Circular frame for inserting a picture

A circular advertising frame for receiving a picture, comprising

• a main frame;
• a socket half-frame;
• an insert half-frame;
• a hanging ring;
• a concave-convex locking device;
• and
• a diaphragm;
• wherein
• the main frame is a bilaterally symmetrical;
• a socket frame starting from a center point of the top of the main frame and terminating at a center point at the bottom of the main frame is disposed on one side of the main frame;
• a cross section of the socket frame is socket-shaped;
• an inner wall of the socket frame is matched with an outer edge on one side of the main frame;
• the main frame is integrally connected to a side wall in the socket frame to form a socket half-frame with a socket;
• another side of the main frame is an insert half-frame;
• the width of the socket of the socket half-frame is a sum of thicknesses of the insert half-frame and of a picture to be received;
• a hanging ring is disposed in the center of the top of the main frame;
• a hanging ring socket is disposed on the socket half-frame in the vicinity of the hanging ring;
• a plurality of concave-convex locking devices is disposed in the center of the bottom of the main frame;
• the concave-convex locking devices are protrusions and grooves with corresponding shape and size,
• a locking device socket is disposed at the socket half-frame of the concave-convex locking device;
• a frame-shaped groove is disposed on one side of the main frame opposite to the socket half-frame;
• and
• a diaphragm is embedded in and fixed to the frame-shaped groove, to form a plane.