Hi and welcome to Physics Forums.
I am not sure what your question is - and what is "the screen"?
Have you tried a Google search for "Concave Mirror Ray diagram"? There is no point in my giving you a home made ray diagram when there are thousands available on the Web but you will notice something about concave mirrors. Depending on where the object is relative to the mirror centre of curvature (object distance and r) you can get a real image 'inside' the mirror or a virtual image behind the mirror. If the object is at the centre of curvature, all rays from the object will come back and hit the object.
This effect is also obtainable with a convex Lens, where either a real or virtual image can be formed. Again, Google (Images) is your friend.
With convex mirrors or concave lenses, there is only one image is formed, wherever the object is.
PS I don't agree with your diagram showing an inverted image behind the mirror. Google will put you right. (Thy Hyperphysics website)