US-12621914-B2 - Lamp system

US12621914B2US 12621914 B2US12621914 B2US 12621914B2US-12621914-B2

Abstract

A lamp system is provided. The lamp system includes: a light source driver module to provide driving power, a light source array module including a light source, among light sources, connected in parallel with the driving power, a switch connected in series with the light source to control an operation of the light source; and a processor to control the switch, control the light source driver module to provide the driving power, and control the driving power based on a voltage across at least some of the light sources.

Inventors

Myeong Je Kim

Assignees

HYUNDAI MOBIS CO., LTD.

Dates

Publication Date: 20260505
Application Date: 20231219
Priority Date: 20230427

Claims (15)

1 . A lamp system comprising: a light source driver module configured to provide a driving power; a light source array module including a light source, among a plurality of light sources, connected in parallel with the driving power; a switch connected in series with the light source to control an operation of the light source; and a processor configured to: control the switch; control the light source driver module to provide the driving power; control the driving power based on a voltage across at least some of the plurality of light sources; measure the voltage across the plurality of light sources; and control the driving power by including a predetermined margin value in a maximum value among the measured voltages across the light sources.
2 . The system of claim 1 , wherein the processor is further configured to: list up initially-measured voltages across the plurality of light sources in descending order; select a predetermined number of light sources having a highest voltage across the plurality of light sources, and extract the maximum value of the selected light sources.
3 . The system of claim 2 , wherein the processor is further configured to monitor each of the voltages across the plurality of light sources at a predetermined period to update the predetermined number of light sources having the highest voltage across the plurality of light sources.
4 . The system of claim 2 , wherein the processor is further configured to measure the voltage across the plurality of light sources in real time.
5 . The system of claim 2 , wherein the processor is further configured to periodically monitor the predetermined number of light sources having the highest voltage across the plurality of light sources, and wherein the plurality of light sources comprises light-emitting diodes (LEDs).
6 . The system of claim 2 , wherein the processor is further configured to control deviations in forward voltages of the LEDs to reduce heat generation and increase efficiency in outputting light intensity of the LEDs.
7 . The system of claim 1 , wherein the processor is further configured to: generate a control table for the increase and decrease of the maximum value; and control each driving power to be different for the increase or decrease of a current maximum value compared to a previous maximum value based on the control table.
8 . The system of claim 1 , wherein the processor is further configured to: set a first section which is a predetermined voltage section; maintain the driving power to have a constant value when the maximum value is included in the first section; and apply hysteresis to each section when the maximum value is included in a section before or after the first section to control the driving power to have different predetermined maximum values when a current maximum value is increased or decreased compared to a previous maximum value.
9 . The system of claim 1 , wherein the processor is further configured to: monitor a temperature of the light source having the maximum value among the voltages across the plurality of light sources, while predicting a voltage change based on the temperature; and control the driving power based on the voltage change.
10 . The system of claim 1 , wherein the processor is further configured to: calculate the voltage across the switch based on the measured voltage across the plurality of light sources, while causing an interruption when any one of the measured plurality of voltages is outside a preset range; and control the driving power based on the interruption.
11 . The system of claim 10 , wherein the processor is further configured to: control the driving power to be increased by causing the interruption exceeding a lower limit when any one of the measured plurality of voltages is outside the lower limit of the preset range; and control the driving power to be decreased by causing the interruption exceeding an upper limit when any one of the measured plurality of voltages is outside the upper limit of the preset range.
12 . The system of claim 1 , wherein the light source array module comprises a light emitting diode (LED) array module (LAM).
13 . The system of claim 1 , wherein the light source driver module comprises a light emitting diode (LED) driver module (LDM).
14 . A processor-implemented method for controlling a lamp system, the method comprising: providing driving power; providing a light source, among a plurality of light sources, connected in parallel with the driving power; providing a switch connected in series with the light source to control the light source; controlling the switch; controlling a light source driver module to provide the driving power; and controlling the driving power based on a voltage across at least some of the plurality of light sources; measuring the voltage across the plurality of light sources; and controlling the driving power by including a predetermined margin value in a maximum value among the measured voltages across the light sources.
15 . A lamp system comprising: a light source array including a plurality of light sources connected in parallel; a plurality of switches, each connected in series with a respective light source to control current flow through the respective light source; a driver configured to supply driving power to the light source array; a processor configured to: measure forward voltages across a predetermined subset of the plurality of light sources, and dynamically adjust the driving power supplied to the light source array based on the measured forward voltages using a control method comprising hysteresis, wherein the control method applies different adjustment rules depending on whether the maximum measured forward voltage increases or decreases.

Description

CROSS-REFERENCE TO RELATED APPLICATION(S) This application claims the benefit under 35 U.S.C. § 119 to Korean Patent Application No. 10-2023-0055353, filed on Apr. 27, 2023, in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference for all purposes. BACKGROUND 1. Field The present disclosure relates to a lamp system, and more particularly, to a lamp system that may efficiently supply driving power to a light source. 2. Description of Related Art In the recent development of an automobile headlamp, the development of an intelligent headlamp with a large emphasis on safety has been actively progressing around the world, and the automobile headlamp has evolved along with the development of lighting technology using electricity. New types of light sources such as a sealed beam lamp utilizing a headlamp like a single filament bulb, a halogen lamp using a halogen gas, and a high-intensity discharge (HID) lamp using a high voltage discharge method have emerged one after another. A light emitting diode (LED) lamp using light emitting diodes has been spotlighted after the 21st century. Accordingly, a high-resolution LED market is gradually expanding, and an application for road image projection of a high-resolution LED is gradually expanding. Meanwhile, as shown in FIG. 1, many LEDs may be mounted on a narrow substrate in a conventional high-resolution LED lamp system. In addition, these LEDs may be driven by the same power supply, and LED driving power may be supplied based on the largest forward voltage in consideration of a deviation in forward voltage drops of the respective LEDs. However, when supplying the driving power in this way, in a node having a small LED forward voltage drop, a high voltage may be applied to a switch (e.g., a field-effect transistor (FET)) terminal of the LED driving power, which may be dissipated as heat. Therefore, the lamp may have lower efficiency due to heat occurrence. Related art includes Korean Patent Publication No. 10-2018-0136799 entitled “CURRENT CONTROL SYSTEM FOR LEDS” and published on Dec. 26, 2018. SUMMARY This Summary is provided to introduce a selection of concepts in simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. In one general aspect of the disclosure, a lamp system includes: a light source driver module to provide driving power; a light source array module including a light source, among light sources, connected in parallel with the driving power; a switch connected in series with the light source to control an operation of the light source; and a processor to control the switch, control the light source driver module to provide the driving power, and control the driving power based on a voltage across at least some of the light sources. The processor may further: measure the voltage across the light sources; and control the driving power by including a predetermined margin value in a maximum value among the measured voltages across the light sources. The processor may: list up initially-measured voltages across the light sources in descending order; select a predetermined number of light sources having a highest voltage across the light sources; and extract the maximum value of the selected light sources. The processor may monitor each of the voltages across the light sources at a predetermined period to update the predetermined number of light sources having the highest voltage across the light sources. The processor may: generate a control table for the increase and decrease of the maximum value; and control each driving power to be different for the increase or decrease of a current maximum value compared to a previous maximum value based on the control table. The processor may: set a first section which is a predetermined voltage section; maintain the driving power to have a constant value when the maximum value is included in the first section; and apply hysteresis to each section when the maximum value is included in a section before or after the first section to control the driving power to have different predetermined maximum values when a current maximum value is increased or decreased compared to a previous maximum value. The processor may: monitor a temperature of the light source having the maximum value among the voltages across the light sources, while predicting a voltage change based on the temperature; and control the driving power based on the voltage change. The processor may: calculate the voltage across the switch based on the measured voltage across the light sources, while causing an interruption when any one of the measured voltages is outside a preset range; and control the driving power based on the interruption. The processor may: control the driving power to be increase