Method and apparatus for detecting media level in a cassette
AssigneeHewlett-Packard Company
InventorsJamison B. Slippy, Steven R. Folkner
Life of this patent
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Abstract
This invention relates to a method and apparatus for determining media level in a cassette. A single, fixed media level sensor is located adjacent to where the media is fed from the cassette. The bottom of the cassette is moved up until the top piece of media triggers the fixed sensor. The number of steps of the stepper motor (or the time an analog motor is on) indicates the distance the bottom of the cassette must be raised before the top of the media stack hits the sensor. The number of steps is used directly to determine the height of the stack of media and, therefore, the level of media in the cassette.
Claims11
A method for detecting media level in a media cassette, comprising the steps of:
- determining a range of motion of an empty media cassette;
- installing an amount of a media in said empty media cassette;
- determining a height of said amount of said media in said media cassette, wherein said determining step is further comprised of the steps of;
- moving said empty media cassette, contacting said empty media cassette against a media sensing means located a predetermined distance above said empty media cassette, and calculating a range of motion of said empty media cassette;
- and
- detecting a level of said media in said media cassette.
Dependencies are inferred from the claim text.