JP7527557B2 - Printer and printing method thereof - Google Patents

Description

The present invention relates to a printer that uses, as label printing paper, rolled continuous paper that does not have a liner that prevents the adhesive applied to the back side of the printed surface from sticking to each other, and a printing method for the printer.

There are label printers that have a platen roller that faces the print head that prints on the label paper, an upstream paper guide that is provided upstream of the nip between the print head and the platen to guide the label paper, and a downstream paper guide that is provided downstream of the nip to guide the label paper between the fixed blade and movable blade of the cutter.

In general, in a label printer, label paper is pulled out from the label paper loading section, and the leading edge of the label paper is clamped in the nip between the print head and the platen with the printing surface of the leading edge of the label paper facing the print head such as a thermal head and the adhesive surface facing the platen, and the printer is placed in a standby state for the start of printing. Then, when printing starts, the platen is rotated in a predetermined direction by a predetermined angle, the label paper is conveyed a predetermined amount by the conveying means including the platen, and the print head prints on the printing surface of the label paper. The label paper continues to be conveyed, and the leading edge of the label paper is guided between the movable blade and fixed blade of the cutter by the downstream paper guide. When the predetermined amount of conveying is completed, the label paper is cut by the cutter, printed on the front side, and a label of the specified size with adhesive on the back side is issued. After the label paper is cut, the conveying means is reversed to pull the leading edge of the label paper back to a position where it is clamped in the nip between the print head and the platen, and the printer waits for the next printing.

The platen, which constitutes part of the transport means, is often made of a roller or a belt. In either case, the adhesive side of the label paper comes into direct contact or is pressed against the platen, so the longer the print standby time, the more the adhesive sticks to the platen, and when printing starts again, the leading edge of the label paper cannot be properly separated from the platen, causing a jam.

An example of a conventional label printer will be described in further detail with reference to Figures 18 to 22c.
Fig. 18 is a perspective view of the label printer RP' with label paper p loaded in the paper loading section 102, and Fig. 19 is a perspective view of the label printer RP' with the upper unit 200 of Fig. 18 removed. The label printer RP' has an upper unit 200 that can be opened and closed by rotating around a horizontal axis s1 at the top front (left side in Fig. 18) of the lower unit 100. As shown in Fig. 20, the upper unit 200 has a print head 203 on the underside of its front part, and an upstream paper guide 202 is provided on the upstream side of the print head 203, i.e., on the side closer to the paper loading section 102, and a downstream paper guide 202' is provided on the downstream side of the print head 203, i.e., on the side farther from the paper loading section 102.

A platen 104 is rotatably provided on the front top surface of the lower unit 100 in a position facing the print head 203 of the upper unit 200, and an upstream paper guide 103 and a downstream paper guide 103' are provided in front of and behind the platen 104. The downstream paper guide 103' is formed of a thin plate that is continuous in the width direction of the label paper p and has a separation section formed in a wedge shape at its downstream tip, and the tip of the separation section is fixed as close as possible to the peripheral surface of the platen 104.

A motor 107 driven by a control device (not shown) is attached to the lower unit 100 as a means for transporting the label paper p. Power from the motor 107 is applied to the platen 104 via a belt and pulley, and the label paper p is transported a predetermined amount by rotating the platen 104 at a predetermined angle.

The upstream paper guide 202 and downstream paper guide 202' of the upper unit 200 and the upstream paper guide 103 and downstream paper guide 103' of the lower unit 100 form a transport path for the label paper p.

In the above-described conventional configuration, (a) when label paper p affixed to the platen 104 was attempted to be transported downstream, the label paper p did not separate properly from the platen 104, and as shown in FIG. 21a, the leading edge of the label paper p got into the gap between the platen 104 and the downstream paper guide 103' and became wrapped around the platen 104, as shown in FIG. 21b.
A conventional preventative measure for this in thermal printers and laser printers is to impregnate or coat the platen 104 with oil to make it difficult for the adhesive of the label paper p to stick to the platen 104 .

(a) If the leading edge of the label paper p is moved without entering the gap between the platen 104 and the downstream paper guide 103', as shown in FIG. 22a, when the leading edge of the label paper p hits the rough upper surface of the downstream paper guide 103' or becomes unable to move due to frictional resistance, the label paper p pushed out from the upstream cannot move forward and buckles significantly, as shown in FIG. 22b. Eventually, the buckled label paper p is pushed into the gap between the platen 104 and the downstream paper guide 103' and, as shown in FIG. 22c, wraps around the platen 104, or, although it does not wrap around, bends in the transport path, causing a jam.

(c) When continuous label printing or transport operations are completed or interrupted and the label paper continues to be pressed against the platen, the adhesive force (peeling force) between the label paper and the platen increases over time, and the frequency of the label paper getting wrapped around the platen increases. Furthermore, when printing is interrupted after printing on a thermal printer, the heat stored in the print head causes the glue to soften and spread to the outer periphery of the platen. When the glue cools, the adhesive force (peeling force) increases further, causing the label paper to get wrapped around the platen more frequently.

When label paper p wraps around the platen 104 or a jam occurs, recovery processing takes time, which may result in a lot of losses, such as the halting or slowdown of smooth operations, damage to parts, and the waste of media.

JP 2009-107287 A JP 2016-221839 A

The present invention was made in consideration of the above circumstances, and aims to provide a label printer that can prevent label paper from being forced into the gap between the platen and the downstream paper guide and wrapping around the platen, or from bending on the transport path without wrapping, causing jams, and to provide a printing method for the printer.

To achieve the above object, in one aspect, the present invention provides a printer that conveys label paper and cuts the label paper with a cutting unit to produce labels, and is characterized by comprising a printing unit that prints on the label paper, a platen that faces the printing unit, a first guide member that is provided downstream of the platen and guides the adhesive surface of the label paper, and a second guide member that is composed of a rotatable roller and guides the adhesive surface of the label paper.

1 is a perspective view of a printer according to an embodiment of the present invention with an upper unit open; FIG. 2 is a perspective view of the printer of FIG. 1 with an upper unit removed. FIG. 2 is a side view of the printer of FIG. 1 with an upper unit closed. FIG. 4 is a front view of the printer of FIG. 3 . 5 is a cross-sectional view taken along line AA in FIG. 4 with the lower half omitted. 5 is a cross-sectional view of a portion taken along line BB in FIG. 4. FIG. 2 is a perspective view showing a paper guide mechanism included in the printer of FIG. 1 . 6 is an enlarged view of a main portion of FIG. 5, illustrating a gap between a platen and a leading end of a downstream paper guide. FIG. FIG. 9 is an enlarged view similar to FIG. 8, illustrating the difference in height between the upper surface of the platen, the upper surface of the downstream paper guide, and the upper surface of the free roller. 13A and 13B are diagrams illustrating the action immediately after the leading edge of the label paper passes through the nip portion between the print head and the platen. 13A and 13B are diagrams for explaining the action when the leading edge of the label paper reaches a free roller provided on the downstream paper guide. 13A and 13B are diagrams illustrating the action immediately after the leading edge of the label paper reaches a free roller. 13A and 13B are diagrams showing a state in which the leading edge of the label paper has passed over a free roller. FIG. 11 is a perspective view of a paper guide mechanism of a printer according to another embodiment of the present invention. FIG. 12 is a perspective view showing an example of a driving unit of the paper guide mechanism of FIG. 11 . FIG. 13 is a cross-sectional view showing an example in which the fixing roller in FIG. 11 and FIG. 12 is replaced with a grooved roller. FIG. 11 is a perspective view of a paper guide mechanism of a printer according to another embodiment of the present invention. FIG. 11 is a diagram for considering the width of the nip portion between the print head and the platen. FIG. 15b is a similar view to FIG. 15a. FIG. 2 is a functional configuration diagram of a printer. 11 is a first half of a flowchart illustrating a label printing pre-processing operation according to an embodiment. This is the latter half of the flowchart of FIG. 17a. FIG. 1 is a perspective view of a conventional printer. FIG. 19 is a perspective view of the printer in FIG. 18 with an upper unit removed. 19 is an enlarged view of the upper half of a cross-sectional view taken along a vertical plane passing through the center of the front of the printer of FIG. 18. FIG. 21 is an enlarged view of the main part of FIG. 20, showing a state in which the leading edge of the label paper has entered the gap between the platen and the downstream paper guide. FIG. 21 is an enlarged view of the main part of FIG. 20, showing a state in which the leading edge of the label paper is wrapped around the platen. 21 is an enlarged view of the main portion of FIG. 20, showing the state in which the leading edge of the label paper abuts against the upper surface of the downstream paper guide. FIG. FIG. 21 is an enlarged view of the main part of FIG. 20, showing a state in which the leading edge of the label paper is buckled. FIG. 21 is an enlarged view of the main part of FIG. 20, showing the state in which the label paper is further folded and recessed.

The following describes an embodiment of the present invention with reference to the drawings.

(Definitions)
Here, in this specification, a roll-shaped continuous paper that does not have a liner to prevent the adhesive applied to the back side of the printed surface from sticking to each other is referred to as "linerless label printing paper" or simply "label paper", and a paper cut to a specified length from the continuous paper is referred to as a "linerless label" or simply "label". A printer that prints on label paper is referred to as a "label printer" or simply "printer". A roller or belt that is provided opposite a print head that prints on label paper and transports the label paper is referred to as a "platen". In addition, a member that is provided upstream of the nip between the print head and the platen and that guides the label paper is referred to as an "upstream paper guide", and a member that is provided downstream of the nip and that guides the label paper between the fixed blade and movable blade of the cutter is referred to as a "downstream paper guide".

(First embodiment)
The first embodiment will be described with reference to FIGS. 1 to 10d.
The label printer PR according to this embodiment has a lower unit 100 that is placed on a flat surface, and an upper unit 200 that can be opened and closed by rotating about a horizontal axis s1 at the top end of the rear of the lower unit 100. Fig. 1 shows a state in which the front part of the upper unit 200 is lifted up and opened.

The lower unit 100 has a lower frame 101 consisting of a pair of vertical plates 101a, 101b separated left and right when viewed from the front (right side of FIG. 1) and connected by a bottom plate 101c, and a paper loading section 102 that is open upward is provided in the upper rear part of the lower frame 101. At the bottom of the paper loading section 102, between the vertical plates 101a, 101b, a bottom plate (not shown in FIG. 1) with a U-shaped cross section that is open upward can be placed on the bottom plate and rotatably held.

A horizontally long rectangular paper guide (upstream paper guide) 103 is provided downstream of the paper loading section 102 to guide the label paper p pulled out from the paper loading section 102 to the nip section described below. In addition, a horizontally long roll-shaped platen 104 is provided adjacent to the front end of the paper guide 103 on the lower frame 101. A shaft 105 protrudes from both ends of the platen 104 along its central axis and penetrates bearings provided on the vertical plates 101a and 101b of the lower frame 101, so that the platen 104 is rotatably supported.

The lower unit 100 is equipped with a geared pulley 106 provided at one end of the shaft 105, a motor 107 attached to the inner surface of the vertical plate 101b of the lower frame 101, a geared pulley 108 attached to the rotating shaft of the motor, a toothed belt 109 stretched across the geared pulleys 106 and 108, and a control device (not shown) that controls the drive of the motor 107 (Figure 4).

The upper unit 200 has an upper frame 201 consisting of vertical plates 201a and 201b extending forward from the left and right horizontal axis s1, a horizontal plate 201c connecting the front ends of the vertical plates, and a flat rectangular top plate 201d connected to the top surfaces of the left and right vertical plates 201a and 201b and the horizontal plate 201c.

On the underside of the top plate 201d, an upstream paper guide 202 is provided that is parallel to and adjacent to the upstream paper guide 103 of the lower unit 100 when the upper unit 200 is closed as shown in Figures 3 and 4 (Figure 5). A print head 203 is attached downstream of the upstream paper guide 202 so that it abuts against the top surface of the platen 104 when the upper unit 200 is closed.

A feed roller 110 is provided at the upstream end of the upstream paper guide 103, which is rotated in synchronization with the platen 104 by a common driving means, and a driven roller 204 is provided at the upstream end of the upstream paper guide 202 so that it can abut against the feed roller 110. As a result, when the motor 107 is rotated with the leading edge of the label paper p in the paper loading section held in the nip between the feed roller 110 and the driven roller 204, the leading edge of the label paper p smoothly enters between the upstream paper guides 103 and 202 and is smoothly and accurately guided into the nip between the platen 104 and the print head 203.

A paper guide mechanism 300 is provided downstream of the platen 104 of the lower unit 100. This paper guide mechanism 300 replaces the downstream paper guide 103' in the conventional label printer shown in Figures 17 to 20c.

As shown in FIG. 7, the paper guide mechanism 300 has a pivot shaft 301 corresponding to the first axis, a connecting member 302, a roller shaft 303 corresponding to the second axis, a guide member 304, and a free roller 305.

The pivot shaft 301 has a length approximately equal to that of the platen 104, and connecting members 302 are fixed to both ends of the pivot shaft 301. The roller shaft 303 extends parallel to the pivot shaft 301 at a position slightly away from the pivot shaft 301, and is connected to both connecting members 302.

The guide member 304 has a paper guide surface 304a on the top surface, which serves as a path for the label paper, and a separation claw 304b consisting of a sharp claw-like protrusion with an arc surface that intersects with an arc of a radius slightly larger than the radius of the platen 104 is formed at the tip of the paper guide surface 304a. A plurality of guide members 304 are arranged at intervals in the longitudinal direction of the platen 104, and the roller shaft 303 and the pivot shaft 301 are respectively inserted through holes provided in the upper and lower parts of the guide member 304. The pivot shaft 301 is fixed in a predetermined position by a stopper member 306 such as an E-ring. The positions of the separation claws 304b at both ends may be equal to the width of the label paper or slightly smaller than the width of the label paper. The position of the separation claw 304b may also be adjustable according to the width of the label paper. The free roller 305 is attached to the roller shaft 303 on both sides or one side of the guide member 304.

As shown in FIG. 2, the paper guide mechanism 300 is housed in the space downstream of the platen 104 between the left and right vertical plates 101a, 101b of the lower frame 101 of the lower unit 100, and is supported so that it can swing around the pivot shaft 301 by screwing pivot shaft set screws 307a into pivot shaft screw holes 307b at both ends of the pivot shaft 301 (FIG. 7) from the outside of the lower frame 101.

The connecting member 302 is formed in a roughly L-shape, with the end of the pivot shaft 301 connected to the middle bent portion 302a, and the end of the roller shaft 303 supported via a bearing 308 on the end of the arm 302b extending upward. The arm extending diagonally upward from the bent portion 302a of the connecting member 302 has a smooth surface on its underside and forms the cam follower 302c. The cam 309 (Figs. 8 to 10d) abuts against this smooth surface, and the free end of the spring 310 is attached to the tip of the cam follower 302c (Fig. 5). Therefore, the cam follower 302c is always in contact with the upper surface of the cam 309.

The paper guide mechanism 300 is provided with a position adjustment means for adjusting the gap (linear distance) between the separation claws 304b of the multiple guide members 304 and the peripheral surface of the platen 104. As shown in Figures 2 and 3, the position adjustment means is configured with a camshaft 311 rotatably attached to the lower frame 101 of the printer, a cam 309 (Figure 6) fixed to the camshaft 311 and constantly pressed against the cam follower 302c (Figure 7), an adjustment plate 312 fixed to the camshaft 311 and capable of rotating the camshaft 311 within a certain angle range, and a plate fixing screw 314 for fixing the adjustment plate in a position after rotation.

The cam 309 is fixed to a camshaft 311 that passes through the eccentric (Figure 5). The camshaft 311 passes through the left and right vertical plates 101a, 101b of the lower frame 101 and is supported rotatably (Figure 3). One end of the camshaft 311 protrudes to the outside of the vertical plate 101a, and an adjustment plate 312 is fixed to the protruding end (Figures 2 and 3). The adjustment plate 312 has a hole 313 that extends along an arc centered on the camshaft 311, and a plate fixing screw 314 that passes through the hole is screwed into the vertical plate 101a (Figure 3).

The camshaft 311 can be rotated within a certain range by vertically moving the operating piece 315, such as a protrusion, provided on the adjustment plate 312 (Figs. 3 and 5). After rotation, the plate fixing screw 314 can be tightened to fix the adjustment plate 312 (Fig. 3). In other words, the camshaft 311 can be fixed at the angle after rotation.

Each guide member 304 is in a state where the tip of the separation claw 304b is in contact with the outer circumference of the platen 104 or not (Figure 8). When the adjustment plate 312 (Figure 3) is rotated, the cam 309 rotates via the camshaft 311 (Figure 8), causing the cam follower 302 to swing, changing the gap δ between the platen 104 and the tip of the separation claw 304b of each guide member 304 (Figure 8). The swing of the cam follower 302 follows the lift of the cam 309, which changes slightly, so the gap δ can be adjusted to as close to zero as possible. By making this adjustment, the gap δ between the platen 104 and each separation claw 304b can be easily set to less than the thickness of the label paper. Therefore, the tip of the label paper p can be picked up by the tip of the separation claw 304b, preventing the label paper p from being wrapped around the platen 104 from its tip.

As described above, the paper guide mechanism 300 is configured to include a first shaft (301) that extends parallel to the rotation axis of the platen 104 and is rotatably supported on the lower frame 101 on both sides of the printer, a second shaft (303) that is parallel to the first shaft (301) and is spaced a certain distance apart, a connecting member 302 having one end fixed to both ends of the first shaft (301) and the other end supporting both ends of the second shaft (303), guide members 304 that are arranged at multiple locations spaced apart in the longitudinal direction of the first shaft (301) and the second shaft (303), and position adjustment means (311-315) that rotates and stops the connecting member 302 within a certain angular range around the first shaft (301). Therefore, by simply operating a single position adjustment means, the linear distance (gap) between the peripheral surface of the platen 104 and the separation claws 304b of multiple guide members 304 can be adjusted all at once. As a result of this adjustment, all guide members 304 can be brought closer to the platen 104, making it possible to provide a label printer that can prevent label paper from wrapping around the platen 104 and causing jams. In addition, the separation claws 304b of the guide members 304 are not flat and have a small width, so the contact area with the label paper is small, making it less likely for adhesive to adhere to them and for the label paper to get caught.

The position adjustment means is made up of a camshaft 311 rotatably attached to the lower frame 101, a cam 309 fixed to the camshaft 311 and constantly pressed against the cam follower 302c, an adjustment plate 312 fixed to the camshaft 311 and capable of rotating the camshaft 311 within a certain angular range, and a plate fixing screw 314 that fixes the adjustment plate in position after rotation. Since the oscillation of the cam follower 302 follows the lift of the cam 309, which changes slightly, the operator can manually adjust the gap δ to be equal to or less than the thickness of the label paper.

Next, the actual operation will be described.
In the factory, the standard value of the gap δ is adjusted to, for example, 0.02 to 0.03 mm, which is less than the paper thickness. However, when the printer is shipped to the market and a consumable item such as a platen needs to be replaced, an operator performs the following procedure, for example.
(1) The adjustment plate 312 brings the separation claw 304b into contact with the platen 104 until the platen 104 becomes stiff.
(2) Rotate the adjust plate 312 in a direction that makes the platen 104 easier to rotate.
(3) Determine by feel whether the platen 104 is under load or not (whether it rotates smoothly), and set it there.
The rotation load here becomes heavy if there is even the slightest contact with the platen 104, and it rotates lightly if the gap δ is even a few μm, so the operator can intuitively adjust the gap δ between the platen 104 and the separation claws 304b so that it is equal to or less than the thickness of the label paper. If there is even the slightest load rather than idling, the separation claws 304b will be in contact with the surface of the platen 104, and in reality, the contacting portion of the platen 104 may be slightly scraped off by the printing operation, but this will not cause any problems with transport performance or print quality.

Another Example 1
9, the outer periphery of the free roller 305 is lower than the upper outer periphery of the platen 104 (paper discharge height position) by h1, and the upper flat surface (paper guide surface) of the separation claw 304b is lower than the upper outer periphery of the free roller 305 by h2.
In this case, label paper is more effectively prevented from getting wrapped around the platen. The load downstream after it is discharged from the platen 104, that is, the impact of the leading edge of the label paper p against the paper guide surface 304a, is weakened and there is no surface contact between the paper guide surface 304a and the label paper p, so the label paper p flows smoothly downstream. Also, because it is less likely for the label paper p to stick to the paper guide surface 304a, it is possible to prevent the label paper from getting wrapped around the platen 104 even with continuous use.
It should be noted that the label paper p can be prevented from sticking to the paper guide surface 304a by impregnating the separation claws 304b with oil or by providing minute irregularities on the paper guide surface 304a. Even if a non-rotating roller is used instead of the free roller 305, a certain degree of effect can be obtained as long as it has the configuration shown in FIG.

In addition, since the free rollers 305 rotate with a slight external force, even if the leading edge of the label paper p lands on the top surface of the separation claw 304b just before the free rollers 305 in FIG. 10a, when the leading edge of the label paper p hits the free rollers 305 during subsequent transport (FIG. 10b), the free rollers 305 rotate, causing the leading edge of the label paper p to run up onto the free rollers 305 (FIG. 10c). Therefore, the leading edge of the label paper p passes the free rollers 305, travels through the air, and lands near the end of the paper guide surface 304a (FIG. 10d).

The flow of the label paper p is as described above, so there is no load downstream after it is discharged from the platen 104, i.e., the leading edge of the label paper p does not hit the paper guide surface 304a, and the paper guide surface 304a does not come into surface contact with the label paper p, so the label paper p is less likely to stick to the platen 104. This makes it possible to prevent folding jams and wrapping as shown in Figures 20a to 20c.

Another Example 2
Figures 11 and 12 show another example of a paper guide mechanism 300A. Figure 11 is a perspective view of the paper guide mechanism 300A, and Figure 12 is an enlarged view of the left portion around the platen 104. A platen gear g1 is fixed to the shaft of the platen 104. A gear post (not shown) is provided on the vertical plate 101a of the lower frame 101 (Figure 1), and an idle gear g2 is rotatably attached to the gear post.

In the paper guide mechanism 300A, a driven gear g3 is fixed to one end of the roller shaft 303. The idle gear g2 is engaged with both the platen gear g1 and the driven gear g3, so the platen 104 and the roller shaft 303 rotate in the same direction. In addition, a number of rollers 305' corresponding to the free rollers 305 in the first embodiment are fixed to the roller shaft 303 (hereinafter, these rollers are referred to as fixed rollers).

Furthermore, the diameter of the platen 104, the diameter of the adhesion roller 305', and the number of teeth of the platen gear g1 and the driven gear g3 are set so that the linear speed Vp of the outer periphery of the platen 104 and the linear speed Vr of the outer periphery of the adhesion roller 305' are Vr>Vp.

As described above, the platen 104 and the fixing roller 305' are arranged to rotate in conjunction with each other so that the linear speed Vp of the outer periphery of the platen 104 and the linear speed Vr of the outer periphery of the fixing roller 305' satisfy the relationship Vr > Vp. This makes it possible for the fixing roller 305' to scoop up the leading edge of the label paper p and guide it to the discharge side, thereby preventing jamming on the path to the discharge outlet.
The outer periphery of the fixing roller 305' may be non-adhesive and smooth, but it may also be made uneven as shown in Fig. 13. By making the outer periphery uneven, the leading edge of the label paper p can be easily picked up by the fixing roller 305' and guided to the discharge side, preventing it from jamming on the path to the discharge outlet.

Other Example 3
FIG. 14 shows another example of the paper guide mechanism 304. In this embodiment, the paper guide surface is a surface having approximately the same width as the platen 104, and the surface has holes for the free rollers 305 to abut against the label paper, the number of which is equal to the number of the free rollers. The printed label paper is transported downstream by the free rollers 305 appearing on the paper guide surface 304a. Even with this paper guide mechanism, the gap between the paper guide 304 and the platen 104 can be adjusted, and the label paper can be prevented from wrapping around the platen 104. In addition, since the label paper is transported downstream by the free rollers 305, it is possible to prevent the label paper from bending or jamming. In addition, if the surface of the paper guide has fine irregularities, the adhesive side of the label paper is less likely to adhere to the surface.
Note that, in FIG. 14, the separation claw 304b in FIG. 7 is shown as an example in which it is replaced by a single planar paper guide surface 304a; however, even if there is no pivot shaft 301 and only the roller shaft 303, the label paper can be transported downstream by the free roller 305, and the number of shafts may be one.

Other Example 4
15a shows the printing standby state, with the leading edge of label paper p located 3 to 4 mm downstream from the printing position. If the nip width created by the pressure of the print head 203, in this case the width where the adhesive surface of the label paper comes into contact with the outer periphery of the platen 104, is taken as w, it is known that the longer the printing interruption time is, the wider the width w becomes, reaching a maximum of about 2 mm.

Because the label paper p adheres strongly to the platen 104 within this range of width w, the platen 104 is rotated forward and backward in an attempt to reduce the adhesive force. In this example, as a pre-processing step for label printing (hereafter referred to as label printing pre-processing), the leading edge of the label paper p is moved once or several times to a position 3 to 4 mm downstream from the printing position as shown in FIG. 15a, or 1 to 2 mm downstream from the printing position as shown in FIG. 14b. The amount of retreat is preferably equal to or greater than the length of the label formed by cutting the label paper p with a cutter, which will be described later, but in order to ensure the next transport, the leading edge of the label paper p can only be moved to about 1 mm from the printing position, so it is set to around that amount.

1 and 2, the label printer RP is provided with a cutter unit 400 at its front end that cuts the label paper p discharged from the paper guide mechanism 300. The cutter unit 400 is a known unit, and includes a support plate 402 attached to the front lower end of the left and right lower frames 101 of the lower unit 100 by a support shaft 401 so as to be rotatable around the support shaft 401 from a vertical position to an angle diagonally forward, a box 403 fixed between the upper part of the support plate 402, a movable blade b1 (FIGS. 8 and 10d) provided at the rear of the box 403 so as to be movable up and down, and a movable blade lifting means (not shown) provided in the box 403 for lifting and lowering the movable blade b1. Furthermore, when the cutter unit 400 is raised to the vertical position as shown in Figures 1 and 2, the cutting edge of the movable blade b1 is positioned at a cutting position adjacent to the cutting edge of the fixed blade b2, which is attached with its cutting edge facing downward to the front end of the top plate 201d (Figure 1) of the upper unit 200, as shown in Figure 10d.

When the cutter unit 400 is raised to the vertical position as shown in Figures 1 and 2, it is held in place by known locking links 404 provided on the outer surfaces of the lower frames 101 on the left and right sides of the lower unit 100.

Figure 16 shows the functional configuration of the label printer RP for executing label printing pre-processing. That is, it is configured with an input unit 1 for inputting the print contents to be printed and giving print commands to the label printer RP, an output unit 2 for checking the input contents and print commands from the input unit 1 and displaying the operating status of the label printer RP, and a control unit 3 for controlling the drive unit 4 of the label printer RP to control the label printing pre-processing and label printing process. The control unit 3 is configured with a ROM 31 for storing basic programs, application programs, etc., a RAM 32 for storing data such as the print contents, and a CPU 33 for performing predetermined calculation control based on the programs and data.

Next, the label printing pre-processing operation in the label printer according to this embodiment will be described with reference to the flowcharts in Figures 17a and 17b. This label printing pre-processing is performed before label printing, and after this processing is completed, the label printing processing starts.
The control unit 3 waits until an operation to issue a label is performed on the input unit 1, and if it determines that the operation has been performed, it determines whether or not label paper has been conveyed immediately before (S2). If it determines that label paper has not been conveyed immediately before, the control unit 3 determines whether or not printing has been performed immediately before (S3). If it determines that printing has been performed immediately before, the control unit 3 determines whether or not five minutes or more have passed since the end of that printing (S4).

If it is determined in step S4 that 5 minutes or more have not passed since printing ended, the control unit 3 ends the label printing pre-processing operation. If it is determined in step S4 that 5 minutes or more have passed since printing ended, the control unit 3 determines whether 30 minutes or more have passed since printing ended (S5).

If it is determined in step S2 that the label paper has been transported, or if it is determined in step S3 that printing will not be performed immediately before, then in step S6 the control unit 3 determines whether or not one hour has passed since printing ended. If it is determined that one hour or more has not passed since printing ended, the control unit 3 ends the label printing pre-processing operation. In contrast, if it is determined in step S6 that one hour or more has passed since printing ended, then in step S7 the control unit 3 controls the drive unit 4 to move the label paper backward 2 mm and then forward 2 mm, and then ends the label printing pre-processing operation.

If it is determined in step S5 that 30 minutes or more have not passed since printing ended, then in step S7 the control unit 3 controls the drive unit 4 to move the label paper backward by 2 mm and then forward by 2 mm, and then ends the label printing pre-processing operation. On the other hand, if it is determined in step S5 that 30 minutes or more have passed since printing ended, the control unit 3 determines whether 2 hours have passed since printing ended (S8).

If it is determined in step S8 that two hours or more have not passed since printing ended, the control unit 3 proceeds to step S9, where it uses the drive unit 4 to move the label paper backward by 2 mm and then forward by 2 mm twice, and then ends the label printing pre-processing operation.

If it is determined in step S8 that more than two hours have passed since printing ended, the control unit 3 determines whether or not more than 12 hours have passed since printing ended (S10). If it is determined that more than 12 hours have not passed since printing ended, in step S11 the control unit 3 causes the drive unit 4 to move the label paper backward by 2 mm and then forward by 2 mm three times, and then ends the label printing pre-processing operation.

If it is determined in step S10 that 12 hours or more have passed since printing ended, the control unit 3 determines whether 10 days or more have passed since printing ended (S12). If it is determined that 10 days or more have not passed, in step S11, the control unit 3 causes the drive unit 4 to move the label paper backward by 2 mm and then forward by 2 mm three times, and then ends the label printing pre-processing operation.

On the other hand, if it is determined in step S12 that 10 days or more have passed since printing ended, the control unit 3 determines whether the label paper has been reset (S13). If it is determined that the label paper has been reset, the control unit 3 ends the label printing pre-processing operation, and if it is determined that the label paper has not been reset, in step S14 the control unit 3 displays a message via the output unit 2 encouraging the user to reset the label paper, and then returns to step S13. The message prompting the user to reset the label paper may be displayed on a display screen of the connected device or printer, for example, saying "Please reset the label."

We propose a printing method for use with the printer described above. In this printing method, when a printing operation is to be performed, if the previous operation was only paper transport without printing (if the result of the determination in step S3 is NO), the printing operation can be performed immediately if the time since the paper transport is within a specified time, but if the specified time has elapsed, the paper is moved back and forth before the printing operation (steps S6 and S7).
That is, when printing labels, if the leading edge of the label paper p is pressed against the print head 203 for a long time even when no printing is being performed and the leading edge of the label paper p may be adhered to the platen with glue, the leading edge can be moved (peel-off operation) to remove the adhesive, thereby making it possible to prevent label paper jams from occurring.

We propose another printing method. In this printing method, when starting a printing operation, if the previous operation was a printing operation without paper transport (if judged Yes in step S3), depending on the time that has elapsed since then, printing may start immediately, or the printing operation may be performed after transporting the paper back and forth, but the number of back and forth transports can be changed depending on the length of the elapsed time (steps S9, S11), and if the elapsed time spans several days, the printing operation cannot be started unless the paper is reset (steps S13, S14).
In other words, when printing a label, if a label has been printed, the peeling operation can be set more frequently (two or three times), so that problems caused by the leading edge sticking to the platen 104 can be more effectively prevented.

As described above, the label printer according to an embodiment of the present invention is a printer that transports label paper and cuts the label paper using the cutting unit 400 to issue labels, and is equipped with the printing unit 203 that prints on the label paper, the platen 104 arranged opposite the printing unit 203, a first guide member (guide member 304) arranged downstream of the platen 104 and guiding the adhesive surface of the label paper, and a second guide member (free roller 305) formed by a rotatable roller that guides the adhesive surface of the label paper.
This prevents the linerless label paper from being forced into the gap between the platen and the first downstream guide member and wrapping around the platen, or from bending on the transport path, causing a jam.

Further, the upper end of the second guide member (free roller 305) of the label printer according to the embodiment of the present invention is lower than the upper end of the platen 104 and higher than the upper end of the first guide member (guide member 304).
This reduces the impact of the label paper against the paper guide surface 304a of the guide member 304, allowing the label paper to flow smoothly downstream and making it less likely for the label paper to stick to the paper guide surface, thereby preventing the label paper from getting wrapped around the platen 104.

Furthermore, the separation claws 304b of the guide member 304 of the label printer according to the embodiment of the present invention are arranged at multiple locations spaced apart in the width direction of the label paper, and multiple free rollers 305 are arranged near these separation claws 304b.
As a result, the separation claw 304b has a small overall width and a small contact area with the label paper, so that the adhesive side of the label paper is less likely to stick to the separation claw 304b.

The label printer according to an embodiment of the present invention further includes position adjustment means (311-315) that enables adjustment of the gap between the peripheral surface of the platen 104 and the upstream end of the guide member 304, and is connected to a first shaft (pivot shaft 301) that is rotatably supported on frames on both sides of the printer, and a second shaft (roller shaft 303) that is provided at a certain distance above the first shaft (301).The position adjustment means (311-315) can adjust the gap between the peripheral surface of the platen 104 and the upstream end of the guide member 304 by rotating the first shaft (301) within a certain angle range.
This allows the gap between the platen 104 and the guide member 304 to be adjusted at once by a simple operation of one position adjustment means, and the guide member 304 can be brought closer to the platen 104, thereby preventing the label paper from wrapping around the platen 104 and jamming.

Furthermore, in the printing method of the label printer according to the embodiment of the present invention, when a print operation is to be performed, if the time that has elapsed since the print operation is within a specified time, the print operation is performed immediately, and if the specified time has elapsed, the paper is moved back and forth before the print operation is performed.
As a result, if the specified time has not elapsed since printing was performed, printing can be performed without moving the label paper back and forth as a pre-printing process, thereby reducing printing time.

Furthermore, in the printing method of the label printer according to the embodiment of the present invention, when a print operation is to be performed, if the time that has elapsed since the print operation is within a specified time, the print operation is performed immediately, the number of forward and backward movements is changed depending on the length of the elapsed time, and if the elapsed time spans several days, the printer will not proceed to the print operation unless the paper is reloaded.
This allows the label paper peeling operation to be performed precisely according to the elapsed time, making it possible to more effectively prevent problems caused by the leading edge of the label paper sticking to the platen 104.

1 Input section 2 Output section 3 Control section 4 Drive section 100 Lower unit 101 Lower frame 102 Paper loading section p Label paper (backing-less label printing paper)
103: upstream paper guide 104: platen 200: upper unit 201: upper frame 203: print head 300: paper guide mechanism 300A
Paper guide mechanism 301 Pivot shaft 302 Cam follower 303 Roller shaft 304 Guide member 304a Paper guide surface 304b Separation claw 305 Free roller 305' Adhesion roller 309 Cam 310 Spring 311 Camshaft 312 Adjustment plate 314 Plate fixing screw 400 Cutter unit b1 Cutter fixed blade b2 Cutter movable blade

Claims (7)

A printer that conveys a linerless label printing paper and cuts the linerless label printing paper with a cutting unit to produce a label,
a printing unit that prints on the linerless label printing paper ;
a platen disposed opposite the printing unit and configured to transport the linerless label printing paper ;
a first guide member that is disposed immediately behind the platen and that guides an adhesive surface of the linerless label printing paper ;
a second guide member that is configured as a rotatable roller and is disposed immediately behind the gap formed between the first guide member and the platen, and that guides the adhesive surface of the linerless label printing paper ;
A printer comprising: The printer according to claim 1, characterized in that the upper end of the second guide member is lower than the upper end of the platen and higher than the upper end of the first guide member. the first guide members are disposed at a plurality of locations spaced apart in a width direction of the linerless label printing paper ,
3. The printer according to claim 2, wherein a plurality of the second guide members are disposed in the vicinity of the first guide member. The printer according to any one of claims 1 to 3, further comprising a position adjustment means that allows adjustment of the gap between the peripheral surface of the platen and the upstream end of the first guide member. The first guide member is connected to a first shaft rotatably supported on a frame on both sides of the printer and a second shaft provided at a position above the first shaft and spaced a certain distance therefrom,
5. The printer according to claim 4, wherein the position adjustment means adjusts the gap between the peripheral surface of the platen and the upstream end of the first guide member by rotating the first axis within a certain angular range. 6. A printing method for a printer according to claim 1 or 5, characterized in that, when a printing operation is to be performed, if the time elapsed since the printing operation is within a specified time, the printing operation is performed immediately, and if the specified time has elapsed, the linerless label printing paper is moved back and forth before the printing operation is performed. 6. A printing method for a printer according to claim 1 or 5, characterized in that, when a printing operation is to be performed, if the elapsed time since the printing operation is within a specified time, the printing operation is performed immediately, the number of forward and backward movements is changed depending on the length of the elapsed time, and if the elapsed time spans several days, the printer will not proceed to the printing operation until the linerless label printing paper is reset.

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