Measuring toner level in a closed container

• US 6,600,882 B1
• Filed: 10/17/2002
• Issued: 07/29/2003
• Est. Priority Date: 05/30/2002
• Status: Expired due to Term

• Current Assignee: Lexmark International Incorporated (Ninestar Corporation)
• Original Assignee: Lexmark International Incorporated (Ninestar Corporation)
• Inventors: Molloy, James John, Applegate, Steven Lewis
• Primary Examiner(s): Lee, Susan S. Y.
• Assistant Examiner(s): Campbell, Candice C.
• Application Number:
  US10/272,920
• Time in Patent Office: 285 Days
• Field of Search: 399/27, 399/63, 399/61, 399/30, 732/90.R, 732/97, 733/04.R, 222/23, 222/232
• US Class Current: 399/27
• CPC Class Codes: G03G 15/0856 Detection or control means for the developer level
• CPC Class Codes: G03G 15/0858 the level being measured by mechanical means
• CPC Class Codes: G03G 15/0872 the developer cartridges being generally horizontally mounted parallel to its longitudinal rotational axis

Abstract

Toner (5) is measured in a toner cartridge (1) by compressing the air in the upper part (7) of the toner hopper (3). The result of the compression is observed by a diaphragm (13) or, alternatively, by a pressure transducer (25). The volume of air is inversely proportional to the resonant frequency of diaphragm (13) or the pressure at pressure transducer (25). This is converted by control system (23) using direct equations or table look-up of empirical data. The diaphragm (13) carries a magnet (15), which is driven by coil (19) from the imaging device and then frequency of current induced by magnet (15) is then sensed by coil (19). Uneven toner piling is not a significant factor in the results measured.

Claims

1. A method of measuring toner volume in a closed container having a responsive member facing air in said container comprising:

perturbing said air in said container with a diaphragm or plunger facing said air,

observing the response of said responsive member resulting from said perturbing, and

converting said observed response into volume of toner in said container.

2. A method of measuring toner volume in a closed container having a responsive member facing air in said container comprising:

perturbing said air in said container,

observing the response of said responsive member resulting from said perturbing, and

converting said observed response into volume of toner in said container,

wherein said responsive member is a diaphragm and said observing is by measuring the resonant frequency of said diaphragm resulting from said perturbing.

3. The method of claim 2 in which said diaphragm contains a magnet and said perturbing is by reaction of said magnet to a magnetic coil.

4. The method of claim 2 in which said diaphragm contains a magnet and said measuring the resonant frequency is by measuring the current induced in a magnetic coil by said magnet.

5. The method of claim 4 in which said perturbing is by reaction of said magnet to said magnetic coil.

6. A method of measuring toner in a closed container having a pressure transducer facing air in said container comprising:

perturbing said air in said container with a plunger,

measuring the pressure resulting from said perturbing with said pressure transducer, and,

converting said measured pressure into volume of toner in said container.

7. The method of claim 6 in which said plunger is in a confined passage, wherein mathematical predictability of change of said pressure is improved.