Irradiation apparatus with angle detection unit

An irradiation apparatus, comprising:

• a first light source which radiates a first light;
• a light deflector including a light deflecting mirror which reflects the first light radiated from the first light source, a support portion which supports the light deflecting mirror and is rotatable around a first axial line, and a rotation portion which rotates the light deflecting mirror around a second axial line which is orthogonal to the first axial line, the light deflector being configured to scan the first light by changing a reflection direction of the first light into which the first light is reflected by the light deflecting mirror, the reflection direction being changed by rotating the support portion to thereby rotate the light deflecting mirror around the first axial line and also by rotating the light deflecting mirror around the second axial line by the rotation portion;
• a second light source which radiates a second light;
• a light receiver which receives the second light radiated from the second light source and reflected by the support portion of the light deflector;
• an angle detection unit which detects a rotation angle of the light deflecting mirror around the first axial line, based on the second light received by the light receiver;
• and
• a pair of torsion bars connect the support portion and the light deflecting mirror,
• the support portion configured to support the light deflecting mirror via the pair of torsion bars, such that the first light is directed to the center of the light deflecting mirror, and the second light is directed to a reflection position on the support portion, the reflection position being spaced from and not on the first axial line, such that the second light reflects at the reflection position.