PROJECTION TYPE VIDEO DISPLAY DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a projection type video display device in which reduction in a projection distance (a wider angle) and miniaturization of a projection optical system are achieved.

SOLUTION: A projection optical system 1 comprises: a lens group 10 which is arranged in a traveling direction of light relative to an image display element 8 and includes a plurality of lenses; a first lens 11 which is arranged in the traveling direction of light relative to the lens group 10; a second lens 12 which is arranged in the traveling direction of light relative to the first lens 11; and a mirror 13 which reflects light emitted from the second lens 12 and projects the light onto a screen at an angle. The first lens 11 has a positive refractive power and the second lens 12 has a negative refractive power. In focusing, the first lens 11 and the second lens 12 are moved on the optical axis in a synchronized manner such that an amount of movement of the first lens 11 is larger than an amount of movement of the second lens 12.

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