To trace the origin of liquid crystal display, we must first start with the birth of "liquid crystal". In 1888, an Austrian botanist, Friedrich Reinitzer, discovered a special substance. He extracted a compound called helical benzoate from plants. When doing a heating experiment for this compound, he unexpectedly found that this compound has two melting points at different temperatures. Its state is between the liquid and solid substances we are generally familiar with, a bit like the colloidal solution of soapy water, but it has the properties of both liquid and crystal within a certain temperature range. Due to its unique state, it was later named "Liquid Crystal", which means liquid crystalline substance. However, although liquid crystal was discovered as early as 1888, it was not until 80 years later that it was truly used in daily life.
In 1968, engineers at the Sarnoff Research and Development Center of RCA (the inventor of radio and television) in the United States discovered that liquid crystal molecules would be affected by voltage, change the arrangement of their molecules, and deflect the incident light. Using this principle, RCA invented the world's first screen using liquid crystal display. Since then, liquid crystal display technology has been widely used in general electronic products, including calculators, electronic watches, mobile phone screens, instruments used in hospitals (because of radiation measurement considerations) or screens on digital cameras. Interestingly, the discovery of liquid crystals was earlier than vacuum tubes or cathode ray tubes, but not many people in the world knew about this phenomenon. It was not until 1962 that the first book published by Mr. Joe Castellano, a chemist from the RCA research group, described it. Similar to the image tube, although these two technologies were invented by RCA in the United States, they were respectively developed by Sony and Sharp in Japan.