Before scanners between inexpensive and popular in modern homes and offices, any document that was not digital could only be duplicated by a time consuming process such as photocopying. If a document was not digital, it simply could not be sent through email, making some documents much more difficult to manage and manipulate. Signed documents for instance, had to be sent via fax. This often incurred expensive long distance charges, not to mention the hassles of using a fax machine. Luckily for harried office workers and other who wanted the power to digitize and share documents, images, and even scans of objects, flatbed scanners emerged on the scene and saved the day.
The basic definition of a scanner is that it is a device that can be used to convert a document, an image, handwriting or even an object into digital format. Flatbed scanners are the most common types of scanners. They are called flatbed scanners due to the way they are made and used. The scanning surface is flat, and papers or images are laid on it in order to be scanned. The usage of a flatbed scanner is very simple. Someone places something that they want to convert to a digital image – perhaps a contract they just had signed or a technical drawing just received from the research and development department, or even a knick knack that they wish to sell on an online auction site – onto the document scanner’s flat surface, and push the button (usually located on the document scanner itself or accessed through software used to program the document scanner.) This produces a document on the computer to which the scanner is hooked up. From there, the user can manipulate the document, share it with the world, or generally do just about whatever he or she wants with it. Document scanners are very handy devices in the home, office or anywhere else, and the technology is older than you might think.
Document scanners can actually trace their history back to the 1920′s with the early telephotography input devices. Basically, these early versions of document scanners consisted of a rotating drum with a single photodetector at a standard speed of 60 or 120 rpm (later models up to 240 rpm). They sent a linear analog AM signal through the standard telephone voice lines to receptors, which synchronously printed the proportional intensity on special paper. As with much modern technology, document scanners have been around for quite a bit longer than they have been commercial available and affordable to the majority of consumers.
Flatbed scanners are some of the most versatile and commonly known types of scanners, but they are most definitely not the only type of scanner available. There are other types of scanners, including sheet fed scanners. These scanners look like small portable printers and their only difference from flatbed scanners is that the scan head does not move and the sheet to be scanned does. This is directly opposite from the function of a flatbed scanner. Another type of scanner is the handheld scanner. These scanners use basically the same technology as their flatbed scanner counterparts, but rely on the users to move them. These are used to quickly capture images and text, but do not provide the good quality that is provided by a flatbed scanner. When an incredibly detailed image is needed, a drum scanner does the trick. These scanners use something called a photomultiplier tube or PMT, which is mounted in a glass cylinder. A sensor is in the center of the sensor and it splits light into three beams that create a highly detailed scan of an image.