How Scanning Works

Overview

The power of scanning and the opportunity for placement of scanning technology into a customer's environment is endless. Advances in scanner technology, archiving, and retrieval software make it possible to virtually eliminate the mountains of paper generated and repeatedly handled in today's business processes. Sharp's goal is to offer systems and software in conjunction with our Authorized Dealers to enable your business to take advantage of this revolutionary, yet easy-to-use, technology. The advent of Sharp's Network Scanner technology available on our IMAGER™ and Document Communication System product lines allow for the rapid integration of hard copy documents into a system where they can be accessed on demand. This not only eliminates the need to copy these documents and forward them to internally or to outside constituents, but it makes for easy retrieval if the document is ever needed in the future.

What is a Network Scanner?

Most people are familiar with desktop scanners. A scanner converts pictures, graphics, drawings, photographs or text into digital characters for transfer to a computer. The transferred object can then be edited in diverse ways with the aid of image editing software, or "read" with the aid of text recognition software ("OCR" software). The primary task of a scanner is to digitize a two-dimensional document, e.g. a sheet of paper or a page of book. Digitization involves creating an image of the original document based on digital data. A Network Scanner works the same way as a desktop scanner, except it that is transmits the scanned image data over the office network to a designated file directory or email address.

How a scanner works

The most important part of the scanner is the CCD (Charge Couple Device) unit. The CCD, in short, is the "eye" of the scanner.
Following are the steps that take place when the scanner performs its intended operation:

• The document is placed on the glass platen or in the auto-document feeder and the scanning process is started (either via hardware by pressing a scan button or by a software prompt)
• A lamp is used to illuminate the document on the platen
• The scan head (i.e the lamp and the CCD) moves across the document to make a pass
• The light from the lamp hits the document and reflects. It then goes via a set of mirrors to the CCD array.
• The captured image is sent to the computer

Resolution

Scanning resolution determines the quality and readability of the scanned document. The resolution is defined as the number of digital dots per inch captured by the scanner. Scanners can extend this resolution with interpolation, a mathematical process which produces more dots per inch, but the basic optical resolution is the important number. Modern consumer scanners have optical resolutions in the range of 600 dpi to 1600 dpi.

Included Software

Most scanners come with basic image editing software, and software which converts a printed page into a typed document for your word processor (called "Optical Character Recognition", or OCR). Sharp include Sharpdesk software for this purpose. Sharpdesk allows you to OCR (convert to text), annotate, edit, email and file scanned files.

Optical Character Recognition (OCR)

OCR (Optical Character Recognition) is the process of turning a picture of words (such as a scan of a typed letter) into an editable document that you can open and use in your desktop publishing software, word processor, or other text editor.

Tips for Better OCR Results

Whatever type of program you use (and no matter what accuracy rate the program claims) there are things you can do to insure the best possible results from your OCR software:

• Start with a good original: Wrinkled or smudged originals tend to affect the OCR accuracy.
• Make the scan the best you can: Make sure the scanner bed/glass is clean, smudge-free. Keep the document straight and even so you don't end up with a "skewed" image. Adjust the color/contrast/brightness so the background is light/white and free of "artifacts" (such as a pattern in the paper) and the text is dark. Scan at 300dpi or better.
• Turn one document into many: With older or stripped-down software, graphics, lines on forms, columns of text, and other formatting may cause problems. Try breaking the scanned original down into smaller chunks (crop out non-text elements or save columns of text as individual images) and run your OCR software on each part separately. You'll lose formatting but gain a more accurate text document.
• Try different settings: Experiment with different options in your software. If your first attempt is less than usable, adjust the controls.
• Proofread: No matter how accurate the program, all are fallible. Proofread the finished document.

Features to Consider

When buying a scanner, take into account the many available features. Here's what you should consider:

Optical resolution: Resolution is a measurement in dots per inch (dpi) of the sharpness and clarity of an image. A scanner with 300-dpi resolution can capture an image with 90,000 dots per square inch. In general, 300 dpi is adequate for scanning. But if you plan to print what you scan, look for a scanner with a higher dpi, such as 600 or 1200.

Sheet-feeder: Scanners with Auto document feeders (or sheetfeeders) are excellent to scan multiple pages for document management (like invoices or receipts) or edit in a word processor, then a sheet-fed scanner should be your first choice. A sheet-feeder is also required to scan documents longer that 8.5" x 14" (legal) sized documents.

Bit depth: This refers to the number of bits used to capture each dot. The higher the number, the more color gradations will be visible. A 24-bit scanner will be suitable for scanning photos, drawings, and texts, while a 30- or 36-bit scanner is best for scanning film or transparencies.

Speed: If you're planning use a network scanner to scan tens to hundreds of pages at a time, speed is a major consideration.

Ease of use: This feature is more important than numbers. After all, it doesn't matter how high a resolution your scanner has if you can't figure out how to use it. Features such as one-step buttons (which allow you to complete routine tasks in one step) and user-friendly software greatly contribute to ease of use.