Head-mounted display device containing relay optical system between image display unit and light guide member and display system

A head-mounted display device comprising:

• an image display located posterior to a plane that is in contact with both eyeballs of the wearer to emit image light;
• a light guide plate to guide the image light and emit the image light to an eye of a wearer who wears the head-mounted display device, the light guide plate including a reflection structure and a light guide structure to reflect the image light to outside of the light guide plate toward the eye of the wearer;
• a relay optical structure arranged between the image display and the light guide plate to relay the image light from the image display to the light guide plate;
• an optical structure located between the relay optical structure and the light guide plate to transform the image light to one of parallel light and telecentric light;
• and
• a control substrate disposed at a side of an optical axis of the image light, which is from the image display to the light guide plate, opposite from the eye,
• wherein the optical structure comprises a collimator optical structure,
• a first intermediate image is formed after the image light is emitted from the relay optical structure and before the image light enters the collimator optical structure,
• the relay optical structure is a relay lens group that includes a plurality of lenses each having a diameter in a range of equal to or larger than 2 mm and equal to or smaller than 8 mm and arranged inside a housing frame,
• the housing frame is disposed at a side of the wearer's head and connects the image display to the light guide plate, and
• a longitudinal direction of the control substrate is orthogonal to a light emitting surface of the image display.