Denys Fisher sale in Schofields department store in Leeds in 1965. A year later, Fisher licensed Spirograph to Kenner Products in the United States. In 1967 Spirograph was chosen as the UK Toy of the Year. Denys Fisher Toys, which also produced other toys and board games, was sold to Palitoy in 1970 and it was subsequently bought by Hasbro. Through the 1980s & 1990s Fisher continued to work with Hasbro in developing new toys and refining Spirograph. Denys Fisher Toys produced the following toys and games: Denys Fisher Denys Fisher (11 May 1918 – 17 September 2002) was an English engineer
Geometric function theory Geometric function theory Geometric function theory is the study of geometric properties of analytic functions. A fundamental result in the theory is the Riemann mapping theorem. The following are some of the most important topics in geometric function theory: A conformal map is a function which preserves angles locally. In the most common case the function has a domain and range in the complex plane. More formally, a map, is called conformal (or angle-preserving) at a point formula_3 if it preserves oriented angles between curves through formula_3 with respect to their orientation (i.e., not just the magnitude of the angle).