| 摘要 |
PURPOSE:To improve resolution by writing position information on a laser readout type encoding disk at right angles to its moving direction, and scanning a readout laser beam in the track lengthwise direction and obtaining the position information on the moving body. CONSTITUTION:Tracks 3 on which information bits are formed corresponding to position information codes are formed at equal intervals breadthwise at right angles to the moving direction of the encoding disk 1, and a pickup 11 including a readout optical system is movable at right angles to the lengthwise direction of the encoding disk 1. Thus, the tracks 3 are not formed in the lengthwise direction of the encoding disk 1, so the resolution is not limited by the number of bits per track (information recording density) and determined only by the pitch of the tracks 3. For the purpose, the track pitch is narrowed down and a read is taken with the laser beam to improve the resolution. |
