The effect of the changing transparency of a liquid crystal when an electric field is applied, had been described in 1888. The first patent, however, was only to be filed in 1936.
There are three types of LCD used in watches:
| 1 | Dynamic Scattering LCD. Optel, Microma, Texas Instruments. |
| 2 | Field effect LCD. Special applications: Dichroic, Pseudo Analogue, Divers. |
| 3 | Electrochromic LCD. |