INPUT DEVICES (2)- scanning devices

Disadvantages of POS Systems

1. Barcodes cannot be read by people 2. Barcodes hold less information than QR Codes

Disadvantages of OCR

1. Can have difficulty reading handwriting if the letters are not formed properly. May not recognize unusual fonts. 2. Not 100% accurate. It may recognise a 5 for an S etc. 3. Information needs to be checked manually after scanning.

RFID (radio frequency identification) Reader

A chip connected to a small antenna makes up the RFID tag. This RFID tag can be placed in or attached to an object. Information such as a serial number is transmitted to an RFID receiver that converts the radio waves to digital information so that it can be processed by the computer. RFID tags are used for tracking animals by embedding them into the skins of an animal and the tag can be read once the animal is within range of the reader. Some stores are tagging their merchandise with RFID tags to record POS information, and also as a means of security to reduce theft.

Sheet-fed scanner

A fixed scanning device that automatically pulls a page over the reader; limited to single page scans.

Hand-held scanner

Held in the hand and reads the picture as the user drags it over the document. The quality of the image provided by this scanner is poor, but it is useful for quick data transfer.

Magnetic Ink Character Recognition (MICR)

Input device that reads text printed in special magnetic ink. The magnetic ink text is often used at the bottom of bank cheques and contain routing information to identify the bank and the number of the individual account.

Disadvantage of RFID Tags

RFID tags are much more expensive than QR coding and Barcoding

Photo Scanner

Specifically designed to scan photographs because it supports high resolution and the colour depth required to capture a good image.

Point of Sale (POS) System

Transaction processing systems that capture customer purchases. Cash registers and store checkout systems are examples. These systems are connected to a central computer and are critical for capturing sales data and are usually linked to inventory systems to subtract out any sold items (stock control).

Optical Character Recognition (OCR)

Used for reading characters from paper, using special readers (scanners) and software. The shapes of different characters are detected by shining light on them from a photoelectric device and sensing the patterns of reflected light. Sophisticated software allows each pattern to be compared with a set of stored patterns until the closest match is found. This match is translated into electronic text in the computer, so it can be manipulated by the user.

Drum Scanner

Usually used in the publishing industry (magazines, books) to capture images with high detail. These scanners tend to be expensive, often costing thousands of US dollars.

Magnetic stripe card reader

reads the stripe on the back of credit cards, entertainment cards, bank cards, security cards and other similar cards. The strip is a short length of magnetic coated tape printed on the surface of or sealed into a ticket or card. It contains information to identify the ticket or card and its user.

Disadvantages of Magnetic Stripe Cards

1. The data can be changed, altered forged or erased by magnetic fields. 2. The stripe can be damaged by scratching. 3. The stripe can store only a limited amount of information.

Disadvantages of Barcode Readers

1. Expensive way to gather information as each item needs a barcode. 2. Reader has to be held directly in front of the barcode. 3. They can be swapped on items. 4. Damaged barcodes will make you have to type the numbers by hand. 5. Do not identify single unique examples of a single product type but RFID can. 6. Can hold only a small amount of data conpared with the RFID.

Advantages of using a Barcode Reader

1. Fast data entry. 2. Error free data entry.

Disadvantages of OMR

1. Forms need to be accurately designed. 2. If forms are incorrectly filled in they can't be read properly eg. using a light coloured ink and not shading the correct area on the form. 3. Can only read shaded areas. 4. Forms can jam in the machine. 5. The document cannot have extra marks or be folded.

Two advantages of MICR Readers

1. Documents are difficult to forge 2. Documents can still be read after being written on, folded, marked and so on.

Advantages of Magnetic Stripe Cards

1. Easy and cheap to produce. 2. The strip can store enough information for simple transactions. 3. They reduce the amount of paperwork that would otherwise be involved in a transaction.

Advantages of OMR

1. No problem with having to understand someone's handwriting. 2. Allows for the use of an automated input device for data input. 3. Very quick input of data.

Two disadvantages of MICR Readers

1. This type of reader and the associated printer are expensive 2. The system can accept only a few characters

Advantages of OCR

1. Very fast conversion of large amounts of printed data into an editable format. 2. Cheaper than to pay an employee to retype text manually. 3. Avoids typing errors.

Barcode Reader

A device that uses lasers or LEDs to read the black and white lines of a barcode. Can be found on many products and barcode readers are used at point of sale (POS) terminals like groceries, bookstores and also to scan books in a library.

Advantages of POS Systems

1. Customers get quicker and more accurate service, which improved efficiency 2. Supermarkets can get instant or continuous stock checks 3. Saves on paperwork 4. Customers gets itemized bills.

Advantages of RFID Tags

1. Can be linked up to an alarm system to alert security when someone tries to exit a store without paying for an item. 2. Can be used to track lost keys or other small items. 3. Can be used to distinguish one product of the same type from another from the same manufacturer. 4. RFID tags can be reused again and again compared to barcodes.

Optical Mark Recognition (OMR) Reader

Detects the position of black marks on white paper. The documents to be read have empty boxes pre-printed on them. The user makes pencil or ink marks to fill the appropriate boxes. The intensity of the reflected light from these marks on these forms are detected by the scanner. Uses include multiple choice examinations, university applications, forms give out by researchers.

Advantages of QR Codes

QR codes can store much more information than bar codes. Data types stored in QR codes include numbers, text, URLs, and even Japanese characters. The size of QR codes is small because these codes store information horizontally and vertically. QR codes are more resistant to damage than bar codes. QR codes can be read from any direction or angle, so they are less likely to be misread.

QR Code Reader

Scans a QR code and then displays the corresponding webpage in a browser. QR is short for Quick Response code and is similar to a barcode. The QR code stores information about the item to which it is attached and requires a scanner to read it. Unlike barcodes, QR Codes store information in two directions - vertically and horizontally. This allows it to store more information than a barcode. These days the most common scanning device would be a camera on a cellphone.

Scanners

Were originally designed to scan pictures (images scanners) but now their use is extended, for example to scan a text into word processing program. Turns a hardcopy into a softcopy.

Flatbed Scanner

With this device a document is placed on a flat surface and the image is captured, similarly to how a photocopying machine works.