Introduction: Head Mounted Dispaly (HMD) Hack/modification to Make a Bigger Screen
Hello .... in my first instructables I would like to show you how to hack/modify the monochrome HMD from Wild Planet.
This modification makes the whole thing SMALLER and it makes you feel, that you are sitting in a CINEMA !!!
The disadvantage is, that you have to put it very close to your eye, so people with long eyelashes will not feel comfortable when using it :(
Step 1: About the Head Mounted Display ...
Allowed me some words about the HMD( Head Mounted Display ) and the history of this modification. You can find the HMD in few toys from Wild Planet (www.wildplanet.com) = like Spy Video Car, Spy Video Tank. I can remember, that you could buy it separately - just the Eye Wear - as spare parts for 25$ + cca 30$ shipping. I've got my from the Spy Video Car.
The reason, why I bought this HMD was, that I wanted to use it for a NIGHT VISION*. But when I tried it (with the car or with a small spy camera) & I wasn't really happy about the picture that I can see. I knew before, that the resolution would be something about 320x240 = it's not that bad. The real annoying thing was the size of the picture. I had the feeling, that I'm watching a small TV from a big distance !!! I thought a more powerful lens would do it & but I couldn't imagine where to get it. My first thoughts were, to use the jewellery magnifying glass. Unfortunately I didn't try it L, because one day (I don't know why) I was playing with the lens from my spy camera. To my surprise, it is a very powerful !!! And then I've got the idea ... INSTRUCTABLE :)
Step 2: What Do You Need ...
What do you need :
1. small cctv spy camera & or just the LENS
2. HMD - Eye Wear (it used to be 25$ USD)
3. glue gun or any glue
4. rotary tool (Proxxon, Dremel, &)
5. multitool (Leatherman :) ) & or just small Philips screwdriver
Step 3: Take a Part / Disassemble the Eye Wear ...
As the first thing, you want to get the big cover off, so you can get to the circuit board and the LCD. The cover is glued to the eye piece so apply force & Use just the tip of the normal screwdriver. The circuit board is about 7mm under the cover, so be careful.
(For this session I'm using pictures from internet, because I didn't make them by my own. I just forgot to take pictures, but these are good as well - maybe even better)
Unscrew the two screws. When you don that, unplug the LCDs ribbon cable first. Just gently push the dark piece to right. Do not remove it & just push = it will slide and release the ribbon cable. Take the circuit board away by pulling by the cable.
(I didn't remove the cable from the eye piece yet, because I don't have soldering iron, so I wouldn't be able to test the modification & and I didn't want to damage the cover)
After removing the circuit board, unscrew the four screws, that are holding the LCD with the viewfinder (magnifying glass) and take it out.
Step 4: Disassemble the Viewfinder ...
Now, you have the viewfinder = magnifying glass with LCD display. If you take a close look, it is a SANDWICH. The LCD display is between two parts = magnifying glass and a small part (I call it SHADER). The viewfinder is attached to shader by 4 pins. So just take them apart by pulling. You should end up with something like this.
NOW !!! Big attention !!! Do not think, that now you have the LCD and that's it = WRONG !!! Take a closer look the magnifying glass - to the smaller end. Look carefully. What can you see ??? Nothing ??? Wrong & there is a thin film on the bottom !!! You can see it better on the shader where the thin film comes in contrast with the white shader film. WITHOUT THESE SEE THROUGH FILMS IT WILL NOT WORK !!! YOU WOUN'T GET THE PICTURE !!!
(It was really funny, when I realized this fact. At first, I didn't know, that there is a film on the magnifying glass. A was playing with it, looking through it & and I didn't realized anything. But I power the HMD, connected to a movie & look through the mag. glass and it worked. Then I take the mag.glass away and use the camera lens, but I couldn't see the picture ?!?! So I checked the connection, between my DVD player and HMD. I used the mag.glass again = picture. I used the cam.lens = no picture. After 3th changing between mag.glass and cam.lens I realized, that there must be something on the mag.glass that the lens doesn't have & and voil� = thin film glued with a small piece of red glue )
Step 5: Sandwich and the Cover ...
So, now we know that we need the films to get a picture. In this point, I decide NOT to remove the films from the plastic for good - but just cut rectangles from the plastic with the films = so I can create the same sandwich like before, but with just small pieces. Here comes the rotary tool & and you should end up with something like this.
I used the glue gun, to hold the sandwich together. As you can see, I already put it in the camera casing = I unscrew the two screws, that holds the camera together. Take the circuit board out (just by pulling). Then I drill a hole in the casing for the ribbon cable & and put the sandwich inside. The side, where is the shader film is on the NON lens side.
(you can see on the picture, that I put/hold the shader film with a glue gun additionally. I realized, that with the shader film it's better. It makes the light passing through the LCD more nicely - equally - general diffused )
Step 6: Fixing the Sandwich (new HMD) in the Camera Casing ...
I hold the sandwich in the casing with a glue gun & but before fixing it, do this first :
1. hold the cam casing with sandwich against source of light. Focus the lens, so you can clearly see the pixels of the LCD.
2. centre the sandwich in the casing so, that you can see the whole LCD through the lens and fix it in this position with the glue gun.
Step 7: Final Product, the NEW IMPROVED HUD :)
Now, drill a hole in the other part of the camera casing. Why ??? Because we need a source of light for the LCD & and we will use the same light on the circuit board. Put the camera together and it should look like this.
Use your rotary tool and cut/drill away a piece of the plastic, where were the 2 camera screws = you can notice, that the HEADs of these two camera screw are higher then the surface of the casing. That means if you would put the camera with the non lens side on the table, it would be standing on the head of the screws. We don't want this & so we need to drill away a piece of the plastic = so when you screw those screws back, they will be in one row with the casing.
(you can see it on the picture)
Now, connect the LCD ribbon cable to the circuit board. Connect the circuit board to the 9V battery, connect to a video signal (DVD player, cam, use the Spy Car &) and attached the camera casing = your new HMD to the light on the circuit board. The reason, why we are doing it like this, is to fit the light in the centre of the HMD / LCD display. When you find the right position, make a mark, unplug 9V and video signal & and glue it with the glue gun.
Now, you have your new improved HMD. Traraaaaaaaaa :)
Step 8: Some Ideas / Thoughts ...
1. You can use a brighter LED diode as a source of light. The picture is more nicer. I used the LED from the Solar Light (mentioned on the picture at the beginning)
2. If you are not scared (I was) & you can use just the thin FILMS to cover the LCD casing & and it would be even more smaller !!!
3. Keep the films and LCD in clean environment, because the rotary tool makes a lot of mess & I have some dust on the films and LCD.
- - mentioned at the beginning & you can use the Eye Wear to make a small night vision. To do this, you can/must do it before this modification & because you will need the whole untouched Eye Wear. Just glue the camera to this black cover, attached the cable (power cable and video cable) from camera to the Eye Wear and you can put some IR LED diodes to the cover as well. I will make a INSTRUCTABLE for this as well - latter.
PS : I found on internet a very nice steps with pictures, how to disassemble the original HMD. Here is the link http://www.machinegrid.com/2009/02/taking-apart-the-atv-360-eyepiece-head-mounted-display/comment-page-1/#comment-256