Abstract: An electronic device includes an image output module and a button module. The image output module has a storage unit storing a resolution table, and the resolution table has a plurality of resolution. The button module outputs a resolution adjusting signal. The image output module outputs an image having predetermined resolution and adjusts resolution of the image after receiving the resolution adjusting signal. This invention also provides an adjusting control method of projection resolution.

Abstract: A multimedia playing device and an operation method thereof are provided. The multimedia playing device stores an image having a plurality of multimedia options. The operation method sequentially includes the following steps. A portion of the image is defined as a projecting area. The portion of the image corresponding to the projecting area is projected. A movement of the multimedia playing device is sensed. According to the movement of the multimedia playing device, the projecting area is moved in the image. Thereby, the multimedia options are presented in a projecting mode, and a user can browse the multimedia options in a dynamic sensing mode thus to facilitate search and selection.