when was the first fiber optic endoscope introduced
Endoscopy Basil Hirschowitz and Larry Curtiss invented the first fiber optic endoscope in 1957.[20] Earlier in the 1950s Harold Hopkins had designed a "fibroscope" consisting of a bundle of flexible glass fibres able to coherently transmit an image. This proved useful both medically and industrially, and subsequent research led to further improvements in image quality. Further innovations included using additional fibres to channel light to the objective end from a powerful external source, thereby achieving the high level of full spectrum illumination that was needed for detailed viewing, and colour photography.[citation needed]
Refracting telescope The design Galileo Galilei used in 1609 is commonly called a Galilean telescope. It used a convergent (plano-convex) objective lens and a divergent (plano-concave) eyepiece lens (Galileo, 1610).[6] A Galilean telescope, because the design has no intermediary focus, results in a non-inverted and upright image.