# US 2021/0277586 A1 · Laundry drying machine and controlling method of laundry drying machine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0277586 A1 - Document ID: US20210277586A1 - Status: Published application - Kind: A1 - Application number: 17/191,108 - Filed: 2021-03-03 - Published: 2021-09-09 - Earliest claimed: 2020-03-03 - Assignees: LG Electronics Inc. - Applicants: LG Electronics Inc. - Inventors: Woonje CHOE; Myunghun IM; Seungwoo HAN; Nagyoung LEE - Web page: https://patentgrep.com/patent/US20210277586A1 ## CPC - D06F 58/44: of conditioning or finishing, e.g. for smoothing or removing creases - D06F 34/26: Condition of the drying air, e.g. air humidity or temperature - D06F 58/203: {Laundry conditioning arrangements} - D06F 58/24: Condensing arrangements - D06F 58/263: {Gas heating equipment} - D06F 58/40: Control of the initial heating of the drying chamber to its operating temperature - D06F 58/206: {Heat pump arrangements} - D06F 58/38: of drying, e.g. to achieve the target humidity - D06F 2103/06: Type or material - D06F 2103/32: Temperature - D06F 2103/62: related to systems for water or steam used for conditioning or finishing - D06F 2105/20: Temperature - D06F 2105/26: Heat pumps - D06F 2105/30: Blowers - D06F 2105/40: using water or steam - D06F 2105/46: Drum speed; Actuation of motors, e.g. starting or interrupting - D06F: LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES ## Abstract Disclosed herein is a method of controlling a laundry dryer for generating high-temperature steam through a steam part and controlling each of rotation of a drum and rotation of a circulation fan. The method includes a steam drying procedure drying operation of increasing an internal temperature of the drum to dry an object to be dried, a steam drying procedure steam supply operation of supplying steam into the drum after the steam drying procedure drying operation, and a re-drying operation of supplying hot air into the drum after the steam drying procedure steam supply operation. When steam is sprayed from the steam part, the rotation of the drum is maintained, the rotation of the circulation fan is stopped, such that the steam is evenly supplied to the object to be dried, damage to the object is prevented, and sterilization of the object is enhanced. ## Claims ### Claim 1 A laundry dryer comprising: a cabinet that defines an exterior of the laundry dryer; a drum rotatably disposed inside the cabinet and configured to receive an object to be dried; a duct part configured to guide air discharged from the drum and to supply the air to the drum; a circulation fan configured to move the air along the duct part; a heat exchanger disposed at the duct part and configured to perform heat exchange with the air guided along the duct part; a compressor configured to compress refrigerant that is configured to exchange heat with the air guided along the duct part; a steam part configured to generate steam and to supply the steam into the drum; and a controller configured to control the drum, the circulation fan, the compressor, and the steam part, wherein the controller is configured to, while supplying the steam into the drum through the steam part, rotate the drum and stop rotation of the circulation fan. ### Claim 2 (depends on 1) The laundry dryer of claim 1, wherein the controller is configured to, while supplying the steam into the drum through the steam part, stop driving the compressor. ### Claim 3 (depends on 1) The laundry dryer of claim 1, wherein the controller is configured to: increase an internal temperature of the drum by driving the compressor; and based on a temperature of the compressor being increased to a preset drying temperature, operate the steam part to supply the steam into the drum. ### Claim 4 (depends on 3) The laundry dryer of claim 3, wherein the controller is configured to drive the compressor after supplying the steam into the drum through the steam part. ### Claim 5 (depends on 1) The laundry dryer of claim 1, wherein the controller is configured to rotate the circulation fan after supplying water to the steam part for generating the steam. ### Claim 6 (depends on 1) The laundry dryer of claim 1, wherein the controller is configured to drive the compressor after supplying water to the steam part for generating the steam. ### Claim 7 (depends on 5) The laundry dryer of claim 5, wherein the controller is configured to rotate the circulation fan at a preset first drying speed for a preset drying time, and then accelerate the circulation fan to a preset second drying speed. ### Claim 8 (depends on 7) The laundry dryer of claim 7, wherein the controller is configured to, based on a temperature of the compressor being greater than or equal to a preset drying temperature, increase a rotational speed of the circulation fan from the preset second drying speed to a preset third drying speed. ### Claim 9 (depends on 1) The laundry dryer of claim 1, further comprising a drum motor configured to rotate the drum, wherein the circulation fan comprises an impeller motor that is configured to rotate the circulation fan, the impeller motor being configured to operate independently of the drum motor, and wherein the controller is configured to control the drum motor and the impeller motor independently of each other. ### Claim 10 (depends on 1) The laundry dryer of claim 1, wherein the controller is configured to operate the steam part for a preset preheating time to thereby heat water for generating the steam. ### Claim 11 (depends on 10) The laundry dryer of claim 10, wherein the controller is configured to rotate the circulation fan for the preset preheating time, and then stop rotating the circulation fan while spraying the steam through the steam part. ### Claim 12 (depends on 11) The laundry dryer of claim 11, wherein the controller is configured to: rotate the circulation fan at a first rotational speed for the preset preheating time; and after spraying the steam through the steam part, operate the compressor and the circulation fan to thereby dry the object in the drum, and wherein the controller is configured to, after spraying the steam through the steam part, rotate the circulation fan at a second rotation speed that is different from the first rotational speed of the circulation fan. ### Claim 13 (depends on 1) The laundry dryer of claim 1, wherein the controller is configured to: after supplying the steam into the drum by operating the steam part, drive the compressor to increase an internal temperature of the drum; and based on the internal temperature of the drum being increased to a preset sterilization temperature, operate the steam part to supply additional steam from the steam part into the drum. ### Claim 14 (depends on 13) The laundry dryer of claim 13, wherein the controller is configured to, after operating the steam part to supply the additional steam into the drum, drive the compressor at a preset safety frequency. ### Claim 15 (depends on 14) The laundry dryer of claim 14, further comprising a sensor configured to sense a temperature inside the duct part, wherein the controller is configured to: measure the temperature inside the duct part through the sensor, and control an operating frequency of the compressor based on the temperature inside the duct part to thereby maintain the temperature inside the duct part. ### Claim 16 (depends on 15) The laundry dryer of claim 15, wherein the controller is configured to stop driving the compressor after maintaining the temperature inside the duct part above the preset sterilization temperature for a preset temperature maintenance time. ### Claim 17 A method for controlling a laundry dryer, the laundry dryer including a steam part configured to generate steam, a drum configured to receive an object to be dried, and a circulation fan, the method comprising: perform a drying operation that comprises increasing an internal temperature of the drum to thereby dry the object in the drum; supplying the steam into the drum after the drying operation; supplying hot air into the drum after supplying the steam into the drum; and controlling rotation of each of the drum and the circulation fan. ### Claim 18 (depends on 17) The method of claim 17, wherein supplying the steam into the drum comprises: supplying water to the steam part; heating the water in the steam part for a preset preheating time to generate the steam by applying power to the steam part; and spraying the steam generated from the steam part. ### Claim 19 (depends on 17) The method of claim 17, wherein the drying operation further comprises: driving the circulation fan at a preset first drying speed; increasing a rotational speed of the circulation fan from the preset first drying speed to a preset second drying speed; and driving the circulation fan at the preset second drying speed. ### Claim 20 (depends on 17) The method of claim 17, further comprising: before performing the drying operation, receiving a control input for performing a steam drying procedure predetermined for reducing damage to the object and enhancing sterilization of the object, wherein the steam drying procedure comprises a first steam drying procedure and a second steam drying procedure, wherein receiving the control input comprises receiving the control input for performing one of the first steam drying procedure or the second steam drying procedure according to a material of the object.