The most important constituent of an optical disc drive is an optical path, Cassette to CD Recorder placed in a pickup head (PUH), normally consisting of semiconductor laser, a lense for guiding the laser beam, and photodiodes detecting the flashing reflection from disc's surface.
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But switching to CAV requires considerable changes in hardware design, so instead most drives custom the zoned constant linear velocity (Z-CLV) scheme |
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| This divides the disc into several zones, each having its own different constant linear velocity |
| A Z-CLV recorder rated at "52X", for example, would write at 20X on the innermost zone and then progressively expansion the speed in a lot discrete steps up to 52X at the outer rim. |