A pinhead mirror can be used to create a

camera A camera is an Optics, optical instrument that can capture an image. Most cameras can capture 2D images, with some more advanced models being able to capture 3D images. At a basic level, most cameras consist of sealed boxes (the camera body), ...

similar to a

pinhole camera A pinhole camera is a simple camera without a lens but with a tiny aperture (the so-called ''pinhole'')—effectively a light-proof box with a small hole in one side. Light from a scene passes through the aperture and projects an inverted image o ...

. Instead of passing through a tiny aperature, the

light Light or visible light is electromagnetic radiation that can be perceived by the human eye. Visible light is usually defined as having wavelengths in the range of 400–700 nanometres (nm), corresponding to frequencies of 750–420 tera ...

to form the

image An image is a visual representation of something. It can be two-dimensional, three-dimensional, or somehow otherwise feed into the visual system to convey information. An image can be an artifact, such as a photograph or other two-dimensiona ...

is reflected by a small disc-shaped

mirror A mirror or looking glass is an object that Reflection (physics), reflects an image. Light that bounces off a mirror will show an image of whatever is in front of it, when focused through the lens of the eye or a camera. Mirrors reverse the ...

(with a

diameter In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints lie on the circle. It can also be defined as the longest chord of the circle. Both definitions are also valid for ...

the same as that of a

pinhole A hole is an opening in or through a particular medium, usually a solid body. Holes occur through natural and artificial processes, and may be useful for various purposes, or may represent a problem needing to be addressed in many fields of en ...

; about 0.15 mm - 0.4 mm). One advantage is that a pinhead mirror can be swiveled to

scan Scan may refer to: Acronyms * Schedules for Clinical Assessment in Neuropsychiatry (SCAN), a psychiatric diagnostic tool developed by WHO * Shared Check Authorization Network (SCAN), a database of bad check writers and collection agency for bad ...

a scene or

project A project is any undertaking, carried out individually or collaboratively and possibly involving research or design, that is carefully planned to achieve a particular goal. An alternative view sees a project managerially as a sequence of even ...

a scene to different locations. Pinhead mirror technology was protected under US

patent A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an enabling disclosure of the invention."A p ...

4,948,211 - "Method and Apparatus for

Optical Imaging Medical optical imaging is the use of light as an investigational :wikt:imaging, imaging technique for medical applications. Examples include optical microscopy, spectroscopy, endoscopy, scanning laser ophthalmoscopy, laser Doppler imaging, and opti ...

Using a Small, Flat Reflecting Surface" until the patent expired in 2009.

References

* TH Nilsson (1986) "The Pinhead mirror: A previously undiscovered imaging device?" ''Applied Optics'', 25, 2863-2864 * TH Nilsson (1987) "Pinhead mirrors: imaging, computing and the nature of light" ''Pinhole Journal'', 4, 2–5. Cameras by type {{photo-stub