Abstract: An electronic device includes an input unit to generate input signals according to a users input. A storage unit to store audio files, an alarm speaker unit to sound the alarm audio files and execute the alarm commands. In addition, a processing unit to sound the alarm after a system time reaches a preset time period. Moreover, analyses operation type according to the input signals to control the speaker unit to resound the alarm or not sound the alarm after a time period according to the operation type. An alarm method is also provided.

Abstract: A combination signal receiving device includes a printed circuit board, a light source, a light cover, a receiving cover, and at least one signal receiver. The light source is mounted on the printed circuit board. The light cover is lighttight except a light transmissive logo. The light cover covers the light source. The receiving cover surrounds the light cover. The signal receiver is mounted on the printed circuit board beneath the receiving cover, configured for receiving outside signal passing through the receiving cover. Light emitted by the light source is incapable of reaching the signal receiver. The combination signal receiving device does not negatively influence the appearance of an electronic apparatus.

Abstract: An electronic device comprises a back cover and a support. The back cover defines a first contact area. The support is pivoted to the back cover by a pivot shaft, defines a second contact area contacting the first contact area. A plurality of positioning holes are defined in and disposed on the second contact area around the pivot shaft. The electronic device further comprises at least one retractable spring balls projected from the first contact area of the back cover. The spring balls are configured for cooperating with the positioning holes of the support. The support can stay at a variety of positions.