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 picture-exhibiting device with an audio system which can be used to demonstrate paintings or photos. The picture-exhibiting device with an audio system includes a frame, a picture fixed on the frame, an electret speaker positioned on the backside of the picture, a fixer disposed at a back side of the picture, a back frame fixed on the frame, a cover covering part of the back frame and the electret speaker, a post amplifier coupling the electret speaker, and an audio signal provider coupling the post amplifier.