Types of scanners and scanner choosing


     The information transmitted by printing on paper since ancient times in our society. We learn history and literary works from books, office documents are also printed on paper etc.  Paper documents are replaced by electronic with the emergence and development of computer hardware very often now. There is a need to transfer printed documents to electronic form in this regard in many cases. Special devices – scanners were invented to solve these and similar problems. This topic will subscribe what is a scanner and how to choose a scanner for home.

Digital scanner is an electronic device by which different types of graphical information (pictures, text, pictures) transferred to a digital format and saved as files of different types. After that a variety of operations can be done with these files – copying, editing, etc.

The scanner principle is as follows: light from the light source hits the scanned object, it is reflected from the light through the optical system reaches the light element, and then to a special converter that converts analog information into digital.

Information transmitted to the computer through the controller after converting and processing, where it is processed with special programs. That is the main purpose of the scanner – to transform printed or other graphic information to image files.

Scanner history begins in 1857, when device called pantelohraf was invented, according to many researchers. German physicist Arthur Korn received a patent on the technology of photoelectric scanning, which became the basis of modern fax machines and other scanning devices in 1902.Digital scanner

There are different types of scanners (flatbed, hand held, drum, slide, planetary, portable) depending on the specific of their structure and intended use, but the most widely used are the so-called flatbed scanners (in which you put the document under cover and scanning by using a moving carriage).

Most scanners which are used for office or home use are flatbed scanners, so we will concentrate our attention on them.

Let’s list the main scanner parameters and look at them in more detail:

1. Scanner matrix type.

Scanner matrix is the photosensitive element which receives the reflected light from the scan object. Sometimes referred to a matrix types scanners types are determined.

Matrix of two basic types are installed to scanners currently – CCD and CIS.

CCD matrix installation requires a special scanner lens and mirror system. These CCD scanners have very high scanning quality and a large depth of field. Thus, optical scanner with such matrix is a more expensive. In addition, this scanner lamp warms for a long time, what reduces the scanning speed.

Optics are absent in CIS scanner and its role played by special light-sensitive element sensors. These scanners have relatively lower quality scan, but the scan speed is greater. However CIS scanners have lower size and cost less.

We can recommend the following when choosing a matrix: if you want to quickly scan a lot of text documents without any requirements for quality graphics – choose a CIS scanner, but if you want to scan graphic documents with high demands for quality graphics – choose CCD scanner.

2. Scanner optical resolution.

We have already talked about the resolution in the topics about webcams and digital photo frames.

Scanner resolution indicates how many dots per inch scanned horizontally and vertically.

For example, a Canon Cano Scan 5600F scanner model has a standard resolution of 4800 x 9600 dpi, which means that the horizontal resolution of the scanner is 4800 dpi and vertical 9600 dpi.

Clearly, the greater resolution helps to obtain the better image from the scanner. When you will buy the scanner pay your primary attention to the horizontal resolution (i.e. the first digit in the resolution indicator).

Basically, horizontal resolution of 300 dpi is sufficient to scan text. We can recommend choosing a home scanner with an optical resolution from 600×1200 dpi, and preferably from 1200×1200 dpi.

Some scanner manufacturers also specify a parameter as an interpolated resolution, which is larger than the optical. This resolution is obtained by the scanner software and almost never used, so do not pay attention to this advertising option.

3. Scanner color depth.

The scanner is used to scan color images very often and depth of color is very important in this case. This figure indicates how much color cast can recognize the scanner and is measured in bits.

Color depth can range from 24 to 48 bits in modern scanners.

Color scanner is able to detect about 16 million colors with a color depth of 24 bits, this is enough for high-quality color reproduction.

Human eye will not notice the difference between the 24 and 48 bit if to be honest. Another thing is that most scanners now have a color depth of 48 bits.

4. Scanning speed.

If you want to scan one or two pages, the speed of the scanner is not a critical feature for you, but if you want to scan 100-200 sheets this speed is very important.

Scanner speed is measured in number of pages that the scanner can scan for 1 minute or in number of seconds required for the processing of 1 page by scanner.

This figure indicates separately for text and graphics very often.

The shorter canning time is better. Quick scanner helps to save considerable time.

5. Scanner connection type.

Scanner connecting to computer carried via USB (USB scanners) in almost all cases now.

New scanners can be connected through a dedicated SCSI interface.

You should be aware of the availability of support necessary connection type in your computer.

I want to say a few words about scanner software for conclusion. Please ask about software compatible with your operating system in general and its specific version in particular. Though, the manufacturers are trying to produce drivers for canner for all existing operating systems in most cases.

     Well, I hopefully that after reading about the scanner you will know more about this device and this help you to buy the best scanner for your needs.

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