Device and method for controlling light source in gradual brightness change manner

The invention discloses a device and a method for controlling a light source in a gradual brightness change manner. The device for controlling the light source in the gradual brightness change manner comprises a light source, a light source driving unit, a switch unit, and an MCU (Microgrammed Control Unit), wherein the MCU is used for detecting a switching action of the switch unit and whether the light source is turned on, calculating the duty cycle of drive pulses, outputting the drive pulses to the light source driving unit, detecting the time span for outputting the drive pulses, and storing the duty cycle of the drive pulses, the variation step length of the duty cycles of the drive pulses, the duty cycle of the maximum drive pulse, the duty cycle of the minimum drive pulse and the variation time period of the duty cycle of the drive pulse. According to the invention, According to the invention, the gradual lighting of gradual dimming of a lamp is realized by controlling the duty cycle of the drive pulses of the drive light source, so that the service life of the lamp is prolonged, in addition, by addition of a brightness detection unit, the brightness of the light source is regulated based on ambient brightness, so that the brightness sensed by human eyes is stabilized, and the stimulations to the human eyes are reduced and the health of the human eyes is protected.