A digitizer and liquid-crystal display (LCD) are two essential components found in nearly all touchscreen devices. Whether it’s a smartphone, tablet, monitor or human machine interface (HMI), touchscreen devices typically contain both of these components. The digitizer and LCD work in harmony to ensure the touchscreen device works as intended. With that said, each of these components has its own specific purpose and mechanism of operation. To learn more about the differences between a touchscreen digitizer and an LCD, keep reading.
What Is an LCD?
An LCD is a type of display device that’s characterized by the use of liquid crystals. The liquid pixels are typically made of polymeric organic compounds that, when exposed to electricity, are able to rotate polarized light. The liquid pixels themselves don’t produce light. Rather, they are illuminated by a backlight, with common backlighting solutions for LCDs including cold-cathode fluorescent lamps (CCFL), WLED array, EL-WLED array and RGB-LED array.
Without an LCD, a touchscreen device wouldn’t be able to produce images. The LCD is the component that’s responsible for producing images. As a result, all touchscreen devices have an LCD (or a similar display component).
Capacitive touchscreen devices are designed to detect touch commands by measuring capacitance. The digitizer constantly measures the device’s capacitance, and if it drops, the digitizer registers the location where the capacitance dropped as a touch command.
What Is a Digitizer?
A digitizer, on the other hand, is a component in touchscreen devices that’s designed to convert analog touch signals into digital touch signals. The LCD can’t display the appropriate images without first receiving these digital touch signals.
Digitizers are typically embedded in the outermost glass layer of a touchscreen device. Many people assume that the glass layer is the LCD, but this isn’t necessarily true. Although there are exceptions, the outermost glass layer is typically the digitizer. The digitizer is then connected to the LCD via a flex cable. When you perform a touch command, the digitizer will convert the analog touch signal into a digital touch signal that the LCD can respond by displaying the appropriate image.
Both LCDs and digitizers are essential components found in touchscreen devices. The LCD is the display component that’s responsible for producing images, whereas the digitizer is the component found in the outermost glass layer that’s responsible for converting analog touch signals into digital touch signals. The two components work synergistically to provide a functional touchscreen device that’s able to detect and respond to a user’s touch commands.