Some printers include a cutter assembly which can cut a print medium before or after a printing operation. The cutter assembly may include a cutter module having a cutting blade supported on a carriage to move across a print zone. By movement of the carriage across the print zone and/or movement of the print medium along a media advance path through the print zone, the cutter module may cut in one or two linear directions, such as the X and Y directions.
The following description references the drawings, wherein
In the present disclosure it is describer a cutter assembly including: a cutter module including a cutting blade; a guiding element extending along a cutting direction; and a carriage module to move the cutter module along the guiding element; wherein the carriage module is moved by a motor, the motor being controlled by a controller to move at a substantially constant speed along the cutting direction, and wherein the controller monitors a power signal of the motor and detects a cutting feature in the cutting direction based on the power signal.
In an example, the controller may detect the cutting feature upon comparison between the power signal and a reference signal. The reference signal may be, e.g., a threshold range and/or a predefined cutter calibration signal.
Also, the cutter assembly may comprise a speed sensor to determine the speed of the motor being the speed sensor to provide a speed signal to the controller. Examples of such sensors may be a quadrature encoder that may be associated to the shaft of the motor.
In an example, the controller is to detect the cutting feature in the cutting direction based on both the power signal and the speed signal.
The cutting feature may be an abnormality along the cutting path, for example, one selected from a bump, a media jam, and a motor slippage.
Also, the present disclosure refers to a method to detect cutting features along a cutting direction of a cutting assembly, the method being implemented in a controller, being the controller to: issue a power signal to a motor associated to the cutting assembly to move the cutting assembly at a substantially constant speed; monitor the power signal; and determine a presence of a cutting feature as a result of the monitoring of the power signal.
In an example, an increase in the power signal over a reference signal is determined as a cutting feature. Such increase may be, e.g., an increase above a threshold or a gradient increase in a determined period.
In a further example, the cutting feature comprises one selected from a bump, a media jam or a motor slippage.
Also, the controller may be to further monitor, by a speed sensor, the speed of the motor and wherein the controller is to determine based on the speed of the motor and the power signal the presence of the cutting feature.
Finally, the present disclosure also refers to a non-transitory computer-readable medium containing program instructions for causing a controller to perform any of the above-mentioned methods.
An implementation of the present cutter assembly may be incorporated in a printing system. In such a case the printing system, may include: a controller; a cutter module including a cutting blade; a guiding element extending along a cutting direction; and a carriage module to move, by a motor, the cutter module along the guiding element; wherein the controller monitors a power signal of the motor and to compare the power signal with a reference signal and identify a cutting feature based on the comparison.
In an example, the system may further comprise a speed sensor to determine the speed of the motor and wherein the controller is to receive a speed signal from the speed sensor and identify a cutting feature based on the speed signal and the comparison.
A print zone may be defined as the entire area or part of the area which can be traversed by the carriage. The scanning direction of the carriage also may be designated as X direction, the print media advance direction also may be designated as Y direction, and the direction of gravity also may be designated as Z direction. In the context of this application, a front view of the printer and of cutter assembly corresponds to a view in the X-Z plane, and a side view corresponds to a view in the Y-Z plane. A top view corresponds to a view in the X-Y plane. Directions, such as up and down, above and below, or right and left are defined as shown in the drawings.
As for the movement along the cutting direction, the assembly may further comprise a toothed belt 40 which extends along the support component 20 in the cutting direction X and which is arranged to engage with the gear. A distal end of the belt 40 may be recognized that the right-hand side of
In operation, a print medium may be transported through the print zone above platen 10 where a print fluid is to be deposited on the print medium. The printer may further comprise a print medium advance system to transport the print medium through the print zone in the media advance direction Y. The print media advance system may comprise media transport rollers, for example. Further, if the print medium is to be cut in a direction orthogonal to the print media advance direction, the cutter module 30 can be engaged with the carriage and the carriage can be moved in the scanning direction X, with the cutter module following movement of the carriage along the support component. During movement of the cutter module 30 along the support component 20, the gear may engage with the belt 40 to rotate the gear wherein rotation of the gear is transmitted to the rotary cutting blade to rotate the blade to cut the print medium. During movement of the cutter module 30, the support component 20 supports and guides both the cutter module 30 and the belt 40. Further, during movement of the cutter module 30, the cutter assembly may bias the gear against the belt 40 to ensure rotation of the rotary cutting blade and avoid slippage even if cutting thick print media, such as canvas.
Further details of an example of a cutter assembly including a cutter module 30 are described with reference to
In the example of
The carriage module 50 is connected to a motor so that a power signal sent to the motor moves the carriage module 50 bidirectionally along the cutting direction 500. In an example, the power signal may be a direct current (DC) signal, an alternate current (AC) signal or, in an example, a pulsed signal controlled by pulse-width modulation (PWM). In an example, a controller is to determine the power signal that is sent to the carriage module 50.
In an alternative configuration, not shown in the drawings, the printer includes a page wide print bar which extends across the width of the print medium 20, perpendicular to the medium advance direction Y. Also, in this case, the print bar can print swathes on the print medium 20 after each medium advance movement. The cutter module is carried by an associated carriage module 50 and scans and cuts along a cut line 501, for example, downstream of the print zone.
A controller instructs the printhead assembly 12 to print respective image slices between two medium advance movements for printing on subsequent portions of the print medium 200, instructs the cutter assembly 1 to cut between two defined medium advance movements, for separating a printed image from the print medium during the scanning action and without interrupting the print process of the print medium 20 currently undergoing printing.
In an example, a controller is to instruct the controller to move along the cutting direction 501 when a cutting operation is needed. In an example, the carriage module 50 is moved by a motor along a guiding element 60. The motor may be coupled to the carriage, e.g., by a gear-belt assembly and may be to move the carriage module 50 bidirectionally along the guiding element. Further, the carriage module 50 may move between parking zones 50′ wherein deceleration and acceleration of the carriage module 50 is performed and a print zone Pz wherein the carriage module 50 may be moved by the motor at a substantially constant speed. In an example, the parking zones 50′ are adjacent to the print zone. The movement of the carriage at a constant speed on the print zone helps achieve a uniform cut throughout the media.
A controller may be provided to monitor the power signal applied to the motor to maintain the motor moving at a substantially constant speed along the print zone Pz. Therefore, the controller may monitor such power signal to identify possible cutting features that may be present along a cutting operation, such cutting features may be, e.g., a bump defining a limit of movement of the carriage module 50, a media jam, a belt slippage, lack of lubrication, defects on the guiding element, or the like. For example, an increase on the power signal to maintain the carriage module 50 at a constant speed may indicate that further energy is needed to move the carriage module 50 which may be indicative of cutting features.
In a further example, the motor may be provided with a sensor associated to the speed transmitted to the carriage module 50, for example, the motor may comprise a quadrature encoder sensor associated to its shaft, such sensor is indicative of the speed of the shaft that is later transmitted to the carriage module 50. The speed sensor may be feedback to the controller so that the controller is provided with information regarding the power applied to the motor as to move the carriage module 50 at a reference speed and the actual speed provided by the motor.
Then, a controller may receive the power signal 401a and monitor such signal determine features in the cutting operation 403. Following the example in which the power signal is a PWM signal, the controller may monitor the root mean square (RMS) value, an average value or the like of the power signal and determine possible abnormalities in such a signal. As will be described later with reference to
In an example, the controller may be provided with access to a reference database 406 wherein, for example, a reference signal is provided so that the controller may compare the power signal 401a with a reference signal and, in view of such a comparison determine if a feature is present or if the signal does not have any abnormalities. In an example, the reference signal may be a power signal obtained in a calibration pass of the carriage module, i.e., without media in the cutting path.
Finally, the controller may act if the previously determined feature may affect the cutting and/or the printing operation 404. For example, the controller may instruct the cutting assembly 1 or the printing system 100 to stop their operations, nonetheless, in a further example, even if an abnormality is detected, the controller may decide that it is not severe enough to stop a cutting and/or printing operation
In view of
At instant t1a steep increase of the power signal is determined. Such steep increase is caused due to a further effort was required from the motor to maintain the reference speed. In the example of
In an example, the controller may monitor the power signal and determine a differential increase between an instant before t1 and t1 and determine that, if such difference exceeds a threshold, the presence of a feature is identified, such as a bump or an artifact that causes a stop on the carriage and, as a result, the controller may take actions, e.g., communicate with the motor to perform an emergency stop.
In an example, the controller would be to determine features in a cutting operation based on the power signal 701 and, optionally, based on the speed signal 703.
In the example of
At instant t1 the power signal starts increasing at a moderate rate until, in instant t2 exceeds the threshold 704. The controller may, on one hand, compare the increase rate at different instants, if the rate of increase is too high it may trigger an emergency stop of the motor. If the increase rate is moderate but the power signal 701 exceed the threshold 704 the controller may identify the feature as a possible media jam and decide whether to continue moving the carriage module or stop.
Additionally, if the controller is provided with the speed signal 703, it may determine whether the increase of the power signal 701 causes the motor to move or if the motor is stopped, i.e., if the feature is severe enough to cause damages on the motor. The speed signal 703 may help the controller differentiate a media jam, in which the motor has enough torque to continue the cutting path, or if the feature is so severe that is better to stop the motor, e.g., a severe jam, a bump or an obstacle in the cutting path.
The cutter assembly may include comprises a belt extending in the cutting direction X and being arranged so that the teeth of the belt are facing a gear associated to the motor as to couple thereto. The belt may be made of or include material having some elasticity, such as including either of or a combination of some of silicon rubber, polyurethane, nylon and Aramide fibers. The belt may have a stretch or extension ratio of about 102% to 110% at room temperature.
In the example of
As for the speed, in this case a non-stable signal is measured with amean value 801 around −7. This kind of behavior is representative of reaching a bump but still being able to move the shaft of the motor while not moving the carrage, i.e., a slippage between the motor shaft and the carriage, in this case, the belt that connects them.
The controller may be provided to determine a possible slippage abnormality by, e.g., having predetermined period of movement of the carriage, if the motor is still able to move (if some speed is detected in a sensor associated to the motor and/or if the motor has not reached the power threshold), then the controller may determine that an abnormality due to slippage may be occurring.
In a further example, a user may position or determine that the carriage is in the bump position and instruct the controller to move the carriage towards the bump position. If there is no abnormality, the power signal should reach the threshold power and/or the speed sensor should detect that the motor is static, if at least one of these conditions is not met, an abnormality due to slippage may be occurring and the controller may, e.g., issue an alert signal to the user.
Drive of the carriage (i.e., the issuance of the power signal to the motor), the print system and any actuator(s), e.g. for coupling the cutter module and the carriage, may be controlled by a controller (not shown). The controller can be a microcontroller, ASIC, or other control device, including control devices operating based on software or firmware, including machine readable instructions, hardware, or a combination thereof. It can include an integrated memory or communicate with an external memory or both. The same controller or separate controllers may be provided for controlling carriage movement, print engine and any actuators. Different parts of the controller may be located internally or externally to a printer or a separate cutting device, in a concentrated or distributed environment.
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/US2019/044412 | 7/31/2019 | WO | 00 |