micro projectors

Type 3 micro projector:

 

This is the third iteration of the micro slide projector concept for light graffiti.  It uses an led, 

two plastic lenses and lith film media to project images. In the first two models, the projector body has been upgraded from a hard to find size cardboard tube to a can based body and 

an internal condenser lens has been added to make the image more evenly lit. While this solved the focus and materials problems and allowed the type 2 to be used as the optical guts if the electrotachyscopes, with out the tachyscope's pulsed power supply the type 2s were just too dim to be useful. So I decided to over do it for this 3rd attempt and using a 80 lumens green cree xr-e star led running at 1.5 watts vs. the old 27,000 mcd 5mm led.  It is very bright but has some focus problems given it has the led lens and the original condenser lens. My guess is it would project a visible 12ft(≈3.6m) image at about 30 ft (≈9m) in near darkness. The down side of this version other than the correctable focus problem is price, where as the type 1 and 2 cost about $1.50 to make the type 3 is closer to $22. 

type 3 projection at about 12ft (≈3.6m) with some direct light from the near by porch light

 note the distortion in the edges of the image and the over exposure  

 

type 3 projection at about 12ft(≈3.6m) in near darkness

Type 4 micro projector:

While a good bit dimer than the type 3, it is way cheaper to build about $3 and still brighter than the type 1 and 2  employing a 10mm led at 256,000 mcd vs 27,000 mcd 5 mm leds of the first 2 models.  The low price and the maintenance of brightness makes this the first to viably address the original concept, allowing multiple projectors to be deployed in a space while not having the stringent requirement of complete darkness.     

type 4 projection at about 12ft (≈3.6m) with some direct light from the near by porch light

type 4 projection at about 12ft(≈3.6m) in near darkness