| What is the definition of 2D scanners | An input device that is used as a method of inputting paper documents and storing them in computer as digital form |
| How does 2D scanners work? | 1. Documents are placed on the glass panel of the scanner
2. A bright light is shined onto the document
3. A scan head moves under the panel, scanning the document
4. An image is produced and sent to a lens by mirrors, which focuses on the image
5. The focused image then falls onto the CCD Charge Couple device which consist of Integrated Circuit coated by silicon
6. It scans image and makes it into digital form |
| What does CCD stand for | Charged Couple Device |
| What is CCD made up of | It is made up of thousands of light-sensitive elements, which produces electrical charges when light is shined on |
| After document is scanned by the scan head, where has it be sent to? | A lens using mirrors which focuses on the documents image |
| After the document is sent to the lens of mirrors, where does the focused image go? | It falls onto a Charged Couple Device (CCD) |
| What does the CCD consist of | It consists of integrated circuit coated by silicon |
| What does a scan head do | A scan head moves from under the panel and scans the document |
| What does OCR software stand for | Optical Character Recognition software |
| What does a OCR do? | It allows scanned text to convert into text file format |
| What are the uses of 2D scanners? | Airport to read passport, OCR can change copy text into digital form of password information |
| When image of person in passport are compared to real life face, how do they examine it? | By scanning distance between eye, nose width, shape of cheek bones, length of jawline, shape of eyebrows |
| What is the definition of a 3D scanner | An input device that scans a solid object and produce a 3D digital image of it |
| What does a 3D scanner use to scan? | It uses tomography |
| What is the definition of tomography | It means object are scanned by scanner taking multiple pictures of object with different angle and put them together to form 3D object |
| What are the 3 rays used in 3D scanner | X-ray, radio waves and gamma rays |
| What type of scanner uses X-ray | CT (computerised tomography) |
| What type of scanner uses radio waves | MRI (magnetic resonance imaging ) |
| What type of scanner uses Gamma Rays | SPECT (single photon emission computed tomography ) |
| Scanned image form 3D scanners can be used in? | CAD (computer aided degign) |
| What is the definition of barcode? | A series of black and white parallel line of different thickness |
| Why can a barcode be scanned from any direction? | The digit on the left starts with white bar, right hand side stars with black |
| How can a barcode be read | Barcode is read by LED or red laser, white bars reflects light, black bars absorb light, barcode is then read |
| How can the reflected light by be read form a barcode | It is read by photoelectric cells, pattern generated and converted to digital data |
| What are the 3 advantages of barcodes | Fast and easy to check price or info of product, automatic stock control, reduction of errors |
| What are the disadvantages of barcode | If not printed properly or been blocked or tore then it can’t be scanned |
| How does a barcode scanner in the mall work? | 1. Barcode is scanned and numbers looked up in stock database
2. When number is found, stock items record look up
3. Details of item shown
4. Number of stock reduced by 1, new value written
5. Number of stock compared to reordered level |
| What does QR code stand for | Quick Response code |
| What is the definition of QR code | Quick response code is made out of matrix of black squares on white background |
| What are the difference between barcode and QR code | Barcode can hold up to 30 digits, QR code could hold up to 7000 digit |
| What are the 3 advantages or QR code? | No need to type url, easily scanned, can be displayed everywhere |
| What are the 2 disadvantages of QR code | Can be easily scam, not as well known |
| What is the definition of digital cameras | A camera which can produce digital image that can be stored in computer |
| What controls digital camera | Microprocessor |
| What are the 6 things that a microprocessor of digital camera can do | Automatically focus on image, auto operate flash, adjust speed of taking photos, adjust aperture size, adjust size of image, remove red eye |
| How are photograph taken? | They are taken when light passes through the lens onto light-sensitive cells which are made of pixels |
| Why are ergonomic keyboards formed? | To prevent RSI |
| What does RSI stand for | Repetitive Strain Injury |
| What is the definition of keyboard | An input device which is used to input data by pressing a set of keys |
| What are the advantages of keyboard? | Easy to use, keys are letters that humans understand |
| What is the definition of a pointing device | A device used to control the moves ment of cursor on computer screen |
| What is the definition of microphone | An input device that can input sound into a device |
| What are the two types of recognition of microphone? | Voice and speech recognition |
| How does a microphone work? | When microphone detects sound, a diaphragm vibrates producing on electrical signals, the signal is then transmitted to sound card and converted into digital data |
| After microphone detects sound, what happens? | Diaphragm vibrates producing electrical signals |
| Where does the signal produced by diaphragm form a microphone go to? | It is transmitted to sound card and converted to digital data |
| What is The difference between Voice recognition speech recognition? | Voice recognition detects a person speaking, speech recognition detects the words spoken |
| How does a voice recognition work? | User voice is detected and converted into digital wave pattern, software compared wave pattern with stored wave pattern, if true, person has been correctly identified. |
| What are the limitation of voice recognition | They are limited in recognising words and phrases |
| How does a speech recognition work? | When sound is inputted, sound card in device converts sound wave into digital data, software takes digital value and breaks them up into phonemes, phonemes compared with words in dictionary, word spoken will then be suggested and output |
| After a sound is inputted in speech recognition, what happens | the Sound card in device converts sound wave into digital data |
| During speech recognition, after sound waves are converted into digital data, what happens? | Software breaks digital values down into phonemes, phonemes is compared to dictionary |
| What is the definition of touchscreen? | A device that allows the user to interact with a device by touching areas on the screen |
| What are the three types of touchscreen? | Capacitive, resistive, infra-red |
| What is capacitive touchscreen made out of | It is made up of multiple layers of glass, creating electric fields between them |
| When capacitive touchscreen is touched, what happens? | The electric current changes when glass is touched. Then coordination where it is touched is determined by microprocessor |
| What are the 4 advantages of capacitive touchscreen? | Medium cost, good screen visibility, durable screen, multitouch capability |
| What are the disadvantages of capacitive touchscreen | Allows only to touch by finger (not gloves) |
| What is resistive touchscreen made up of? | It’s upper layer is made up of polyester while bottom layer is glass |
| What happens when resistive touchscreen is touched? | When surface (top layer) is touched, it completes circuit with he bottom layer, signals are then send to microprocessor which calculate coordination on where is touched |
| What is the 2 advantages of resistive touchscreen? | Cheap, can use bare fingers, gloves to touch |
| What are the 3 disadvantages of resistive touchscreen? | Poor screen visibility, no multitouch, fair screen durability |
| What is the definition of interactive whiteboard | A device which can display computer image on whiteboard using projector |
| What are the 3 advantages of interactive whiteboard | Can do what computers can do (play games), many can view form big screen, can save data written on board and use further |
