What Is an LCD Display?
An LCD display (Liquid Crystal Display) is a display technology that forms an image on the principle of liquid crystals being steered by voltage to pass or block light. It's the most common indicator type in electronics.
How Does It Work?
The liquid crystal itself doesn't produce light; it acts like a shutter. Depending on the voltage applied to it, it passes or blocks polarized light. For color, red-green-blue filters are added to each pixel.
The Need for a Backlight
Since an LCD doesn't produce light, it needs illumination behind it; in modern displays white LEDs do this job. Readability in the dark depends on this backlight.
| Type | Use |
|---|---|
| Character LCD (16x2) | Text display |
| Graphic LCD | Pixel-based drawing |
| TFT LCD | Color, high resolution |
Difference From OLED
Since each OLED pixel produces its own light it needs no backlight and gives deeper black; an LCD is cheaper and usually brighter in daylight. Other types include the pixel-based graphic/dot-matrix display and the very-low-power E-Ink (e-paper) display.
Where Is It Used?
Calculators, measurement instruments, home-appliance panels, monitors, televisions and embedded-system interfaces.
Reflective and Backlit Types
LCDs split into three by backlight: transmissive (backlight only, good in the dark), reflective (reflects external light, excellent in the sun but unreadable in the dark) and transflective (a mix of the two). The right type must be chosen for the application's light environment.
Common Mistakes
- Contrast setting: in character LCDs, if the contrast pin (V0) isn't set, the image is invisible.
- Backlight current: the LED backlight needs a series resistor/current limit.
- Viewing angle: in cheap LCDs the contrast degrades with angle.
Frequently Asked Questions
Why is an LCD invisible in the dark?+
What does a 16x2 LCD mean?+
Search parts related to "What Is an LCD Display?"
Find the right part by comparing price, stock and distributors.