Scanner

SCANNER

Scanner is a device that scans documents such as photographs and pages of text.It is a input device. Scanners have become an important part of the home office over the last few years. Scanner refer to the Computer peripheral device that converts a document, film, graphic, or photograph to a digital image, manipulable through an appropriate software.

The basic principle of a scanner is to analyze an image and process it in some way. Image and text capture allow you to save information to a file on your computer. You can then alter or enhance the image and also print it out or use it on your Web page . The purpose of greater scanning resolution is to create more pixels, to create a larger image size.



EXAMPLE:

Using it can be a quick and efficient way to make a copy of a drivers license or pass port if you need that done.The cashier used a scanner on all of my grocery items so that they could input the price of the items a lot easier than entering them manually.And many more.

Using different interfaces you can connected computer to USB. Scanning process may include through software as well as hardware.

HARDWARE SCANNER:

A scanner or optical scanner is a hardware input device for a computer. It allow a user to take a printed picture, drawing, or document and convert it into a digital file (either an image or a text file) so that it can stored, viewed, and edited on a computer. This is generally include usb, firewalls etc mode of connectivity.

TYPES OF SCANNERS USED IN COMPUTER:

Sheetfed scanner – scanner that scans paper by feeding paper into the scanner.

Handheld scanner – scanner that scans information by holding the scanner and dragging it over a page you want to scan.

Card scanner – scanner designed to scan business cards.

Software scanners:

A scanner may refer to any program that scans computer files for errors. It also scan problems like anti-virus program . scans the files on the computer for any computer viruses or other malware.

.When used with an optical character recognition (OCR) software, a scanner can convert printed, typewritten (and, with some devices, handwritten) text into a digital file that can be read by aword processor.

SCANNER TECHNOLOGY IS EVERYWHERE AND USED IN MANY WAYS:

Flatbed scanners:It is also termed as desktop scanners.it is the most commonly used scanners. The flatbed scanner bed is 8.5 inches wide, so a 1200 dpi CCD sensor is an array of (1200 dpi x 8.5 inches) = 10200 pixels in one horizontal line. A wide-angle optical lens focuses the 8.5 inch image width onto a much smaller CCD chip, using mirrors to fold the long optical path inside the scanner.

A typical flatbed CCD array is perhaps 72 mm wide, with 7×7 micron cells being popular today. Most flatbed choices are 600 or 1200 dpi now, and some are 2400 dpi. Flatbed scanner specifications are stated with two numbers, like 200×2400 dpi . Flatbeds also usually specify a maximum resolution, like perhaps 9600 dpi. A scanners scans one horizontal row of pixels at a time, moving that scan line down the page with a carriage motor. The smaller dpi number is the optical resolution of the CCD sensor cells.

Sheet-fed scanners :It is similar to flatbed scanners except the document is moved and the scan head is immobile. A sheet-fed scanner lookt like a small portable printer.

Handheld scanners : It use the same basic technology as a flatbed scannerS, but rely on the user to move them instead of a motorized belt. This type of scannerS typically does not provide good image quality. However, it can be useful for quickly capturing text.

DRUM SCANNERS

It is used by the publishing industry to capture incredibly detailed images. They use a technology called a photomultiplier tube (PMT). In PMT, the document to be scanned is mounted on a glass cylinder. At the center of the cylinder is a sensor that splits light bounced from the document into three beams.