Scanner Types

Tuesday, November 3, 2009

Flatbed Scanners

Flatbed scanners will take up some desktop space but provide a lot of bang for the buck. They look like miniature printers with a flip-up cover protecting the glass platen. Depending on its size, a flatbed scanner can fit standard or legal-sized documents, and the flexible cover allows you to scan large items such as books. These scanners are great for scanning the occasional newspaper article, book chapter, or photograph; or for those who may need to scan or bulky items such as the cover of a DVD. Flatbed scanners are often built into multifunction printers (MFPs). You can find a decent flatbed scanner for $100 or less.

Photo Scanners
Scanning documents doesn’t require high resolution or color depth; but scanning photos does. Many all-purpose scanners can also scan photos, meaning that you don’t need a separate device to handle your photographs. But if you need a scanner primarily to digitize film negatives or slides, a photo scanner might be better deal (even if it is considerably more expensive than an all-purpose scanner). Photo scanners include specialized technology so that they can deal with slides and negatives; they also have built-in software to clean up old photos. Decent photo scanners will start at about $130 (and go way up from there). Here are my Top Picks.

Sheetfed Scanners
Sheetfed scanners are smaller than flatbed scanners; as the name implies, you feed a document or photo into the scanner rather than place it on top. You’ll win back some of that desktop space with a sheetfed scanner but you may sacrifice some resolution in the process. If you’re only scanning documents, however, it may be a worthwhile trade, especially if you’ve got a lot of them since you can feed them in bunches. With a flatbed scanner, you’ll have to scan one page at a time (unless it comes with an automatic document feeder). Sheetfed scanners start around $300.

Portable Scanners
Portable scanners are small enough to bring on the road. In fact, some are small enough to put in your pocket; pen scanners are just a bit bigger than fountain pens and can scan the text of a document line by line. Some are as wide as a page and roll easily down the page. They’re not going to give high-resolution scans and so aren’t good for scanning photographs or other applications where you need a high-quality result. Since they’re not cheaper than flatbed scanners, they’re probably only useful if you are a student, a researcher, or a spy. Figure on spending about $150 for one.

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Image Scanner

In computing, a scanner is a device that optically scans images, printed text, handwriting, or an object, and converts it to a digital image. Common examples found in offices are variations of the desktop (or flatbed) scanner where the document is placed on a glass window for scanning. Hand-held scanners, where the device is moved by hand, have evolved from text scanning "wands" to 3D scanners used for industrial design, reverse engineering, test and measurement, orthotics, gaming and other applications. Mechanically driven scanners that move the document are typically used for large-format documents, where a flatbed design would be impractical.

Modern scanners typically use a charge-coupled device (CCD) or a Contact Image Sensor (CIS) as the image sensor, whereas older drum scanners use a photomultiplier tube as the image sensor. A rotary scanner, used for high-speed document scanning, is another type of drum scanner, using a CCD array instead of a photomultiplier. Other types of scanners are planetary scanners, which take photographs of books and documents, and 3D scanners, for producing three-dimensional models of objects.

Another category of scanner is digital camera scanners, which are based on the concept of reprographic cameras. Due to increasing resolution and new features such as anti-shake, digital cameras have become an attractive alternative to regular scanners. While still having disadvantages compared to traditional scanners (such as distortion, reflections, shadows, low contrast), digital cameras offer advantages such as speed, portability, gentle digitizing of thick documents without damaging the book spine. New scanning technologies are combining 3D scanners with digital cameras to create full-color, photo-realistic 3D models of objects.


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Buying Better Computer Hardware

Computers are essential to keep pace with the high speed world. If you don't have a personal computer, you are surely going to lose some amazing opportunities to move ahead in life. But, if you're interested in buying computer
for yourself, it is important to pay attention to few important things.

Although there are many things to take into consideration at the time of buying a PC, you need to make sure you have checked it for hardware configuration. You should also make sure your computer can easily be upgraded after purchase. This is the point where you will have to install new hardware to replace the older one. But, if you don't know how to find right type of computer hardware, you should keep following things in mind.

* It doesn't matter if you want a Hard Disk, Floppy Drive, Power Supply or any other type of computer hardware, you should consider shopping over the internet. The reason is that it will help you make a choice form the wider range of options and you will be able to upgrade your computer in the right way.

* Another important thing to keep in mind is that you should always shop from an authentic site. This is one big issue associated with the option of buying hardware over the internet. There are many sites selling substandard parts and these are the sites that should be avoided at all cost.

* While shopping for computer hardware, you should always try to shop around. It means you should try to find few popular sites to make a comparison for price and variety. First check for the available variety of hardware. This is important to get everything from one single site. Then, compare these sites for price and available discounts to proceed with your shopping.

* In case you don't have enough money to upgrade your PC, you should consider the option of buying used hardware. This is the option that helps you get a faster PC without spending a fortune on hardware. But, as mentioned earlier, always shop from an authentic site for used hardware to get the better bang for the buck.

* At the time of buying computer hardware, it is essential to pay attention to compatibility. Yes, it seems like all hard drives will work for your PC, but that's not the case. You should read the manual before searching for computer hardware over the internet.

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Multi-core processor

A multi-coreprocessor is a processing system, that from two exists or more independent cores. The cores are on individual integrated circuit die (well-known as splinter multiprocessor system or CMP) usually integrated, or they can be integrated on repeated cubes in individual splinter package. A many core processor is one, in which the number cores is enough large that traditional multiprocessor system techniques are no longer efficient - this threshold is somewhere in the distance of some 10 cores - and probably a net on splinter require. A double core processor contains two cores, and a Viererkabelkern processor contains four cores. A multi-core processor inserts parallel processing in individual physical package.

Cores in a multi-core device can be connected together firmly or loosely. E.G. cores can or know buffer memories possibly not divide, and them methods of report exceeding can would bring in or the divided memory Zwischen-kern communication. Topologies of the general net to the linkage cores cover: Ring, measure into one another 2 and lateral ripple seizes bus. All cores are identical in the homogeneous multi-core systems and them are identical not in the heterogeneous multi-coresystems. Straight ones as with particular processor systems, know cores in the multi-coresystems architecture as superscalar, VLIW, which, SIMD would bring processing vector in or multithreading.

Multi-core processors are used over many areas of application inclusively at most: universally, embedded, net, digital signal processing and diagrams. The quantity of the achievement won with use of a multi-core processor depends strongly on the software algorithms and - implementation. In particular the possible profits are limited by the break of the software, which can be made parallel, in order to run on repeated cores at the same time; this effect becomes by Amdahl' described; S-law. In the best case embarrassingly parallel problems so called can realise Speedupfaktoren close of the number cores. Many typical applications however realise not such large Speed up faktoren and therefore, are the Paralellisierung of software an important current topic of the research.

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Types of Computer Hardware

Computer Hardware computer hardware within the physical part of the show. It has several computer software or data that can be changed often or to destroy computer has changed. Computer hardware and has not changed frequently, such as reading hardware units, is stored in memory only (Rome), where it is not easily changed. Most computer hardware and therefore does not appear embedded normal users. Different types of computer hardware is found below.

Motherboard: This is the central or primary circuit, a complex system like a computer that is electronically. Main Committee a one motherboard, logic board or system board is known as.

CPU: A CPU in a digital computer, the computer program instructions and data interpretation process is the main component. Random access memory: a RAM stored data will be received in any order allows. Ram used to work in a computer that is considered indicative of the central memory and manipulating data.

Understanding output system: BIOS program, computer load, makes software for implementation and management.

Power supply: power supply production of electrical energy supplied to load or load group.

Video Display Controller: It is an indication that a display can be used as an investment in visual information is converted logical representation. Computer bus: The data or a computer or between computer components inside a computer is used to bring the power.

CD-ROM drive: This is data that are available through a computer disk includes: a data storage device, Zip drive: it a removable magnetic disk storage system capacity is moderate.

Hard Disk: This is a permanent data storage system, data is a magnetic surface, which is charged on Festplattenservierplatten stored on.

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Microprocessor

Most include a microprocessor or central processing unit (CPU), an integrated function of all circuit (IC) on. The first microprocessors emerged in the early seventies and for 4 Bitwörtern binary coded decimal (BCD) using the computer for math has been used. Use other embedded 4 - and 8 terminals, printers, etc.
Various types of automation as Bitmikroprozessoren, not that quickly followed. Affordable 8 Bitwenden also with 70 per cent year-Bitmikroprozessoren 16 between the first micro computers under universal. Computer processor is a long time, who was out for the construction of small and medium size of the IC from several hundred transistors.
Integration of the entire CPU on one chip, consequently reducing the high cost of processing capacity. Humble beginning, other types of computers increases in microprocessor capacity have continued almost entirely obsolete (rechnenhardware see history), the large and small embedded systems to mainframes and everything from handheld devices as the processing elem

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