Recently, the market for portable instruments has been increasing markedly. If a very small optical disc drive can be realized, it is expected that a new market for memories will be created, because the running cost of an optical disc is very low. The main issues in such realization are miniaturization of a loading mechanism with a disc cartridge and recording density growth. In this paper, we propose a miniaturized optical pickup and mechanism that realizes a 5-mm-high drive usable with a cartridge disc. An optical axis shift using a prism pair is introduced for using conventional optical parts. A plano-concave lens and a hologram lens are used to compensate for achromatic aberration. Finally, signals reproduced by the miniaturized pickup are showed. Data-to-clock jitter was 6.3% for Blu-ray Disc (BD) storage density.