# US 9,439,258 B2 · Control circuit of LED lighting apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,439,258 B2 - Document ID: US9439258B2 - Status: Granted - Kind: B2 - Application number: 14/770,186 - Filed: 2014-02-27 - Published: 2016-01-14 - Granted: 2016-09-06 - Earliest claimed: 2013-02-28 - Assignees: Silicon Works Co., Ltd. - Applicants: Silicon Works Co., Ltd. - Inventors: Yong Geun Kim; Ki Chul An; Sang Young Lee - Web page: https://patentgrep.com/patent/US9439258B2 ## CPC - H05B 45/44: with an active control inside an LED matrix - H05B 45/48: having LEDs organised in strings and incorporating parallel shunting devices - H05B 45/10: Controlling the intensity of the light - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL ## Abstract Provided is a control circuit of an LED lighting apparatus, which is capable of reducing the occurrence of a flicker while performing lighting. The control circuit of the LED lighting apparatus may include a charge and discharge module charged by a rectified voltage and discharging LED channels, and control one or more of charge timing, a charged voltage, and discharge timing of the charge and discharge module such that the charge and discharge module supplies a voltage to the LED channels at least during a control period at which the amount of current supplied to the LED channels is the smallest. Thus, the occurrence of a flicker in the LED lighting apparatus can be improved. ## Claims ### Claim 1 A control circuit of an LED lighting apparatus divided into a plurality of LED channels, comprising: a current control circuit configured to provide a current path corresponding to sequential emissions of the LED channels in response to a rectified voltage; and a flicker reduction circuit comprising a charge and discharge module charged by the rectified voltage and discharging the LED channels, and configured to control one or more of charge timing, a charged voltage, and discharge timing of the charge and discharge module such that the charge and discharge module supplies a voltage to the LED channels at least during a control period at which the amount of current supplied to the LED channels is the smallest. ### Claim 2 (depends on 1) The control circuit of claim 1, wherein the charge and discharge module comprises any one of a capacitor and a valley fill circuit. ### Claim 3 (depends on 1) The control circuit of claim 1, wherein the flicker reduction circuit controls one or more of the charge timing, the charged voltage, and the discharge timing, using one or more of the rectified voltage, the current supplied to the LED channels, a current of the current path for each LED channel, and a sensing current of the current control circuit as a common determination source or each determination source. ### Claim 4 (depends on 1) The control circuit of claim 1, wherein the flicker reduction circuit supplies the voltage in response to the control period including a period in which the rectified voltage becomes lower than a level of a minimum light emission state of the LED channels. ### Claim 5 (depends on 1) The control circuit of claim 1, wherein the flicker reduction circuit comprises one or more of: a charge control circuit configured to supply the rectified voltage to the charge and discharge module during a predetermined charge period; and a discharge control circuit configured to supply the voltage of the charge and discharge module to the LED channels during the control period. ### Claim 6 (depends on 5) The control circuit of claim 5, wherein the charge period is set to include a period having a level equal to or higher than a light emitting voltage at which the LED channels maintain the minimum light emission state. ### Claim 7 (depends on 6) The control circuit of claim 6, wherein the charge period is set to have a lower level than the light emitting voltage at which the LED channels maintain a maximum light emission state. ### Claim 8 (depends on 5) The control circuit of claim 5, wherein the charge period is set in one or more of a region in which the rectified voltage rises and a region in which the rectified voltage falls. ### Claim 9 (depends on 5) The control circuit of claim 5, wherein the charge control circuit comprises: a charge switch configured to switch supplying the rectified voltage to the charge and discharge module; and a charge timing control unit configured to turn on the charge switch during the charge period. ### Claim 10 (depends on 5) The control circuit of claim 5, wherein the discharge control circuit comprises: a discharge switch configured to switch supplying the voltage of the charge and discharge module to the plurality of LED channels; and a discharge timing control unit configured to turn on the discharge switch during the control period. ### Claim 11 (depends on 5) The control circuit of claim 5, wherein the discharge control circuit supplies the voltage of the charge and discharge module to an input terminal of any one of the LED channels. ### Claim 12 (depends on 1) The control circuit of claim 1, wherein the flicker reduction circuit comprises a voltage control unit configured to provide a voltage control signal indicating a charging unsuitable state, the charging unsuitable state including one or more of a first state in which the voltage of the charge and discharge module is equal to or more than a predetermined charge level, a second state in which the voltage of the charge and discharge module is equal to or more than the rectified voltage level, and a third state in which the rectified voltage is equal to or less than a predetermined level, and stops the charging operation using the rectified voltage in response to the charging unsuitable state. ### Claim 13 (depends on 12) The control circuit of claim 12, wherein the flicker reduction circuit comprises: a charge control circuit configured to provide the rectified voltage to the charge and discharge module during a predetermined charge period which does not correspond to the charging unsuitable state; and a discharge control circuit configured to supply the voltage of the charge and discharge module to the LED channels during the control period. ### Claim 14 (depends on 13) The control circuit of claim 13, wherein the charge control circuit comprises: a charge switch configured to switch supplying the rectified voltage to the charge and discharge module; a charge timing control unit configured to provide a turn-on signal for turning on the charge switch during the charge period; and a switching control circuit configured to turn on the charge switch during a time which does not correspond to the charging unsuitable state but satisfies the charge period, according to the voltage control signal and the turn-on signal. ### Claim 15 (depends on 1) The control circuit of claim 1, wherein the current control circuit comprises switching elements for forming a current path at the respective LED channels, and an active region of each of the switching elements is formed at a different size in response to the current amount, and has a resistance value adjusted in response to current consumption. ### Claim 16 A control circuit of an LED lighting apparatus divided into a plurality of LED channels, comprising a charge and discharge module charged by a rectified voltage provided to the plurality of LED channels and discharging the LED channels, wherein the control circuit controls one or more of charge timing, a charged voltage, and discharge timing of the charge and discharge module such that the charge and discharge module supplies a voltage to the LED channels at least during a control period at which the amount of current supplied to the LED channels is the smallest. ### Claim 17 (depends on 16) The control circuit of claim 16, wherein the charge and discharge module comprises any one of a capacitor and a valley fill circuit. ### Claim 18 (depends on 16) The control circuit of claim 16, wherein the control circuit controls one or more of the charge timing, the charged voltage, and the discharge timing, using one or more of the rectified voltage, the current supplied to the LED channels, a current of the current path for each of the LED channels, and a sensing current of a current control circuit for providing the current path to the LED channels, as a common determination source or each determination source. ### Claim 19 (depends on 16) The control circuit of claim 16, further comprising one or more of: a charge control circuit configured to supply the rectified voltage to the charge and discharge module during a predetermined charge period; and a discharge control circuit configured to supply the voltage of the charge and discharge module to the LED channels during the control period. ### Claim 20 (depends on 19) The control circuit of claim 19, further comprising a voltage control unit configured to provide a voltage control signal indicating a charging unsuitable state, the charging unsuitable state including one or more of a first state in which the voltage of the charge and discharge module is equal to or more than a predetermined charge level, a second state in which the voltage of the charge and discharge module is equal to or more than the rectified voltage level, and a third state in which the rectified voltage is equal to or less than a predetermined level, wherein the control circuit stops the charging operation using the rectified voltage in response to the charging unsuitable state. ### Claim 21 (depends on 20) The control circuit of claim 20, wherein the charge control circuit comprises: a charge switch configured to switch supplying the rectified voltage to the charge and discharge module; a charge timing control unit configured to provide a turn-on signal for turning on the charge switch during the charge period; and a switching control circuit configured to turn on the charge switch during a time which does not correspond to the charging unsuitable state but satisfies the charge period, according to the voltage control signal and the turn-on signal, wherein the charge control circuit provides the rectified voltage to the charge and discharge module during a predetermined charge period which does not correspond to the charging unsuitable state.