Visual disk-capacity indicator for disk recording systems

A floppy disk cartridge, comprising:

• a rigid housing for containing a floppy disk recording medium therein;
• a cover plate located at a peripheral edge of the housing for selectively covering an aperture formed in the housing and providing access to a portion of the recording medium contained in the housing, the cover plate being slidable with respect to the housing;
• a spring mechanism for biasing the cover plate to a normally closed position covering the aperture formed in the housing, the spring mechanism located in the housing on a side of the cover plate and proximate the peripheral edge whereat the cover plate is located;
• a visual disk-capacity indicator for indicating an approximate amount of disk space available for recording data on the recording medium, the disk-capacity indicator located in the housing on a side of the cover plate opposite to the spring mechanism and proximate the peripheral edge whereat the cover plate is located, the disk-capacity indicator being visible through a transparent window in the housing for viewing an indicator needle positioned to indicate an approximate amount of disk space available for recording on the recording medium;
• and
• an access opening located proximate the disk-capacity indicator at the peripheral edge of the housing whereat the cover plate is located for providing access to position the indicator needle.

A floppy disk cartridge, comprising:

• a rigid housing for containing a floppy disk recording medium therein;
• a cover plate located at a peripheral edge of the housing for selectively covering an aperture formed in the housing and providing access to a portion of the recording medium contained in the housing, the cover plate being slidable with respect to the housing;
• a spring mechanism for biasing the cover plate to a normally closed position covering the aperture formed in the housing, the spring mechanism located in the housing on a side of the cover plate and proximate the peripheral edge whereat the cover plate is located;
• and
• a visual disk-capacity indicator for indicating an approximate amount of disk space available for recording data on the recording medium, the disk-capacity indicator located in the housing on a side of the cover plate opposite to the spring mechanism and proximate the peripheral edge whereat the cover plate is located, the disk-capacity indicator being visible through a transparent window in the housing for viewing an indicator needle positioned to indicate an approximate amount of disk space available for recording on the recording medium, wherein the visual disk-capacity indicator comprises:
• a first guide rail slidably engaged with a first end of the indicator needle;
• a second guide rail slidably engaged with a second end of the indicator needle;
• and
• a lint-free cloth gently contacting the indicator needle for providing friction to prevent the indicator needle from arbitrarily sliding along the first and second guide rails.