Printer

Abstract

In order to prevent a paper sensor from becoming an obstruction when a sheet of paper is being set in a printer (100), the printer (100) is provided with a platen roller (62) which is fixed to a main body side, a thermal print head (61) which is provided with freedom to pivot from a position facing the platen roller (62), and a first paper sensor (70) which detects label paper (201), wherein: the printer (100) includes an arm member (74) that pivots in response to the pivoting of the thermal print head (61) and that is provided downstream, in the forward conveying direction of the label paper (201), of the position at which the platen roller (62) and the thermal print head (61) face each other; and a light receiving unit (72), which is a portion of the first paper sensor (70), is provided on the arm member (74) to prevent the first paper sensor (70) from becoming an obstruction when a sheet of paper is being set in the printer (100).

Description

printer

[0001] The present invention relates to a printer.

[0002] Thermal transfer and thermal printers sandwich paper between a platen roller and a heated print head, and transport the paper by rotating the platen roller. Some printers also use label paper, which is made of a long, continuous backing sheet with labels affixed with adhesive in the transport direction.

[0003] When a printer prints on label paper, it needs to know the position of the label relative to the print head, so a sensor (hereinafter referred to as a paper sensor) is provided on the label paper transport path. The paper sensor is sometimes located downstream in the label paper feed direction from the printing unit where the platen roller and print head face each other (see, for example, Patent Document 1).

[0004] Japanese Utility Model Application Laid-Open Publication No. 5-068813

[0005] Incidentally, in a configuration in which the paper sensor is positioned downstream of the printing unit in the paper feed direction, when setting the paper in the printer, it is appropriate to temporarily retract the paper sensor from the printing unit, and then return the paper sensor to its original position after the paper is set, in order to prevent the leading edge of the paper passing through the printing unit from getting caught on the paper sensor and causing a paper jam.

[0006] SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a printer that can prevent a paper sensor from getting in the way when loading paper into the printer.

[0007] The present invention is a printer comprising a platen roller fixed to the main body, a print head rotatable from a position opposite the platen roller, and a paper sensor that detects paper, and an arm member that rotates in response to the rotation of the print head and is located downstream in the paper feed direction from the position where the platen roller and the print head are opposed, and at least a part of the paper sensor is located on the arm member.

[0008] The printer according to the present invention can prevent the paper sensor from getting in the way when loading paper into the printer.

[0009] 1 is a perspective view showing the appearance of the entire printer with the cover closed. FIG. 2 is a perspective view showing the appearance of the entire printer with the cover open. FIG. 3 is a perspective view showing the appearance of the entire printer with the print head unit further opened from FIG. 2. FIG. 4 is a cross-sectional view showing a cross section taken along a vertical plane including the front-to-rear direction in FIG. 1. FIG. 5 is a perspective view showing the arrangement of the first paper sensor when the print head unit is open. FIG. 6 is a perspective view showing the arrangement of the first paper sensor when the print head unit is closed. FIG. 7 is an exploded perspective view showing the arrangement of the light source and light guiding member of the first paper sensor. FIG. 8 is an exploded perspective view showing the arrangement of the light receiving section of the first paper sensor. FIG. 9 is a cross-sectional view showing a cross section taken along a vertical plane along the front-to-rear direction, illustrating a structure that prevents the arm member from swinging in the front-to-rear direction. FIG. 11 is a cross-sectional view equivalent to FIG. 4 , showing the appearance of a portion of the printer of Variation 1 where the peeler unit is installed. FIG. 12 is a perspective view showing the interlocking mechanism in the printer of Variation 2, showing the print head unit in the closed position. FIG. 13 is a perspective view showing the interlocking mechanism in the printer of Variation 2, showing the print head unit in the open position. FIG. 14 is a perspective view showing the printer of Variation 3. FIG. 11 is a perspective view showing an arm member in a printer according to a third modified example.

[0010] An embodiment of a printer according to the present invention will be described below with reference to the accompanying drawings.

[0011] 1 and 2 are perspective views showing the overall appearance of a printer 100, with Fig. 1 being a perspective view with the cover 12 closed, Fig. 2 being a perspective view with the cover 12 open, Fig. 3 being a perspective view with the print head unit 41 further opened from Fig. 2, and Fig. 4 being a cross-sectional view taken along a vertical plane including the front-rear direction L in Fig. 1. The illustrated printer is a printer according to a first embodiment of the present invention.

[0012] As shown in FIG. 1, the printer 100 has various functional components arranged inside a housing 10 formed into an overall rectangular parallelepiped shape. The housing 10 is configured by covering a case 11, which is located on the lower side in the height direction H, with an upper cover 12. The cover 12 opens from the closed state shown in FIG. 1 by pivoting upward and rearward about an axis C1 extending along the width direction W at the rear portion in the front-to-rear direction L, as shown in FIG. 2. With the cover 12 open, the interior of the printer 100 can be exposed. A narrow rectangular paper outlet 13 extending in the width direction W is opened at the front of the housing 10, at the boundary between the case 11 and the cover 12.

[0013] The printer 100 includes a paper storage chamber 30, a ribbon storage chamber 40, a print unit 60, a first paper sensor 70, a second paper sensor 50, and a control unit (not shown).

[0014] 2 and 4, the ribbon storage chamber 40 is provided with a print head unit 41. The print head unit 41 is provided with a thermal print head 61 of the printing section 60, and also has a ribbon drive section that sets the ribbon unit 300 in a predetermined position and pays out the ribbon 303 of the ribbon unit 300.

[0015] The print head unit 41 opens from the closed position shown in FIG. 2 by rotating upward and leftward by a predetermined angle β (see FIG. 5 , described later) around an axis C2 extending along the front-to-rear direction L at the left side of the width direction W, as shown in FIG. 3 . The state in which the print head unit 41 has rotated by the predetermined angle β from the closed position is the open state. The position of the print head unit 41 when it is closed is called the closed position, and the position in which the print head unit 41 has rotated by the predetermined angle β from the closed position is called the open position. The print head unit 41 is freely rotatable between the closed and open positions. When the print head unit 41 is in the open position, the paper storage chamber 30 is completely exposed, allowing the roll paper 200 to be inserted or removed from the paper storage chamber 30.

[0016] As shown in Figure 4, the print head unit 41 has a thermal print head 61 and, as a ribbon drive unit, a supply-side ribbon holder 42, a take-up-side ribbon holder 43, and a ribbon path 44. The supply-side ribbon holder 42 and the take-up-side ribbon holder 43 are each formed in a cylindrical shape and are driven to rotate about their axes by a control unit. The supply-side ribbon holder 42 has a ribbon roll 301 (described later) attached to its outer periphery, and the take-up-side ribbon holder 43 has an empty roll 302 (described later) attached to its outer periphery. The ribbon path 44 is the path along which the ribbon 304 passes. The thermal print head 61 is disposed in the ribbon path 44.

[0017] As shown in FIG. 4, the ribbon unit 300 includes a ribbon roll 301 around which a long unused ribbon 303 is wound in a roll, and an empty roll 302 around which the ribbon 303 unwound from the ribbon roll 301 is wound.

[0018] As shown in FIG. 4 , ribbon roll 301 is attached to the unwinding side ribbon holder 42, empty roll 302 is attached to the winding side ribbon holder 43, the outermost portion of ribbon 303 wound around ribbon roll 301 is pulled out from ribbon roll 301, the pulled out ribbon 303 is placed along the underside of ribbon path 44 up to empty roll 302, and the tip of the pulled out ribbon 303 is fixed to empty roll 302, whereby ribbon unit 300 is set in print head unit 41.

[0019] The unwinding side ribbon holder 42 and the winding side ribbon holder 43 are controlled by a control unit (not shown) to rotate in the direction of winding the ribbon 303 onto the empty roll 302, whereby the ribbon 303 wound around the ribbon roll 301 is unwound and wound onto the empty roll 302 via the ribbon path 44 on which the thermal print head 61 is provided.

[0020] The speed of the ribbon 303 as it passes the thermal print head 61 is controlled to be the same as the speed of the label paper 201 as it is transported in the forward direction of the thermal print head 61 while superimposed on the ribbon 303. The forward direction corresponds to the transport direction (feed direction) in which the label paper 201 is transported when printing on it, and is the direction in which the label paper 201 is discharged from the paper discharge slot 13 (see Figures 1, 2 and 4).

[0021] In addition, the unwinding side ribbon holder 42 and the winding side ribbon holder 43 are controlled by a control unit (not shown) to rotate in the direction of winding the ribbon 303 onto the ribbon roll 301, whereby the ribbon 303 wound around the empty roll 302 is unwound and rewound onto the ribbon roll 301 via the ribbon path 44.

[0022] The speed of the ribbon 303 as it passes the thermal print head 61 in the rewinding direction is controlled to be the same as the speed of the label paper 201 as it is transported (backfed) in the reverse direction of the thermal print head 61 while overlapped with the ribbon 303. The reverse direction is the opposite of the forward direction, and corresponds to the transport direction in which the label paper 201 is rewound onto the roll paper 200.

[0023] 3 and 4, the paper storage chamber 30 stores roll paper 200, which is a roll of long label paper 201. As shown in Figures 2 and 4, when the print head unit 41 is closed, the paper storage chamber 30 is partially blocked by the print head unit 41, so it is not possible to insert or remove the roll paper 200 from the paper storage chamber 30, or to pull out the label paper 201 from the roll paper 200 and set it in the printing unit 60.

[0024] On the other hand, as shown in Figure 3, when the print head unit 41 is open at the top left, the paper storage chamber 30 can be loaded and unloaded from the roll paper 200 without being obstructed by the print head unit 41, and the label paper 201 can be pulled out from the roll paper 200 and set in the printing section 60.

[0025] 3, the label paper 201 wound into the roll paper 200 is formed by arranging a number of labels 203 in the longitudinal direction on a single, continuous backing sheet 202. The labels 203 are affixed to the backing sheet 202 so that they are positioned on the outer circumferential surface of the roll of the roll paper 200.

[0026] The label paper 201 has a small gap between adjacent labels 203 along the longitudinal direction of the line of the labels 203, and only the backing paper 202 is present in this gap. In other words, in the part where the label 203 exists, the label 203 and the backing paper 202 are overlapped in the thickness direction, while in the gap part where no label 203 exists, only the backing paper 202 is present in the thickness direction.

[0027] Therefore, when a transmission optical sensor is used to irradiate light onto the label paper 201 from one side in the thickness direction of the label paper 201, a significant difference in the amount of transmitted light detected on the opposite side of the label paper 201 can be detected between the area where the label 203 is present and the area where the label 203 is not present. The first paper sensor 70, which will be described later, is a transmission optical sensor of this type.

[0028] When the print head unit 41 shown in FIG. 3 is open to the upper left, the roll paper 200 stored in the paper storage chamber 30 is pulled out of the outermost portion of the wound label paper 201, and the leading edge of the pulled label paper 201 is placed downstream of the peel plate 63 located downstream of the printing unit 60 in the forward direction, over the platen roller 62 shown in FIG. 4, and then the print head unit 41 shown in FIGS. 2 and 4 is closed, and the label paper 201 is set in a usable state.

[0029] The peel plate 63 can be used as a manual cutter when the peeler unit 80, which will be described later, is not provided. That is, the control unit controls the conveyance of the label paper 201 printed by the printing unit 60 so that the portion of the backing paper 202 between the rear end of the printed label 203 and the front end of the next label 203 reaches the front end of the peel plate 63, stopping the conveyance. In this state, by manually holding the printed label paper 201 that protrudes forward beyond the peel plate 63 and pulling it diagonally downward, the leading edge of the peel plate 63 can tear off the label paper 201 (the portion of the backing paper 202 only).

[0030] (Second Paper Sensor) The second paper sensor 50 is located on the path of the label paper 201 between the paper storage chamber 30 and the printing unit 60, which will be described later. The second paper sensor 50 is located upstream of the printing unit 60 in the forward direction of the label paper 201. The second paper sensor 50 includes a light source 51 and a reflected light receiving unit 52 located on the back side of the label paper 201, i.e., on the underside of the backing paper 202, and a transmitted light receiving unit 53 located on the front side of the label paper 201, i.e., on the upper surface where the label 203 is arranged.

[0031] Not only label paper 201, but also roll paper 200 housed in paper storage chamber 30 may have a black mark, for example, formed on the side opposite the printing side, which serves as the paper's printing reference position.

[0032] The second paper sensor 50, by combining a light source 51 and a reflected light receiving unit 52, forms a reflective optical sensor that detects a black mark on the back side of the paper, and by detecting the black mark, the second paper sensor 50 detects the printing reference position of the paper on the upstream side of the forward direction of the paper.

[0033] In addition, the second paper sensor 50, by combining a light source 51 and a transmitted light receiving unit 53, constitutes a transmission type optical sensor that detects the difference in the amount of transmitted light that passes through the paper, and detects the leading and trailing end positions of the label 203 on the upstream side of the forward direction of the label paper 201.

[0034] (Printing Unit) The printing unit 60 has a thermal printhead 61 and a platen roller 62. The thermal printhead 61 has multiple heating elements arranged in the width direction W, and as described above, is provided on the ribbon path 44 of the printhead unit 41. The heating elements of the thermal printhead 61 generate heat in a predetermined pattern under the control of the control unit. The platen roller 62 is fixedly disposed on the side of the case 11 (the main body side). Under the control of the control unit, the platen roller 62 rotates to drive the label paper 201 forward or backward in the transport direction.

[0035] When the printhead unit 41 is in the closed position, as shown in Fig. 4, the thermal printhead 61 is disposed above the platen roller 62, facing and parallel to the platen roller 62, and in contact with the platen roller 62, with the thermal printhead 61 and the platen roller 62 sandwiching the ribbon 303 and the label paper 201 with them overlapping in the thickness direction. This causes the printer 100 to bring the ribbon 303, which is disposed in the ribbon path 44, into close contact with the label 203 of the label paper 201, which is disposed on the platen roller 62. When the printhead unit 41 is in the open position, as shown in Fig. 3, the thermal printhead 61 is spaced away from the platen roller 62.

[0036] With the print head unit 41 in the closed position as shown in FIG. 4, the control unit controls the thermal print head 61 to generate heat in a predetermined pattern, while rotating the platen roller 62, the supply-side ribbon holder 42, and the take-up-side ribbon holder 43 so that the label paper 201 and ribbon 303 move forward in the transport direction. As a result, the ribbon 303 and label paper 201 are sent forward in the transport direction in synchronization, and the ink on the ribbon 303 is transferred to the label 203 in the predetermined pattern, printing the predetermined pattern on the label 203.

[0037] (First paper sensor) Figure 5 is an oblique view showing the arrangement of the first paper sensor 70 when the print head unit 41 is open, Figure 6 is an oblique view showing the arrangement of the first paper sensor 70 when the print head unit 41 is closed, Figure 7 is an exploded oblique view showing the arrangement of the light source 71 and light-guiding member 73 of the first paper sensor 70, and Figure 8 is an exploded oblique view showing the arrangement of the light-receiving unit 72 of the first paper sensor 70.

[0038] A peel plate 63 is provided downstream in the forward transport direction of the label paper 201 from the position where the platen roller 62 and thermal printhead 61 face each other, in close proximity to the platen roller 62. The peel plate 63 is a path member over which the label paper 201 passes, and as mentioned above, also functions as a manual cutter that manually tears off the printed label paper 201 using the leading edge of the peel plate 63. The peel plate 63 extends in the width direction W.

[0039] The first paper sensor 70 includes a light source 71 (light-emitting element), a light-guiding member 73, and a light-receiving unit 72 (light-receiving element). The light source 71 is, for example, an infrared light-emitting diode (IR-LED), but is not limited to an IR-LED and may be a light source that emits visible light or a light source that emits other light. As shown in FIG. 4 , the light source 71 is disposed so as to emit infrared light diagonally upward and forward along the top plate portion of the peel plate 63.

[0040] The light guide member 73 is provided on the peel plate 63 diagonally upward and forward of the light source 71. The light guide member 73 is a prism that reflects the infrared rays emitted diagonally upward and forward from the light source 71 upward in the height direction H. As shown in FIGS. 4 to 8 , a hole 63a is formed in the top plate of the peel plate 63 to allow the infrared rays reflected upward by the light guide member 73 to pass through.

[0041] The light receiving unit 72 receives infrared rays. When the print head unit 41 is in the closed position shown in FIG. 6 , the light receiving unit 72 is located above the hole 63a in the peel plate 63 with a small gap between it and the peel plate 63. The light receiving unit 72 is located in a position where it can receive infrared rays that have been reflected by the light guiding member 73 and passed through the hole 63a.

[0042] The light receiving unit 72 is a phototransistor and is located directly above the peel plate 63 on an arm member 74 that rotates in response to the rotation of the print head unit 41, as shown in Figures 5 to 8. As shown in Figure 8, the arm member 74 is configured to be rotatable coaxially with the axis C2 of rotation of the print head unit 41. The arm member 74 is located opposite the peel plate 63, downstream in the forward transport direction of the label paper 201 from the position in the printing unit 60 where the platen roller 62 and print head 61 face each other.

[0043] 5 and 8, a coil spring 75 is disposed on the left side of the axis C2 of the arm member 74. The coil spring 75 pulls the left side of the arm member 74 downward, thereby applying a biasing force to the arm member 74 to rotate it counterclockwise as shown in the figure.

[0044] When the print head unit 41 is in the open position, the arm member 74 is rotated counterclockwise by the coil spring 75, but when the arm member 74 rotates a predetermined angle α relative to the top plate portion of the peel plate 63 and reaches a position (retracted position) away from the label paper 201, the lower left side 74b of the arm member 74 hits a stopper 65 that is formed in a convex shape on the base plate 67 of the frame member that forms the skeleton of the printer 100, and the arm member 74 is prevented from rotating counterclockwise by more than the predetermined angle α.

[0045] The predetermined angle α by which the arm member 74 rotates is set smaller than the predetermined angle β by which the print head unit 41 rotates from the closed position (FIG. 6) to the open position (FIG. 5) (α<β). As an example, the predetermined angle α is set to approximately half the predetermined angle β. For example, the predetermined angle α is 35 degrees, and the predetermined angle β is 70 degrees.

[0046] 5, 6, and 8, the print head unit 41 is provided with a pressing protrusion 48. As the print head unit 41 rotates from the open position to the closed position, the pressing protrusion 48 abuts from above against the upper surface 74a of the arm member 74, which is stopped at a predetermined angle α. Then, while the print head unit 41 rotates from the predetermined angle α to the closed position, the pressing protrusion 48 continues to press downward against the upper surface 74a of the arm member 74 against the biasing force of the coil spring 75. This causes the print head unit 41 to rotate the arm member 74 clockwise until it is parallel to the top plate portion of the peel plate 63.

[0047] As described above, when the print head unit 41 rotates to the closed position, the arm member 74 is rotated clockwise by the pressing protrusion 48, but when the arm member 74 reaches a position (detection position) parallel to the top plate portion of the peel plate 63, the lower right portion 74c of the arm member 74 abuts against the stopper 66 formed on the peel plate 63, as shown in Figure 6. This prevents the arm member 74 from rotating clockwise beyond the position parallel to the top plate portion of the peel plate 63.

[0048] Therefore, the arm member 74 is stopped at a position where it is parallel to the top plate portion of the peel plate 63. When the arm member 74 is in a position where it is parallel to the top plate portion of the peel plate 63, the light receiving unit 72 receives infrared light that is reflected by the light guiding member 73 and passes through the hole 63a. Therefore, the position where the arm member 74 is parallel to the top plate portion of the peel plate 63 is set as the detection position of the first paper sensor 70.

[0049] When the arm member 74 is rotated counterclockwise from a position parallel to the top plate portion of the peel plate 63, the light receiving unit 72 is outside the irradiation range of the infrared rays reflected by the light guiding member 73, and therefore the light receiving unit 72 cannot detect the infrared rays.

[0050] As described above, the arm member 74 rotates in response to the rotation of the print head unit 41. Specifically, the pressing protrusion 48 and coil spring 75 provided on the print head unit 41 constitute an interlocking mechanism that rotates the arm member 74 in conjunction with the rotation of the print head unit 41 between a detection position close to the label paper 201 and a retracted position away from the label paper 201.

[0051] As a result, in order to pull out and set the label paper 201 from the roll paper 200 stored in the paper storage chamber 30 to the position of the peel plate 63, the print head unit 41 covering the path of the label paper 201 is flipped up (rotated) to a position of a predetermined angle β (open position), and the pressing protrusion 48 and coil spring 75 provided on the print head unit 41 flip up the arm member 74 covering the upper part of the peel plate 63, away from the label paper 201, to a position of a predetermined angle α (retracted position).

[0052] 5, the arm member 74 retracts above the peel plate 63 where the label paper 201 is placed, forming a space S1 at a predetermined angle α below the arm member 74. This prevents the arm member 74 from getting in the way when setting the label paper 201 above the peel plate 63, which is part of the space S1, making it easier to set the label paper 201.

[0053] Furthermore, since the arm member 74 is positioned above the peel plate 63 and facing the peel plate 63, it is located downstream in the conveying direction of the label paper 201 from the thermal print head 61, which is positioned above the platen roller 62 and facing the platen roller.

[0054] The ribbon 303 needs to be positioned downstream in the transport direction of the thermal print head 61 in the ribbon path 44. If the arm member 74 were formed to rotate integrally with the print head unit 41 up to a predetermined angle β, the arm member 74 would be positioned immediately in front of the ribbon path 44 of the print head unit 41 in the open position, and the arm member 74 would get in the way when setting the ribbon 303.

[0055] However, in the printer 100 of this embodiment, the print head unit 41 stops at a position (open position) where it has rotated a predetermined angle β, and the arm member 74 stops at a position (retracted position) where it has rotated a predetermined angle α that is smaller than the predetermined angle β due to stopper 65. Therefore, in the open position, the arm member 74 is not located immediately in front of the ribbon path 44 of the print head unit 41, and moreover, a space S2 of an angle (β - α) which is the difference between the rotation angles of the print head unit 41 and the arm member 74 is formed below and to the right of the print head unit 41.

[0056] This allows the arm member 74 to be out of the way when the ribbon roll 301 and empty roll 302 are attached to the print head unit 41 and the ribbon 303 is set through the underside of the ribbon path 44, which is part of the space S2, making it easier to set the ribbon unit 300.

[0057] Furthermore, when the print head unit 41 is in the open position, the arm member 74 also rotates to a position at a predetermined angle α, but while the print head unit 41 is maintained in the open position, the arm member 74 can be pushed and rotated against the biasing force of the coil spring 75 to a detection position opposite the peel plate 63.

[0058] Therefore, when setting the ribbon 303 through the underside of the ribbon path 44, if the space of the above-mentioned difference angle (β-α) is insufficient, the arm member 74 can be rotated downward to ensure a larger space below and to the right of the print head unit 41.

[0059] In the printer 100, the specific angles α at which the arm member 74 rotates and β at which the print head unit 41 rotates are not limited to the combination of 35 degrees and 70 degrees mentioned above, and the ratio of the predetermined angles α and β is not limited to the 1:2 mentioned above.

[0060] That is, the predetermined angle α in the printer 100 may be any angle that allows the arm member 74 to avoid interfering with the space formed below the arm member 74 when setting the label paper 201 above the peel plate 63. The predetermined angle α may also be any angle that allows the arm member 74 to avoid interfering with the space formed below the print head unit 41 when setting the ribbon 303.

[0061] FIG. 9 is a cross-sectional view showing a cross section along a vertical plane along the front-rear direction L, illustrating a structure that prevents the arm member 74 from swinging in the front-rear direction L.

[0062] As shown in Fig. 6, the arm member 74 is journaled on the shaft C2 with its rear surface in close contact with the front surface of the base plate 67. As shown in Figs. 5 and 7, the peel plate 63 is formed with an upwardly protruding anti-vibration piece 63b. When the arm member 74 is in the detection position facing the peel plate 63 shown in Fig. 6, the anti-vibration piece 63b is disposed so that it contacts or is close to the arm member 74 from the front side in the front-to-rear direction L, as shown in Fig. 9.

[0063] As a result, the vibration prevention piece 63b prevents the arm member 74, which is at the detection position, from swinging forward. In addition, the rear surface of the arm member 74 is in close contact with the front surface of the base plate 67, preventing the arm member 74 from swinging backward. Therefore, it is possible to prevent the arm member 74 from swinging back and forth at the detection position, which would cause instability in the light reception of the light receiving unit 72.

[0064] In the printer 100 of this embodiment, the ribbon unit 300 is set in the print head unit 41, and the label paper 201 is set on the platen roller 62 and peel plate 63. When the print head unit 41 is rotated to the closed position, the ribbon 303 and the label paper 201 are sandwiched between the thermal print head 61 and the platen roller 62 with the ribbon 303 and the label paper 201 overlapping in the thickness direction, as shown in FIG. 4 .

[0065] Furthermore, directly above the label paper 201, which is placed on the peel plate 63 on which the light source 71 and light guide member 73 of the first paper sensor 70 are provided, is a light receiving unit 72 that is attached to the arm member 74 and receives light that has passed through the label paper 201. This allows the first paper sensor 70 to detect, based on the difference in the amount of transmitted light detected by the light receiving unit 72, whether the portion of the label paper 201 that has passed the position where the first paper sensor 70 is provided is a portion of the backing paper 202 with a label 203 affixed thereto, or a portion of only the backing paper 202 without a label 203.

[0066] Here, before printing by the printing unit 60 begins, if the printer 100 detects that the portion of the label paper 201 detected by the first paper sensor 70, which is located downstream of the printing unit 60 in the transport direction of the label paper 201, is a portion consisting of only the backing paper 202, the control unit rotates the platen roller 62 in the forward direction to feed the label paper 201 further forward in the transport direction.

[0067] Then, when the first paper sensor 70 detects the boundary where the part that contains only the backing paper 202 changes to the part where the label 203 is affixed to the backing paper 202 based on the difference in the amount of transmitted light received, the position of the leading edge of the label 203 in the transport direction is detected, and the control unit stops the rotation of the platen roller 62 and then rotates the platen roller 62 in the opposite direction so as to pull (backfeed) the leading edge of the detected label 203 back to the position of the printing unit 60.

[0068] The length from the position of the first paper sensor 70 to the printing unit 60 along the transport direction of the label paper 201 is measured in advance and is known, so the control unit rotates the platen roller 62 so as to backfeed the label paper 201 by that known length.

[0069] On the other hand, when the printer 100 detects, prior to the start of printing by the printing unit 60, that the portion of the label paper 201 detected by the first paper sensor 70 located downstream of the printing unit 60 in the conveying direction of the label paper 201 is the portion where the label 203 is affixed to the backing paper 202, the control unit rotates the platen roller 62 in the opposite direction to pull the label paper 201 back in the opposite direction to the forward conveying direction.

[0070] Then, when the first paper sensor 70 detects the boundary where the part of the backing paper 202 where the label 203 is affixed changes to the part where only the backing paper 202 remains, due to the difference in the amount of transmitted light received, the position of the leading edge of the label 203 in the transport direction is detected, and the control unit continues to rotate the platen roller 62 in the opposite direction so as to pull the detected leading edge of the backing paper 202 back to the position of the printing unit 60.

[0071] By using the above-described control based on the detection results of the first paper sensor 70, which is located downstream of the printing unit 60 in the conveying direction of the label paper 201, the printer 100 can also print on the label 203 located at the tip of the label paper 201 that has been unwound from the roll paper 200 using the printing unit 60, and the first label 203 located at the tip of the label paper 201 is not wasted.

[0072] The printer 100 has been described with the first paper sensor 70 as a transmissive optical sensor having a light source 71 arranged above and below the label paper 201 and a light receiving unit 72 that detects the amount of transmitted light, but the first paper sensor 70 may be configured to include both a transmissive optical sensor and a reflective optical sensor, as with the second paper sensor 50, or may be configured to include only a reflective optical sensor.

[0073] When the printer 100 is configured with the first paper sensor 70 as a reflective optical sensor, the light source 71 and the light receiving unit that detects the reference printing position of the paper depending on the amount of light reflected by the label paper 201 may be provided on the arm member 74. Alternatively, the printer 100 may be configured with the light source 71 and the light receiving unit that detects the reference printing position of the paper depending on the amount of light reflected by the label paper 201 provided on the peel plate 63.

[0074] If the printer 100 is configured with the first paper sensor 70 as a reflective optical sensor and a transmissive optical sensor, the light source 71 and the light receiving unit that detects the print reference position of the paper in accordance with the amount of light reflected by the label paper 201 may be provided on the arm member 74, and the light receiving unit 72 that detects the label in accordance with the amount of light transmitted through the label paper 201 may be provided on the peel plate 63. In this case, the arrangement of the light source 71 and the light receiving unit 72 is reversed from that shown in Figure 4. Alternatively, the printer 100 may be configured with the light source 71 and the light receiving unit that detects the print reference position of the paper in accordance with the amount of light reflected by the label paper 201 provided on the peel plate 63, and the light receiving unit 72 that detects the label in accordance with the amount of light transmitted through the label paper 201 provided on the arm member 74.

[0075] The above-described variations in the configuration and arrangement of the first paper sensor 70 can also be applied to the modified examples described below.

[0076] 10 is a cross-sectional view equivalent to FIG. 4 showing a printer 400 of Modification 1, and FIG. 11 is a perspective view showing the appearance of a portion of printer 400 of Modification 1 where peeler unit 80 is attached. While printer 100 of Embodiment 1 does not include peeler unit 80, printer 400, which is Modification 1 of printer 100, is printer 100 with peeler unit 80 attached.

[0077] As shown in Figures 10 and 11, the peeler unit 80 has a path for conveying the backing paper 202 by bending it at an acute angle downward and rearward at the tip of the peel plate 63, and automatically peels off the label 203, which is discharged from the paper discharge outlet 13 without being bent at the tip of the peel plate 63, from the backing paper 202.

[0078] As shown in the figure, the peeler unit 80 is disposed in the space below the peel plate 63. Therefore, it is difficult to secure a space below the peel plate 63 in which the light source 71 is disposed directly below the light receiving unit 72 in a position in which infrared rays are emitted upward toward the light receiving unit 72 disposed above in the height direction H.

[0079] However, in the printer 400 of variant 1, the light source 71 is positioned upstream of the light receiving unit 72 in the forward direction rather than directly below the light receiving unit 72, thereby minimizing the space below occupied by the peel plate 63, and the infrared light emitted from the light source 71 toward the front and upper direction is reflected by the light guiding member 73 to the light receiving unit 72, thereby making it possible to detect the label 203 on the label paper 201.

[0080] In addition to the effects described above, the printer 400 of the first modified example also exhibits the effects of the printer 100 of the first embodiment.

[0081] 12 and 13 are perspective views showing the interlocking mechanism in printer 500 of modified example 2, with FIG. 12 showing print head unit 41 in the closed position and FIG. 13 showing print head unit 41 in the open position.

[0082] The printer 100 of the first embodiment uses a pressing protrusion 48 and a coil spring 75 as an interlocking mechanism that rotates the arm member 74 in conjunction with the rotation of the print head unit 41. However, a printer 500, which is a second variation of the printer 100, uses a gear train consisting of three gears 68a, 68b, and 68c as an interlocking mechanism. Gear 68b is a two-stage gear in which two gears are stacked one above the other along the axial direction. The two gears that make up gear 68b are coaxial but have different numbers of teeth (pitch circle radii).

[0083] Gear 68a is fixed to axis C2, which rotates the print head unit 41, and rotates integrally with the print head unit 41. Gear 68a has teeth only within an angular range corresponding to a predetermined angle β, which is the rotation range of the print head unit 41. Gear 68c is provided at the rotation center of arm member 74, and as gear 68c rotates, arm member 74 rotates integrally with gear 68c. Gear 68b is a two-stage gear that mediates between gears 68a and 68c via upper and lower gears, transmitting the rotation of gear 68a to gear 68c and the rotation of gear 68c to gear 68a.

[0084] Specifically, gear 68a meshes with the gear having the fewer teeth and the smaller pitch circle of the two gears that make up gear 68b, and gear 68c meshes with the gear having the more teeth and the larger pitch circle of the two gears that make up gear 68b.

[0085] The arm member 74 rotates in conjunction with the print head unit 41 via the three gears 68a, 68b, and 68c, so that the arm member 74 rotates in the same direction as the print head unit 41. The gear train consisting of the gears 68a, 68b, and 68c is formed so that the input / output gear ratio is 1:1.95, so that when the print head unit 41 rotates a predetermined angle β from the closed position shown in Fig. 12 to the open position shown in Fig. 13, the arm member 74 rotates a predetermined angle γ from the detection position shown in Fig. 12 to the retracted position shown in Fig. 13.

[0086] Here, the predetermined angle γ, which is the rotation angle of the arm member 74, is 1.95 times the predetermined angle β due to the input / output gear ratio of the gear train, which is the interlocking mechanism described above.

[0087] In this way, when the print head unit 41 of the printer 500 of Modification 2 is in the open position, the arm member 74 also retracts above the peel plate 63 on which the label paper 201 is placed, forming a space at the specified angle γ below the arm member 74. This prevents the arm member 74 from getting in the way when setting the label paper 201 above the peel plate 63, making it easier to set the label paper 201.

[0088] Furthermore, the arm member 74 stops at a position (retracted position) after rotating to a predetermined angle γ that exceeds the open position (predetermined angle β) of the print head unit 41. Therefore, when the print head unit 41 is in the open position, the arm member 74 is not present downstream in the transport direction of the print head unit 41, and a space of the predetermined angle β is formed below and to the right of the print head unit 41.

[0089] This allows the ribbon roll 301 and empty roll 302 to be attached to the print head unit 41, and the arm member 74 to be out of the way when setting the ribbon 303 through the underside of the ribbon path 44, making it easier to set the ribbon unit 300.

[0090] The input / output gear ratio of the gear train consisting of gears 68a, 68b, and 68c that make up the interlocking mechanism is not limited to the example of modified example 2 described above, and may be at least the same as in the printer of embodiment 1, as long as it is stopped at a position where arm member 74 does not get in the way when ribbon roll 301 and empty roll 302 are attached to print head unit 41 and ribbon 303 is set through the underside of ribbon path 44.

[0091] In addition to the effects described above, the printer 500 of the second modified example also exhibits the effects of the printer 100 of the first embodiment.

[0092] The printers 100, 400, and 500 of the above-described embodiment 1 and variants 1 and 2 are thermal transfer printers that have a ribbon unit 300 in the ribbon storage chamber 40 and perform printing by thermally transferring the ink of the ribbon 303 to the label 203 of the label paper 201. However, these printers 100, 400, and 500 can also perform printing without using the ribbon unit 300.

[0093] That is, the printers 100, 400, and 500 can use thermal paper as the roll paper 200 without setting the ribbon unit 300 in the ribbon storage chamber 40. In this case, the printers 100, 400, and 500 can print on the thermal paper by causing the thermal paper to develop color due to the heat generated by the thermal print head 61, and the printers 100, 400, and 500 function as thermal printers.

[0094] [Modification 3] FIG. 14 is a perspective view showing a printer 600 according to a modification 3, and FIG. 15 is a perspective view showing an arm member 174 in the printer 600 according to the modification 3. As shown in FIG.

[0095] The printers 100, 400, and 500 described above are thermal transfer printers, but the illustrated printer 600 is a thermal printer, which is a third variation of the printer 100. That is, the printer 600 does not use the ribbon unit 300, and therefore, unlike the printer 100, does not have a ribbon storage chamber 40. Therefore, in the printer 600, the print head unit 141 provided with the thermal print head 61 does not have a ribbon drive unit.

[0096] As described above, the printer 600 does not have the ribbon unit 300, so there is no need to arrange the ribbon 303, and the arm member 74 does not get in the way in relation to the print head unit 141. For this reason, in the printer 600, as shown in Figures 14 and 15, the arm member 174 on which the light receiving unit 72 of the first paper sensor 70 is mounted is fixed to the print head unit 141.

[0097] That is, the arm member 174 rotates integrally with the print head in response to the rotation of the print head. Therefore, when the predetermined angle through which the print head unit 141 rotates is β, the predetermined angle through which the arm member 174 rotates is also β.

[0098] In this way, when the print head unit 141 of the printer 600 of Modification 3 is in the open position, the arm member 174 also retracts above the peel plate 63 on which the label paper 201 is placed, forming a space of a predetermined angle β below the arm member 174. This prevents the arm member 174 from getting in the way when setting the label paper 201 above the peel plate 63, making it easier to set the label paper 201.

[0099] The printers 100, 400, 500, and 600 of the first embodiment and each of the modified examples are provided with the second paper sensor 50, but the printer according to the present invention does not need to be provided with the second paper sensor 50, and may instead be provided with the first paper sensor 70 as the paper sensor.

[0100] The printers 100, 400, 500, and 600 of the first embodiment and each of the modified examples have been described as using label paper 201 or thermal paper as the paper stored in the paper storage chamber 30, and as the first paper sensor 70 detecting the label 203 on the label paper 201 or a specific mark on the thermal paper, but the printer according to the present invention is not limited to using label paper 201 or thermal paper and detecting the label on the label paper 201 or a specific mark on the thermal paper. Therefore, the printer according to the present invention may use other types of paper other than label paper or thermal paper, and the first paper sensor 70 may detect the other types of paper. CROSS-REFERENCE TO RELATED APPLICATIONS

[0101] This application claims priority based on Japanese Patent Application No. 2024-008128, filed with the Japan Patent Office on January 23, 2024, the entire disclosure of which is incorporated herein by reference in its entirety.

Claims

1. A printer comprising a platen roller fixed to the main body side, a print head rotatably provided at a position facing the platen roller, and a paper sensor for detecting paper, having an arm member provided downstream in the paper feeding direction from the position where the platen roller and the print head face each other and rotating in response to the rotation of the print head, and at least a part of the paper sensor being provided on the arm member.

2. The printer according to claim 1, wherein the print head is rotatable between a closed position where the print head is close to and faces the platen roller and an open position where the print head is away from the platen roller, and the arm member is provided with an interlocking mechanism that rotates the arm member in conjunction with the rotation of the print head between a detection position close to the paper corresponding to the closed position and a retracted position away from the paper corresponding to the open position.

3. The printer according to claim 2, wherein the angle of rotation of the interlocking mechanism between the detection position and the retracted position is smaller than the angle of rotation between the closed position and the open position, and a space along the direction of rotation is formed between the arm member arranged at the retracted position and the print head arranged at the open position.

4. The printer according to claim 2, wherein the rotation angle of the interlocking mechanism from the detection position to the retracted position is set to be larger than the rotation angle from the closed position to the open position.

5. The printer according to claim 2, wherein the interlocking mechanism is set to allow the arm member to rotate from the retracted position toward the detection position with the print head arranged at the open position.

6. The printer according to any one of claims 1 to 5, wherein the paper sensor is an optical sensor having a light emitting element and a light receiving element, and one of the light emitting element and the light receiving element is arranged on the arm member, and the other element is arranged on a path member through which the paper passes and provided downstream of the platen roller together with a light guide member.

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