A pattern imaging apparatus for using light to pattern at least one layer of a photo-sensitive material, comprising multiple light sources, a plurality of imaging devices and a combiner, wherein: each of said imaging devices has a maximum power input limit; said light sources are configured to provide a plurality of light components that have substantially the same wavelength spectrum respectively to said imaging devices; each of the light components has a power smaller than or equal to the maximum power input limit, and a sum of the powers of the light components is greater than the maximum power input limit of each of said imaging devices; said imaging devices convert the light components provided by said light sources respectively into a plurality of light beams each representing a same image, and provide the light beams to said combiner; and said combiner combines and redirects the light beams provided by said imaging devices toward the at least one layer of the photo-sensitive material in such a way that the images represented by the light beams completely overlap each other on the at least one layer of the photo-sensitive material; wherein said combiner has a plurality of combiner elements, each having a pair of connection surfaces opposite to each other, and a plurality mount surfaces each of which connects the connection surfaces; wherein for each of said combiner elements, one of said connection surfaces thereof is connected to one of said connection surfaces of another one of said combiner elements, and said combiner elements are connected in series; and wherein said imaging devices are disposed such that each of the light beams is provided into said combiner through an individual one of said mount surfaces of said combiner elements, and said combiner redirects and outputs the light beams from a terminal one of said connection surfaces of said combiner elements that are connected in series. each of said imaging devices has a maximum power input limit; said light sources are configured to provide a plurality of light components that have substantially the same wavelength spectrum respectively to said imaging devices; each of the light components has a power smaller than or equal to the maximum power input limit, and a sum of the powers of the light components is greater than the maximum power input limit of each of said imaging devices; said imaging devices convert the light components provided by said light sources respectively into a plurality of light beams each representing a same image, and provide the light beams to said combiner; and said combiner combines and redirects the light beams provided by said imaging devices toward the at least one layer of the photo-sensitive material in such a way that the images represented by the light beams completely overlap each other on the at least one layer of the photo-sensitive material; wherein said combiner has a plurality of combiner elements, each having a pair of connection surfaces opposite to each other, and a plurality mount surfaces each of which connects the connection surfaces; wherein for each of said combiner elements, one of said connection surfaces thereof is connected to one of said connection surfaces of another one of said combiner elements, and said combiner elements are connected in series; and wherein said imaging devices are disposed such that each of the light beams is provided into said combiner through an individual one of said mount surfaces of said combiner elements, and said combiner redirects and outputs the light beams from a terminal one of said connection surfaces of said combiner elements that are connected in series.