Image display device and head mounted display using the same

A head mounted display equipped with an image display device that projects an image to a user, a sensing unit that detects external information, a communication unit that communicates with an external server, a power supply unit that supplies power, a recording medium that records information, an operation input unit that allows a user to operate, and a control unit that performs control of the entire device,

• wherein the image display device includes:
• an image generation unit that generates image light;
• a projection optical unit that projects the image light generated by the image generation unit;
• an image light duplication unit that duplicates and emits the image light projected by the projection optical unit;
• and
• a light-guiding unit that projects the image light duplicated by the image light duplication unit to a user,
• wherein the projection optical unit includes at least one projection lens, and
• wherein the image light duplication unit is configured with a prism having an incident surface on which the image light is incident, a plurality of partial reflection surfaces that reflect and transmit a portion of the incident image light, and an outgoing surface that emits the duplicated image light, and
• wherein the plurality of partial reflection surfaces are arranged inclinedly with respect to an optical axis of the incident image light, and intervals between the plurality of partial reflection surfaces are smaller than an outer diameter of the projection lens.