Applying unit

[0001] This application is based upon and claims the benefit of priority of Japanese Patent Application No. 2022-037735, filed on Mar. 11, 2022, the entire contents of which are incorporated herein by reference.

[0002] A certain aspect of the embodiment is related to an applying unit.

[0003] There are printers that are known to include a printing part that prints on a recording sheet and a transfer part that transfers an adhesive to the recording sheet.

• [0004] [Patent Document 1] Unexamined Japanese Patent Application Publication No. 2020-019582
• [0005] [Patent Document 2] Unexamined Japanese Patent Application Publication No. 2014-097851
• [0006] [Patent Document 3] Unexamined Japanese Patent Application Publication No. 2011-235595
• [0007] [Patent Document 4] Unexamined Japanese Patent Application Publication No. 2001-018478

[0028] Assuming that a printer has no part for transferring an adhesive, it is conceivable to retrofit a transfer part to the printer and transfer an adhesive to a recording sheet that has been printed. However, retrofitting a transfer part to a printer is not an easy task and requires complex control.

[0029] Therefore, there is a demand for an applying unit that can be retrofitted to various printers without necessitating complex control.

[0030] According to one aspect of the present disclosure, an applying unit that can be connected to a printer and apply an adhesive to a recording sheet includes: a roller configured to transport the recording sheet that is discharged from the printer; a sensor configured to detect the bend of the recording sheet; an applying portion configured to apply the adhesive to the recording sheet; and a control device configured to adjust the rotation speed of the roller according to the value detected by the sensor.

[0031] Hereinafter, a description will be given of an embodiment of the present invention with reference to the drawings.

[0032] Now, a non-limiting example embodiment of the present disclosure will be described with reference to the accompanying drawings. Throughout the drawings, the same or corresponding members or parts will be assigned the same or corresponding reference numerals, and overlapping description will be omitted.

[0033] Now, an example of a printer to which the applying unit of this embodiment is attached will be described with reference to FIG. 1 to FIG. 3.

[0034] A printer 10 is, for example, a thermal printer, and is installed in an ATM (Automated Teller Machine), a ticket vending machine, a kiosk terminal, or the like. However, the type of the printer is not limited to a thermal printer, and other printers such as an inkjet printer and a laser printer may be used as well.

[0035] The printer 10 has a thermal head 11, a platen roller 12, a motor 13, a movable blade 14, a fixed blade 15, a frame 16, and a control substrate 17. The printer 10 sandwiches a recording sheet P between the thermal head 11 and the platen roller 12, and prints on the recording sheet P by feeding the recording paper P by the rotation of the platen roller 12, and by pressing the recording sheet P against the thermal head 11. The motor 13 rotates the platen roller 12. The movable blade 14 and the fixed blade 15 constitute a cutter, and the recording sheet P is cut by moving the movable blade 14 toward the fixed blade 15. The control substrate 17 is attached to the frame 16. The control substrate 17 controls the operation of the printer 10.

[0036] An example of the applying unit of this embodiment will be described with reference to FIG. 4 to FIG. 8. In the drawings, the X direction is the width direction of the sheet, and the Z direction is the vertical direction with respect to the sheet surface.

[0037] The applying unit 20 has a housing 21, rollers 22, a gear array 23, a motor 24, a pressing portion 25, a sensor 26, an applying portion 27, and a control device 28.

[0038] The housing 21 accommodates the rollers 22, the gear array 23, the motor 24, the pressing portion 25, the sensor 26, the applying portion 27, and the control device 28. The frame 16 is screwed to the housing 21 with a screw 18. By this means, the applying unit 20 is connected to the printer 10. The housing 21 includes a feed port 21a and a discharge port 21b. The feed port 21a is an opening for carrying the recording sheet P, discharged from the printer 10, into the housing 21. The discharge port 21b is an opening for discharging the recording sheet P to the outside of the housing 21.

[0039] The rollers 22 transport the recording sheet P discharged from the printer 10. In this embodiment, the rollers 22 include upper rollers 22a and lower rollers 22b. A pair of upper rollers 22a are provided near both widthwise ends of the recording sheet P. A pair of lower rollers 22b are provided below the upper rollers 22a so as to be in contact with the upper rollers 22a. The lower rollers 22b are connected to the motor 24 via the gear array 23. By rotating the motor 24, the gear array 23 also rotates, and this rotation is transmitted to rotate the lower rollers 22b. As a result of this, when the recording sheet P is carried into the housing 21 from the feed port 21a, both end portions of the recording paper P are sandwiched between the upper rollers 22a and the lower rollers 22b, and discharged out of the housing 21 from the discharge port 21b. Note that the upper rollers 22a may be rotated by connecting the motor to the upper rollers 22a via the gear array. The upper rollers 22a and the lower rollers 22b may also be rotated by connecting the motor to both the upper rollers 22a and the lower rollers 22b via the gear array.

[0040] The gear array 23 includes a plurality of gears, and transmits the power of the motor 24 to the lower rollers 22b.

[0041] The motor 24 rotates the lower rollers 22b via the gear array 23. The rotation of the motor 24 is controlled based on commands from the control device 28. The motor 24 is, for example, a servo motor.

[0042] The pressing portion 25 is provided on the transport path of the recording sheet P between the feed port 21a and the rollers 22. The recording sheet P to be transported by the rollers 22 is preloaded by the pressing portion 25 in a direction away from the sensor 26 and pressed in the +Z direction, thereby causing the recording sheet P to bend. The pressing portion 25 is provided with an opening 25a, so that the light projected by the sensor 26 can pass therethrough. The shape of the opening 25a is, for example, rectangular. The pressing portion 25 is, for example, a leaf spring.

[0043] The sensor 26 is, for example, a photoelectric sensor, and provided at a position corresponding to the opening 25a. The sensor 26 projects light toward the opening 25a, detects the light reflected by the recording sheet P, converts the changes in the amount of detected light into a voltage signal, and transmits the voltage signal to the control device 28. FIG. 7 is a diagram illustrating an example of the sensor's output waveform, where the horizontal axis is the distance from the sensor 26 to the recording sheet P, and the vertical axis is the voltage output by the sensor 26 (sensor voltage). As shown in FIG. 7, the sensor 26 has a characteristic of showing the maximum value when the distance from the sensor 26 to the recording sheet P is equal to a distance d, which is the distance from the sensor 26 to the +Z-side wall of the transport path (see FIG. 5). When the recording sheet P transported by the rollers 22 is bent the most, the distance from the sensor 26 to the recording sheet P becomes equal to the distance d, and therefore the sensor voltage shows the maximum value. On the other hand, when the transported the recording sheet P is bent only a little, the distance from the sensor 26 to the recording sheet P becomes shorter than the distance d, and so the sensor voltage becomes smaller than the maximum value. The transport path is made of a material that reflects a smaller amount of light than the recording sheet P, such as black resin. When there is no recording sheet P at the detection position of the sensor 26, the sensor voltage becomes smaller than when the distance from the sensor 26 to the recording sheet P is d. Note that the above-described characteristic of the sensor 26 is by no means limiting, and, for example, the sensor 26 may have a characteristic in which the sensor voltage decreases or increases as the distance from the sensor 26 to the recording sheet P increases.

[0044] The applying portion 27 is provided between the pair of lower rollers 22b. The applying portion 27 applies an adhesive to the lower surface of the recording sheet P transported by the rollers 22. In this embodiment, the applying portion 27 includes a holding portion 27a, an adhesive portion 27b, and a pressing portion 27c. The holding portion 27a holds the adhesive portion 27b exposed upward (facing the recording sheet P). The adhesive portion 27b is a solid adhesive. However, the adhesive portion 27b may be a liquid adhesive as well. The pressing portion 27c presses the holding portion 27a upward, so as to press the adhesive portion 27b against the lower surface of the recording sheet P and apply the adhesive. The pressing portion 27c is, for example, a coil spring.

[0045] The control device 28 adjusts the rotation speed of the lower rollers 22b according to the detection value of the sensor 26. The control device 28 includes a determining portion 28a, a storage portion 28b, and a control portion 28c.

[0046] When the detection value of the sensor 26 is equal to or greater than a presence determining value, the determining portion 28a determines that the recording sheet P is in the applying unit 20. On the other hand, when the detection value of the sensor 26 is less than the presence determining value, the determining portion 28a determines that the recording sheet P is not in the applying unit 20. The presence determining value is a preset value.

[0047] Also, when the detection value of the sensor 26 is equal to or greater than a bend determining value, the determining portion 28a determines that the recording sheet P is bent. On the other hand, when the detection value of the sensor 26 is less than the bend determining value, the determining portion 28a determines that the recording sheet P is not bent or is bent only a little. The bend determining value is a preset value, set to a larger value than the presence determining value, and set to a smaller value than the sensor voltage when the recording sheet P is present at a position corresponding to the distance d.

[0048] The storage portion 28b stores various information. The various information includes the presence determining value and the bend determining value.

[0049] The control portion 28c adjusts the rotation speed of the lower rollers 22b based on the determination result of the determining portion 28a. When the determining portion 28a determines that the recording sheet P is not present in the applying unit 20, the control portion 28c stops the lower rollers 22b by stopping the motor 24.

[0050] Also, when the determining portion 28a determines that the recording sheet P is bent, the control portion 28c increases the rotation speed of the motor 24 according to the difference between the sensor voltage and the bend determining value, and rotates the lower rollers 22b at a higher speed. By this means, the transport speed of the recording sheet P in the applying unit 20 becomes closer to the transport speed in the printer 10, and the bend of the recording sheet P becomes smaller. On the other hand, when the determining portion 28a determines that the recording sheet P transported by the rollers 22 is not bent or is bent only a little, the control portion 28c slows down the rotation speed of the motor 24 according to the difference between the sensor voltage and the bend determining value, and rotates the lower rollers 22b at a lower speed. By this means, the transport speed in the applying unit 20 becomes closer to the transport speed in the printer 10.

[0051] Now, an example operation of the applying unit 20 when the printer 10 prints on the upper surface of the recording sheet P and the applying unit 20 applies an adhesive to the lower surface of the recording sheet P will be described with reference to FIG. 9A to FIG. 14B. FIG. 9A to FIG. 14B are diagrams for explaining the states of the applying unit 20, in which the printer 10 prints on the recording sheet P, the applying unit 20 applies an adhesive to the recording sheet P, and the recording sheet P is discharged from the applying unit 20. In FIG. 9A to FIG. 14B, each “A” diagram is a schematic view that illustrates an internal structure of the applying unit 20, and each “B” diagram is a view that illustrates the detected values of the sensor 26.

[0052] FIGS. 9A and 9B are diagrams for explaining the state of the applying unit 20 when the printer 10 starts operating. As shown in FIG. 9A, no the recording sheet P has been transported to the rollers 22 of the applying unit 20 when the printer 10 starts operating. At this point in time, as shown in FIG. 9B, the sensor 26 outputs a voltage value V1 that is smaller than a presence determining value Vth1. The control device 28 determines that the recording sheet P is not present in the applying unit 20, based on the output of the sensor 26.

[0053] FIGS. 10A and 10B are diagrams for explaining the state of the applying unit 20 when the recording sheet P is passed from the printer 10 onto the applying unit 20. As shown in FIG. 10A, when the recording sheet P is passed from the printer 10 onto the applying unit 20, the recording sheet P is pressed by the pressing portion 25 in a direction away from the sensor 26, and therefore the distance from the sensor 26 to the recording sheet P becomes d, and the recording sheet P is transported in the direction of the rollers 22. At this time, as shown in FIG. 10B, the sensor 26 outputs a voltage value V2, which is larger than a presence determining value Vth1 and a bend determining value Vth2. Based on the output of the sensor 26, the control device 28 determines that the recording sheet P is present in the applying unit 20 and that the recording sheet P is bent. Also, in accordance with this determination result, the control device 28 increases the rotation speed of the motor 24 to rotate the lower rollers 22b at a higher speed and reduce the bend of the recording sheet P.

[0054] FIG. 11 is a diagram for explaining the state of the applying unit 20 when the transport speed of the recording sheet P in the applying unit 20 is higher than the transport speed in the printer 10. As shown in FIG. 11A, in the event the transport speed in the applying unit 20 is faster than the transport speed in the printer 10, the recording sheet P is pulled by the rollers 22, so that the pressing portion 25 is pressed downward in the −Z direction, and the recording sheet P approaches the sensor 26. At this time, as shown in FIG. 11B, the sensor 26 outputs a voltage value V3 that is larger than presence determining value Vth1 and smaller than bend determining value Vth2. Based on the output of the sensor 26, the control device 28 determines that the recording sheet P is present in the applying unit 20 and that the recording sheet P is not bent or is bent only a little. Also, in accordance with this determination result, the control device 28 lowers the rotation speed of the motor 24 to rotate the lower rollers 22b at a lower speed. By this means, the transport speed in the applying unit 20 becomes closer to the transport speed in the printer 10, and the bend of the recording sheet P becomes smaller. The applying portion 27 applies an adhesive A to the recording sheet P, and the recording sheet P is transported toward the discharge port 21b.

[0055] FIGS. 12A and 12B are diagrams for explaining the state of the applying unit 20 when the transport speed of the recording sheet P in the applying unit 20 is slower than the transport speed of the recording sheet P in the printer 10. As shown in FIG. 12A, in the event the transport speed in the applying unit 20 is slower than the transport speed in the printer 10, the tension of the recording sheet P between the printer 10 and the rollers 22 weakens, and the recording sheet P is pressed by the pressing portion 25 in a direction away from the sensor 26. Consequently, the recording sheet P moves away from the sensor 26. At this time, as shown in FIG. 12B, the sensor 26 outputs a voltage value V4 that is greater than presence determining value Vth1 and bend determining value Vth2. Based on the output of the sensor 26, the control device 28 determines that the recording sheet P is in the applying unit 20 and that the recording sheet P is bent. Also, in accordance with this determination result, the control device 28 receives and increases the rotation speed of the motor 24 to rotate the lower rollers 22b at a higher speed. By this means, the transport speed in the applying unit 20 becomes closer to the transport speed in the printer 10.

[0056] The control device 28 thus repeatedly controls the rotation speed of the motor 24 shown in FIGS. 11A and 11B and FIGS. 12A and 12B while the recording sheet P is transported by the rollers 22. By this means, regardless of the transport speed in the printer 10, the transport speed in the applying unit 20 can be made to follow the transport speed in the printer 10. As a result of this, even when the applying unit 20 is connected to various printers, the recording sheet P can be uniformly coated with the adhesive. That is, it is possible to provide a highly versatile applying unit 20 that can be retrofitted to various printers without necessitating complex control.

[0057] FIGS. 13A and 13B are diagrams for explaining the state of the applying unit 20 when the recording sheet P is cut in the printer 10. As shown in FIG. 13A, when the recording sheet P is cut, the recording sheet P is pressed by the pre-loading of the pressing portion 25 in a direction away from the sensor 26, and so the distance from the sensor 26 to the recording sheet P is d. At this time, as shown in FIG. 13B, the sensor 26 outputs a voltage value V5 that is greater than presence determining value Vth1 and bend determining value Vth2. Based on the output of the sensor 26, the control device 28 determines that the recording sheet P is in the applying unit 20 and that the recording sheet P is bent. Also, in accordance with this determination result, the control device 28 increases the rotation speed of the motor 24 to a higher speed than shortly before the recording sheet P is cut, so as to rotate the lower rollers 22b at a higher speed. By this means, the recording sheet P coated with the adhesive A is discharged from the discharge port 21b.

[0058] FIGS. 14A and 14B are diagrams for explaining the state of the applying unit 20 when the recording sheet P is discharged from the applying unit 20. As shown in FIG. 14A, when the recording sheet P is discharged from the applying unit 20, the recording sheet P is not at the detection position of the sensor 26. Consequently, as shown in FIG. 14B, the sensor 26 outputs a voltage value V6 that is smaller than presence determining value Vth1. Based on the output of the sensor 26, the control device 28 determines that the recording sheet P is not in the applying unit 20. Also, in accordance with this determination result, the control device 28 transports the recording sheet P for a distance that is longer than the distance from the sensor 26 to the rollers 22, and then stops the rotation of the lower rollers 22b. Note that it is also possible to stop the recording sheet P at a position where the rollers 22 grip the recording sheet P, and let the user pull out the recording sheet P.

[0059] Upon completion of the above, a label sheet is created, the upper surface of which is printed, and the lower surface of which is coated with the adhesive A.

[0060] As described above, with the applying unit 20 of this embodiment, the control device 28 adjusts the rotation speed of the rollers 22 in accordance with the bend of the recording sheet P discharged from the printer 10, the bend being detected by the sensor 26. By this means, regardless of the transport speed of the recording sheet P, the transport speed of the recording sheet P in the applying unit 20 can be made to follow the transport speed in the printer 10. Therefore, even when the applying unit 20 is connected to the printer, it is still possible to apply an adhesive to the recording sheet P. That is, it is possible to provide a highly versatile applying unit 20 that can be retrofitted to various printers without necessitating complex control such as synchronizing the printer and the applying unit.

[0061] Also, the applying unit 20 of this embodiment applies an adhesive to the recording sheet P after the recording sheet P is cut in the printer 10. That is, when the recording sheet P is cut, the adhesive is not transferred to the recording sheet P yet, so that no adhesive sticks to the movable blade 14 and the fixed blade 15 of the printer 10. As a result of this, the frequency of cleaning and replacing the movable blade 14 and fixed blade 15 can be reduced.

[0062] Also, according to the applying unit 20 of this embodiment, the control device 28 determines the presence or absence of the recording sheet P and adjusts the transport speed of the lower rollers 22b based on the detection value obtained by one sensor 26, so that the number of parts does not increase.

[0063] Also, according to the applying unit 20 of this embodiment, an adhesive is transferred to the recording sheet P by pressing the adhesive portion 27b against the recording sheet P being transported by the rollers 22 and thus applying the adhesive to the recording sheet P. As a result of this, any commercially available solid adhesives and liquid adhesives can be used, without using special adhesives such as adhesive tapes.

[0064] Note that, although the recording sheet transported by the rollers was detected by using a photoelectric sensor in the case described in the above embodiment, the present invention is by no means limited to this. For example, another sensor such as a mechanical sensor may be used to detect the bend of the recording sheet.

[0065] Also, although the applying portion applied adhesive to the lower surface of the recording sheet in the case described in the above embodiment, the present invention is by no means limited to this. For example, the applying portion may be provided between a pair of upper rollers and apply an adhesive to the upper surface of the recording sheet transported by the rollers. Also, for example, it is possible to provide applying portions between a pair of upper rollers and between a pair of lower rollers, and apply an adhesive to the upper surface of the recording sheet transported by the rollers.

[0066] Also, although the applying portion was provided separately from the rollers in the case described in the above embodiment, the present invention is by no means limited to this. For example, the upper rollers themselves and/or the lower rollers themselves may be configured as adhesive portions.

[0067] All examples and conditional language provided herein are intended for the purposes of aiding the reader in understanding the invention and the concepts contributed by the inventor to further the art, and are not to be construed as limitations to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although one or more embodiments of the present invention have been described in detail, it should be understood that various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.