# US 2019/0174598 A1 · Control device having buttons with automatically adjustable backlighting > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0174598 A1 - Document ID: US20190174598A1 - Status: Published application - Kind: A1 - Application number: 16/271,463 - Filed: 2019-02-08 - Published: 2019-06-06 - Earliest claimed: 2015-05-26 - Assignees: Lutron Electronics Co., Inc. - Applicants: Lutron Electronics Co., Inc. - Inventors: Daniel L. Twaddell; Matthew Philip McDonald; Jason C. Killo; Jonathan Robert Quayle - Web page: https://patentgrep.com/patent/US20190174598A1 ## CPC - H05B 31/50: specially adapted for AC - H01H 13/83: characterised by legends, e.g. Braille, liquid crystal displays, light emitting or optical elements - H05B 45/12: using optical feedback - H05B 47/10: Controlling the light source - H05B 47/11: by determining the brightness or colour temperature of ambient light - H01H 2219/038: ambient light dependent - H01H 2219/039: Selective or different modes of illumination - H02B 15/00: Supervisory desks or panels for centralised control or display - H05B 47/175: by remote control - H05B 47/196: {characterised by user interface arrangements} - Y02B 20/40: Control techniques providing energy savings, e.g. smart controller or presence detection - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL - H01H: ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES (contact cables H01B7/10; electrolytic self-interrupters H01G9/18; emergency protective circuit arrangements H02H; switching by electronic means without contact-making H03K17/00) - H02B: BOARDS, SUBSTATIONS OR SWITCHING ARRANGEMENTS FOR THE SUPPLY OR DISTRIBUTION OF ELECTRIC POWER - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS ## Abstract A control device may comprise a plurality of buttons, a plurality of light sources located behind the respective buttons and configured to illuminate the buttons, a light detector circuit configured to measure an ambient light level around the control device, and/or a control circuit configured to control the light sources to adjust surface illumination intensities of the respective buttons in response to the measured ambient light level. Each button may comprise indicia indicating a function of the button. The control circuit set the first button as active and the second button as inactive in response to an actuation of the first button. The control circuit may, based on the measured ambient light level, control the light sources to illuminate the first button to an active surface illumination intensity, and to illuminate the second button to an inactive surface illumination intensity that is less than the active surface illumination intensity. ## Claims ### Claim 1 A keypad for use in a load control system for controlling power delivered to one or more electrical loads, the keypad comprising: a first button and a second button; a first light source configured to illuminate the first button, and a second light source configured to illuminate the second button; a light detector circuit configured to measure an ambient light level in a vicinity of the keypad; a memory for storing a first adjustment curve and a second adjustment curve; a communication circuit configured to communicate messages; and a control circuit configured to: transmit a message for causing the power to the one or more electrical loads to be controlled according a preset selected in response to an actuation of the first button; control, in response to the actuation of the first button, the first light source to illuminate the first button to a first surface illumination intensity and the second light source to illuminate the second button to a second surface illumination intensity, the first surface illumination intensity being greater than the second surface illumination intensity; and adjust the first surface illumination intensity in response to the ambient light level measured by the light detector circuit using the first adjustment curve, and adjust the second surface illumination intensity in response to the ambient light level measured by the light detector circuit using the second adjustment curve. ### Claim 2 (depends on 1) The keypad of claim 1, wherein the control circuit is configured to receive a message from an external device via the communication circuit, the message comprising information relating to at least one of the first adjustment curve or the second adjustment curve, the control circuit configured to adjust at least one of the first adjustment curve or the second adjustment curve stored in the memory in response to the information received via the message. ### Claim 3 (depends on 2) The keypad of claim 2, wherein the control circuit is configured to adjust the first adjustment curve and maintain the second adjustment curve the same in response to the information received via the message to control a contrast between the first and second surface illumination intensities associated with the first and second adjustment curves. ### Claim 4 (depends on 2) The keypad of claim 2, wherein the information relating to the at least one of the first adjustment curve or the second adjustment curve comprises at least one of a scaling factor or an offset, the control circuit is configured to generate the first and second adjustment curves based on the at least one of the scaling factor or the offset. ### Claim 5 (depends on 1) The keypad of claim 1, wherein the first and second light sources comprise respective first and second light-emitting diodes (LEDs), and the control circuit is configured to pulse-width modulate first LED current conducted through the first LEDs to adjust the first surface illumination intensity, and to pulse-width modulate second LED current conducted through the second LEDs to adjust the second surface illumination intensity. ### Claim 6 (depends on 5) The keypad of claim 5, wherein the control circuit is configured to determine a first LED duty cycle for the first LED current based on the first adjustment curve, and to determine a second LED duty cycle for the second LED current based on the second adjustment curve. ### Claim 7 (depends on 1) The keypad of claim 1, wherein the control circuit is configured to transmit a message to an external load control device via a communication link for controlling at least one of the one or more electrical loads. ### Claim 8 (depends on 7) The keypad of claim 7, wherein the communication link comprises a wired communication link or a wireless communication link. ### Claim 9 (depends on 1) The keypad of claim 1, wherein the control circuit is further configured to set the first button as active and the second button as inactive in response to the actuation of the first button. ### Claim 10 (depends on 9) The keypad of claim 9, wherein the control circuit is configured to set the first button as active and the second button as inactive based on a message received via the communication circuit. ### Claim 11 (depends on 1) The keypad of claim 1, wherein the first light source is located behind the first button and the second light source is located behind the second button, or the first light source is located to the side of the first button and the second light source is located to the side of the second button. ### Claim 12 (depends on 1) The keypad of claim 1, wherein the first button comprises first indicia indicating the preset that is selected in response to the actuation of the first button. ### Claim 13 (depends on 1) The keypad of claim 1, wherein the first and second adjustment curves are non-linearly related. ### Claim 14 A keypad for use in a load control system for controlling power delivered to one or more electrical loads, the keypad comprising: a first button and a second button; a first light source configured to illuminate a first location of the keypad, and a second light source configured to illuminate a second location of the keypad; a light detector circuit configured to measure an ambient light level in a vicinity around the keypad; a memory for storing a first adjustment curve and a second adjustment curve; a communication circuit configured to communicate messages; and a control circuit configured to: transmit a message for causing the power to the one or more electrical loads to be in response to an actuation of the at least one button; control the first light source to illuminate the first location to a first surface illumination intensity and control the second light source to illuminate the second location to a second surface illumination intensity, the second surface illumination intensity being less than the first surface illumination intensity; and adjust the first surface illumination intensity in response to the ambient light level measured by the light detector circuit using the first adjustment curve, and adjust the second surface illumination intensity in response to the ambient light level measured by the light detector circuit using the second adjustment curve. ### Claim 15 (depends on 14) The keypad of claim 14, wherein the at least one button defines the first location and the second location. ### Claim 16 (depends on 15) The keypad of claim 15, wherein the at least one button comprises first indicia indicating a function of the first location of the at least one button, and second indicia indicating a function of the second location of the at least one button. ### Claim 17 (depends on 14) The keypad of claim 14, further comprising: a faceplate comprising indicia, the indicia defining the first location; wherein the at least one button defines the second location. ### Claim 18 (depends on 14) The keypad of claim 14, further comprising: a faceplate comprising first indicia and second indicia, the first indicia defining the first location and the second indicia defining the second location. ### Claim 19 (depends on 14) The keypad of claim 14, wherein the first and second light sources comprise respective first and second light-emitting diodes (LEDs); wherein the control circuit is configured to pulse-width modulate first LED current conducted through the first LEDs to adjust the first surface illumination intensity, and to pulse-width modulate second LED current conducted through the second LEDs to adjust the second surface illumination intensity, and wherein the control circuit is configured to determine a first LED duty cycle for the first LED current based on the first adjustment curve, and to determine a second LED duty cycle for the second LED current based on the second adjustment curve. ### Claim 20 (depends on 14) The keypad of claim 14, wherein the first and second adjustment curves are non-linearly related.