1980 - Lorus Solar
Lorus is a division of Seiko. Casio and Seiko developed thin, inexpensive watches with plastic case and band with a large solar cell array. The date is estimated by the design.
There are a number LCD watches with a similar design configuration of a prominent solar cell on the face – as large or larger than the LCD display.
Comment: The Lorus model seemed to get all the design elements perfect on their version. Simple, inexpensive, elegant.