A collapsible, self-expanding display unit comprising: two opposite panels (10, 20) joined at their lateral edges (11, 12 and 21, 22), and which in a collapsed situation adopt a flat configuration, and in a service position adopt a convex configuration able to stand upright; a push element located between said two opposite panels (10, 20) of the display unit and comprising a sheet joined to at least one of the two panels (10, 20) of the display unit, said push element adopting a flat configuration together with the two panels (10, 20) of the display unit in said collapsed situation and a three-dimensional configuration together with the two panels (10, 20) in said service position, said push element comprising a bend line dividing the push element into first and second portions (30a, 30b); and a pull element having a first end connected to said first portion or to one of the two panels (10, 20) of the display unit and a second end connected to said second portion, said the pull element attracting the first and second portions (30a, 30b) towards one another to bend said push element about said bend line, characterized in that: the first and second portions (30a, 30b) of the push element have respective opposite first and second edges (31, 32) at either sides of the bend line, said first and second edges (31, 32) being parallel to the bend line and parallel to at least one of said lateral edges (11, 12 and 21, 22) of the panels (10, 20) of the display unit; said first edge is joined to one of the panels (10, 20) of the display unit; and said second edge is a free edge, thereby said free second edge of the push element pushes from the inside one of the panels (10, 20) of the display unit and an edge coinciding with said bend line of the push element pushes from the inside the other of the panels (10, 20) of the display unit when the push element is bent along the bend line by said pull element to automatically expand said panels (10, 20) of the display unit from the collapsed situation to the service position, and keep them in the service position. two opposite panels (10, 20) joined at their lateral edges (11, 12 and 21, 22), and which in a collapsed situation adopt a flat configuration, and in a service position adopt a convex configuration able to stand upright; a push element located between said two opposite panels (10, 20) of the display unit and comprising a sheet joined to at least one of the two panels (10, 20) of the display unit, said push element adopting a flat configuration together with the two panels (10, 20) of the display unit in said collapsed situation and a three-dimensional configuration together with the two panels (10, 20) in said service position, said push element comprising a bend line dividing the push element into first and second portions (30a, 30b); and a pull element having a first end connected to said first portion or to one of the two panels (10, 20) of the display unit and a second end connected to said second portion, said the pull element attracting the first and second portions (30a, 30b) towards one another to bend said push element about said bend line, the first and second portions (30a, 30b) of the push element have respective opposite first and second edges (31, 32) at either sides of the bend line, said first and second edges (31, 32) being parallel to the bend line and parallel to at least one of said lateral edges (11, 12 and 21, 22) of the panels (10, 20) of the display unit; said first edge is joined to one of the panels (10, 20) of the display unit; and said second edge is a free edge, thereby said free second edge of the push element pushes from the inside one of the panels (10, 20) of the display unit and an edge coinciding with said bend line of the push element pushes from the inside the other of the panels (10, 20) of the display unit when the push element is bent along the bend line by said pull element to automatically expand said panels (10, 20) of the display unit from the collapsed situation to the service position, and keep them in the service position.