Optical system and display apparatus

A display apparatus comprising:

• a display device which displays an image;
• and
• a magnifying optical system which directs an image displayed by the display device to an observer's pupil as a virtual image,
• wherein the magnifying optical system comprises a free curved reflective surface of which curvature fluctuates with inflection points.

A display apparatus comprising:

• a light source which emits bundles of rays of different wavelengths;
• an image forming device which forms a color image by a field sequential driving method in which while the image forming device is illuminated with the bundles of rays sequentially, the bundles of rays are modulated in accordance with the respective wavelengths in each pixel of the image forming device;
• and
• a magnifying optical system which directs light of the image formed by the image forming device to an observer's pupil by reflecting the light on a surface which performs surface reflection.

A display apparatus comprising:

• a display device which displays an image;
• a magnifying optical system which directs light of the image displayed by the display device to an observer's pupil as a virtual image;
• and
• a polarizer which is located between the magnifying optical system and an optical pupil of the magnifying optical system;
• wherein:
• the magnifying optical system is composed of one reflective surface;
• the light of the image emitted from the display device is linearly polarized light;
• and
• the polarizer is arranged so as to transmit the linearly polarized light.