Ch4 Flashcards
What is active matrix of LCD screen?
page 187
Active-matrix LCDs depend on thin film transistors (TFT). Basically, TFTs are tiny switching transistors and capacitors. They are arranged in a matrix on a glass substrate. To address a particular pixel, the proper row is switched on, and then a charge is sent down the correct column. Since all of the other rows that the column intersects are turned off, only the capacitor at the designated pixel receives a charge. The capacitor is able to hold the charge until the next refresh cycle.
What is passive matrix of LCD screen?
page 187
Passive-matrix LCD is an LCD technology that uses a grid of vertical and horizontal conductors
comprised of Indium Tin Oxide (ITO) to create an image. Each pixel is controlled by an
intersection of two conductors. By creating a potential voltage difference at an intersection, the
LC fluid is able to respond by creating an “on” state at that intersection, also commonly referred
to as a pixel.
What is dual scan display?
page 188
Dual scan is a variation of the passive-matrix display
what is privacy screen filter?
Privacy filter is a filter that is placed over a display to make it difficult or impossible for someone to see the screen without being directly in front of the display
what is anti-glare filter?
Page 189
Antiglare filter is a filter placed over a screen that helps prevent sun and light glare on a screen
what is contrast ratio of display?
page 189
Contrast ratio of the brightest color (white) to that of the darkest color (black) that the system is capable of producing.
what is Plasma display?
page 189
Plasma display mostly uses of the Xenon and neon atoms. When the energy is liberated during collision, light is produced by them. These light photons are mostly ultraviolet in nature. Though they are not visible to us, they play a very important factor in exciting the photons that are visible to us.
what is Cathode ray tube technology?
page 189
Cathode ray tube ( CRT) the technology used in most televisions and computer display screens. A CRT works by moving an electron beam back and forth across the back of the screen. Each time the beam makes a pass across the screen, it lights up phosphor dots on the inside of the glass tube, thereby illuminating the active portions of the screen. By drawing many such lines from the top to the bottom of the screen, it creates an entire screen full of images.
What is PDP?
page 189
Plasma Display panel
What is OLED displays
page 190
OLED displaysis a flat light emitting technology, made by placing a series of organic thin films between two conductors. When electrical current is applied, a bright light is emitted. OLEDs can be used to make displays and lighting. Because OLEDs emit light they do not require a backlight and so are thinner and more efficient than LCD displays (which do require a white backlight).
what is refresh rate of displays?
page 190
Refresh rate is the frequency with which a monitor’s display is updated.
what is AMOLED technology?
page 191
AMOLED is an ‘active-matrix organic light-emitting diode’. It adds a layer of semiconducting film behind the OLED panel which allows it to more quickly activate each pixel. That increased speed makes it ideal for larger, higher definition displays with a lot of pixels
what is PMOLED technology?
page 191
PMOLED display uses a simple control scheme in which you control each row (or line) in the display sequentially (one at a time). PMOLED electronics do not contain a storage capacitor and so the pixels in each line are actually off most of the time. To compensate for this you need to use more voltage to make them brighter. If you have 10 lines, for example, you have to make the one line that is on 10 times as bright (the real number is less then 10, but that’s the general idea).
What is projector?
page 192
Projectors can be thought of as condensed video display units with a lighting system that projects the VDU’s image onto a screen or other flat surface for a group viewing.
what is Digital Light Processing (DLP) display?
Digital Light Processing (DLP) is a display device based on optical micro-electro-mechanical technology that uses a digital micro-mirror device
