Fluid level sensing system and method having controlled surface pairs

An ink jet printing system, comprising:

• an ink level detection device having an energy emitting portion and an energy receiving portion;
• a plurality of ink jet printheads for selectively depositing an ink on print media;
• plurality of ink containers, each of said ink containers being associated with an inkjet printhead of said plurality of inkjet printheads for providing said ink to said corresponding ink jet printhead with each of said plurality of ink containers having a plurality of controlled surface pairs arranged vertically along an interior side wall of the ink container;
• and
• means for moving said ink level sensing device to said plurality of ink containers so that said energy emitting portion emits energy that selectively impinges each of said controlled surface pairs and is received by said energy receiving portion to selectively determine ink level information from each of said plurality of ink containers.

An ink containment device for use with an ink jet printing system, said ink containment device including:

• a housing for containing an ink, said housing having an interior wall;
• a plurality of controlled surface pairs disposed along said interior wall of said housing, each controlled surface of said plurality of controlled surface pairs having a first reflected light characteristic when said ink is in contact with said controlled surface and a second reflected light characteristic when said ink is not in contact with said controlled surface;
• and
• wherein each of said plurality of controlled surface pairs is disposed and arranged on said housing so that incident light rays impinging upon each of said plurality of controlled surface pairs produce one of said first or said second reflected light characteristics having a combined light intensity value based on ink level in said ink containment device.

A method for detecting a fluid level in a fluid container, said method comprising:

• providing said fluid container wherein a plurality of controlled surface pairs of said fluid container are disposed vertically along an interior side wall of said fluid container, said plurality of controlled surface pairs being within detecting range of a fluid level sensing device;
• emitting light rays incident on said plurality of controlled surface pairs;
• reflecting said light rays off of each controlled surface wherein said fluid is not in contact with said controlled surface and returning said light rays as a plurality of reflected light rays back to a single light receiving device of said fluid level detecting device;
• diffusing said light rays into said fluid wherein said fluid is in contact with said controlled surface;
• determining said fluid level by said fluid level sensing device analyzing a total amount of said reflected light rays received by said light receiving device;
• and
• sending a signal to a control device reporting said fluid level.