Head-mounted display device

A head-mounted display device, comprising:

• a display unit projecting an image beam to user's eyes, thus enabling the user to see an enlarged virtual image;
• a headphone unit configured to transmit sound information to the user's ears;
• and
• a connecting unit being substantially C-shaped and defining a C-shaped opening, a middle portion of the connecting unit coupling to the display unit;
• wherein two opposite sides of the C-shaped opening of the connecting unit couples to the headphone unit;
• the connecting unit comprises an outer frame, a connecting assembly, and an inner frame;
• the connecting assembly comprises at least two independent connecting members;
• the connecting assembly couples to the outer frame;
• the inner frame couples to the connecting assembly, and portions near the two opposite sides of the connecting unit of the inner frame fix to the outer frame, thus sandwiching the connecting assembly between the inner frame and the outer frame;
• wherein the connecting assembly further comprises a first connecting member located at the middle portion of the connecting unit, and a second connecting member and a third connecting member which are near the two opposite sides of the connecting unit respectively;
• and
• wherein the outer frame comprises a plurality of first hooks arranged on an inner side of the outer frame;
• the first connecting member, the second connecting member, and the third connecting member are spaced apart from each other;
• at least the first connecting member defines a plurality of second hooks;
• and each of the plurality of second hooks is slidable relative to a corresponding first hook when the plurality of second hooks clamp the plurality of first hooks.