Flat screen alignment device

In a screen printing machine comprising a sheet print means including a printing table on which a sheet material to be printed is placed and set at a predetermined position, a printing machine frame above said printing table, a rectangular shaped screen fixing frame, having opposed frame sections, to be mounted to said printing machine frame, and a non-transparent screen attached to said fixing frame and having a pattern to be printed on said sheet material (2), the improvement of which comprising a screen setting apparatus comprising first reference points (5, 5', 5a, 5b) provided on said sheet print means, first reference members (30, 30') slidably mounted on said printing machine frame (10) to have a predetermined distance and direction (D) from said first reference points (5, 5'), second reference points (22, 22', 22a, 22b) provided on said screen (21), a pair of brackets (42, 42', 63, 63') slidably mounted on said opposite fixing frame sections (20b, 20d), a bar member (40, 60) removably mounted on said brackets at both end portions thereof, said bar member having first reference marks (49, 49', 49a, 49b) to be vertically lined up with said second reference points on said screen, and second reference means (64, 64', 46, 46') to be vertically lined up and physically engaged with said first reference members (30, 30') with the horizontal distance and direction (D') between said first reference marks and said second reference means being fixedly predetermined, wherein after sliding and adjusting said first reference members along the printing machine frame in such a manner that the horizontal distance and direction (D) from said first reference points on said sheet material are made equal to those between said first reference marks and second reference means on said bar member and when said first reference marks and second reference means on said bar member are vertically lined up and physically engaged with second reference points on said screen and said first reference members, respectively, said second reference points on said screen are registered with said first reference points on said sheet print means, thereby aligning said pattern with said sheet print means.