| 摘要 |
PURPOSE:To facilitate producing a lens included in a light projection optical system of a pickup head by forming the lens included in the optical system and a substrate into one body. CONSTITUTION:A micro-lens like an aspherical plastic lens 2 having a concave is formed on a part of a substrate 1, and a semiconductor laser 4 functioning as a light source is fixed under the lens 2. The lens 2 allows the light, which is emitted from the semiconductor laser 4 and goes in the substrate 1 while diverging, to emit to the air and condenses the light. The light emitted to the air is condensed by the lens 2 to form a minute spot (about 1mum diameter). Arrangement relations between an optical disk 20 and the substrate 1 are so determined that this spot is placed just on a pit 24 of the optical disk 20. |
