On home appliances, it is often necessary to display numbers and words to convey information, such as the current time displayed on the clock, the current temperature information on the kettle… etc. The two most commonly used displays are LED displays and LCD displays, this article will compare the advantages and disadvantages of LED displays and LCD displays, and provide a two-step quick way to quickly determine whether this product is an LCD or LED display.

Introduction to LCD display

LCD displays are the most common displays in daily life, from your mobile phone screen to home appliances, you can use LCD displays, but whether it is a color or black and white LCD display, in fact, the principle is the same. There are two main components within the LCD display:

• Backlight module
• Liquid crystal panel

The general structure of the display can be shown by the following figure, the liquid crystal panel itself is actually not illuminated, so if you want to see the color in front of the LCD display, the back should have a backlight module to emit light through the liquid crystal panel, usually the backlight module’s luminous color is white light, the liquid crystal panel can control the white light through, and display any color light on the front of the LCD display, which is the basic principle of the LCD display.

Common LCD display

There are two most common LCD display:

• Black and white LCD display.
• Full color LCD display

Common LCD Displays- Monochrome LCD displays

Black-and-white LCD displays are widely used in a variety of low-cost products, and the picture above is a black-and-white LCD display used in science calculator.

Advantages of monochrome LCD displays:

1. Can show very compact information.
   • Each display point of the calculator as shown below is very close to each other, and high-resolution text can be displayed
2. Power saving
   • Black and white LCD displays can operated without a lot of power compared to full-color LCD, when products that do not require full-color demand and need to control power consumption are often used.
3. Cheap
   • If you just want to display a set of numbers or a few ICONs, the price of using a black-and-white LCD display is much cheaper than that of a full-color LCD, and it is often used in a large number of consumer products.
4. Clear
   • The contrast of the monochrome LCD display is sufficient and clear enough for indoor use.

Disadvantages of monochrome LCD displays:

1. Small viewing angle, not easy to use for outdoor application.
   • Usually black and white liquid crystal display in the front view, the display is the clearest, but due to the LCD panel characteristics, as long as the side view, the clarity will be declined, outdoor will be affected by strong light, the viewing angle is not large, the clarity is not enough, LED display due to the word luminescence characteristics, there is no viewing angle problem.
2. Can only be used in monochrome
   • If you need multi-color applications, you can only upgrade to a full-color LCD display that is many times more expensive, and the LED display can simply add different colors to the LED display without significantly increasing the cost

Common LCD displays vs. Full color LCD displays.

　　The most common display in daily life is a full-color LCD display, in your mobile phone, the computer is a full-color LCD display, full-color LCD display through a finer adjustment of the LCD screen transmittance, bringing higher resolution, more color monitor, the following picture is a liquid crystal damaged computer screen, broken outside the place are normal display of high-resolution graphics

Features of the LED display

The structure and basic introduction of the display in this article this article, compared with LCD displays, self-illumination characteristics, so that LED displays in the outdoor visibility is high, high brightness, but also no viewing angle problem. LED displays are the same as black and white LCD liquid crystals, and the display information must be designed in advance and cannot be arbitrarily transformed. The price of LED displays is between full-color LCDs and monochrome LCDs, and if properly designed, they can save the cost of achieving display performance.

Two-step differentiation between LED displays and LCD displays?

The following process can be used to confirm that the display in your hand is an LCD display or an LED display:

• Observe if the information on the display is fixed? If it is not fixed, it must be not an LED display

Comparison of LED displays and full-color LCD displays on computer screens

• If the monitor’s information is fixed, turn on the monitor to see if there is a backlight in the location that is not displayed?

Schematic diagram of the contrast between the LED display and the monochrome LCD display

Conclusion

This article briefly introduces the basic principles and advantages and disadvantages of two common LCD displays, and provides two steps to quickly determine whether the display in hand is an LED display, and product designers can follow these two steps to understand which display the product is used when observing the product.