| 摘要 |
PROBLEM TO BE SOLVED: To obtain an optical head device in which protruding of an optical recording medium of a light source unit to the outside of a circumference is less and height of the device is low by making the angle between a direction being parallel with a junction layer of a semiconductor laser and a line segment connecting the center of an optical detector and an ignition point of the semiconductor laser into the prescribed angle range. SOLUTION: In this optical head device, reflected light from an optical recording medium is diffracted by a holographic beam splitter 3 and detection is performed by an optical detector 2. A direction A being parallel with a junction layer of a semiconductor laser 1 and a straight line X including a line segment connecting the center of an optical detector 2 and an ignition point of the semiconductor laser 1 crosses with an angle θ of 20-70 degrees. A straight line B shows a direction of a diffraction lattice of a holographic beam splitter 3 and crosses with the straight line X with an angle ϕ1 of approximately 90 degrees. Light emitted from the semiconductor laser 1 is reflected by a rising mirror tilting by 20-70 degrees, converged to an optical disk, reflected, diffracted by the splitter 3, and reaches the optical detector 2. Height of a while device can be made low by an angle of the rising mirror. |
