The LCD is made with either a passive matrix or an active matrix display grid

The lcd is made with either a passive matrix or an

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light rather than emitting it. The LCD is made with either a passive matrix or an active matrix display grid. The active matrix LCD is also known as a thin film transistor (TFT) display. Figure 1.0 shows the Passive-matrix VS Active-matrix (TFT) driving of LCD Display Figure 1.0
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Passive-Matrix LCD The passive matrix LCD has a grid of conductors with pixels located at each intersection in the grid. A current is sent across two conductors on the grid to control the light for any pixel. Advantages of Passive-Matrix LCD The technology for Passive-Matrix, for example HPA and CSTN is inexpensive to produce. Therefore, pricing for a Passive-Matrix LCD is much cheaper if compare to a TFT LCD. The design for the Passive- Matrix is very simple. It reduces the number of electrodes. Disadvantages of Passive-Matrix LCD The addressing of a PMLCD produces a kind of crosstalk that produces unclear images because non-selected pixels are driven throughout a secondary signal-voltage path. The response time for Passive-Matrix LCD is slow. This cause slow image refreshment rate and hence lower quality of changing display. The voltage control for Passive-Matrix is inherence imprecise. TFT LCD (Active-Matrix LCD) TFT LCD (Thin Film Transistor Liquid Crystal Display) act like switches elements. It consists of transistors and capacitors. Capacitors help to retain charge until next refreshment cycle. The transistor is place at every pixel in the display.
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Advantages of TFT LCD The TFT has a transistor located at every pixel in the display, requiring less current to control the luminance of a pixel. This is the reason that the current in TFT display can be switched on and off more frequently; improving the screen refresh time (for example, your mouse will appear to move more smoothly across the screen). By using the technology of transistor, TFT LCD display able to creating brighter pictures with greater contrast and better colour. Disadvantages of TFT LCD The technology of TFT LCD is costly. Buyer and user need to pay more for the TFT LCD display. The design for TFT LCD panels is more complicated.
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Answer No. 3(b) Introduction The concept in data compression is to eliminate the unnecessary or redundant information. There are many techniques for data compression, varying in computational complexity and effectiveness. Theoretically, a minimum amount of data (or maximum compression ratio) for a set of data are be able to restructure the original. Practically, compression technique normally does not achieve this limit. However, in many cases if the lossy technique is applied, the restructure data may have some errors or the file size is varying after decompression. How lossy compression work The lossy compression schemes allow redundant and nonessential information to be lost. There is a trade-off between compression and image quality with lossy schemes. Lossy image compression schemes can remove the data from an image that the human eye could not detect. If the image is viewed by human that means it works well. However, if the image is to analyst by a machine, lossy compression schemes my not be suitable. Computers are easily
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  • Fall '16
  • Pixel, Liquid crystal display

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