FLUID TILT SENSOR WITHIN INK TANK SUPPLY ITEM FOR MICRO-FLUID APPLICATIONS

• US 20130074595A1
• Filed: 09/23/2011
• Published: 03/28/2013
• Est. Priority Date: 09/23/2011
• Status: Active Grant

• Current Assignee: Lexmark International Incorporated (Ninestar Corporation)
• Original Assignee: Lexmark International Incorporated (Ninestar Corporation)
• Inventors: Muyskens, Robert H., Webb, Gregory T., McReynolds, Jason T., Gray, Trevor D.
• Granted Patent: US 8,549,764 B2
• Time in Patent Office: Days
• US Class Current: 73/304.C
• CPC Class Codes: B41J 2/175 Ink supply systems ; Circuit parts therefor
• CPC Class Codes: B41J 2/17566 Ink level or ink residue control
• CPC Class Codes: G01C 9/20 the indication being based on the inclination of the surface of a liquid relative to its container
• CPC Class Codes: G01F 23/266 measuring circuits therefor
• CPC Class Codes: G01F 23/268 mounting arrangements of probes
• CPC Class Codes: G01F 23/804 containing circuits handling parameters other than liquid level

Abstract

A container for holding a volume of fluid and having a housing defining an interior for retaining the volume of fluid; at least one in-tank tilt sensor connected to a controller and disposed inside the housing for generating a signal corresponding to a level of fluid inside the housing; and a support material attached to the housing and connected to the at least one in-tank tilt sensor to mechanically support the at least one in-tank tilt sensor such that the at least one in-tank tilt sensor is not in direct contact with the fluid inside the housing. The in-tank tilt sensor detects a change in fluid level which may only be caused by tilting of the imaging device. When tilting is registered, protective action is taken to prevent fluid from leaking.

Claims

1. A method of detecting tilting of a container for holding a volume of fluid, the container for consumable use of the fluid in an imaging device, comprising:

setting a plurality of allowable values;

obtaining a first capacitance measurement value corresponding to a level of fluid on a side of the container; and

determining whether the first capacitance measurement value is higher or lower than a reference capacitance thereby indicating tilt or not, wherein the reference capacitance is a previously-saved capacitance measurement value.

2. The method of claim 1, wherein the plurality of allowable values include allowable positive and negative variances corresponding to an increase and decrease in the level of fluid caused by movements of the fluid in the container during an operation of the imaging device.

3. The method of claim 1, wherein the plurality of allowable values include:

an allowable positive variance corresponding to an allowable tilt of the container towards a first direction; and

an allowable negative variance corresponding to an allowable tilt of the container towards a second direction.

4. The method of claim 1, wherein the plurality of allowable values include an allowable negative variance corresponding to an estimated reduction in the level of fluid due to fluid consumption during an operation of the imaging device.

5. The method of claim 1, wherein the plurality of allowable values include:

allowable positive and negative variances corresponding respectively to an increase and decrease in the level of fluid caused by movements of the fluid in the container during an operation of the imaging device;

an allowable positive variance corresponding to an allowable tilt of the container towards a first direction; and

an allowable negative variance corresponding to an allowable tilt of the container towards a second direction.

6. The method of claim 5, wherein the plurality of allowable values further include an allowable negative variance corresponding to an estimated reduction in the level of fluid due to fluid consumption during an operation of the imaging device.

7. The method of claim 1, wherein determining whether the first capacitance measurement value is higher or lower than the reference capacitance includes:

comparing the first capacitance measurement value to the reference capacitance such that a first actual variance between the first capacitance measurement value and the reference capacitance is determined;

determining if the first actual variance is within the allowable values;

saving the first capacitance measurement value into a memory when the first actual variance is within the allowable values such that the first capacitance measurement value becomes a reference capacitance for a succeeding tilt detection;

obtaining a second capacitance measurement value after a predetermined period of time when the first actual variance is outside the allowable values;

comparing the second capacitance measurement value to the reference capacitance such that a second actual variance between the second capacitance measurement value and the reference capacitance is determined;

determining if the second actual variance is within the allowable values;

saving the second capacitance measurement value into the memory when the second actual variance is within the allowable values such that the second capacitance measurement value becomes a reference capacitance for the succeeding tilt detection; and

indicating a tilt if the second actual variance is outside the allowable values.

8. The method of claim 1, further including disabling a fluid supply in the imaging device if said tilt is indicated, wherein the disabling includes:

closing at least one valve in the imaging device;

de-priming a printhead;

alerting a user;

prompting a user to perform corrective measures;

or

checking whether a succeeding capacitance measurement value is within allowable limits.

9. A method of detecting tilting of a container for holding a volume of fluid, the container for consumable use of the fluid in an imaging device and having a housing defining an interior to retain the volume of fluid and at least one pair of opposed electrodes disposed in the interior having a capacitance that varies in response to an amount of fluid existing between the opposed electrodes, a higher said capacitance corresponding to a higher said amount of fluid existing between the opposed electrodes, comprising:

obtaining a first capacitance measurement value from the pair of opposed electrodes;

obtaining a second capacitance measurement value from the pair of opposed electrodes; and

ascertaining tilt of the housing by determining whether the second capacitance measurement value is higher than the first capacitance measurement value.

10. The method of claim 9, further including determining whether the second capacitance measurement value remains higher than the first capacitance measurement value for a predetermined amount of time.

11. The method of claim 10, further including pinching closed a valve in the imaging device to stop fluid flow if the second capacitance measurement value remains said higher than the first capacitance measurement value for at least one second.

12. A method of detecting tilting of a container for holding a volume of fluid, the container for consumable use of the fluid in an imaging device and having a housing defining an interior to retain the volume of fluid and at least two pairs of opposed electrodes disposed on opposing sides of the interior, each pair having a capacitance that varies in response to an amount of fluid existing between said each pair of opposed electrodes, a higher said capacitance corresponding to a higher said amount of fluid existing between said each pair of opposed electrodes, comprising:

obtaining first and second capacitance values one each from said each pair of opposed electrodes; and

ascertaining tilt of the housing by determining whether one of the first and second capacitance values increases while the other of the first and second capacitance values decreases over a same time period.

13. The method of claim 12, further including disabling a fluid supply in the imaging device to prevent the fluid from leaking out if a tilt of the housing is said ascertained

14. The method of claim 12, further including allowing a fluid supply to flow in the imaging device when a tilt of the housing is corrected or is not said ascertained.

15. The method of claim 12, further including simultaneously obtaining the first and second capacitance values from said each pair of opposed electrodes.