Joint for modular shelves and modular shelf system using the same

A modular shelf comprising:

• a plurality of joints, each of said joints comprising a flattened columnar body one end surface of which forms a front surface, and another, opposite end surface of which forms a rear surface, said joints being characterized in that at least one circumferential side surface of said flattened columnar body is provided with a plurality of slits comprising rear frame-fitting slits extending to left and right side surface and in parallel with said front surface, side frame-fitting slits extending at right angles to said rear frame-fitting slits, and L-shaped shelf-fitting slits which comprise first side parts extending along said rear frame-fitting slits and second side parts extending along said side frame-fitting slits, and which are provided on left and right sides of said side frame-fitting slits, each of said rear frame-fitting slits, said side frame-fitting slits, and said L-shaped shelf-fitting slits comprising upwardly opened slits and downwardly opened slits;
• a plurality of quadrangular rear frames, quadrangular side frames and reticulate shelves assembled together with said joints, each of said rear frames being fitted in said rear frame-fitting slits in corresponding ones of said joints, each of said side frames being fitted in said side frame-fitting slits in corresponding ones of said joints, and each of said frame members of said reticulate shelves being fitted in said shelf-fitting slits in corresponding ones of said joints.