Large viewing window and automatically changing picture type advertisement lamp

The utility model arranges a low speed motor (35) in picture shafts (19) (20), and the low speed motor (35) is fixed in a lamp box shell. A friction wheel (34) which is provided with a spring piece (33) is unfixedly arranged on the rotating shaft (31) of the low speed motor, and the friction wheel (34) is provided with a spring (38) and a movable pin (37). The rotating shaft (31) of the low speed motor is provided with four bulge points (40) which form a small movable space with a cruciform wheel (32) that is arranged on the friction wheel (34). The inner walls of the picture shafts (19) (20) are provided with internal gears (32), which can form a driven friction with the spring piece (33). The top end of the rotating shaft (31) of the low speed motor is arranged in a bearing (30). The effective length of the picture shafts is increased, which can lead to borderless of a viewing window.