This invention relates to a view angle adjustment mechanism. A view element tilting section is tiltably supported by the tilting support section. Upon a motor being driven, a nut member rotates together with a gear member, the nut member rises/falls along a male thread member, whereby the view element tilting section is tilted. At a barrel of the nut member, a protrusion is formed. The protrusion is fitted in a groove of the gear member and causes the nut member to rotate together with the gear member. At the tilting support section, a protrusion abutment portion is formed. When the nut member moves in a direction in which the nut member comes off from the male thread member, the protrusion abutment portion abuts on the protrusion and thereby prevents movement of the nut member.