# US 2019/0169783 A1 · Dryer and method of controlling the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0169783 A1 - Document ID: US20190169783A1 - Status: Published application - Kind: A1 - Application number: 16/207,909 - Filed: 2018-12-03 - Published: 2019-06-06 - Earliest claimed: 2017-12-01 - Assignees: LG Electronics Inc. - Applicants: LG Electronics Inc. - Inventors: Ilman Seo; Deokjoon Jeong; Minho Jang - Web page: https://patentgrep.com/patent/US20190169783A1 ## CPC - D06F 58/38: of drying, e.g. to achieve the target humidity - D06F 58/36: Control of operational steps, e.g. for optimisation or improvement of operational steps depending on the condition of the laundry - D06F 58/50: Responding to irregular working conditions, e.g. malfunctioning of blowers - D06F 58/46: Control of the operating time - D06F 2103/02: Characteristics of laundry or load - D06F 2103/04: Quantity, e.g. weight or variation of weight - D06F 2103/06: Type or material - D06F 2103/24: Spin speed; Drum movements - D06F 2103/34: Humidity - D06F 2103/44: Current or voltage - D06F 2103/46: of the motor driving the drum - D06F 2105/00: Systems or parameters controlled or affected by the control systems of washing machines, washer-dryers or laundry dryers - D06F 2105/46: Drum speed; Actuation of motors, e.g. starting or interrupting - D06F 2105/48: Drum speed - D06F 2105/52: Changing sequence of operational steps; Carrying out additional operational steps; Modifying operational steps, e.g. by extending duration of steps - D06F: LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES ## Abstract Disclosed are a dryer and a method of controlling the same, the dryer which is capable of: quickly and accurately determining an amount of laundry loaded in the dryer and controlling a drying operation according to the amount of the laundry: measuring a current supplied to rotate the drum and extracting a force applied to laundry in the drum to measure an amount of the laundry, thereby minimizing an error in the amount of laundry and thus enhancing accuracy of the measurement and improving a drying time; setting a drying time in consideration of both a calculated amount of laundry and a type of the laundry, such that damage to the laundry is prevented and over-drying or less-drying of the laundry is solved, thereby efficiently drying the laundry. ## Claims ### Claim 1 A dryer comprising: a drum configured to accommodate laundry; a motor connected to the drum by a drive belt and configured to rotate the drum; a blow fan configured to circulate air through the drum in response to driving of the motor; a driving controller configured to apply operation power to the motor to operate and stop the motor, the driving controller being configured to control a rotation speed of the motor; a current sensing unit configured to measure a current value of the motor; and a controller that is configured to provide a control command to the driving controller, that is configured to control the motor to rotate the drum based on the control command, and that is configured to sense an amount of laundry based on the current value sensed by the current sensing unit during a rotation of the drum, wherein the controller is further configured to, in sensing the amount of laundry, control the driving controller to control the drum based on (i) an acceleration stage in which a rotation speed of the drum increases and (ii) a maintaining stage in which the rotation speed of the drum is maintained, and wherein the controller is further configured to, in the acceleration stage, increase the rotation speed of the drum at an acceleration gradient set in a range from 500 rpm/s to 1500 rpm/s. ### Claim 2 (depends on 1) The dryer of claim 1, wherein the controller is further configured to control the driving controller to increase the rotation speed of the drum at the acceleration gradient set at 750 rpm/s in the acceleration stage. ### Claim 3 (depends on 1) The dryer of claim 1, wherein the controller is further configured to set a duration of the acceleration stage to be greater than a duration of the maintaining stage to limit a slip between the drive belt and the drum based on an increase of the rotation speed of the drum in the acceleration stage. ### Claim 4 (depends on 1) The dryer of claim 1, wherein the controller is further configured to control the rotation speed of the drum at the acceleration gradient that is set according to a linearity value corresponding to a change of measurements of the amount of laundry with respect to an increase of the amount of laundry, and a resolution value corresponding to a variation range of measurements of the amount of laundry. ### Claim 5 (depends on 4) The dryer of claim 4, wherein the controller is further configured to control the rotation speed of the drum at the acceleration gradient that is set according to the resolution value less than or equal to 1.5. ### Claim 6 (depends on 4) The dryer of claim 4, wherein the controller is further configured to control the rotation speed of the drum at the acceleration gradient set according to the linearity value greater than or equal to 0.8. ### Claim 7 (depends on 1) The dryer of claim 1, wherein the controller is further configured to, in the acceleration stage, control the rotation speed of the drum at the acceleration gradient set in a first range from 500 rpm/s to 1000 rpm/s or in a second range from 1250 rpm/s or 1500 rpm/s. ### Claim 8 (depends on 1) The dryer of claim 1, wherein the controller is further configured to control the driving controller to rotate the drum at the rotation speed of the drum in a range from 36 rpm to 63 rpm at an end time point of the acceleration stage. ### Claim 9 (depends on 1) The dryer of claim 1, wherein the controller is further configured to determine the amount of laundry based on repeating the acceleration stage and the maintaining stage for a predetermined number of times. ### Claim 10 (depends on 9) The dryer of claim 9, wherein the controller is further configured to control the driving controller to change a rotation direction of the drum after the maintaining stage. ### Claim 11 (depends on 9) The dryer of claim 9, wherein the controller is further configured to control the driving controller to rotate the drum five to six times based on an operation pattern comprising the acceleration stage and the maintaining stage. ### Claim 12 (depends on 1) The dryer of claim 1, wherein the controller is further configured to control the drum in a stopping stage until the drum stops rotating after the maintaining stage. ### Claim 13 (depends on 1) The dryer of claim 1, wherein the controller is further configured to determine the amount of laundry based on excluding a friction component from a plurality of force components acting on the drum during rotation of the drum, the friction component comprising friction force between the drive belt and the drum, and wherein the controller is further configured to exclude the friction component based on a difference of current values of the motor sensed in the acceleration stage and the maintaining stage. ### Claim 14 (depends on 1) The dryer of claim 1, wherein the controller is further configured to determine the amount of laundry based on a force of gravity acting on the laundry in the maintaining stage and a force of inertia acting on the laundry in the acceleration stage. ### Claim 15 A method of controlling a dryer, comprising: receiving laundry at a drum of the dryer; rotating the drum by driving a motor of the dryer based on receiving the laundry; increasing a rotation speed of the drum in an acceleration stage; after the acceleration stage, maintaining the rotation speed of the drum in a maintaining stage; determining an amount of laundry by sensing current values of the motor during rotation of the drum; and performing a drying operation based on the amount of laundry, wherein increasing the rotation speed of the drum in the acceleration stage comprises increasing the rotation speed of the drum at an acceleration gradient set in a range from 500 rpm/s to 1500 rpm/s. ### Claim 16 (depends on 15) The method of claim 15, wherein increasing the rotation speed of the drum further comprises: controlling an acceleration of the drum in the acceleration stage according to a linearity value corresponding to a change of measurements of the amount of laundry with respect to an increase of the amount of laundry, and a resolution value corresponding to a variation range of measurements of the amount of laundry, and wherein the resolution value and the linearity value are calculated based on the current values corresponding to the amount of laundry. ### Claim 17 (depends on 16) The method of claim 16, wherein increasing the rotation speed of the drum further comprises: controlling the rotation speed of the drum at an acceleration gradient calculated according to the resolution value less than or equal to 1.5 and the linearity value greater than or equal to 0.8. ### Claim 18 (depends on 15) The method of claim 15, wherein increasing the rotation speed of the drum further comprises: setting a duration of the acceleration stage to be greater than a duration of the maintaining stage to avoid a slip between a drive belt and the drum based on an increase of the rotation speed of the drum in the acceleration stage to a first rotation speed for the maintaining stage. ### Claim 19 (depends on 15) The method of claim 15, wherein increasing the rotation speed of the drum further comprises increasing the rotation speed of the drum at the acceleration gradient of 750 rpm/s in the acceleration stage. ### Claim 20 (depends on 15) The method of claim 15, further comprising: changing a rotation direction of the drum after the maintaining stage; and repeating the acceleration stage and the maintaining stage for a predetermined number of times.