FR2890597A1 - Digital inkjet printer has an automatically adjusting elevating table with a support plate on which different media can be placed so that the printer can readily be used with said different media - Google Patents

Abstract

Digital inkjet printer has an elevating table (T) with a suction plate (1) which automatically and immediately adapts to the thickness of the print medium (Z axis) and above which a support beam (P) is displaced along the Y-axis, which the inkjet head (5) is traversed rapidly backwards and forwards along the X-axis according to a kinematic movement which enables the inkjet head to sweep over the print medium. The invention also relates to a corresponding digital printing method.

Description

Digital printing machine on various flexible or rigid supports

dishes.

  Technical field and state of the art.

  These machines use multi-color inkjet printheads to reproduce any scanned image on flat surfaces. The printheads scan the surface along two axes X and Y. The X axis is transverse, and goes back and forth after each stepwise advance of the longitudinal Y axis. It is during the back and forth of the X axis, ejected micro-drops from the printheads. The arrangement of these millions of drops in frames, combined with the movements of the heads, creates the image.

  A height adjustment (Z axis) makes it possible to adapt to the different thicknesses of the media to be printed to be at the correct printing distance (distance between the medium to be printed and the print head, at the ejection nozzles drops: 1 to 2 mm).

  The size of the media to be printed is limited only by the dimension of the length of each X and Y axis. DISPLAY MAKER 72 SRTM Adjustment of the printing height by moving the heads: 4.76 mm. 20 Movement of the support along the Y axis. Capacity 1850 x 1520 mm (option 1850 x 3200).

  Automatic detection of the edges of the print media.

DURST RHOTM

  Adjustment of the printing height by moving the heads: 70 mm. Displacement of the support along Y axis. Capacity 1580 x 2050 mm.

INCA SPIDERTM

  Adjustment of the print height by moving the heads: 30 mm. Movement of the heads on gantry along Y axis. Capacity 1524 x 1016 mm.

  MIMAKI DM2 1810TM Adjustment of print height by moving the heads: 50 mm. Displacement of the support along Y axis. Capacity 1580 x 2050 mm.

MUTOH TOUCAN HYBRIDTM

  Adjustment of the print height (manual) by moving the heads: 90 mm.

  Displacement of the support along Y axis. Capacity 1575 x 3000 mm.

NUR TEMPOTM

  Adjustment of the printing height by moving the heads: 50 mm. Displacement of the support along Y axis. Capacity 2000 x 3200 mm.

  OCE ARIZONA T220TM Adjustment of print height by moving the heads: 50 mm. Movement of heads on gantry along Y axis. Capacity 1570 x 3040 mm.

RUNJIANG FLORATM

  Adjustment of the printing height by moving the heads: 50 mm. Displacement of the support along Y axis. Capacity width 1800 mm.

SCITEX VEEJETTM

  Adjustment of the print height by moving the heads: 40 mm. Displacement of the support along Y axis. Capacity 2000 x 3000 mm.

VUTEK PRESSTM

  Adjustment of the printing height by moving the heads: 44 mm. Displacement of the support along Y axis. Capacity width 2000 mm.

ZUND UVJETTM

  Adjustment of the print height by moving the heads: 100 mm. Displacement of the support along Y axis. Capacity 1220 x 1160 mm.

  TAMPOPRINT DMD U1500TM Adjustment of print height by moving the heads: 100 mm. Displacement of the support along Y axis. Capacity 1500 x 2500 mm.

LUSCHER JET PRINTTM

  Adjustment of the printing height by moving the heads: 50 mm. Moving heads on gantry along Y axis. Capacity 3050 x 3500 mm.

Disadvantages.

  The height capacity (to adapt to the thickness of the medium to be printed) is currently limited to 100 mm. This setting is manual and unsafe on most of these machines.

  The media is moved along the Y axis on most machines. This setting in motion is performed by a mobile suction plate or a drive system of the support by rollers and rollers. The latter system (the most common) limits the type of media to be printed because of the problems of adhesion training that this entails. These techniques are only suitable for media whose two large flat faces are parallel.

  The mobile suction tray along the Y axis is a heavy system and very bulky (the size is at least equal to twice the Y capacity).

  Roller drive systems do not have original registration points for the print media.

  There are no integrated security systems that avoid a destructive collision between the print head and impromptu obstacles (lack of flatness of the support, object left on the support, hand of an operator ...). Safety systems (when they exist) are generally global (protection of the work area) and therefore limit access to the machine, or may be subject to nuisance tripping unrelated to the machine (passage of a machine). operator in the vicinity of a detector ...).

  The loss of a print job can be expensive because of the price of special print media and the cost of inks.

  Most of these machines require several high energy sources (electric and pneumatic).

  General technical problem It is a matter of printing on any medium comprising at least one flat surface (face to be printed). This support can be any object, and therefore relatively bulky in thickness. Hence the technical difficulty to solve this problem and give satisfaction to users, it being understood that of course the quality of the print must be or remain faultless. Another important difficulty lies in the great diversity of materials.

  TECHNICAL SOLUTION The technical solution of the present invention comprises the use of a preferably aspirating table lift table T 1 automatically and immediately adapting to the thickness of the support to be printed (Z axis), above that It moves a gantry along the Y axis, itself causing an inkjet printing head 5 along a fast X axis.

  This general solution comprises the combination in the general sense of displacement along these two axes X and Y and allows the print head 5 to scan the surface to be printed.

  The height position of the plane to be printed is detected by a tangent optical system, which also allows the control of the surface (verification of the absence of obstacles), and the print head 5 is protected by detector shutters. obstacles.

  The lift table allows a large travel height (over 300 mm) with a small footprint, which allows for a machine compact height (less than 1.6 m), and easy access to the tray.

  The printer comprising this table according to the invention requires only a simple single-phase standard power supply.

  Detailed solution The solution is shown in detail in the accompanying FIGS. 1 to 4, where the same references denote the same parts or elements.

  The lifting table T (FIG. 1 and FIG. 3) comprises a rectified and hollow plate 1, pierced with multiple holes (visible in FIG. 1 and 3 but not referenced) on the laying face 2, in order to flatten the supports by suction. fine and flexible such as tarpaulins, paper and other cardboard supports.

  This suction of air also allows to maintain by vacuum specific tools to position and fix objects of all shapes.

  This plate is carried by a pair of braces 3 whose spacing height is driven by a motor driving a screw (on each spider 3). The control of the motor M (by an electronics not shown, according to the preferred embodiment) provides sufficient precision that allows to set the optimum printing distance.

  This optimum printing distance is detected by means of an optical sensor 4 visible in FIG. 2 (which is a partial enlarged view of FIG. 1) and FIG. 3, whose axis of the light beam is set parallel to the axis. X. After placing the support to be printed on the plate 1, the latter is set in vertical movement (Z axis) upwards, in order to get closer to the printing heads 5. When the edge of the support intersects the light beam optical sensor 4, the movement is stopped because it is the height mark that indicates that the plane to print is in the print area. Then the tray goes down slightly to position itself at the correct printing distance. This arrangement also makes it possible to control the state of the plane of the support to be printed, and thus to detect before the printing the presence of possible obstacles. This will avoid stopping a print in progress if the media plan was not cleared. To do this, once the printing distance is reached, the gantry moves along the Y axis, and the optical sensor 4 again released, sweeps the surface of the support. If an obstacle is present, it again cuts the light beam of the sensor, and is thus detected, another important advantage of the present invention. This triggers an alarm that warns the operator to clear the plan to print.

  For the safety of the machine and the operators, the X and Y movement axes are equipped with obstacle detection shutters. These shutters are always active during each move, whether during printing, as during any additional maneuver. These shutters are directly connected to mechanical contactors. When they fire, any movement is immediately and firmly stopped, and an alarm indicates to the operator a problem related to an impromptu obstacle. On the other hand, the flaps mounted on the fast axis X, near and in front of the printing heads, prevent them from being destroyed during a possible impact with an impromptu obstacle (for example, a support poorly adapted printing, which deforms under the action of heating the UV drying lamps 6). These shutters are integrated closer to the moving elements. They avoid any trigger. A hood is thus provided.

  As for the vertical displacement of the plate (Z axis), the latter slides in a fairing or housing that prevents jamming. In addition, the interior of this fairing makes it possible to repeatedly position the object to be printed.

  The object to be printed is wedged in an angle of the plate, cf. figure 2.

  FIG. 3 represents a general view of the digital printing machine, characterized by the micro-suction plate 1, the mechanical and electronic control means ensuring the kinematics along the X, Y, Z axes as indicated above, as well as the particular kinematics of optical detection of possible obstacles.

  FIG. 3 also shows the braces 3, the motor M, the gantry P, and the printing heads 5, as well as the UV drying lamp 6, and the carriage movable along the X axis (7).

  FIG. 4 shows a print head, as well as the carriage movable along the X axis (7), the X axis itself, a plate 8 for positioning the head on said carriage, the UV lamp 6 for drying , the module 9 of the head (disconnectable and interchangeable), the ink jets (arrows) and a fixing screw.

  According to the present invention, the origin point "0" of the printing is automatic. The operator comes to "wedge" the object to be printed in the angle according to X and Y formed by the frame. There is no need to say then to the machine, when it is the case, or is the starting point of the printing on the support.

  The invention relates to the general concept which has just been described, the motorized printing table according to certain cinematics, the printing method comprising the kinematics described, and employing said printing table and the digital printing machines comprising these elements.

Claims (9)

  A digital printing machine, of the type using multi-color inkjet print heads to reproduce any scanned image on flat surfaces, the print heads scanning the surface along two axes X and Y, the X axis being transverse, and makes back and forth, after each step-by-step advance of the longitudinal Y axis, X axis forward and backward movements during which micro-drops are ejected from the heads of the X axis; impression, the arrangement of these millions of drops in frames, combined with the movements of the heads, creating the image, characterized in that it comprises the use of a lift table T with a plate 1 automatically adapting and immediately to the thickness of the medium to print (Z axis), and in that above it moves a gantry P along the Y axis, itself causing an inkjet printing head 5 along an axis X fast, according to a kinematic that involves the combination of the unfolding acement along these two axes X and Y and allows the print head 5 to scan the surface to be printed.   2 Machine according to claim 1, characterized in that the plate 1 is a suction plate.   3 Machine according to claim 1 or 2, characterized in that the height position of the plane to be printed 1 is detected by a tangent optical system 4, which also allows the control of the surface, checking the absence of obstacles.   4 Machine according to claim 3, characterized in that the print head 5 is protected by obstacle detection shutters.   Machine according to any one of claims 1 to 4, characterized in that the lift table T is adapted to allow a large clearance in height, more than 300 mm, with a small footprint, which allows to have a compact machine in height less than 1.6 m, and easy access to the plateau.   6 Machine according to any one of claims 1 to 5, characterized in that the lifting table T comprises a rectified and hollow plate 1, pierced with multiple holes on the laying face 2, to flatten by suction the thin media and flexible such as tarpaulins, paper and other cardboard supports; this suction of air also allows to maintain by vacuum specific tools to position and fix objects of all shapes.   7 Machine according to claim 6, characterized in that the plate 1 is carried by a pair of braces 3, the spacing height is controlled by a motor driving a screw on each spider 3, the motor control M being adapted for ensure sufficient accuracy to set the optimum print distance.   Machine according to Claim 7, characterized in that this optimum printing distance is detected by means of an optical sensor 4, the axis of the light beam of which is set parallel to the axis X. 9 Process for digital printing characterized in that that - it employs a machine according to any one of claims 1 to 8; after placing the support to be printed on the plate 1, the latter is set in vertical movement (Z axis) upwards, in order to approach the printing heads 5, - when the edge of the support intersects the light beam of the 4 optical sensor, the movement is stopped because it is the height mark that indicates that the plane to be printed is in the printing area, then the tray 1 down slightly to position at the correct printing distance.   in order to check the state of the plane of the medium to be printed, and thus to detect the presence of any obstacles before printing, once the printing distance has been reached, the gantry P starts moving along the Y axis, and the optical sensor 4, again released, sweeps the surface of the support 1; if an obstacle is present, the latter again cuts off the light beam of the sensor, and is thus detected, which triggers an alarm which warns the operator that he must clear the plane to be printed.   A method for digital printing according to claim 9, characterized in that the origin point "0" of the printing is automatic; the operator comes to "wedge" the object to print in the angle according to X and Y formed by the frame.   Process according to claims 9 and 10, characterized in that the printing medium comprises any support of variable thickness, including tarpaulins, paper and other cardboard supports.