When shopping for a smartphone, tablet computer, monitor, human machine interface (HMI) or other device with a digital display, you’ll probably come across the term “refresh rate.” Different devices have a different refresh rate. And while this is just one many specifications to consider when choosing a display device, it plays an important role in the device’s functionality. To learn more about refresh rate and what it means, keep reading.
Understanding Refresh Rate
Refresh rate, also known as vertical scan rate for cathode rate tube (CRT) display devices, is a specification for display devices that refers to the number of times per second the device updates its buffer. Some people assume that refresh rate is just another word for frame rate, but this isn’t necessarily true. They both affect the visual display of the device, but refresh rate measures the repeated production of identical frames, whereas frame rate only measures the frequency of which the device can feed the frame.
You’ll probably discover that most display devices sold today have a refresh rate of around 60 to 120Hz. What does this mean exactly? Each Hertz (Hz) refers to a single frame per second. Therefore, display devices with a high refresh rate produce more frames in less time than devices with a low refresh rate. A device with a 120Hz refresh rate will produce 120 frames per second, whereas a device with a 60Hz refresh rate will only produce 60 frames per second. It’s a pretty substantial difference that can affect the image quality produced by the device.
Refresh Rate in LCDs
In liquid-crystal displays (LCDs), refresh rate is the number of times per second the device pulls data from its source. One of the great things about LCDs is that the individual LCD bulbs don’t turn on and turn off between frames. Therefore, they don’t suffer from “flickering” like other display devices. Even if an LCD has a low refresh rate, it still won’t produce flickering.
A high refresh rate in an LCD can actually cause visual distortions. To combat this problem, manufacturers of LCDs with a high refresh rate use digital processing to automatically force frames between the standard frames to create a smoother transaction.
Closing Thoughts on Refresh Rate
Refresh rate is just one of many specifications to consider when choosing a display device. Other specifications to consider include resolution, color performance, contrast ratio, spatial performance and brightness. By taking these specifications into account, you’ll be able to select the perfect display device for your needs.