Contact image sensor

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act image sensors (CIS) are image sensors used in flatbed scanners almost in direct contact with the object to be scanned. Charge-coupled devices (CCDs), often used for this application, use mirrors to bounce light to a stationary sensor. CISs are much smaller than CCDs, use typically a tenth as much power, and are particularly suitable for low power and portable applications, often powered over USB. [1]

Image scanner device that optically scans images, printed text, handwriting, or an object, and converts it to a digital image

An image scanner—often abbreviated to just scanner, although the term is ambiguous out of context —is a device that optically scans images, printed text, handwriting or an object and converts it to a digital image. Commonly used in offices are variations of the desktop flatbed scanner where the document is placed on a glass window for scanning. Hand-held scanners, where the device is moved by hand, have evolved from text scanning "wands" to 3D scanners used for industrial design, reverse engineering, test and measurement, orthotics, gaming and other applications. Mechanically driven scanners that move the document are typically used for large-format documents, where a flatbed design would be impractical.

Charge-coupled device device for the movement of electrical charge

A charge-coupled device (CCD) is a device for the movement of electrical charge, usually from within the device to an area where the charge can be manipulated, for example conversion into a digital value. This is achieved by "shifting" the signals between stages within the device one at a time. CCDs move charge between capacitive bins in the device, with the shift allowing for the transfer of charge between bins.

USB Industry standard

Universal Serial Bus (USB) is an industry standard that establishes specifications for cables and connectors and protocols for connection, communication and power supply between computers, peripheral devices and other computers. Released in 1996, the USB standard is currently maintained by the USB Implementers Forum. There have been three generations of USB specifications: USB 1.x, USB 2.0 and USB 3.x; the fourth called USB4 is scheduled to be published in the middle of 2019.

Scanner unit with CIS. A: assembled, B: disassembled; 1: housing, 2: light conductor, 3: lenses, 4: chip with two RGB-LEDs, 5: CIS Overwiew - Scanner unit CIS Canon MP500 5of5.jpg
Scanner unit with CIS. A: assembled, B: disassembled; 1: housing, 2: light conductor, 3: lenses, 4: chip with two RGB-LEDs, 5: CIS

A CIS typically consists of a linear array of detectors, covered by focusing lenses and flanked by red, green, and blue LEDs for illumination. The use of LEDs allows the CIS to be highly power efficient, allowing scanners to be powered through the minimal line voltage supplied via a USB connection. CIS devices typically produce lower image quality compared to CCD devices; in particular, the depth of field is greatly limited, which poses a problem for material that is not perfectly flat. However, a CIS contact sensor is smaller and lighter than a CCD line sensor, and allows all the necessary optical elements to be included in a compact module, thus helping to simplify the inner structure of the scanner. With a CIS contact sensor, the scanner can be portable, with a height of only around 30 mm. CIS is both a key component of, and widely used in, scanners (especially portable scanners), electrographs, bar code readers and optical identification technology.

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Optical mouse

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Photonics branch of physics

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Barcode reader electronic device that can read and output printed barcodes to a computer

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USB flash drive data storage device

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The following are common definitions related to the machine vision field.

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References

  1. "Canon CIS technology overview" . Retrieved Jan 25, 2012.