Heads-up Display Mounts On Brim Of Your Cap

[Matt Kwan] says that coming up with a personal heads-up display wasn’t that hard. Well that’s because he made design choices that make all the difference.

The goal here was to add some augmented reality to his field of vision. He went with a baseball cap because it’s a pretty easy way to strap something to your head. You can’t see it from this angle, but the setup requires you to cut a rather large hole in brim. The image from a smartphone (HTC Desire Z in this case) which is situated with the screen pointing toward [Matt’s] forehead. The screen reflects off of a small mirror, guiding the image down through a Fresnel lens mounted in the hole of the brim. The image is reflected a second time by the plastic in front of his eyes which is coated with a slightly mirrored material. Since the image is reflected twice it appears right-side up, and the use of the Fresnel lens places the image out about 20 cm in front of his view. He tried to get some images of the effect, but we think you’ve got to see it in person before passing judgement.

This does away with the need to track head movement (there’s a few hacks for that out there though). Augmented reality software is used to turn the view from the smartphone camera into overlay data for the display.

[Thanks Tom]

14 thoughts on “Heads-up Display Mounts On Brim Of Your Cap

    1. First of all, it’s only for the display’s image, since the plastic is semi-transparent you’d see the world at it’s natural focal length (barring any distortion).

      Second, HAD says 20cm but is wrong as usual. The article says 50cm. Not perfect but definitely usable.

  1. @JC Thanks, you owe me a new keyboard as I just ruined this one when reading your comment. :-P

    This is very clever, BTW you can get little fresnels from Oatlands here, also WH Smith have some.

    Maybe that “broken” smart phone isn’t as useless as it seems, if turned into a head up display.
    What someone needs to do is make a microSD card with video input.

  2. Sure, mounted on a hat this looks stupid, but if you took the camera, put it on the NOG mount of a combat helmet, and used a hinge to flip the display down, it would be much more awesome. It bypasses the hole-fresnel lens-reflection aspect, but combined with one of the transparent Samsung OLED displays recently featured here, it would be frickin’ awesome.

  3. I’m no expert on optics, but couldn’t you keep the phone flat on the cap/lens by simply having the software render the image as if it were at a 45 degree angle (in 3D)?
    The only downside is that you’d increase the aspect ratio, since there’s less usable screen, but it would improve the design’s aesthetics remarkably (and also allow for more flexibility in the angle of the mirrors.)

    1. But those would be eye wear instead of head wear.
      The advantage of the head wear solution over eye wear is that it doesn’t collide with existing eye wear (spectacles, shades…)
      Also you can hang more weight on it when you need to.

  4. Not everyone has $300 to spare.

    Sometimes people throw out a broken
    smartphone when it has some use.
    What about using the mic input to
    send video data from a miniPC to the
    phone and use a custom app?

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