# How Liquid Crystal Displays (LCDs) Were Invented > This 1962 patent describes the first practical way to use organic liquid crystals to create a display that scatters light when an electric current is applied. - **Patent:** US 3322485 - **Original title:** Electro-optical elements utilizing an organic nematic compound - **Owner:** RCA Corp - **Granted:** 1967 - **Status:** Public domain (expired) - **Times cited:** 90 - **Field:** consumer_electronics, semiconductors, materials ## What it does The device uses two parallel plates spaced less than 500 microns apart, with the gap filled by an organic nematic mesomorphic compound, commonly known as a liquid crystal. One plate is transparent and the other is reflective, with conductive films on both to allow an electric current to pass through the material. When the electric field reaches a specific threshold, the molecules in the liquid crystal rearrange, causing the material to scatter light. This scattering effect changes the appearance of the display, allowing it to toggle between transparent and opaque states. ## What it does NOT cover - Does not cover color display technology, which requires additional filters not described here. - Does not cover active-matrix displays (TFTs) that use individual transistors for each pixel. - Does not cover the use of liquid crystals for anything other than light scattering (e.g., polarization-based twisting). - Does not cover backlighting systems, as this design relies on reflecting ambient light. ## The clever bit The invention identified that a specific class of organic compounds (nematic liquid crystals) could be physically manipulated by an electric field to alter their optical properties, effectively creating a light valve. ## Real-world examples 1. Early digital watch displays 2. Calculator screens from the 1970s 3. Basic monochrome information displays ## Why it matters This patent is the foundational document for the entire LCD industry. It proved that liquid crystals could be used for electronic displays, moving them from a laboratory curiosity to a functional technology that eventually replaced bulky cathode ray tubes in everything from calculators to televisions. ## Frequently asked questions ### What does How Liquid Crystal Displays (LCDs) Were Invented cover? This 1962 patent describes the first practical way to use organic liquid crystals to create a display that scatters light when an electric current is applied. ### Who owns patent US 3322485? RCA Corp owns this patent, granted in 1967. ### When does this patent expire? This patent has expired and is now in the public domain — anyone can use the invention freely. ### What is patent US 3322485 cited by? This patent has been cited by 90 later patents that build on its ideas. ### What problem does this patent solve? This patent is the foundational document for the entire LCD industry. It proved that liquid crystals could be used for electronic displays, moving them from a laboratory curiosity to a functional technology that eventually replaced bulky cathode ray tubes in everything from calculators to televisions. ### What does this patent NOT cover? Does not cover color display technology, which requires additional filters not described here. **Full plain-English explainer:** https://patentbrief.org/patent/us/3322485/lcd-liquid-crystal-display **Original patent:** https://patents.google.com/patent/US3322485 --- _Source: PatentBrief — https://patentbrief.org. Patent facts are from public records; the plain-English explanation is PatentBrief's._ ## Related patents Semantically similar inventions in the PatentBrief corpus: - [How Organic Diodes Make Light Using Special Molecules](https://patentbrief.org/patent/us/4356429/oled-organic-light-emitting-diode) — Eastman Kodak's 1982 patent on creating light-emitting diodes (OLEDs) using organic materials, specifically a layer of porphyrinic compounds to help inject electrical charges. - [Tiny Capsules for Electronic Paper Displays](https://patentbrief.org/patent/us/5961804/e-ink-electronic-paper-display) — MIT's 1999 patent on a special ink made of tiny capsules that can change color when an electric field is applied, forming the basis for early e-readers. - [The Invention of the Modern Field-Effect Transistor](https://patentbrief.org/patent/us/3102230/mosfet-field-effect-transistor) — This 1960 patent describes the fundamental structure of the MOSFET, the tiny electronic switch that powers every modern computer processor. - [Hamilton's Early Digital Watch with LED Display](https://patentbrief.org/patent/us/3672155/digital-watch-pulsar) — Hamilton's 1972 patent for a digital watch that uses electronic circuits and light-emitting diodes (LEDs) to show time, instead of gears and hands, powered by a rechargeable battery. - [How Amorphous Silicon Changed Solar Power](https://patentbrief.org/patent/us/4064521/semiconductor-device-having-a-body-of-amorphous-silicon) — This 1976 patent describes using a specific form of non-crystalline silicon to create cheap, thin semiconductor devices like solar cells.