Method for estimating temperature of light emitting module, light emitting module, and automotive unit

An automotive unit comprising:

• a light emitting module mountable on a vehicle, the light emitting module including a wiring board, a plurality of light emitting elements on the wiring board, and a plurality of temperature sensors provided in correspondence with a first part, and not all, of the light emitting elements, respectively;
• and
• a controller mountable on the vehicle, the controller being configured to:
• control the plurality of light emitting elements to operate in accordance with a lighting pattern, which represents an intensity of light emitted from each of the light emitting elements;
• based on the lighting pattern of the light emitting module and respective temperatures of the first part of the light emitting elements measured by the plurality of temperature sensors, respectively, estimate respective temperatures of at least a second part of the light emitting elements that are different from the first part of the light emitting elements;
• and
• control at least one of the second part of the light emitting elements based on the estimated temperature of the at least one of the second part of the light emitting elements,
• in estimating the respective temperatures of at least the second part of the light emitting elements, the controller being configured to
• calculate, with respect to each of the light emitting elements that are operated in accordance with the lighting pattern, a variable corresponding to an amount of heat received by the light emitting element, based on the lighting pattern;
• and
• calculate the respective temperatures of the second part of the light emitting elements, based on a relationship among the measured respective temperatures of the first part of the light emitting elements and the calculated respective variables of the light emitting elements,
• in calculating the respective temperatures of the second part of the light emitting elements, the controller being configured to
• determine a value of one or more conversion factors using a relationship among an average value of the measured respective temperatures of the first part of the light emitting elements, a difference between a maximum value and a minimum value of the measured respective temperatures of the first part of the light emitting elements, an average value of the respective variables of the light emitting elements, and a difference between a maximum value and a minimum value of the respective variables of the light emitting elements;
• and
• convert respective variables of said at least a part of the light emitting elements to the respective temperatures of said at least a part of the light emitting elements using the determined value of one or more conversion factors,
• the one or more conversion factors including a first conversion factor K1 and a second conversion factor K2,
• K1=Sen_r/Sim_r, and
• K2=Sen_a-Sim_a×K1,
• wherein Sen_a is the average value of the measured respective temperatures of the first part of the light emitting elements, Sen_r is the difference between the maximum value and the minimum value of the measured respective temperature of the first part of the light emitting elements, Sim_a is the average value of the respective variables of the light emitting elements, and Sim_r is the difference between the maximum value and the minimum value of the respective variables of the light emitting elements,
• in converting the respective variables, the controller being configured to use a following formula:
• T=K1×Σh+K2,
• wherein T is a temperature and Σh is the variable of a light emitting element.