Abstract: A quick-change blade structure comprises a blade, a fixed seat, a locking device, and a resilient component. The fixed seat is equipped with a guide groove for inserting the blade. The blade features a locking groove, and the locking device is rotatably mounted on the fixed seat. One end of the locking device has a protruding locking head, while the other end has a pressing part connected to the resilient component. The elastic force of the resilient component presses the locking head into the locking groove, securing the blade. Pressing the part allows the locking device to rotate, releasing the locking head from the locking groove for blade removal. Installing the blade involves, inserting it directly along the guide groove into the fixed seat. The locking head of the locking device automatically presses onto the locking groove under the action of the resilient component, achieving blade installation.

Abstract: A laser projection device has at least one laser light source and a plurality of gratings, each grating having a light receiving side and a light emitting side. The plurality of gratings are arranged in a ring-shape having at least one row with the light receiving side of each grating facing a center of the ring. The laser projection device also has a motor configured to rotate the plurality of gratings about a rotational axis passing through the center of the ring. The plurality of gratings each comprise a pattern for forming an image when light is passed through the pattern. The plurality of gratings are arranged around the ring such that the plurality of patterns are configured to project an animated image when the plurality of gratings sequentially receive light from the at least one laser light source upon rotation of the grating set.