Planetary scanner
Encyclopedia
A planetary scanner is a type of image scanner
for making scans of rare book
s and other easily damaged documents. In essence, such a scanner is a mounted camera taking photos
of a well-lit environment. Originally, such scanners were expensive and could only be found in archive
s and museum
s, but with the availability of cheap, high-resolution
digital camera
s, DIY planetary scanners have become affordable, and for instance are being used by volunteer scan providers for Project Gutenberg
.
Flatbed scanners often come in contact with at least part of the object to be scanned. They also require books to be fully opened most of the time (there are some exceptions where the scanning surface ends at the edge of the flatbed scanner, so that a book can be opened partially). Both practices can damage rare books; For example, opening a book 180 degrees can be damaging to its spine. These scanners are also implemented to scan other fragile documents such as old maps.
Planetary scanners tend to touch fewer parts of a book, and provide an option of only opening a book partially.
Image scanner
In computing, an image scanner—often abbreviated to just scanner—is a device that optically scans images, printed text, handwriting, or an object, and converts it to a digital image. Common examples found in offices are variations of the desktop scanner where the document is placed on a glass...
for making scans of rare book
Book
A book is a set or collection of written, printed, illustrated, or blank sheets, made of hot lava, paper, parchment, or other materials, usually fastened together to hinge at one side. A single sheet within a book is called a leaf or leaflet, and each side of a leaf is called a page...
s and other easily damaged documents. In essence, such a scanner is a mounted camera taking photos
Photograph
A photograph is an image created by light falling on a light-sensitive surface, usually photographic film or an electronic imager such as a CCD or a CMOS chip. Most photographs are created using a camera, which uses a lens to focus the scene's visible wavelengths of light into a reproduction of...
of a well-lit environment. Originally, such scanners were expensive and could only be found in archive
Archive
An archive is a collection of historical records, or the physical place they are located. Archives contain primary source documents that have accumulated over the course of an individual or organization's lifetime, and are kept to show the function of an organization...
s and museum
Museum
A museum is an institution that cares for a collection of artifacts and other objects of scientific, artistic, cultural, or historical importance and makes them available for public viewing through exhibits that may be permanent or temporary. Most large museums are located in major cities...
s, but with the availability of cheap, high-resolution
Display resolution
The display resolution of a digital television or display device is the number of distinct pixels in each dimension that can be displayed. It can be an ambiguous term especially as the displayed resolution is controlled by all different factors in cathode ray tube , flat panel or projection...
digital camera
Digital camera
A digital camera is a camera that takes video or still photographs, or both, digitally by recording images via an electronic image sensor. It is the main device used in the field of digital photography...
s, DIY planetary scanners have become affordable, and for instance are being used by volunteer scan providers for Project Gutenberg
Project Gutenberg
Project Gutenberg is a volunteer effort to digitize and archive cultural works, to "encourage the creation and distribution of eBooks". Founded in 1971 by Michael S. Hart, it is the oldest digital library. Most of the items in its collection are the full texts of public domain books...
.
Flatbed scanners often come in contact with at least part of the object to be scanned. They also require books to be fully opened most of the time (there are some exceptions where the scanning surface ends at the edge of the flatbed scanner, so that a book can be opened partially). Both practices can damage rare books; For example, opening a book 180 degrees can be damaging to its spine. These scanners are also implemented to scan other fragile documents such as old maps.
Planetary scanners tend to touch fewer parts of a book, and provide an option of only opening a book partially.