted display. However the outputs to a raspberry pie or equivalent is oftentimes only digital or really simple composite video. The latter you want to avoid.

There are microcontrollers that would do very well to drive a headmounted display the parallax propeller chip can output VGA and composite video.


And this ends the first section on heads-up displays.
 
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