Flashcards
Computer Science - Chapter 5 Input devices
Cards in this deck (16)
- 1Explain the process of scanning documents in a 2D Scanner1. Document placed on glass panel
2. Xenon lamp produces white light, which illuminates the document
3. Scan head moves across document until whole page is scanned
4. Image of document is sent to lens by series of mirrors.
5. Focus image falls onto CCD, converts into electronic form - 2How does 3D Scanner work?Takes images at several points along coordinates of x, y and z of the solid.
Producing digital image of solid image. - 3What could happen after digital image is taken from 3D Scanner?1. Can be used in Computer Aided Design 2. Sent to 3D printer to produce working model of scanned image.
- 4List 3 technologies used in 3D Scanners1. Lasers
2. Magnetic resonance
3. White light - 5What is OCR technology used for?Producing digital images of passports
- 6How does OCR Technology work?It compares the key parts of 2D image of passenger's face to the 2D image of passport photo.
- Distance between eyes
- width of nose
- Shape of cheek bones - 7What does tomography technology do?Builds up image of solid through series of thin 2D 'slices'
- 8List 3 components that the slice is made of- X rays
- Radio frequencies
- Gamma imaging - 9List the 6 types of tomographic scanners1. X rays
2. CT Scanners
3. Radio frequencies
4. MRI
5. Gamma rays
6. SPECT - 10What separates the left and right side of the barcode?Guard bars
- 11What is the difference between the digits on left and right of the barcode?Digit on left:
- Odd number of dark bars
- Always begin with light bar
Digit on right:
- Even number of dark bars
- Always begin with dark bar - 12How is the barcode scanned?Read by red LED. Light is only reflected from white bars to the sensor. Pattern generated is converted into digital data (binary form), allowing computer to understand barcode.
- 13List 3 advantages of using barcodes to management1. Easier and faster to change prices on stock items
2. No need to price every stock item on shelves - reduces time and cost
3. Check customer buying habits by linking barcodes - 14List 3 advantages of using barcodes to customers1. Faster queues
2. Less errors in charging customers
3. Better track of 'sell by dates' for fresh food - 15List 6 functions of microprocessor in digital cameras1. Adjust shutter speed
2. Focus image automatically
3. Operate flash automatically
4. Adjust aperture size
5. Adjust size of image
6. Remove 'red eye' when flash is used - 16—
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- IGCSE Computer and Information Technology Flashcards on Computer Science - Chapter 5 Input devices, created by Yolanda Hung (9W) on 08/08/2017.
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- Yolanda Hung (9W)
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