From Wikipedia, the free encyclopedia
Principle of a pinhead camera. Light rays from the object reflect off a small mirror and are projected as an image.
A pinhead mirror can be used to create a
camera similar to a
pinhole camera . Instead of passing through a tiny
aperature , the
light to form the
image is
reflected by a small
disc -shaped
mirror (with a
diameter the same as that of a
pinhole ; about 0.15 mm - 0.4 mm). One advantage is that a pinhead mirror can be
swiveled to
scan a scene or
project a scene to different locations.
[1]
[2]
Pinhead mirror technology was protected under US
patent 4,948,211 - "Method and Apparatus for
Optical Imaging Using a Small, Flat Reflecting Surface" until the patent expired in 2009.
Disco balls can be used as pinhead mirrors to project solar images. The math behind them is the same as for a square pinhole.
[3]
References
^ Nilsson, T. H. (1986).
"Pinhead mirror: a previously undiscovered imaging device?" . Applied Optics . 25 (17). Optica Publishing Group: 2863.
doi :
10.1364/ao.25.002863 .
^ Nilsson, Thomy H. (1988). "Pinhead Mirrors: Imaging, Computing and the Nature of Light". Psychology. Pinhole Journal . 4 : 2–5.
^ Cumming, Robert J.; Pietrow, Alexander G. M.; Pietrow, Livia; Cavallius, Maria; Petit dit de la Roche, Dominique; Pietrow, Casper; Schroetter, Ilane; Skan, Moa (2024).
"Why every observatory needs a disco ball" . Physics Education . 59 (2). IOP Publishing Ltd: 025012.
arXiv :
2309.14173 .
doi :
10.1088/1361-6552/ad1fa0 .