Tag Archives: LASER scanners

LASER scanners for vector projection

I made a LASER projector with DC motors. This can display only circular forms. I wanted to make one that can display vector graphics. There is an instructable to make these from speakers. I am also trying that but my setup has a lot of distortion.

In this alternative I have used the read head of the CD ROMs to move the mirrors and bounce the LASERS to make figures

What you need

Junk CD drives, screw driver star head, small round mirrors, glue and lot of patience.

You need to open the CD drives part by part till you reach the actual lens mechanism.

cd drive

What we need is a the actual read head with all the mechanism built around it.

lens mechanism

This is actually a set of two coils in between two very powerful magnets and it is used to focus the laser and read the CD. One of the coils moves the lens up and down and the other coil moves it left and right.

My concept was as follows.

Apply a constant voltage to push up the lens. Attach a mirror to it. and use the varying High, Low voltage at both ends to move the mirror left and right.

Following are the pictures that I have taken for my setup.

2012-02-05 22.38.59 2012-02-05 22.38.39

2012-02-05 22.46.51 2012-02-05 23.40.45

2012-02-05 22.38.23

The pictures show different views of the lens mechanisms. Wires have been soldered to the coil ends for the ease of connecting it to the microcontroller board. Mirrors have been glued on the lens and the mirror moves with the lens. Following is the video that shows these in action.

Following pictures have been taken after the setup was done and the microcontroller was programmed to move the mirrors.

I am able to draw something but one of the heads seems to be having some issues as it is creating a lot of distortion.

2012-02-06 00.21.08  2012-02-06 00.21.37

2012-02-06 00.12.43  2012-02-06 00.15.23

2012-02-06 00.55.21  2012-02-06 00.56.44

The pictures show the setup on a cardboard box wit the LASER. A small paper screen has been setup to have a look at the drawing. I was successful in drawing a horizontal and vertical lines. Slanted lines have some distortion and a lot more distortion is noticed when drawing characters.

I will be working on a more stable version and will post all the updates when it is done.