Optical system and display apparatus

A display apparatus comprising:

• an optical system;
• and
• a display element including a display surface,
• wherein the optical system is configured to guide a light beam from the display surface to a pupil surface, the optical system comprising, in order from a pupil surface side to a display surface side:
• a front group having a first lens having positive refractive power;
• and
• a rear group having a plurality of lenses,
• wherein a surface closest to the pupil surface of the rear group is a first transmissive reflective surface, and a surface closest to the display surface of the rear group is a second transmissive reflective surface, and
• wherein the following inequality is satisfied:
• 2.
• <
• Ff
• /
• F
• <
• 7
• .
• 0
• ,
• where Ff is a focal length of the front group.