Today in Class we learned about scanners and why they are used.
The period started with mr Stratton talking about the previous lesson in which Peripherals mainly the keyboard were discussed.

The Qwerty keyboard has its roots in mechanical typewriters, this type of keyboard was designed in on order to slow down operators in order to avoid jamming the keys.

After a recap on the previous lesson Mr Stratton started discussing with the class about scanners .
A flat bed scanner allows for up to a4 size documents, the document is placed downwards on a glass panel and then scanned, a light beam reflects the light form the document and the photocells measure the light reflected. Also when scanning Analogue data it needs to be converted to digital.
Mr Stratton also told us that Modern Scanners use high bit depths to allow high resolutions.
Furthermore we learned that images that are being scanned must match their purpose meaning that there is no point in scanning at a resolution of more than 75 dpi for a screen based display. Likewise there is no point in scanning at 600 dpi for a printer that is rated at only 300 dpi.

Then we learned about the accuracy of scanners. In scanners accuracy is measured by how close the image is to the original. Resolution was described as the dots per inch (dpi) that can be detected by the scanner hardware.
For example a 600 dpi scanner has 600 photocells per linear inch.
Also the Bit depth of a scanner is usually 24 bits meaning it consists of 8 red bits, 8 green bits and 8 green bits.

Mr Stratton then continued the lesson by teaching us about the capacity of scanners. Such as there is little internal buffering and they rely on different techniques to transfer the data. Also storage can be high for example A4 page at 600 dpi requires 33.28 mb for 8 bit and around 100 MB for full colour.

Then Mr Stratton spoke about the cost of Scanners which have dropped dramatically in recent years and bundles software is often the major selling point.

The towards the end of the period Mr Stratton taught us briefly about sound.
Naturally occuring sound- is analogue in form. To input sound to a computer software samples the incoming signal and then proceeds to convert the signal into digital form and then usually compresses the file.
Then at the end of the lesson we were told to make some music using www.jamstudio.com in order to show us how the process works.

The End!