Head-up display device

A head-up display device comprising:

• a display unit that emits display light;
• and a mirror unit that reflects the display light from the display unit onto a projection member, wherein
• the mirror unit includes:
• a concave mirror including a mirror surface that reflects the display light;
• a concave mirror holder including a main body that holds the concave mirror, a pair of rotational shafts that extends along a rotational axis from both sides of the main body, and a held section that extends from the main body in a direction crossing the rotational axis;
• a mirror drive unit that includes a holding concave section sandwiching the held section from a direction orthogonal to the rotation axis and causes the concave mirror holder to rotate with the concave mirror about the rotation axis by moving the holding concave section along the direction orthogonal to the rotation axis;
• a torsion spring including a coil that is inserted through any one of the pair of rotational shafts and a biasing part that extends from the coil and biases the concave mirror holder so as to bring the held section into contact with the holding concave section;
• and
• a contact section that contacts the concave mirror provided in the concave mirror holder, and
• the contact section is provided in a region of the concave mirror holder excluding a displacement occurrence region where displacement possibly occurs when the biasing part biases the concave mirror holder.