Pixel can be considered the main concept that is mentioned when raising the topic of LED screens. But what is it, what does it consist of, and where did it come from?
Most people in the world cannot instantly, without first mastering a certain base, answer these questions, even considering that the term itself has long become commonplace. A modern person is faced with pixels literally every day.
Even now, many of those who read this article are unaware that they are looking at pixels.
The concept of a pixel is an integral part of a raster image, which consists of many dots. The very concept of “raster” (derived from the Latin ‘rastrum’, which means “rake”) was borrowed from the lexicon of master printers and means a special grid that is used to prepare an image for printing.
Unlike artistic drawing or photographs, in which the image is built from lines that smoothly “flow” with each other, a printed image is built from dots. At the same time, there is the concept of DPI (Dots Per Inch – the number of dots per unit area), which indicates the quality of printing – the more, the better.
If you look closely at the image in the newspaper, you can see that it consists entirely of dots. In cheap editions, this will be literally visible to the naked eye. While in expensive magazines you have to use a microscope to view them.
By the same principle, an image is created on LED screens, whether it is an outdoor LED screen, a mobile phone, a display or a tablet, they all also consist of dots distributed with a certain density.
For monitors, for example, it is customary to use 72 dpi. It should be understood that the dpi value is calculated for a segment one inch long and one pixel wide.
Of course, 72 dpi is far from the limit, and some modern screens have long increased this value. As an example, devices with Super LCD technology have screens with a density of more than 430 dpi.
But, it is also worth noting that such a density in most cases is superfluous. Since it no longer has a special effect on the quality of the picture for the human eye.
Returning to the topic of the article, a luminous dot, the smallest unit of an image on the screen, can be called a pixel. Literally, a pixel is an abbreviation for the English “pictures element” – an image element.
However, this definition is only partly true. After all, for LED outdoor screens, the smallest physical unit is the LED lamp. And there can be several such lamps in one pixel of the screen. Depending on the properties of the screen. Therefore, for LED screens, the smallest element of the image will be called a pixel.
Dead pixels on the monitor. What is it and how to live with them?
Imagine the situation – you are about to upgrade your home PC. Select components for your future system unit; looked after the mouse, pad, keyboard. And now we get to the choice of monitor. We reviewed the offers of stores 10 times, read reviews, looked at reviews and asked friends. After all, a thorough approach is needed. Usually the monitor is rarely changed – once every 4-5 years.
The decision is made and you go for the long-awaited brand new PC (or wait for the courier). It’s time to turn on the system for the first time… What will be your surprise and indignation when you find 2 bright green dots right in the center of the monitor screen that do not react in any way to changing the picture?
You play games, watch movies or photos, and these dots prevent you from enjoying the picture. Using such a monitor will be very uncomfortable. These are the so-called dead pixels.
Questions and disputes often arise regarding broken pixels due to the subtleties in the manufacturer’s warranty conditions. We tried to briefly and clearly describe the basic concepts and ways to protect yourself from an unsuccessful purchase.
In fact, with any device that has a pixel grid screen (TVs, smartphones, monitors, tablets, etc.), a similar problem can occur. A dead pixel is a common matrix defect that manifests itself as an unchanged output signal.
But let’s focus on monitors. From our practice, it is with monitors that such situations most often arise. Since 2008, the ISO-9241-302, 303, 305, 307 standard defines requirements and recommendations for monitors on the acceptability of dead pixels on displays.