Label dispenser with roll end detection and method for operating a label dispenser

Abstract

Label dispenser (1) comprising a controller (2), an unwinding device (3) with a core (4) for receiving a label roll (5) with a label tape (6), a dispenser unit (7), a rewinding device (8), and a motor (9) for driving a drive roller (10) of the dispenser unit (7), wherein a sensor (11) is provided to detect a rotation of the drive roller (10) when the label roll (5) is unwound, and a rotation angle sensor (12) is provided on the unwinding device (3) to detect the degree of rotation of the core (4) when the label roll (5) is unwound, wherein the controller (2) is configured to calculate a dispensing length (13) of the label tape (6) from the rotation of the drive roller (10) and, if the dispensing length (13) corresponds to or exceeds a measuring length (14) set in the controller,based on the degree of rotation determined by the rotation angle sensor (12) and the dispensing length (13), to calculate a label roll diameter (15) and to generate a roll change signal depending on the calculated label roll diameter (15), characterized in that the label dispenser (1) is configured to automatically detect the angle degree state of a new label roll (5).

Description

[0001] The invention relates to a label dispenser comprising a control unit, a winding device with a core for receiving a label roll with a label tape, a dispenser unit, a winding device and a motor for driving a drive roller of the dispenser unit with the features of claim 1, and to a method for operating a label dispenser with the features of claim 6.

[0002] A labeling device comprising a dispenser unit and a transfer unit with at least one label transport belt for applying a label to a product is known from EP 2 679 505 B1. DE 20 2015 007 327 U1 discloses a label dispenser, e.g., for cross-web labelers, with a controller, an unwinding device, a dispenser unit, and a rewinding device, wherein the unwinding device is designed to receive a label roll. An RFID reading unit is provided in the immediate vicinity of the label roll, which is attached to record and transmit the data of the label roll, as well as the dimensions of the labels, the number of labels on the label roll, and / or the distance between two consecutive labels to the controller. US6764235B2 discloses a label dispenser for a franking machine. DE10318845A1 discloses a label application device unwinding sensor.US2009 / 0283565A1 discloses a measurement method for determining the dimensions of roll media.

[0003] The object of the invention is to provide an improved label dispenser.

[0004] This problem is solved by a label dispenser having the features of claim 1 or by the method for operating a label dispenser having the features of claim 6.

[0005] The label dispenser according to the invention comprises a controller, an unwinding device with a core for receiving a label roll with a label strip, a dispenser unit, a rewinding device, and a motor for driving a drive roller of the dispenser unit. A sensor is provided and configured to detect the rotation of the drive roller as the label roll is unwound. The sensor can, for example, be a rotary encoder. Such an electronic device converts the angular position or revolutions of a shaft into analog or digital output signals. A rotation angle sensor is provided on the unwinding device to detect the degree of rotation of the core as the label roll is unwound. Furthermore, the controller is configured to calculate the dispensing length of the label strip from the rotation detection.During the unwinding of the label roll, the labels are transferred from the label tape to a dispensing edge of the dispensing unit, for example, onto a film transport device, to be applied to films to be labeled. The length of the label tape from which the labels have already been dispensed is called the dispensing length. This corresponds to the label-free tape length that is fed to the rewinding device by the drive roller after the labels have been dispensed. The dispensing length is calculated using the rotational position values ​​of the drive roller transmitted by the sensor.

[0006] When the dispensing length corresponds to a user-defined measuring length based on the degree of rotation and the measuring length determined by the rotary angle sensor, a label roll diameter is calculated. The label roll diameter changes with each rotation. To calculate an initial label roll diameter, the change in the data for the rotary angle and dispensing length is measured multiple times. Data for a label roll diameter is derived from the change in the ratio of the rotary angle to the dispensing length. After an initial label roll diameter has been calculated, the change in the label roll diameter is further determined. The controller is also configured to generate a roll change signal depending on the calculated label roll diameter. The roll change signal is an electronic signal. This signal may trigger further processes in the controller that can initiate a roll change.

[0007] The label dispenser according to the invention allows the length of label tape that has not yet been dispensed and remains wound on the label roll, which is referred to here as the roll end, to be detected more precisely, thus enabling, for example, a timely roll change or the uninterrupted application of a new label roll.

[0008] Preferably, a minimum label roll diameter value can be set. This operator-defined label roll diameter is a threshold value entered into the controller. During unwinding, the calculated label roll diameter is continuously or intermittently compared to the set label roll diameter. When the calculated label roll diameter reaches this set minimum label roll diameter value, a roll change signal is generated. At higher operating speeds, the label roll unwinds faster, thus reducing the time available for label roll changes. For example, setting a higher label roll diameter value increases the time allotted for label roll changes, ensuring uninterrupted application of a new label roll.

[0009] In another embodiment, the measuring length is adjustable. This allows for a further improvement in the accuracy of the label roll end detection. To detect the initial diameter of a new label roll, more frequent measurements of the label roll diameter are required at the beginning of the winding process. This is achieved by adjusting the measuring length. The shorter the measuring length, the more frequently the label roll diameter is calculated.

[0010] In another embodiment, the control system, based on the roll change signal, e.g., on a display device such as a screen, can generate a display showing the number of substantially remaining labels. Since the dimensions of the labels and / or the spacing between them can vary on different label rolls, the number of substantially remaining labels provides the operator with a quick overview of the label roll's condition.

[0011] A Hall sensor is preferably used as the rotary angle sensor. Since Hall sensors operate without contact and are therefore wear-free, their lifespan is practically unlimited. Furthermore, Hall sensors detect rapid changes in position, resulting in extremely reliable measurement results.

[0012] According to the invention, a method for operating a label dispenser is further provided, wherein the label dispenser comprises a controller, an unwinding device with a core for receiving a label roll with a label tape, a dispenser unit, a rewinding device and a motor for driving a drive roller of the dispenser unit, wherein during unwinding a sensor detects the rotation of the drive roller and calculates a dispensing length, wherein during unwinding the label roll a rotary angle sensor detects the extent of rotation of the label roll and, if the dispensing length corresponds to or exceeds a measuring length, a label roll diameter is calculated depending on the extent of rotation determined by the rotary angle sensor and the measuring length, and a roll change signal is generated depending on the calculated label roll diameter.As explained above, this allows for more accurate detection of a roll end during the unwinding of a label roll, and thus, for example, a more punctual roll change or an uninterrupted application of a new label roll.

[0013] In a further advantageous embodiment, a minimum label roll diameter value is set, and a roll change signal is generated when the currently calculated label roll diameter corresponds at least substantially to the set minimum label roll diameter value. As explained above, this setting ensures uninterrupted application of a new label roll, particularly at high operating speeds.

[0014] In a further advantageous embodiment, the measuring length is adjustable. This allows for a further improvement in the accuracy of the label roll end detection. To detect the initial diameter of a new label roll, more frequent measurements of the label roll diameter are required at the beginning of the winding process. This is achieved by adjusting the measuring length. The shorter the measuring length, the more frequently the label roll diameter is calculated.

[0015] In a further advantageous embodiment, an activation length is set before the start (i.e., before the label dispenser is put into operation), wherein the activation length corresponds to an initial segment of the label tape, and the start for detecting the degree of rotation of the label roll is defined based on the activation length. This, for example, disregards an initial label tape length without labels in the roll end detection, thus further improving the precision of the method.

[0016] It is advantageous to automatically change the label roll based on the roll change signal, or to convert the roll change signal into a display, e.g. on a display device, and subsequently change the label roll manually.

[0017] In an advantageous embodiment, the dimensions of the labels and, if applicable, the spacing between the labels, which may vary between different label rolls, are taken into account when calculating the number of substantially remaining labels. This allows for a more accurate calculation of the number of remaining labels.

[0018] According to the invention, the angle of the new label roll is automatically detected, preferably by the rotation angle value last measured by the rotation angle sensor. This value relates to the angle of a previous label roll. The angle of a label roll is much higher at the end of its unwinding than at the beginning. A high angle indicates that the original label roll has been completely unwound and replaced by a new one. The advantage of this embodiment is that when calculating the diameter of a new label roll, only the rotation angle data from the current label roll is considered, thus further improving the precision of the roll detection.

[0019] In an advantageous embodiment, the thickness of the label tape is taken into account when calculating the label roll diameter in order to further improve the precision of the method, since the size of the diameter of the label roll may depend on the thickness of the label tape.

[0020] Exemplary embodiments of the invention are described in more detail below with reference to the figures.

[0021] This shows Fig. 1. A perspective front view of a cross-web labeling unit with a label dispenser; Fig. 2 a perspective front view of the label dispenser from Fig. 1 with a roll of labels in a wound state at the beginning of the unwinding; Fig. 3 a rear view of the label dispenser from Fig. 2; and Fig. 4 A perspective front view of the label dispenser from Fig. 2 with a label roll in an unwound state at the end of the unwinding.

[0022] Fig. Figure 1 shows a perspective front view of a cross-web labeling unit Q with a label dispenser 1, in which labels 16 located on a label tape 6 are individually transported via a dispenser unit 7 on a film transport device F and applied by a stamp S to films (not shown) transported by means of the rollers R of the film transport device F. The label dispenser 1 is connected to a control unit 2, which can itself be part of the label dispenser 1 or a higher-level control unit 2 of a production machine or system.

[0023] Fig. Figure 2 shows a perspective front view of the label dispenser 1 with a label roll 5 in a wound state at the beginning of the unwinding process. The label dispenser 1 is equipped with an unwinding device 3 for unwinding a label strip 6 with labels 16 and a dispenser unit 7 for dispensing individual labels 16 from the label strip 6. The thickness of the label strip 6 is denoted here by D. A winding device 8 is provided for winding the label strip 6. The winding device 8 comprises a reel 18 onto which the label strip 6 is wound. The reel 18 is driven by a motor (not shown), preferably a stepper motor or servo motor.

[0024] The path of the label tape 6 on the label dispenser 1 during operation is as follows. The label tape 6 with labels 16, which is located on the label roll 5, is pulled off the unwinding device 3 and deflected by two stationary deflection rollers 19a, 19b and a pre-tensioned dancer arm 20 with a deflection roller 21 of the unwinding device 3 in order to maintain a largely constant web tension.

[0025] According to the invention, a label dispenser 1 with roll-end detection during the unwinding of the label roll 5 and a method for operating the label dispenser 1 are provided. For this purpose, the dispenser unit 7 includes a sensor 11 to detect the rotation of the drive roller 10 during unwinding. A gap A is visible between the labels 16. This gap A can vary in different label rolls 5. The controller 2 is configured to calculate a dispensing length 13 of the label tape 6 from the rotation detection of the drive roller 10. The dispensing length 13 refers to the label-free length of the label tape 6 that, after the labels 16 have been dispensed from the dispenser unit 7, runs through one or more drive rollers 10, driven by a motor 9, to the rewinding device 8. The dispensing length 13 can be calculated from the rotation values ​​of the drive roller 10 transmitted by the sensor 11, if the circumferential length of the drive roller 10 is known.

[0026] Fig. Figure 3 shows a perspective rear view of the label dispenser 1, where a rotary angle sensor 12, for example a Hall sensor, and the pre-tensioned dancer arm 20 are visible in more detail. The label dispenser 1 is equipped with a rotary angle sensor 12 to detect the degree of rotation of the roll core 4 when the label roll 5 is unwound. An adjustable measuring length 14 is entered in the controller 2 (see Figure 3). Fig. 2), which defines the length at which the measurement data for calculating a label roll diameter 15 are recorded. If the dispensing length 12 equals or exceeds the set measuring length 14, a label roll diameter 15 can be calculated as follows, based on the degree of rotation determined by the rotation angle sensor 12 and the measuring length 14. The label roll diameter 15 changes with each rotation. To calculate an initial label roll diameter 15, the change in the data for rotation angle and dispensing length 13 is measured multiple times. Data for a label roll diameter 15 are empirically derived from the change in the ratio of the rotation angle to the dispensing length 13. After an initial label roll diameter 15 has been calculated, the change in the label roll diameter 15 continues to be recorded.A parameter such as the thickness D of the label tape 6 can be taken into account when calculating the label roll diameter 15.

[0027] Before starting, an activation length 17 is set, where the activation length 17 corresponds to an initial piece of the label tape 6, where the start for detecting the extent of the rotation of the label roll 5 is defined based on the activation length 17.

[0028] During the unwinding of the label roll 5, the labels 16 are transferred from the label tape 6 to a dispensing edge 22 of the dispensing unit 7, for example, onto a film transport device, in order to be applied by means of this device to films to be labeled (not shown in detail). The remaining label tape 6 is fed without labels 16 in a transport direction T to the rewinding device 4 (see Fig. 2).

[0029] Fig. Figure 4 shows a perspective front view of label dispenser 1 of Fig. 2 with a label roll 5 in an unwound state at the end of the unwinding, and therefore with a smaller diameter 15 than in Fig. 2. A minimum label roll diameter value can be set in the controller, and if the currently calculated label roll diameter 15 corresponds at least substantially to the set minimum label roll diameter value, a roll change signal is generated. The roll change signal is an electronic signal that triggers an automatic change of the label roll 5, or the roll change signal is converted into a display and the label roll 5 is subsequently changed manually.

[0030] The label roll diameter 15 can be considered here as the sum of the thickness of the roll core 4 and the wound label tape 6, or alternatively only as the thickness of the wound label tape 6.

[0031] It is also possible to calculate the number of essentially remaining labels 5 using control 2 and generate the display with this number. A gap A is visible between the labels 16. This gap A can vary in different label rolls 5. The dimensions of the labels 16 and the gap A between them can differ in different label rolls 5. These dimensions and gaps can be taken into account when calculating the number of essentially remaining labels 5.

[0032] When a new label roll 5 is attached to the core 4, the angle of the new label roll 5 is automatically detected by the rotation angle value last measured by the rotation angle sensor 12 and, if necessary, set to zero to correctly measure the rotation of the new label roll 5. This rotation angle value is relative to the angle of a previous label roll. The angle of a label roll 5 is higher at the end of its unwinding than at the beginning.

Claims

[1] Label dispenser (1) comprising a controller (2), an unwinding device (3) with a core (4) for receiving a label roll (5) with a label tape (6), a dispenser unit (7), a rewinding device (8), and a motor (9) for driving a drive roller (10) of the dispenser unit (7), wherein a sensor (11) is provided to detect a rotation of the drive roller (10) when the label roll (5) is unwound, and a rotation angle sensor (12) is provided on the unwinding device (3) to detect the degree of rotation of the core (4) when the label roll (5) is unwound, wherein the controller (2) is configured to calculate a dispensing length (13) of the label tape (6) from the rotation of the drive roller (10) and, if the dispensing length (13) is equal to or exceeds a measuring length (14) set in the controller,based on the degree of rotation determined by the rotation angle sensor (12) and the dispensing length (13), to calculate a label roll diameter (15) and to generate a roll change signal depending on the calculated label roll diameter (15), characterized by , that the label dispenser (1) is configured to automatically detect the angle degree state of a new label roll (5). [2] Label dispenser according to claim 1, characterized by , that a minimum label roll diameter value can be set for comparison with the calculated label roll diameter (15). [3] Label dispenser according to any of the preceding claims, characterized by , that the measuring length (14) is adjustable. [4] Label dispenser according to any of the preceding claims, characterized by , that by means of the control (2) based on the roll change signal a display with a number of the substantially remaining labels (16) can be generated. [5] Label dispenser according to any of the preceding claims, characterized by , that a Hall sensor is provided as the rotation angle sensor (12). [6] Method for operating a label dispenser (1), wherein the label dispenser (1) comprises a controller (2), an unwinding device (3) with a core (4) for receiving a label roll (5) with a label strip (6), a dispenser unit (7), a rewinding device (8), and a motor (9) for driving a drive roller (10) of the dispenser unit (7), wherein, during unwinding, a sensor (11) detects the rotation of the drive roller (10) and calculates a dispensing length (13) of the label strip (6), wherein, during unwinding, the degree of rotation of the label roll (5) is detected by a rotary angle sensor (12), and, if the dispensing length (13) corresponds to or exceeds a measured length (14) entered in the controller, a label roll diameter (15) is calculated depending on the degree of rotation determined by the rotary angle sensor (12) and the dispensing length (13).furthermore, a roll change signal is generated depending on the calculated label roll diameter (15), characterized by , that the angle degree state of a new label roll (5) is automatically detected. [7] Method according to claim 6, characterized by , that a minimum label roll diameter value (15) is set and, if the currently calculated label roll diameter (15) corresponds at least substantially to the set minimum label roll diameter value, the roll change signal is generated. [8] Method according to one of claims 6 or 7, characterized by , that the measuring length (14) is set. [9] Method according to any one of claims 6 to 8, characterized by , that based on the roll change signal the label roll (5) is automatically changed or the roll change signal is converted into a display and subsequently the label roll (5) is changed manually. [10] Method according to claim 9, characterized by , that a dimension of the labels (16) and, if applicable, a distance (A) between the labels (16) is taken into account when calculating a number of substantially remaining labels (16). [11] Method according to claims 6 to 10, characterized by , that a thickness (D) of the label tape (6) is taken into account when calculating the label roll diameter (15).

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