Overview
This tutorial provides step-by-step instructions for building a smartphone projector that projects your phone’s screen onto a wall, featuring improved usability and a vintage-inspired design.
Simple Smartphone Projector Concept
- Use a shoebox with a hole in the front for a magnifying glass as the lens.
- Create an adjustable phone stand inside using a bent piece of cardboard.
- Project the phone’s screen in a pitch-black room and adjust for sharpness.
- The basic design inverts and flips the image, making text unreadable and games unplayable.
Advanced Projector Build Process
- Mark and divide craft cardboard for the main projector body.
- Cut and score the cardboard to create foldable sections and a lens hole.
- Optionally cut a small triangle to enable wall mounting.
- Fold and secure the structure using side tabs, glue, and tape for strength.
Focusing System Assembly
- Make holes in each corner of the projector and insert plant stick dowels.
- Glue straws into the corners to hold dowels vertically.
- Insert and glue a small mirror at a 45° angle inside the projector.
Phone Platform & Lens Selection
- Build a cardboard platform with a screen window and corner holes for dowel mounting.
- Use a bic convex lens; larger size yields a brighter image.
- Select lens focal length based on desired screen size and brightness—shorter focal length = bigger, dimmer image.
- Secure the lens in place and clean fingerprints for clarity.
Light Leakage Prevention & Bellows Construction
- Prevent light leakage with paper bellows inspired by vintage cameras.
- Print and fold templates to assemble concertina-style bellows.
- Paint the bellows black for effective light blocking and attach with double-sided tape.
Final Adjustments & Usage Tips
- Place the phone on the finished projector and adjust for focus in a pitch-black room.
- Use maximum screen brightness for best image quality.
- Design ensures image is no longer flipped due to the mirror.
- Easily remove the phone for calls or swap for tracing paper for a camera-like effect.
- Project stenciled images for added creative uses.
Recommendations / Advice
- Use a lens with a balanced size and focal length suitable for your brightness and screen size needs.
- Ensure all internal surfaces are dark to minimize light leakage and maximize image quality.
Questions / Follow-Ups
- Consider experimenting with different lens types or focal lengths to optimize performance for your environment.