Abstract: Disclosed is a roller offset printing apparatus which comprises image sensors 14 and 15 disposed on a linear stage 4, and position correction motors 8 to 13 disposed in the respective peripheries of a master plate 6 and a work plate 7, wherein positions of the master plate 6 and the work plate 7 on the linear stage 4 are detected by the image sensors 14 and 15 so that the respective positions of the master plate 6 and the work plate 7 are corrected by the motors 8 to 13 in accordance with the quantities of displacement when there is any displacement between the detected positions and reference positions. After correction, the linear stage 4 and a roller transfer drum 1 are moved while being synchronized with each other to thereby perform transfer. As a result, accuracy in positioning of the master plate and the work plate on the linear stage is improved, so that good superposition printing is provided.

Abstract: A roller offset printing apparatus comprising: a linear stage movable forwards and backwards; a stage driving means for driving said linear stage; a master plate and a work plate disposed at a predetermined interval on said linear stage, said master plate having ink pits reserving ink; a roller transfer drum supported rotatably; a roller transfer drum driving means for driving said roller transfer drum so that said roller transfer drum rotates on the surface of said master plate to transfer the ink in said ink pits of said master plate onto the outer circumferential surface of said roller transfer drum and said roller transfer drum further rotates on a surface of said work plate to thereby transfer the ink from the outer circumferential surface of said roller transfer drum onto the surface of said work plate; a rotation force transmission control means for controlling on/off of transmission of rotation force from said roller transfer drum driving means to said roller transfer drum; a rotation angle detection

Abstract: By operating a Z direction position adjustment mechanism by a driving motor, a Z table movable in the X and Y directions can be moved in a Z direction while maintaining its horizontal condition. Vibrations caused in the Z table when the Z table is moved at a high speed in the X and Y directions are damped by vibration damping means provided between the Z table and a base bed fixed to a coarse adjustment table which is mounted on a base and driven in the X and Y directions. Improvement in the accuracy of positioning in the X and Y directions is achieved, as well as a vibration damping effect. A chuck holding member is formed on the table to hold a chuck by suction which in turn holds a mounted member by suction, thereby making the exchange of the chuck easy and preserving the parallelism of the upper surface of the chuck.