US Patent 7787795 Angle adjustment device and image forming apparatus

An angle adjustment device includes a main body, an operation panel supported for up-down rotation with respect to the main body, a block mechanism to block rotation of the operation panel with respect to the main body, a release-hold mechanism to release the rotation of the operation panel by the block mechanism and also to hold a released state, and a recovery mechanism to return from a state in which a blocked operation of the operation panel by means of the block mechanism is released to a state in which a rotation of the operation panel is blocked by means of the block mechanism.