IOSPD exam - Displays
LCD and OLED Displays Quiz
Test your knowledge on the various technologies behind modern displays, including LCD, OLED, and ePaper. This quiz is designed for those interested in understanding the intricacies of display technologies.
- 29 engaging questions
- Multiple choice format
- Perfect for students and enthusiasts alike
In the cholesteric phase of liquid crystals:
- Molecules align in layers, and in each layer they are twisted with respect to adjacent layers.
- Molecules have an approximately parallel orientation order.
- Molecules align in layers, and in each layer they are oriented in the same direction.
In the nematic phase of liquid crystals:
- Molecules have their long axes oriented approximately in parallel.
- Molecules align in layers, and in each layer they are twisted with respect to adjacent layers.
- Molecules align in layers, and in each layer they are oriented in the same direction.
At LCD, the color gamut/color range:
- Is wider when backlighting with LED RGB diodes is used, compared to the case in which backlighting with white LEDs diodes is used.
- Represents the number of colors that can be reproduced.
- Can be improved using frame rate control technique.
In case of LCD, the response time:
- Drops when the contrast is high.
- It is lower for black transition at brighter levels of gray in comparison with black transition at darker levels of gray.
- It depends on the backlight intensity.
In LCD, LED backlight:
- Reduces power consumption compared to fluorescent lamp backlighting.
- Enables to build professional-grade displays with its RGB LED backlighting variant.
- Allows building very thin displays.
- Enables to implement the „Full-Array Local Dimming” feature with its Edge-Lit White LED variant.
- Enables to maintain the uniformity of brightness in the long term.
- Reduces the brightness compared to the backlight with fluorescent lamps.
LCD Full Array Local Dimming (FALD) technique:
- Can determine light dispersion from a zone to the adjacent/neighbor zones.
- Can be implemented when white LED backlighting is used.
- Improves static and dynamic contrast.
At In-Plane Switching (IPS) technology of LCDs:
- Two transistors are required for every sub-pixel.
- Requires a transistor for each sub-pixel.
- Reduces the brightness in comparison with Twisted Nematic technology.
- Response time is reduced compared to Twisted Nematic technology (TN).
- Image remanence occurs when a moving image on the screen is touched.
Is not fit for tactile (touch) displays.
LCD passive-matrix displays:
- There exists a transistor connected to every row or column electrode.
- Compared to active-matrix displays, they have slower response time.
- Compared to active-matrix displays, they have wider viewing angles.
- Do not require/exist any transistor connected to the row electrodes or column electrodes.
- There exists a transistor connected to every pixel.
In a Twisted Nematic (TN) LCD:
- Molecules at the ends of liquid crystal chains are oriented perpendicularly to each other.
- Molecules in the middle of liquid crystal chains tend to align in parallel to an electric field applied between two electrodes.
- Polarized filters are used with polarized directions perpendicular between themselves.
- The layer of liquid crystals rotates the polarized direction of the backlight.
- The polarizing direction of light is not changed, since the liquid crystals are transparent and the light that passes through them is not affected.
- Liquid crystals molecules alignment is controlled using the magnetic field between electrodes.
- The light is re-polarized by the twisting of liquid crystal molecules.
At Super-Twisted Nematic (STN) technology:
- A higher contrast is obtained compared to TN technology.
- The response time is higher compared to TN technology.
- Light polarity direction is rotated/tilted with 90 degrees.
At Multi-Domain Vertical Alignment (MVA) technique of LCD:
- Brightness uniformity is increased compared to the Vertical Alignment (VA) technology.
- Viewing angles are wider compared to those of Twisted Nematic (TN) technology.
- Color reproduction is problematic in the direction perpendicular to the screen.
- Contrast is increased compared to the Vertical Alignment (VA) technology.
La tehnologia Multi-Domain Vertical Alignment (MVA) îmbunătățită a LCD:
- Timpul de răspuns crește dacă schimbarea de culoare necesara este redusa.
- Contrastul este îmbunătățit față de tehnologia MVA de baza.
- Protuberantele de pe ambele substraturi sunt înlocuite cu electrozi.
Compared to LCD, OLED displays:
- Contrast is higher.
- Energy consumption can be increased depending on the images displayed.
- Easier building of flexible and transparent displays.
- Response time is higher.
- Has a more complex fabrication process.
With OLED displays:
- Readability in outdoor conditions may be limited.
- Response time is faster than that of liquid crystal displays.
- Viewing angles are wide.
- Power consumption is always lower than that of liquid crystal displays.
Small-Molecule OLEDs:
- In general, it requires costly manufacturing processes.
- Uses structures with fewer layers compared to Polymer OLEDs.
- Requires lower voltages compared to Polymer OLEDs.
With phosphorescent OLEDs:
- Light emission persists even after the incident radiation has been removed.
- Efficiency is lower than that of fluorescent OLEDs.
- Only singlet states contribute to light emission.
The direct-emission OLED color generation technique:
- Enables high luminous efficiency.
- Requires a complex manufacturing process.
- Solves the color balance problem of other color generation techniques.
At color generation technique using white-emitting OLED (WOLED) diodes
- Light efficiency is reduced, because color filters are used.
- Color balance problems do NOT appear.
Complex manufacturing process due to the required precise positioning of the sub-pixels.
Quantum Dot on OLED (QD-OLED) technology:
- Does not require color filters.
- Uses photo emissive quantum dots.
- Uses OLED emitters to generate backlight.
Quantum Dot Enhancement Film technology (QDEF):
- Use a blue backlight.
- Use quantum dots for primary red and green color reproduction.
- Eliminates the necessity of color filters.
- Is the most widely used color enhancement technology for liquid crystal displays.
The color of light emitted by a quantum dot mostly depends on:
- The semiconductor material used for the quantum dot core.
- The size of the quantum dot.
- The structure of the quantum dot.
Punctele cuantice sunt formate din:
- Nano-cristale semiconductoare.
- Orice material cristalin, cu condiția să aibă dimensiuni nanometrice.
- Diode organice (OLED) cu dimensiuni nanometrice.
Select the properties that are used to design color electrophoretic ePaper displays:
- Pigment aggregation.
- Pigment separation.
- Pigment mobility in an electric field.
- Pigment weight.
At Interferometric Modulator Technology (IMOD) used for ePaper displays:
- Temporal interpolation can be used in order to create additional shades/nuances of the primary colors.
- Spatial dithering can be used to create additional shades of the primary colors.
- Light modulation is obtained using an optical cavity that contains a membrane and a thin film (stack) with the role of some micro-mirrors.
- Primary colors are generated by modifying the voltage applied between a thin film and an electrode from an optical cavity.
Color electrophoretic technology “Advanced Color ePaper” is based on:
- Different electrophoretic mobility of pigments.
- Grouping and separation of pigments under the influence of electric field.
- Both phenomena.
La “Advanced Color ePaper”:
- Se utilizează 3 pigmenti transparenti colorati si un pigment alb opac.
- Culorile roșu, verde și albastru se obțin prin mișcarea selectiva a pigmentilor disponibili.
- Fiecare din culorile cian, magenta și galben se obține prin gruparea a doi pigmenti cu incarcare opusă.
EPaper displays have the following disadvantages:
- They are not suitable for viewing video sequences and animations due to their low refresh rate.
- A permanent shadow image may be visible on the screen if an image is displayed for a long time.
- They are not suitable for outdoor displays since they are not wheatherproof.
{"name":"IOSPD exam - Displays", "url":"https://www.quiz-maker.com/QPREVIEW","txt":"Test your knowledge on the various technologies behind modern displays, including LCD, OLED, and ePaper. This quiz is designed for those interested in understanding the intricacies of display technologies.29 engaging questionsMultiple choice formatPerfect for students and enthusiasts alike","img":"https:/images/course3.png"}
More Quizzes
LG 2020 Technologies
11616
Camera Techniques
15812
Mobile Devices
10522
Quiz 21 - Capturing Demographic and Biometric Details
10583
Guidelines for Enrolment Operator and Supervisor on Quality of Enrolment
10562
Design Mastery Quiz
39200
QUIZ (1)
10526
Basic Electronics ( Test 2)
201041
Topic:Quality of Enrollment Checking
201063
GCM 360
70350
Hi!
100
Birds ( Aves )
100