A new method for X-ray phase contrast imaging is proposed in which only one absorption grating (acting in fact as a coded aperture) and a table-top nano-focus X-ray source are used. This method is based on very precise determination of position of the projected pattern downstreaming from the aperture with and without the inspected object directly from the image of the pattern. The technique is successfully demonstrated on the table-top setup equipped with Medipix family detectors and a nano-focus X-ray source (source-to-detector distance < 1m).