Abstract: An optical system affixed to an electronic apparatus is provided, including a first optical module, a second optical module, and a third optical module. The first optical module is configured to adjust the moving direction of a first light from a first moving direction to a second moving direction, wherein the first moving direction is not parallel to the second moving direction. The second optical module is configured to receive the first light moving in the second moving direction. The first light reaches the third optical module via the first optical module and the second optical module in sequence. The third optical module includes a first photoelectric converter configured to transform the first light into a first image signal.

Abstract: A bonding structure of an electrical contact, a bonding method of the electrical contact and a battery module are provided. The bonding structure of the electrical contact includes an electroconductive part and an electrode sheet welded to the electroconductive part. The electrode sheet is a first metal material, and the electroconductive part is a second metal material. A welding track is formed on an interface formed by combining the electrode sheet with the electroconductive part. The welding track is a mixture of the first metal material and the second metal material. The welding track substantially has no overlap. In addition, the welding track includes a moving path, and a lateral path of performing a wobble movement or an oscillation movement on lateral sides of the moving path.