| 摘要 |
<p>Provided is an optical unit which uses an elliptical mirror configured by a part or whole of the inner circumferential surface of an ellipsoidal body obtained by rotating an ellipse about a predetermined rotation axis. The optical unit changes an irradiation area of adjusted light to output the light. The optical unit is provided with a predetermined point (110), the elliptical mirror (111), and an adjustment means (113). From the predetermined point (110), a light (Ls) derived from light emitted from a light source (21) starts to diffuse. The elliptical mirror (111) is configured by a part or whole of the inner circumferential surface of the ellipsoidal body obtained by rotating the ellipse about a predetermined rotation axis (R1), has a first focus (f1) and a second focus (f2) on the rotation axis (R1), and reflects lights (L11, 21, 31) that have passed through the predetermined point (110) with the first focus (f1) coinciding with the predetermined point (110). The adjustment means (113) is capable of adjusting a position on the elliptical mirror (111) at which the lights (L11, 21, 31) that have passed through the predetermined point (110) are applied, with the first focus (f1) still coinciding with the predetermined point (110).</p> |
