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• Device used to scan text documents, images, objects and convert it into digital image.
• Scanning technology that converts physical image, text into digital image file on the computer.
• Scans light and dark area as well as color on scanned document.
• After scanning these images can be printed on paper or stored on storage devices.
• 3D Scanner also exist but cost is high.

Types & Working

Flatbed scanner:

• Consists of glass pane under which there is bright light.
• This bright light illuminates the pane and a moving optical array in Charge Couple Device (CCD) scanning.
• CCD type scanners contains three rows of sensors with red, green ,blue filters.
• Contact Image Sensor (CIS) scanning consists of moving set of red, green blue LED's strobed.
• LED's are used for illumination and a connected monochromatic photodiode array of light collection.
• Images are kept on face down of the glass an opaque cover is lowered over it.
• Sensor array and light source move across the pane for reading the area.
• An image is therefore visible to detector because of light it reflects.
• It is some what difficult to scan transparent images.

Uses

• Converting text and graphics based document into digital image file.
• Converting Object into graphic image file.
• To display, print on paper and store for later use.

Portable scanner:

• Handheld device that slides across the text, image and object directly.
• Scanning images requires steady hand or uneven scanning would create distorted image.
• Most scanners produced light from an array of green LED's to illuminate the image.
• Can save more than 100 images at a time.

Uses

• Perfect for travelling users to scan text, graphics, objects etc.
• Also helpful for students and researchers to record information.