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How big is an LCD Pixel?

300 micrometers!

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LCD Pixel

An LCD pixel is one of the tiny units that make up the picture on a liquid crystal display, or LCD, such as a computer monitor or a flat-screen television. The word pixel is short for "picture element". On a 27-inch full-HD computer monitor, each pixel is about 0.3 millimeters, or 300 micrometers, wide. A micrometer is a millionth of a meter.

Size

A pixel has no standard size. It depends on how big the screen is and how many pixels it holds. Screens are measured diagonally, from one corner to the opposite corner. A full-HD screen is 1,920 pixels across and 1,080 pixels down, about 2 million pixels in all.

Monitor makers give a pixel's size as its pixel pitch. Dell lists 0.3114 millimeters for a 27-inch full-HD monitor, and 0.2745 millimeters for a full-HD model with a 23.8-inch screen. A 27-inch screen is about 60 centimeters (23.5 inches) wide, and dividing that width by 1,920 pixels gives the same 0.31 millimeters. The explorer's 300 micrometers matches a full-HD monitor of about this size.

Packing more pixels into the same screen makes each one smaller. A 27-inch 4K monitor is 3,840 pixels across, twice as many, so its pixels are 0.1554 millimeters wide, half the width.

Size comparisons

  • About 82 pixels of a 27-inch full-HD monitor fit side by side in one inch (2.54 centimeters). Dell lists this as the screen's pixels per inch.
  • About 40 red blood cells, each about 7–8 micrometers across, would fit across one pixel.
  • A grain of table salt about 0.5 millimeters wide covers about 1.6 pixels.
  • When a pixel's three colored cells sit side by side, as in the explorer's picture, each is about 0.1 millimeters wide. That is about the width of a human hair.

How a pixel makes color

An LCD does not make its own light. A light at the back of the screen shines forward through every pixel. Each pixel is divided into three cells with red, green and blue filters, and each cell is controlled on its own.

Each cell holds a thin layer of liquid crystal, a liquid whose molecules can line up in the same direction. The light reaching it is polarized, meaning its waves vibrate in one direction. The liquid crystal turns that direction by 90 degrees, so the light passes through a polarizing filter at the front.

A voltage across the liquid crystal switches off the turning, and the filter blocks the light. Varying the voltage makes the cell brighter or dimmer. The colors a viewer sees come from mixing the three colors in different strengths. Red and green together look yellow, and all three together look white.

Sources

Scale of the Universe > LCD Pixel
Paramecium
Paramecia vary quite a lot in size, between 50 and 330 micrometers. These little guys are protists and like to swim in water. They can move two millimeters per second!
Ovum (Human Egg)
An ovum is the largest cell in the human body. Animals that develop within eggs within their mother are ovoviviparous, which humans are not. Ovoviviparous is the only English word starting with "vowel-v-vowel-v-vowel-v-vowel".
Smallest Object Visible to the Naked Eye
Under optimal conditions, the naked eye can see objects as small as 0.1 millimeters. That means that anything smaller than this circle is impossible for you to see without a microscope. You're missing out quite a lot, you know!
Grain of Salt
Salt is a compound made of a reactive metal and a toxic gas. Everyone knows that. Also, do not eat too much salt, or else you could die. Eating one thousandth of your body weight all at once will usually do the trick.
Amoeba
Amoebae are unicellular, which means there is only one cell. Some amoebae can grow to an incredible 700 micrometers, which is almost an entire millimeter.
Grain of Sand
Of course, not all grains of sand are the same size. They vary a lot. Arenophiles are people who collect sand samples. Also, did you know that Papakolea Beach has green sand? This is because of crystals in the sand. Whatever.

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