laser image projector

This is a basic note on how to build a portable image projector using a green laser instead of a normal light.
The laser allows images to be taken from a long distance without focusing-
It is always the focus.
This particular design sequence is simple and more so that my attention is kept on track for a short time, long enough to get the job done!
Please let me know if I miss some details and I will correct it.
For more photos, see the flickr page warning: permanent eye damage can occur even with low-power lasers.
Always wear safety glasses and never point to people, animals or police helicopters!
In this method, I use a board about 90 cm long, about 15 cm wide and about 1 cm thick.
You install it almost on any long, hard material.
Note: the length will determine the distance of the first shot from the slide to allow \"do\" to be extended enough to cover the slide area.
Stiffness is essential.
The alignment of the laser is usually difficult-
Unnecessary flex will throw the alignment way too easily.
If the track is used, rule a straight line at the center of the board and install the dead center of the track.
In order to install the track on the board, you may need to cut the track.
Create the center line very accurately without using the track!
Any holes drilled must also be very consistent.
Assuming we install the laser using a pen-type laser indicator, we need to mount the laser onto the holder, which securely holds the laser in a position that does not have any movement.
Because the laser indicator often has a push switch, I will separate them and put a wire on the switch so that when-
Once the battery is connected, it will continue to be used.
Be careful when welding this.
You can easily remove other parts and destroy the laser module.
Heat is often the death of laser!
Assuming it will last for more than a few minutes, you may need a radiator to dissipate heat.
Find an aluminum radiator from the old computer, drill a hole large enough to insert the pointer into it.
Use hot paste around it.
In this quick and dirty example, I just push the laser into the center groove with deformed spots.
To install using a rail, use two 72mm perpex/pcs \'.
The parts at the bottom slot into the mounting block and the other one just above the mounting block with bolts at each 4 corners.
This allows the vertical level to rise up and down accurately.
It is best to create this \"scaffold\" before connecting any component to the top perspex/pcb \".
Positioning laser (in heat-sink)
Loose top.
Turn on the laser and use a fixed square aligned along the center line.
Make sure the laser is aligned in a straight line and is completely parallel to the board/track.
Once you are satisfied with the alignment, mark the position with a pencil.
I leave you the method of the laser, but remember that you may need to relocate a little later, so it may be a pity to stick it down now.
Some form of bolts may be better.
Once the laser is loose in place, I like to place the focus lens on the other end of the track/board.
Use the same method of installing the laser to install the focusing lens.
Use deformation to place the lens-
Stay Central and level!
Now align the laser so that it passes through the dead center of the lens, adjusts the laser and focus lens until the beam passes through the lens and does not deviate from any other direction in the horizontal or vertical direction.
We are almost there once these two are in line!
Only two more modules need to be installed.
Obviously, you need an image to project.
I recommend using a 35mm slide stand with color slides or indirect transparency made by size. Why?
The greater the density of the film, the less light passes through.
If you want to project the maximum distance, clear and transparent OH images are the best for guerrilla art projections that require maximum lighting.
Of course, just try different types of movies!
As for the laser and lens, make scaffolding for the slide frame.
With the deformer you can create a slide stand by simply placing a spot and pasting an empty stand in it.
Let it set up, remove the stand and the instant slide rack!
Next, some adjustments need to be made to the horizontal and vertical positioning of slides and scaffolding so that the point of the laser is precisely centered.
Don\'t move the laser to the center!
Using a concave lens, we extend the beam to all or most of the 35x 24mm areas that are sufficient to cover the slide.
You can use 2 lenses to expand points in a shorter distance, but for each filter the laser has to pass, the brightness does get a little affected.
You can find these lenses in the old disposable camera.
The basic shape is squeezed inward and the beam is expanded.
If you want to buy some high quality glass lenses, there are many reputable laser shops on the Internet that can offer them.
As before, set the lens inside the \"bracket\"
Deformation or other materials are used.
Set up another \"bracket\" and position the lens so that the laser beam goes straight through the center.
Adjust the size of the extension point by moving the slider up and down until you are happy.
Of course, this also means moving the focus lens.
Once all modules are aligned-
You should see some projection.
If the focus is insufficient, move the focus lens back and forth relative to the slide for optimal clarity.
A useful tool for alignment is to align the main \"reflection\" points that always appear in the center of the previous module element.