Light-emitting module, light source and dental photocuring machine

A light-emitting module, comprising a plurality of light-emitting units arranged in a rectangular array in a rectangular light-emitting area, wherein the rectangular light-emitting area is a smallest rectangular area containing all the plurality of light-emitting units;

• all the plurality of light-emitting units are divided into a plurality of first light-emitting units and at least one second light-emitting unit according to different light-emitting colors;
• a center of the rectangular light-emitting area is a reference center;
• when a number of the at least one second light-emitting unit is one, the second light-emitting unit is located at the reference center;
• when a number of the at least one second light-emitting unit is an odd number greater than or equal to 3, one second light-emitting unit is located at the reference center, and the other second light-emitting units are divided into a plurality of array groups;
• when a number of the at least one second light-emitting unit is an even number, all the second light-emitting units are divided into a plurality of array groups;
• second light-emitting units in each of the array groups are distributed in an annular array or a rectangular array, and distances between second light-emitting units in the same array group and the reference center are equal;
• when a number of the each of the array groups is greater than or equal to two, distances between second light-emitting units in at least one array group and the reference center is smaller than distances between second light-emitting units in the other array groups and the reference center;
• wherein when the number of the second light-emitting units is an odd number greater than or equal to 3 and the number of the array groups is greater than or equal to 2, all the array groups comprise a central array group and at least one peripheral array group, and one of the second light-emitting units located at the reference center is a reference light-emitting unit;
• except the reference light-emitting unit, a distance between a second light-emitting unit in the central array group and the reference center is smaller than or equal to a distance between the other light-emitting unit and the reference center;
• and a second light-emitting unit in the peripheral array group is located at an edge of the rectangular light-emitting area;
• wherein the rectangular light-emitting area has a sub light-emitting area concentric with itself, and the length direction and width direction of the sub light-emitting area are respectively in a same direction as the length direction and width direction of the rectangular light-emitting area;
• wherein light-emitting units in the sub light-emitting area contain the reference light-emitting unit and all the second light-emitting units of the central array group, and second light-emitting units of the central array group are all located at an edge of the sub light-emitting area;
• wherein all the light-emitting units in the sub light-emitting area serve as a first electrical module, and the first electrical module is connected to a first power supply;
• except a row or column where the light-emitting units forming the first electrical module are located, the other light-emitting units in a same row or column are connected in series to form a second electrical module;
• the other light-emitting units except those forming the first electrical module and the second electrical module are connected in series to form a third electrical module;
• the second electrical module and the third electrical module are connected in parallel to a second power supply;
• wherein equivalent resistance values of the first electrical module, the second electrical module and the third electrical modules are the same.