Abstract: A parcel box includes a container, a lid, and a lid-closing module. The container has four side walls and a bottom plate. The four side walls respectively have a top edge and a bottom edge. The bottom plate is connected to the bottom edges of the side walls. The top edges of the side walls define an opening. The side walls and the bottom plate define a space. The lid has an edge pivotally connected to the top edge of one of the side walls, and configured to cover the opening at a closed position, and uncover the opening at an open position. The lid-closing module is connected to the lid and includes a contacting part in the space. When the contacting part is pushed toward the bottom plate, the lid-closing module drives the lid to the closed position.

Abstract: A parcel box includes a lid, a container, and a self-closing module. The self-closing module is connected to the lid and includes a contacting part arranged inside the container. When a parcel is placed into the container, the contacting part is pushed downward, and the lid-closing module drives the lid to close on the container.

Abstract: A parcel box includes a lid, a container, and a self-closing module. The self-closing module is connected to the lid and includes a contacting part arranged inside the container. When a parcel is placed into the container, the contacting part is pushed downward, and the lid-closing module drives the lid to close on the container.

Abstract: A device with an environmental sound mixing function includes a case, an input jack, an output jack, a microphone, a mixing module and an output detecting module. The case includes a hole. The input jack and the output jack are disposed on the case. The microphone is disposed in the case and aligned with the hole. The mixing module is electrically connected to the input jack, the output jack and the microphone. The microphone receives an environmental sound through the hole and converts the environmental sound into a microphone signal. The mixing module receives an audio signal through the input jack, mixes the audio signal with the microphone signal to generate a mixed signal, and outputs the mixed signal through the output jack. When the output detecting module detects that headphones are connected to the output jack, the output detecting module drives the mixing module to start operating.

Abstract: A device with an environmental sound mixing function includes a case, an input jack, an output jack, a microphone, a mixing module and an output detecting module. The case includes a hole. The input jack and the output jack are disposed on the case. The microphone is disposed in the case and aligned with the hole. The mixing module is electrically connected to the input jack, the output jack and the microphone. The microphone receives an environmental sound through the hole and converts the environmental sound into a microphone signal. The mixing module receives an audio signal through the input jack, mixes the audio signal with the microphone signal to generate a mixed signal, and outputs the mixed signal through the output jack. When the output detecting module detects that headphones are connected to the output jack, the output detecting module drives the mixing module to start operating.