Scanners: Explained.

 Introduction:

          If you need a copy of a document that is sitting on your table. For this, with your PC, you use your flatbed scanner to convert it into a soft copy.

 

Mechanism:

          A typical scanner uses something called a charge-coupled device or CCD to determine what's on the page. The main idea here is that the CCD can convert light into an electrical charge which it then sends to your computer as digital data. So, when you start scanning a document, that bright light you see coming from inside is typically from either a xenon lamp or a cold cathode which as you may know is similar to what people use in PC case lighting a few years back. It's the sheet of paper and reflected back to a series of mirrors underneath the glass surface, and then focused by a lens onto an array of CCD sensors since darker areas of the page containing things like text and clipart will reflect less light in the blank. Usually, in white areas, the CCD array will see these differences which will show up as an accurate image of your document on your computer screen. If you've ever had a scan of something bulky and had to leave the lid open a little bit you'll have noticed the scan is black in areas that aren't covered by anything. This is because nothing's there to reflect the light. Though, modern software is often smart enough to crop these areas out for you. CCD rates are also what determine the scanner's true resolution. The more sensors in the array the more points of light it can capture and the more pixels it can send to your computer. If you're in the market for a scanner, make sure to check that the resolution on the spec sheet is the hardware resolution that reflects the true abilities of the CCD array, not some fake number achieved through software trickery like interpolation that uses average values of nearby pixels to approximate a higher pixel count image.

But what about color scanning? This uses additional lenses and built-in color filters to separate the scan into red blue and green versions which are then processed to determine what the actual colors of your original document are. Although, this is usually done with just one pass of the scanner. Some older models lack these additional lenses and so, they need multiple passes to complete a color scan which is why they were much slower in color mode. But not every consumer-level scanner works this way. Some flatbeds use something called a contact image sensor or CIS instead of these C CDs. These are simpler and construction uses an array of LEDs to shine a light on the document. So, an image sensor can essentially take a snapshot of it.  Although the scans from the CIS are typically lower quality than CCD scanners, CIS is a cheaper, more lightweight, and more efficient technology. So, you'll find it in a lot of small portable scanners that can be powered solely from a USB port instead of requiring a wall outlet.

Of course, there are other types of scanners out there such as expensive drum scanners with high dynamic range for professional applications as well as 3d scanners but the discussed above were the main focus here.

 

Stay tuned and Bye.

 

Types of Printers along with types: Explained.

 

Types of Printers:        

          There are two widely used types of printers for home and office use that are:

·        Inkjet Printers

·        Laser Printers

 

Working of Laser Printers:

          Let's have a look at them in a little depth. First up, we've got laser printers that use laser beams to create prints. Laser printers also contain a rotating cylinder coated with a photosensitive electrically charged material and a series of mirrors. When you send a document to a laser printer, the laser light is reflected by the mirrors onto the cylinder which neutralizes the electrical charge in specific areas. Thanks to the rotation of both the cylinder and the mirrors as well. As the laser turning on and off at precisely the correct moments the areas hit by the laser correspond to the actual print and when toner particles hit the cylinder, they only stick to the areas exposed to the laser light because the toner itself has an electrical charge to cool. Right then, a sheet of paper is pressed against the cylinder and the toner is transferred through to the paper using heat which fuses the toner to it. That is why pages fresh out of a laser printer are always so nice and cuddly warm due to the precision of the laser.

          These kinds of printers are great for producing crisp clear.

 

Working of Inkjet Printers:

          The inkjet printer is very different like the name says. This sort of printer uses liquid ink instead of solid toner particles. In consumer models, ink inside of those expensive cartridges is heated with an electrical charge causing a small amount to vaporize and form a bubble on the nozzle. The bubble then collapses and the pressure difference pulls a droplet of ink out of the cartridge and onto the paper because their internal workings are simpler than laser printers. They tend to be significantly cheaper and although they can't print as quickly. They give much better print quality for photos making them the go-to choice if you like to print your own snapshots at home.

Unfortunately, though many inkjet owners have been disappointed by their printer’s reliability. So then, why is it that they seem to give people such a hard time? Well, part of it is because printers have so many small moving parts that can break or wear out. Not to mention, the small nozzles that can clog easily but perhaps a bigger part of the reason is that the business model of inkjet manufacturers the printers themselves are frequently sold at a loss.

So, ink refills can cost more than the actual printers themselves. Also, many cartridges contain smart chips that report that they're empty even if there is still leftover ink. But fortunately, there are workarounds for this that you can find online. There are many alternatives as well, such as Epson’s new system that uses permanent high-capacity ink tanks instead of pricey cartridges.

 

That’s all for today.

Stay tuned, and Bye.