• Input ( 2 ) Flashcards
What are some uses of barcodes?
Identification and tracking
What are the two different types of barcode?
- Quick response ( QR ) code
* Linear barcodes
What are the four types of barcode reader?
- Laser scanners
- CCD readers
- Camera based readers
- Pen Type Readers
How do pen type readers work?
- A light source and a photo diode are placed next to each other in the tip of a pen, to read a barcode, the tip of the pen is dragged across all the bars at an even speed.
- The photo diode measures the intensity of the light reflected back from the light source and generates a waveform that is used to measure the widths of the bars and spaces in the barcode.
What are some advantages of pen type readers?
• Feature a simple design, making them the most durable type of barcode scanner,can be sealed against environmental hazards such as dust and dirt.
What is a disadvantage to pen type readers?
• Applications are limited due to having to come into direct contact with a barcode to read it.
Where is a pen type reader suited?
Small size and low weight makes it ideal for:
• Portable computers
• Very low volume scanning applications
How do laser scanners work?
Same method as pen type readers, using a laser as a light source.
Where is a laser scanner best suited?
Reliable and economical for low volume applications such as a super market.
How do camera based readers work?
• A camera based imaging scanner uses a camera and image processing techniques to decode a 1D or 2D barcode.
What is an advantage of using camera based readers?
• An imaging scanner can read a barcode on any surface, printed or onscreen, and can read a code that is damaged or poorly printed.
What are some practical applications of camera based readers?
- Scanning coupons
* Scanning event tickets.
How do digital cameras scan barcodes?
- Digital cameras use a CCD or CMOS sensor.
- These sensors are comprised of millions of tiny light sensors arranged in a gird.
- Binary data from each sensor is recorded onto the camera’s memory memory card, so that the image can be produced using suitable software at a computer.
What are some advantages to digital cameras?
- CCD sensors tend to produce higher quality imagery.
* More reliable, since technology has been around for much longer.
What is a disadvantage to CCD sensors?
Have a large power consumption, relative to a CMOS sensor, they use up to 100x more power.