Many-sided reflection prism and optical pickup

摘要

Provided is a many-sided reflection prism (20) formed as a single body with a plurality of reflection faces (23,25,27,29) which guides a light beam incident through a transmission face in a horizontal direction (ho) perpendicular to a height direction (hi) by reducing a size of the light beam in the height direction by using a difference in angles between the reflection faces (25,27) and reflects the guided light beam in the height direction by one reflection face (29) of an angle less than 45° with respect to the horizontal direction. By using the many-sided reflection prism, the height of an optical system can be reduced regardless of the wavelength used without reducing light beam size, and slim-sized optical pickups can be implemented.