Abstract: A sensor includes: a substrate, a chip, and a protective layer. The chip is arranged on a surface of the substrate, the protective layer includes a silica gel protective layer, a silica gel active layer, and a strength-increasing protective layer. the silica gel protective layer is coated on the chip and adheres to the substrate; the silica gel active layer is coated on an outer surface of the silica gel protective layer, and adhesion of the silica gel active layer is greater than adhesion of the silica gel protective layer; the strength-increasing protective layer is coated on and adheres to an outer surface of the silica gel active layer, and the strength-increasing protective layer adheres to the substrate; and a strength of the strength-increasing protective layer is greater than a strength of the silica gel protective layer.

Abstract: A galvanometer positioning tool and a laser printer. The galvanometer positioning tool includes: a base provided with a bearing surface and provided with a first concave spherical surface; a bracket placed on the bearing surface, a positioning assembly being provided on a side surface of the bracket facing the bearing surface, a galvanometer being mounted on the bracket; and a reflection center of the galvanometer located on the spherical center of the sphere where the first concave spherical surface is located. The rotation assembly includes a first rotation rod fixedly connected to the second rotation rod and rotatably connected to the base. The second rotation rod is slidably connected to the bracket, and when the first rotation rod rotates relative to the base, the first rotation rod is capable of driving the bracket to rotate with the y-axis of the galvanometer as a rotation axis.

Abstract: A sensor includes: a substrate, a chip, and a protective layer. The chip is arranged on a surface of the substrate, the protective layer includes a silica gel protective layer, a silica gel active layer, and a strength-increasing protective layer. the silica gel protective layer is coated on the chip and adheres to the substrate; the silica gel active layer is coated on an outer surface of the silica gel protective layer, and adhesion of the silica gel active layer is greater than adhesion of the silica gel protective layer; the strength-increasing protective layer is coated on and adheres to an outer surface of the silica gel active layer, and the strength-increasing protective layer adheres to the substrate; and a strength of the strength-increasing protective layer is greater than a strength of the silica gel protective layer.