Differences Between LCD And LED

LCD (Liquid Crystal Display) and LED (Light Emitting Diode) Displays are two major display technologies being widely used today. The LED using gallium arsenide and gallium phosphide which when heated emits visible light. The LED is used for showing the numeric and alphanumeric characters. On the opposite hand, the LCD contains a thin layer of liquid filament between the glass electrodes. When the facility is applied across the electrodes they begin emitting light energy within the type of photons. The LCD displays the text or images within the kind of matrix and segments.

Definition of LCD –

LCD (Liquid Crystal Display) is used for displaying the texts and images in the form of a dot matrix or segments. The LCD has liquid crystal filament which is filled between the transparent electrodes. When the current passes between the electrodes, the filaments become energized and emit visible light.

An LCD can be defined as a smooth board with the electronic visuals display which works through the light that has the quality of the liquid crystal. LCDs are super-thin shows that are utilized as a part of tablet phone and level board screens. Smaller LCDs can be utilized as a part of handheld TVs, PDAs, and compact computer game gadgets.

The liquid crystal used in the display has the property of both the solid and therefore the liquid. When the potential isn’t applied across the liquid, it becomes transparent but after activation, the crystal scatters light all told directions and appears to be bright. The LCD consumes less power and even has seven-segment displays. But it’s a slow device and requires more time for switching. The dc reduces their lifespan and hence mostly they’re used with AC having a frequency less than 500 Hz.

Definition of LED –

LED (Light Emitting Diode) is a PN junction diode that emits light when an electric current flows through it in the forward direction. The LED is constructed by doping the p-type and n-type material. When the power is applied across the LED the recombination of P-type and N-type material charges takes place. The recombination of charges gives energy in the form of heat and light.

Early LEDs delivered just red light, however, present-day LEDs can create a few distinct colors, i.e. green, red, and blue (RGB) light. The latest advances in LED innovation have made it feasible for LEDs to create white light also. The several LED is used for representing the one segment and the decimal points are represented by the single LED.

Key Differences between LED and LCD –

LCD stands for “liquid crystal display” and technically, both LED and LCD TVs are liquid crystal displays. The basic technology is the same in that both television types have two layers of polarized glass through which the liquid crystals both block and pass light. So really, LED TVs are a subset of LCD TVs.

  • The LCD uses a cold cathode fluorescent lamp which provides the backlight of the screen, whereas the LED uses the PN-junction diodes for displaying the light. The backlight refers to the turning on and off of the displays for better vision.
  • Contrast and Black Level of the LED screen is better than the LCD screens because the liquid crystals cannot stop 100% of the backlight from cold cathode backlight and hence when the black screen is to be shown on the monitor, it is not completely black. But LED screens perfectly show the black screen as there is no backlight at all.
  • The resolution of the LED is much better than that of LCD. The resolution is the number of pixels on the display of the screen.
  • The LED consumes more power as compared to LCD because of the plasma. The filament used in LCD is made up of plasma, which requires less power for activation.
  • The display area of the LED is less as compared to the LCD because LED use a PN-junction diode which displays light only in one direction, whereas, the LCD display lights in all the directions.
  • LED, which stands for “light-emitting diodes,” differs from general LCD TVs in that LCDs use fluorescent lights while LEDs use those light-emitting diodes. Also, the placement of the lights on an LED TV can differ. The fluorescent lights in an LCD TV are always behind the screen.
  • The cost of the LED is more as compared to LCD. The LED uses gallium arsenide’s which when heated emits light whereas LCD uses liquid crystals which are energized and provides light.
  • Color accuracy for direct and edge LED displays and LCD displays are almost same but the RGB LEDs display has quite better color accuracy. There are three different types of LED monitors available based on the manner how the diodes are arranged in the monitor. These are – Direct LEDs, Edge LEDs, and RGB LEDs. Both Edge and Direct LED display monitors use white diodes that are used to illuminate the LCD panel to produce the improved picture quality.
  • The switching time of the LED is less as compared to LCD. The switching time is the active and deactivated time of their display. The direct current reduces the lifespan of LCD whereas the LED has no effect on it.
  • The LED displays are more modern, iconic, and energy-efficient than LCDs. In an LCD display, the pixels are switched on or off electronically using liquid crystals to rotate polarized light.
  • The LCD uses mercury which pollutes the environments whereas the LED does not use mercury.

The main difference between these two technologies is that lighting technology: cold-cathode fluorescent lighting vs. light diodes. Bigger screens usually mean better resolution. The resolution refers to the number of picture pixels up by the number of pixels down. Pixels are the tiny dots that are the littlest unit wont to create the image. More pixels equal a richer, more colorful, and clearer image. The LED and LCD both are trendy technologies. But LED has more advantages than LCD and hence it’s mostly used for creating the displays.


Information Sources:

  1. circuitglobe.com
  2. quora.com
  3. electronics.howstuffworks.com