# US 7,613,407 B2 · Method and apparatus to detect loads associated with one of a plurality of components driven by a shared motor in an image forming apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,613,407 B2 - Document ID: US7613407B2 - Status: Granted - Kind: B2 - Application number: 11/383,266 - Filed: 2006-05-15 - Published: 2007-11-15 - Granted: 2009-11-03 - Earliest claimed: 2006-05-15 - Assignees: Lexmark International, Inc. - Inventors: Michael William Craig; Steven Michael Turney; Danny Keith Chapman - Web page: https://patentgrep.com/patent/US7613407B2 ## CPC - G03G 21/12: Toner waste containers - G03G 21/105: {Arrangements for conveying toner waste} - G03G 2215/0685: fulfilling a continuous function within the electrographic apparatus during the use of the supplied developer material, e.g. toner discharge on demand, storing residual toner, not acting as a passive closure for the developer replenishing opening - G03G 2215/0888: Arrangements for detecting toner level or concentration in the developing device - G03G 2221/1624: transporting cleaned toner into separate vessels, e.g. photoreceptors, external containers - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract An image forming apparatus includes a waste toner system that collects waste toner in a waste toner container. An amount of waste toner collected in the container is increased by using a driven toner distributing member that distributes accumulated toner within the container. The toner distributing member may be driven by a shared speed-controlled motor that further drives an image forming process member. The waste toner system may detect the accumulation of waste toner by monitoring a drive control circuit while the toner distributing member is being driven. For example, a logic circuit may detect the accumulation of waste toner based on monitoring a predetermined frequency of interest of a frequency domain transform of a motor control signal, the frequency of interest associated with the shared motor driving the toner distributing member. ## Claims ### Claim 1 An image forming device comprising: a member movably positioned within a waste toner container, the member causing an interference with the waste toner container when the amount of toner in the waste toner container reaches a predetermined quantity; an image forming process member; a shared motor operatively connected to the member to move the member in a reciprocating manner, the shared motor further moving the image forming process member in a cyclic manner; a motor control circuit to control the shared motor based at least partly upon a motor control signal; a logic circuit to detect an accumulation of waste toner based on monitoring a predetermined frequency of interest of a frequency domain transform of the motor control signal, the frequency of interest associated with the shared motor moving the member against the interference. ### Claim 2 (depends on 1) The image forming device of claim 1 wherein the image forming process member is a roller. ### Claim 3 (depends on 2) The image forming device of claim 2 wherein the roller is a registration roller. ### Claim 4 (depends on 1) The image forming device of claim 1 wherein the logic circuit detects the interference to detect the accumulation of waste toner at or above the predetermined quantity. ### Claim 5 (depends on 1) The image forming device of claim 1 wherein the logic circuit detects the interference by determining when the amplitude of the motor control signal at the frequency of interest exceeds a predetermined threshold. ### Claim 6 (depends on 1) The image forming device of claim 1 wherein the member and the image forming process member are driven by the shared motor at different respective gear ratios. ### Claim 7 (depends on 6) The image forming device of claim 6 wherein the frequency of interest is derived from the gear ratio between the shared motor and the member. ### Claim 8 (depends on 1) The image forming device of claim 1 wherein the motor control signal is a motor drive signal. ### Claim 9 (depends on 1) The image forming device of claim 1 wherein the motor control signal is an error circuit signal. ### Claim 10 An image forming device comprising: a first member movably positioned within the image forming device; a second member movably positioned within the image forming device; a shared motor operatively connected to the first and second members to move the first and second members in a cyclic manner; a motor control circuit to control the shared motor based at least partly upon a motor control signal; a logic circuit to detect an error associated with the first member based on monitoring, in a frequency domain, a predetermined frequency of interest of the motor control signal, the frequency of interest associated with the shared motor driving the first member against a cyclic load. ### Claim 11 (depends on 10) The image forming device of claim 10 wherein the first member is a toner distributing member positioned within a waste toner container. ### Claim 12 (depends on 10) The image forming device of claim 10 wherein the second member is an image forming process member. ### Claim 13 (depends on 10) The image forming device of claim 10 wherein the cyclic load is an interference between the moving first member and a relatively stationary portion of the image forming device. ### Claim 14 (depends on 10) The image forming device of claim 10 wherein the error is a waste toner accumulation error. ### Claim 15 (depends on 10) The image forming device of claim 10 wherein the motor control signal is a motor drive signal. ### Claim 16 (depends on 10) The image forming device of claim 10 wherein the motor control signal is an error circuit signal. ### Claim 17 An image forming device comprising: a member movably positioned within a waste toner container, the member causing an interference with the container when the amount of toner in the reservoir reaches a predetermined quantity; a motor operatively connected to the member to move the member in a reciprocating manner; a motor control circuit to control the motor based at least partly upon a motor control signal; a logic circuit to detect accumulation of waste toner based on monitoring a predetermined frequency of interest of a frequency domain transform of the motor control signal, the frequency of interest associated with the motor driving the toner distributing member against the interference. ### Claim 18 (depends on 17) The image forming device of claim 17 wherein the frequency domain transform is a Fourier transform. ### Claim 19 (depends on 17) The image forming device of claim 17 wherein the frequency domain transform is an approximation of a Discrete Fourier Transform. ### Claim 20 (depends on 17) The image forming device of claim 17 wherein the frequency of interest is derived from a gear ratio between the motor and the member. ### Claim 21 (depends on 17) The image forming device of claim 17 wherein the motor control signal is a motor drive signal. ### Claim 22 (depends on 17) The image forming device of claim 17 wherein the motor control signal is an error circuit signal. ### Claim 23 A method of operation in an image forming apparatus that includes a waste toner system, the method comprising: using a speed-controlled motor to drive a toner distributing member that distributes waste toner collected in a waste toner container; operating the speed-controlled motor in a feedback loop that uses a motor control signal; and detecting an accumulation of waste toner based on monitoring a predetermined frequency of interest of a frequency domain transform of the motor control signal that varies as needed to substantially maintain a desired motor speed while driving the toner distributing member. ### Claim 24 (depends on 23) The method of claim 23 wherein the frequency of interest is derived from a gear ratio between the speed controlled motor and the toner distributing member. ### Claim 25 (depends on 23) The method of claim 23 wherein the toner distributing member is a reciprocating toner rake, and wherein detecting the accumulation of waste toner comprises detecting when an amplitude of the motor control signal at the predetermined frequency of interest exceeds a predetermined threshold. ### Claim 26 (depends on 23) The method of claim 23 wherein the toner distributing member is a reciprocating toner rake, and wherein the frequency domain transform is a discrete Fourier transform and detecting the accumulation of waste toner comprises detecting when an amplitude of the discrete Fourier transform of the motor control signal at the predetermined frequency of interest exceeds a predetermined threshold. ### Claim 27 (depends on 23) The method of claim 23 wherein the motor control signal is a motor drive signal. ### Claim 28 (depends on 23) The method of claim 23 wherein the motor control signal is an error circuit signal. ### Claim 29 (depends on 23) The method of claim 23 further comprising driving an image forming process member using the speed-controlled motor. ### Claim 30 (depends on 29) The method of claim 29 further comprising driving the toner distributing member and the image forming process member at different gear ratios and determining the frequency of interest based at least partly on the gear ratio between the toner distributing member and the speed-controlled motor. ### Claim 31 A method of operation in an image forming apparatus that includes a waste toner system, the method comprising: using a speed-controlled motor to drive a toner distributing member that distributes waste toner collected in a waste toner container; operating the speed-controlled motor in a feed back loop that uses a motor control signal; causing an interference between the toner distributing member and the waste toner container when the accumulation of waste toner reaches a predetermined value; calculating a frequency domain transform of the motor control signal; and detecting the interference by determining when an amplitude of the frequency domain transform at a predetermined frequency of interest exceeds a predetermined threshold. ### Claim 32 (depends on 31) The method of claim 31 wherein the frequency domain transform is a Fourier transform. ### Claim 33 (depends on 31) The method of claim 31 wherein the frequency domain transform is an approximation of a Discrete Fourier Transform. ### Claim 34 (depends on 31) The method of claim 31 wherein the motor control signal is a motor drive signal. ### Claim 35 (depends on 31) The method of claim 31 wherein the motor control signal is an error circuit signal. ### Claim 36 (depends on 3) The method of claim 3 further comprising driving an image forming process member using the speed-controlled motor. ### Claim 37 (depends on 36) The method of claim 36 further comprising driving the toner distributing member and the image forming process member at different gear ratios and determining the frequency of interest based at least partly on the gear ratio between the toner distributing member and the speed-controlled motor.