Single focal length lens system and image pickup apparatus using the same

• Main Authors: TAKASHI FUJIKURA, KAZUTERU KAWAMURA
• Format: Patent
• Language: English
• Published: 29.04.2015
• Subjects: OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICS; PHYSICS

A single focal length lens system and an image pickup apparatus using the same are provided. The single focal length lens system includes a front lens unit having a positive refractive power, and a rear lens unit in order from the object side to the image side along the optical axis. The front lens unit includes a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, and a third lens unit having a positive refractive power in order from the object side to the image side, and both the first lens unit and the second lens unit include a positive lens and a negative lens. The rear lens unit includes a focusing lens unit and a first predetermined lens unit in order from the object side to the image side. The first predetermined lens unit has a refractive power having a sign different from a refractive power of the focusing lens unit, and does not move at the time of focusing. The front lens unit does not include a lens which moves, and the rear lens unit does not include a lens which moves except at the time of focusing.