Patent ID: 8804247

Claim:
A transmissive display device, comprising: a light source configured to emit light; a display part which receives the light from the light source to generate display light that represents an image; a deflecting element which changes a direction of the display light emitted from the display part; and a transmissive reflector configured to reflect light, which has a wavelength included in the display light emitted from the display part, towards a user and transmits light, which has other wavelengths, wherein the transmissive reflector includes: a diffracting element configured to deflect a direction of the display light; a front transparent member configured to hold the diffracting element at an incident side of the display light which is incident on the transmissive reflector; and a rear transparent member opposite to the front transparent member, the rear transparent member sandwiching the diffracting element together with the front transparent member, the front transparent member includes an air contact surface which contacts air, the diffracting element is inclined with respect to the air contact surface so that a difference between an incident angle of the incident display light on the diffracting element and an emission angle of the display light emitted from the diffracting element becomes small, and the diffracting element includes at least one inclined area, which is inclined with respect to the air contact surface, and one of a non-inclined area, which is not inclined with respect to the air contact surface, and a free-form surface, which has at least one curvature.