Driving device and head-up display device

The invention provides a driving device and a head-up display device, and the driving device can suppress swinging of a movable member and contact sound between the movable member and a driven member in a structure in which the movable member moves along with translation of the driven member. A drive unit (30) has a lead screw (34), a nut part (72), a sliding part (42), a first arm part (78), and a second arm part (83). The nut part (72) receives rotational force from the screw (34). The sliding part (42) translates and moves the nut part (72) in the translation direction of the nut part (72) by its contact with the nut part (72). The first arm part (78) and the second arm part (83) are formed on the nut part (72) and elastically deform in accordance with contact between the nut part (72) and the sliding part (42) in the rotation direction of the screw (34). 本发明提供一种驱动装置及平视显示装置，该驱动装置能够在可动部件随着从动部件的平移而移动的结构中，抑制可动部件的摆动及可动部件和从动部件之间的接触声。驱动单元(30)具有丝杠(34)、螺母部件(72)、滑动部件(42)、第一臂部(78)及第二臂部(83)。螺母部件(72)从丝杠(34)接收旋转力。滑动部件(