Development of a F-Theta Lens for a Laser Scanning Unit

Recently, global applications of aspheric lens have been expanding rapidly in the fields or electronics, optical components, communications, aerospace, defense, medical optics devices, etc. The F-Theta lens, which is one major application of aspheric lens, is a core optical part in a laser scanning unit (LSU) because it mainly affects the optical performance of the LSU. The F-Theta lens is made of the plastic by using the injection molding method because of its cost and weight. In this study, the mold core for a F-Theta lens that consisted of two non-axisymmetric aspheric surfaces, was processed by using the fly-cutting method and the form accuracy of the mold core was measured. The F-Theta, lens produced by using the injection molding method was satisfactory enough to meet actual specifications