Loading mechanisms of optical disc drives
There are four distinct types of loading mechanisms in optical drives.
Tray load[edit]
Tray loading mechanisms are the most commonly used type of loading mechanism in computer optical drives.
Mechanical tray[edit]
A mechanical tray is used by most half-height desktop drives (those running on 12 volts).
It is self-ejectable and self-closeable and allows the user to conveniently place the disc in, rather than pushing it in.
Design-wise, only full-size (12cm) discs are insertable during vertical operation.
In rare occasions, very old optical drives with an improper implementation and/or physical damage might eject a disc before finishing to spin it down, causing it to spin in the tray placeholder, scratching against it.
Most mechanical trays have an additional placeholder that allows vertical insertion and ejection of the disc, if it is a 12cm (full-size) disc.
8cm miniature discs can be inserted in an indentation of the center of the tray, but only if the drive is in a horizontal orientation.
Manual tray[edit]
A manual tray is used by slim optical drives (those running on 5 volts) used in laptop computers and miniature desktop computers and can only manually be closed.
It needs to be handled with care while the tray is opened.[note 1]
Slot load[edit]
A slot loading mechanism is used by the minority of desktop and laptop drives, but most stationary game consoles and all car radio CD players.
The loading mechanism relies on more delicate parts but is more convenient for insertion and ejection.
Support for miniature (8cm) discs does vary. Example: While the Nintendo Wii slot drive supports miniature discs for GameCube compatibility, the Wii U slot drive does not accept miniature discs.
Both slim optical drives (those used in laptops, around 1 cm of height, 5 volts) and half-height optical drives (those used in tower desktop computers, 4 cm of height, 12 volts) with slot loading mechanism exist, including external optical drives.
Top-load[edit]
A top-loading mechanism is used by the minority of external slim drives such as the LiteON eTAU series, but many portable CD players and few game consoles (e.g. Nintendo GameCube).
It is manually opened and closed, and allows the disc to be ejected without the drive being powered on.
It is more convenient to handle than manual tray drives and does not require additional physical space while opened, but relies on the user not to open it during write access.
Also, only the disc inside the uppermost drive of external top-load drives stacked on top of each other is accessible.
Some top-load CD players and most, if not all pocket CD players fasten the disc from the bottom only, like on slim-type optical drives, requiring the user to push the disc in, but being orientation-independent.
Other top-load CD players have a non-fastening bottom spindle holder that does not require insertion force and does fasten the disc from both sides, like half-height (desktop) drives do.
Notes[edit]
- ↑ Because of the main hardware (including the optical pickup unit) being exposed while opened, the slim drives in more recent, more compact computers used in schools are more vulnerable to abuse.
Also see[edit]
Related navigation boxes: Electronics • Mobile phones • Data storage • User experience and user interfaces
