Patent ID: 11927754
Assignee: SEIKO EPSON CORPORATION
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A virtual image display device comprising:
an image light generating device;
a projection optical system configured to project image light emitted from the image light generating device;
a folding mirror configured to reflect, in an intersecting direction, the image light from the projection optical system;
a semi-transmissive mirror configured to reflect a portion of the image light from the folding mirror, wherein the semi-transmissive mirror has a flat reflection surface; and
a concave surface mirror configured to reflect, toward the semi-transmissive mirror, the image light reflected at the semi-transmissive mirror to form an exit pupil, wherein
an optical axis of the image light extending from the image light generating device to the folding mirror is disposed between a first virtual extension plane obtained by imaginarily extending the semi-transmissive mirror and a second virtual extension plane obtained by imaginarily extending the concave surface mirror,
the semi-transmissive mirror is disposed between the concave surface mirror and the exit pupil,
the optical axis of the image light from the image light generating device to the folding mirror is sloped at an angle from 10° to 30° relative to a normal line to a reference plane including a normal line to the semi-transmissive mirror and an axial line of the concave surface mirror,
the folding mirror includes a first mirror and a second mirror in an order of an optical path from the image light generating device, and
when a plane perpendicular to the axial line of the concave surface mirror is set as a reference, the second mirror is sloped at an angle from 20° to 40° in a counterclockwise direction about a horizontal axis relative to the plane as viewed from the image light generating device side.