US Patent 8254736 Prism array

A prism array for collecting light is provided. The prism array includes a first prism module and a coupling joint. The first prism module includes a first guiding prism and at least one first reflective prism. The first reflective prism is close to the first guiding prism, wherein light travels from the first guiding prism to the first reflective prism, and is reflected thereby. The coupling joint includes a first light pipe, a second light pipe, a third light pipe and a light transmitting pipe, wherein the first light pipe, the second light pipe and the third light pipe are coupled to an end of the light transmitting pipe, the third light pipe corresponds to the first reflective prism, and the light travels from the first reflective prism, passing through the third light pipe to the light transmitting pipe.