A microlens array device includes a substrate and a microlens array. The microlens array is disposed on the substrate and includes a plurality of first lenses and a plurality of second lenses. Each of the first lenses is used to project a first pattern on a far field. Each of the second lenses is used to project a second pattern on the far field. The first pattern has a first area on the far field. The second pattern has a second area on the far field. The first area is different from the second area. One of the two patterns is completely overlapped on the other one of the two patterns.