Control device for lighting LED and detecting breakage thereof

A control device that controls lighting of a plurality of LEDs and detects a breakage of each LED, the control device comprising:

• a plurality of LED arrays connected to a ground and connected in parallel to one another, each of the plurality of LED arrays including one or more LEDs connected in series and a resistance element connected in series to the LEDs;
• a first switching circuit disposed between each of the plurality of LED arrays and a power source;
• a second switching circuit disposed between each of the plurality of LED arrays and the power source;
• a capacitor having one end connected to the first switching circuit and another end connected to the plurality of LED arrays;
• a voltage detection circuit having an end connected to the other end of the capacitor;
• and
• a control circuit that controls switching of conduction states of each of the first and second switching circuits, and reads a voltage from the voltage detection circuit,
• wherein the resistance elements connected in series to the corresponding LEDs have different resistances from one another,
• wherein the control circuit sets the first switching circuit to be in a disconnected state, and brings the second switching circuit into conduction to apply a voltage for lighting the LEDs, and
• wherein the control circuit sets the second switching circuit to be a disconnected state, and brings the first switching circuit into conduction to apply a rectangular wave pulse voltage having a pulse duration that does not cause the LEDs to be lighted, to detect presence or absence of breakages of the LEDs in each LED array based on the voltage read from the voltage detection circuit and determine which of the LED arrays is broken.