| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical head capable of detecting focus error signals for a CD and a DVD on the basis of a knife edge method only by one optical detector. <P>SOLUTION: In the optical head, a DVD optical diffraction element 108a is arranged between a deflection beam splitter 104 and an objective lens 107 for transmitting the first optical beam of a first wavelength and the second optical beam of a second wavelength, diffracting a first reflected light obtained from an optical disk corresponding to the first optical beam, and transmitting a second reflected light obtained from the optical disk corresponding to the second optical beam, and a CD optical diffraction element 109a is arranged between the deflection beam splitter 104 and the optical detection element 110a for transmitting the first reflected light and diffracting the second reflected light. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
