Printer

Abstract

Provided is a printer capable of efficiently positioning a medium. This printer (1) comprises a case 20, a cover 3, a thermal head 11, a platen roller 12, and a laser sensor 50. The case 20 has a storage space 10 for storing the medium 6. The cover 3 opens / closes the storage space 10. The thermal head 11 is disposed in the case 20 and performs printing on the medium 6. The medium 6 is fitted between the platen roller 12 and the thermal head 11 and conveyed by the platen roller 12. The laser sensor 50 detects a mark attached to the medium 6 and is used for positioning the medium 6. The platen roller 12 and the laser sensor 50 are both disposed on the case 20 side or the cover 3 side.

Description

Printer

[0001] The present invention relates to a printer.

[0002] The label feeding device described in Patent Document 1 includes a stepping motor and a laser sensor. The stepping motor drives to convey a roll of backing paper. The laser sensor detects a label attached to the roll of backing paper.

[0003] Japanese Patent Laid-Open No. 6-127772

[0004] In the above label feeding device, it is conceivable that printing is performed on the conveyed label by a thermal head. The thermal head sandwiches the label between a platen roller. The platen roller conveys the roll of backing paper by driving of the stepping motor. Before the start of printing by the thermal head, a head-out operation may be performed. The head-out operation is an operation for positioning the label before printing by the laser sensor detecting the label while the platen roller conveys the roll of backing paper. In the head-out operation, if the laser sensor does not detect the label, the label cannot be positioned. Therefore, depending on the arrangement of the laser sensor, the head-out operation may take time and it may be impossible to efficiently position the label.

[0005] An object of the present invention is to provide a printer capable of efficiently performing positioning of a medium.

[0006] A printer according to an aspect of the present invention includes a case having an accommodation space for accommodating a medium having a detected portion, a cover for opening and closing the accommodation space, a thermal head disposed on either the case or the cover for performing printing on the medium, a platen roller disposed on the other of the case or the cover for sandwiching and conveying the medium between the thermal head, and a laser sensor disposed on the other of the case or the cover upstream of the platen roller in the conveyance direction of the medium for irradiating the medium conveyed by the platen roller with laser light to detect the detected portion.

[0007] In this embodiment of the printer, since the platen roller and the sensor are located on the same side, the distance between the laser sensor and the platen roller in the transport direction can be shortened. Therefore, the printer can efficiently position the media.

[0008] In the printer, the thermal head may be housed in the case, and the platen roller and laser sensor may be housed in the cover. The laser sensor is housed in the same cover as the platen roller. Therefore, the printer can shorten the distance between the laser sensor and the platen roller in the transport direction with a simple configuration. Thus, the printer can efficiently position the media.

[0009] In the printer, the cover has a holder that rotatably supports the platen roller and includes a wall that covers a portion of the side surface of the platen roller when viewed from the axial direction of the platen roller, and the laser sensor may be on the opposite side of the platen roller across the wall and in contact with the wall. The laser sensor is in contact with the wall of the holder. The holder supports the platen roller, and the wall covers a portion of the side surface of the platen roller. Therefore, the printer can shorten the distance between the laser sensor and the platen roller in the transport direction with a simple configuration. Thus, the printer can efficiently position the media.

[0010] In a printer, the medium is transported along a transport path between the storage space and the platen roller, and the laser sensor may be positioned on the transport path in the transport direction. The printer can position the laser sensor in close proximity to the platen roller. Therefore, the printer can reduce the time required for operations such as leading out and efficiently position the medium.

[0011] In a printer, the laser sensor may be positioned closer to the platen roller than to the storage space in the transport path. The printer can shorten the distance between the laser sensor and the platen roller in the transport direction. Therefore, the printer can efficiently position the media.

[0012] In a printer, the medium has a printable area where printing is performed by the thermal head, and the distance in the transport direction from the laser sensor to the platen roller may be shorter than the distance in the transport direction from the downstream end of the printable area in the transport direction to the detection unit. The printer can shorten the distance in the transport direction between the laser sensor and the platen roller while the thermal head and the platen roller are sandwiching the medium. Therefore, the printer can efficiently position the medium.

[0013] In a printer, the case has a wall portion extending in the transport direction, which is located downstream of the storage space in the transport direction and faces the cover with a gap between them when the cover is closed to the storage space, and the transport path may be the gap. In a printer, since a part of the transport path is defined by a cover for opening and closing the storage space, media can be transported with a simple configuration.

[0014] In a printer, the laser sensor may include a light-emitting element that emits laser light toward the transported medium, and a light-receiving element positioned alongside the light-emitting element in the width direction of the medium, which receives reflected light from the medium. Compared to a case where the light-emitting element and the light-receiving element are not aligned in the width direction of the medium, the printer can shorten the distance between the laser sensor and the platen roller in the transport direction. Therefore, the printer can efficiently position the medium.

[0015] In a printer, the laser sensor may be positioned offset in the width direction from the center of the medium in the width direction. The laser sensor can detect a part to be detected that is positioned offset from the center of the medium in the width direction.

[0016] The printer may further include a filter that allows the laser light to pass through, positioned between the laser sensor and the medium conveyed by the platen roller in the direction of the laser light irradiation. The printer can prevent dust from adhering to the laser sensor.

[0017] In the printer, the laser light is an infrared laser light, and the filter may block visible light. The printer can suppress false detection of the detection unit due to visible light entering from outside the printer.

[0018] In a printer, the filter may be in contact with the laser sensor. The printer can suppress false detection of the detection area due to laser light reflected from the surface of the filter.

[0019] The printer may further include a control unit, the laser sensor detecting the downstream end of the detected part in the transport direction, and the control unit controlling the printing of the medium based on the downstream end of the detected part in the transport direction detected by the laser sensor. The printer can position the laser sensor in close proximity to the platen roller. Therefore, the printer can reduce the time for operations such as leading the sheet and shorten the time to complete printing.

[0020] In a printer, the medium has a printable area where printing is performed by the thermal head, and when the thermal head starts printing on the medium, the control unit may transport the medium upstream in the transport direction using the platen roller to detect the downstream end of the detected part in the transport direction and position the printable area in the transport direction, and then transport the medium downstream in the transport direction using the platen roller and print on the printable area with the thermal head. The printer detects the detected part and positions the printable area while transporting the medium upstream in the transport direction using the platen roller. And because the distance in the transport direction from the platen roller to the laser sensor is short, the printer can shorten the time for the head-out operation and shorten the time until printing is completed.

[0021] This is a perspective view of printer 1 with cover 3 in the open position, viewed from the upper right front. This is a plan view of printer 1 with cover 3 in the closed position. This is a perspective view of cover 3 from the lower right rear. This is a cross-sectional view of printer 1 with cover 3 in the closed position. This is a schematic diagram of the media 6 transported inside printer 1, viewed from the side. This is a schematic diagram of the media 6 transported inside printer 1, viewed from the top. This is a block diagram of the electrical configuration of printer 1. This is a flowchart of the main process. This is a schematic diagram showing a cross-section of a modified holder 33.

[0022] Hereinafter, one embodiment of the present invention will be described with reference to the drawings. The drawings are used to illustrate the technical features that the present invention may adopt. The configuration of the device shown in the drawings is not intended to be the sole limiting factor, but is merely an illustrative example. Hereafter, the upper left, lower right, lower left, upper right, lower, and upper sides of Figure 1 will be referred to as the left, right, front, rear, lower, and upper sides of the printer 1, respectively.

[0023] Referring to Figure 1, the configuration of printer 1 will be explained. Printer 1 is a thermal printer that prints onto a medium 6 using the thermal head 11 shown in Figure 4, and is a portable printer that can be carried by the user.

[0024] The external structure of printer 1 will be described with reference to Figures 1 to 3. Printer 1 comprises a housing 2, a thermal head 11, a platen roller 12, and a laser sensor 50. The housing 2 is a rectangular box shape extending in the front-to-back direction. The housing 2 houses the thermal head 11, the platen roller 12, and the laser sensor 50.

[0025] The housing 2 consists of a case 20 and a cover 3. The case 20 forms the lower part of the housing 2. The case 20 is a rectangular box shape that opens upwards. The front wall of the case 20 has an outlet 22.

[0026] The case 20 has a storage space 10. The storage space 10 is located at the rear of the case 20. The storage space 10 accommodates a roll 5 on which the medium 6 is wound. The axial direction of the roll 5 is left-right. Therefore, the width direction of the medium 6 is left-right.

[0027] The medium 6 is conveyed forward from the roll 5 towards the discharge port 22. The discharge port 22 discharges the medium 6 forward from the case 20. In this embodiment, the front is downstream in the conveying direction, and the rear is upstream in the conveying direction.

[0028] As shown in Figures 5 and 6, the medium 6 has a backing sheet 60, a label 7, and a mark 8. The backing sheet 60 is elongated. In this embodiment, the backing sheet 60 is white. In the following, unless otherwise specified, the description will be based on the state in which the medium 6 is being transported.

[0029] Multiple labels 7 are arranged on the backing sheet 60. The labels 7 are made of thermal paper that extends in the left-right direction. The multiple labels 7 are arranged in the direction of transport of the medium 6. The labels 7 are located on the bottom surface of the backing sheet 60. The center line C of the medium 6 passes through the center of the labels 7 in the left-right direction.

[0030] Multiple marks 8 are attached to the top surface of the backing sheet 60. The multiple marks 8 are arranged in the direction of transport of the medium 6. The spacing between the multiple marks 8 in the transport direction is the same as the spacing between the multiple labels 7 in the transport direction.

[0031] Mark 8 is positioned slightly downstream in the transport direction from the upstream end of label 7 in the transport direction. Mark 8 is positioned slightly to the left of the right end of label 7. Mark 8 is positioned to the right of the center line C of medium 6.

[0032] In this embodiment, mark 8 is a black rectangular pattern extending in the left-right direction.

[0033] The cover 3 is positioned above the case 20. The rear lower end of the cover 3 is rotatably supported by the rear upper end of the case 20.

[0034] The cover 3 can rotate to move between the closed position shown in Figure 2 and the open position shown in Figure 1. When the cover 3 is in the closed position, it closes off the storage space 10. When the cover 3 is in the open position, it opens up the storage space 10. In the following explanation, unless otherwise specified, the state in which the cover 3 is in the closed position shown in Figure 2 will be used as the reference point.

[0035] As shown in Figure 3, the cover 3 is a rectangular box-shaped structure with an opening at the bottom. A platen roller 12 is positioned inside the cover 3. The platen roller 12 is cylindrical with its axis oriented in the left-right direction. The radius of the platen roller 12 is, for example, 15 millimeters. As shown in Figure 6, the right end of the platen roller 12 is located to the right of the right end of the medium 6, and the left end of the platen roller 12 is located to the left of the left end of the medium 6.

[0036] The platen roller 12 is inserted onto the rotating shaft 14. The rotating shaft 14 extends in the left-right direction. The platen roller 12 is rotatable around the rotating shaft 14.

[0037] The right end of the rotating shaft 14 is located to the right of the right end of the platen roller 12. The left end of the rotating shaft 14 is located to the right of the left end of the platen roller 12. A platen gear 17 is located at the left end of the rotating shaft 14. The platen gear 17 rotates due to the drive of the transport motor 73 shown in Figure 5. The platen roller 12 rotates due to the rotation of the platen gear 17.

[0038] The cover 3 includes a base 30 and a holder 33. The base 30 is plate-shaped and extends in the front-rear direction. The front end of the base 30 is located behind the rear end of the case 20.

[0039] The holder 33 rotatably supports the platen roller 12. The holder 33 has a box body 34 and support parts 35 and 36. The box body 34 is positioned on the lower surface of the base 30. The box body 34 includes an inclined wall 37 and a side wall 39.

[0040] As shown in Figure 4, the inclined wall 37 constitutes the lower part of the box body 34. The inclined wall 37 slopes downward toward the front. The rear end of the inclined wall 37 is positioned at the lower end of the base 30. The rear end of the inclined wall 37 is located slightly forward of the center of the base 30 in the front-rear direction.

[0041] The inclined wall 37 has a hole 38. The hole 38 is located slightly behind the front end of the inclined wall 37. The hole 38 is located to the right of the center of the inclined wall 37 in the left-right direction. The hole 38 penetrates the inclined wall 37 in a direction perpendicular to the inclination direction of the inclined wall 37.

[0042] The side wall 39 extends upward from the front end of the inclined wall 37. The side wall 39 is located slightly behind the front end of the base 30.

[0043] The support portion 35 is a plate-like shape extending forward from the right end of the side wall 39. The right end of the support portion 35 is located to the right of the right end of the platen roller 12. The support portion 35 rotatably supports the rotary shaft 14.

[0044] The support portion 36 is a plate-like shape extending forward from the left end of the side wall 39. The left end of the support portion 36 is located to the left of the left end of the platen roller 12. The support portion 36 rotatably supports the rotary shaft 14.

[0045] By the support portions 35 and 36 rotatably supporting the rotary shaft 14, the platen roller 12 is rotatable about the rotary shaft 14. The platen roller 12 is located between the support portion 35 and the support portion 36 in the left-right direction. As shown in FIG. 4, the side wall 39 is located behind the rear end of the platen roller 12 with a slight gap. The side wall 39 covers a part of the side surface of the platen roller 12 in a side view.

[0046] The box body 34 houses the laser sensor 50. That is, the laser sensor 50 is arranged in the same cover 3 as the platen roller 12. As shown in FIG. 2, the laser sensor 50 is arranged to the right of the center line C passing through the center of the medium 6 being conveyed. The laser sensor 50 includes a substrate 51 and an element portion 52.

[0047] The substrate 51 has a long side extending in the left-right direction. As shown in FIG. 4, the substrate 51 has a short side extending in the inclined direction of the inclined wall 37. The substrate 51 is arranged on the upper surface of the inclined wall 37. The front end of the substrate 51 is in contact with the rear surface of the side wall 39. That is, the laser sensor 50 is located on the opposite side of the platen roller 12 across the side wall 39 and is in contact with the side wall 39.

[0048] The element portion 52 is arranged below the substrate 51. The element portion 52 is arranged inside the hole 38. The element portion 52 includes a light emitting element 53 and a light receiving element 54. As shown in FIG. 3, the light emitting element 53 and the light receiving element 54 are arranged side by side in the left-right direction.

[0049] The light-emitting element 53 is a VCSEL (Vertical Cavity Surface Emitting Laser) element. The light-emitting element 53 is capable of emitting infrared laser light. The light-emitting element 53 irradiates infrared laser light downwards and backwards through the hole 38.

[0050] The light-receiving element 54 is capable of receiving infrared laser light emitted from the light-emitting element 53. The light-receiving element 54 is a phototransistor element. The light-receiving element 54 continuously outputs a current to the CPU 61 shown in Figure 7, corresponding to the amount of infrared laser light it receives.

[0051] Referring to Figure 4, the internal structure of the printer 1 will be explained. The case 20 houses the housing wall 23, the inclined wall 25, the thermal head 11, and the cutter 40. The housing wall 23 extends in an arc shape, bulging downwards from near the upper end of the rear wall of the case 20 toward the front. The housing wall 23 defines the housing space 10.

[0052] The inclined wall 25 slopes downward toward the front. The rear end of the inclined wall 25 is connected to the front end of the housing wall 23. The direction of inclination of the inclined wall 25 is parallel to the direction of inclination of the inclined wall 37. When the cover 3 is in the closed position, the inclined wall 25 is located slightly below the inclined wall 37, with a small gap between them.

[0053] The inclined wall 25 has a recess 26. The recess 26 is located slightly behind the front end of the inclined wall 25. When the cover 3 is in the closed position, the recess 26 is located below the hole 38. Although not shown, when the cover 3 is in the closed position, the left-right position of the recess 26 is approximately the same as the left-right position of the hole 38. The infrared laser light emitted from the light-emitting element 53 is reflected by the recess 26 if there is nothing to block the infrared laser light.

[0054] The thermal head 11 is positioned in front of the inclined wall 25. The thermal head 11 is plate-shaped and extends in the left-right direction. The thermal head 11 has a plurality of heating elements 19 as shown in Figure 5. The plurality of heating elements 19 are positioned at the upper end of the thermal head 11 and are arranged in the left-right direction.

[0055] With the cover 3 in the closed position, the platen roller 12 is positioned above the thermal head 11. The platen roller 12 holds the medium 6 between itself and the thermal head 11. The platen roller 12 rotates due to the drive of the transport motor 73, and nip-transports the medium 6 forward.

[0056] The cutter 40 is located between the thermal head 11 and the discharge port 22 in the front-rear direction. The cutter 40 has a fixed blade 41 and a movable blade 42. The fixed blade 41 extends in the vertical direction. The fixed blade 41 is located above the medium 6 as it is being conveyed.

[0057] The movable blade 42 extends in the vertical direction. The movable blade 42 is located below the medium 6 as it is being transported. The movable blade 42 is movable in the vertical direction. The movable blade 42 is connected to the cutting motor 74 shown in Figure 5. Driven by the cutting motor 74, the movable blade 42 moves upward and cuts the medium 6 between itself and the fixed blade 41.

[0058] Referring to Figure 7, the electrical configuration of printer 1 will be explained. Printer 1 has a CPU 61, ROM 62, RAM 63, storage device 64, drivers 71 and 72, and an input unit 27.

[0059] The CPU 61 controls the printer 1 and functions as a control unit. The CPU 61 is connected to the ROM 62, RAM 63, storage device 64, thermal head 11, drivers 71 and 72, light-emitting element 53, light-receiving element 54, and input unit 27.

[0060] ROM 62 stores the program for executing the main process shown in Figure 8. RAM 63 temporarily stores various information. Storage device 64 is non-volatile and stores various setting information.

[0061] Driver 71 drives the transport motor 73 based on a control signal input from the CPU 61. Driver 72 drives the cutting motor 74 based on a control signal input from the CPU 61. The transport motor 73 and the cutting motor 74 are stepping motors.

[0062] The CPU 61 controls the thermal head 11 to generate heat in the multiple heating elements 19 shown in Figure 5. The CPU 61 also controls the light-emitting element 53 to emit infrared laser light.

[0063] The light-receiving element 54 outputs a current to the CPU 61 that is proportional to the amount of infrared laser light it receives. The input unit 27 receives user input and outputs a signal to the CPU 61 corresponding to the received input.

[0064] Referring to Figures 4 to 6, the printing of media 6 in printer 1 will be explained. Before printing starts, with the cover 3 in the open position, the user places the roll 5 into the storage space 10. The user feeds the media 6 forward from the roll 5 and passes it through the discharge port 22. The media 6 covers the inclined wall 25 and the thermal head 11 from above.

[0065] The user moves cover 3 to the closed position. The media 6 is placed in the gap between inclined wall 25 and inclined wall 37. The platen roller 12 sandwiches the media 6 between itself and the thermal head 11. The user inputs a print command to printer 1 via input unit 27.

[0066] The CPU 61 drives the transport motor 73 in response to a print command, rotating the platen roller 12. As the platen roller 12 rotates, the medium 6 is transported upstream in the transport direction through the gap between the inclined wall 25 and the inclined wall 37. The gap between the inclined wall 25 and the inclined wall 37 is called the transport path 24. The transport path 24 is located between the storage space 10 and the platen roller 12 in the transport direction. In the following description, the rotation of the platen roller 12 that transports the medium 6 downstream in the transport direction is called forward rotation. The rotation of the platen roller 12 that transports the medium 6 upstream in the transport direction is called reverse rotation.

[0067] The laser sensor 50 is positioned on the transport path 24 in the transport direction. As shown in Figure 5, the transport distance L1 from the laser sensor 50 to the platen roller 12 is shorter than the transport distance L2 from the downstream end of the label 7 to the mark 8 in the transport direction. Distance L1 is, for example, the transport distance from the center of the element section 52 in the transport direction to the center of the platen roller 12 in the transport direction. Distance L1 is, for example, 15 millimeters, and distance L2 is, for example, 28 millimeters. The transport length of the label 7 is, for example, 30 millimeters.

[0068] The CPU 61 causes the light-emitting element 53 to emit light. The light-emitting element 53 irradiates infrared laser light toward the medium 6 being transported along the transport path 24.

[0069] As shown in Figure 4, the laser sensor 50 is positioned closer to the platen roller 12 than to the storage space 10 on the transport path 24. Therefore, as shown in Figure 6, the region A in the medium 6 that is irradiated with infrared laser light is located slightly upstream of the platen roller 12 in the transport direction. The size of region A is sufficiently small compared to the size of mark 8.

[0070] The light-receiving element 54 receives reflected infrared laser light. The base paper 60 is white, and the mark 8 is black. Therefore, the magnitude of the current output when the light-receiving element 54 receives reflected light reflected by the base paper 60 is different from the magnitude of the current output when the light-receiving element 54 receives reflected light reflected by the mark 8.

[0071] The CPU 61 detects the mark 8 based on the magnitude of the current output from the light-receiving element 54. In this embodiment, the CPU 61 detects the downstream end of the mark 8 in the transport direction while transporting the medium 6 upstream in the transport direction. Thereafter, the CPU 61 controls the position of the medium 6 in the transport direction based on the detected mark 8.

[0072] When the CPU 61 detects mark 8, it continues to transport the medium 6 upstream in the transport direction while positioning the label 7 on the medium 6. In positioning the label 7, the label 7 is positioned so that its downstream end in the transport direction is sandwiched between the thermal head 11 and the platen roller 12. The CPU 61 positions the label 7 based on the downstream end of mark 8 in the transport direction detected by the laser sensor 50.

[0073] Once the positioning of the label 7 is complete, the drive of the transport motor 73 is stopped, and the rotation of the platen roller 12 is stopped. The CPU 61 drives the transport motor 73 to rotate the platen roller 12 in the forward direction. The medium 6 is transported downstream in the transport direction.

[0074] The CPU 61 selectively heats up multiple heating elements 19 of the thermal head 11, allowing the printer 1 to perform thermal printing on the label 7 while transporting the medium 6. The CPU 61 controls the timing of heating of the multiple heating elements 19 based on the downstream end of the mark 8 in the transport direction detected by the laser sensor 50.

[0075] When printing is complete, the CPU 61 stops driving the transport motor 73 and stops the rotation of the platen roller 12. The transport of the medium 6 is stopped. The CPU 61 drives the cutting motor 74 and moves the movable blade 42 to the information. The cutter 40 cuts the medium 6. The user removes the printed medium 6 from the discharge port 22.

[0076] Referring to Figure 8, the main processing performed by the CPU 61 will be explained. When the user inputs a print command to the CPU 61 via the input unit 27, the CPU 61 reads the main processing program from the ROM 62. The CPU 61 then starts the main processing.

[0077] When the main processing starts, the CPU 61 starts transporting the medium 6 upstream in the transport direction (S1). In the process of S1, the CPU 61 drives the transport motor 73 to start the platen roller 12 rotating in the reverse direction. The CPU 61 determines whether or not it has detected the downstream end of the mark 8 in the transport direction (S3). If the CPU 61 determines that it has not detected the downstream end of the mark 8 in the transport direction (S3: NO), it returns to processing S3.

[0078] If the CPU 61 determines that it has detected the downstream end of the mark 8 in the transport direction (S3: YES), it positions the label 7 on the medium 6 (S5). In the process of S5, the CPU 61 transports the medium 6 upstream in the transport direction and positions the downstream end of the label 7 in the transport direction to be sandwiched between the thermal head 11 and the platen roller 12.

[0079] The upstream transport of the medium 6 in the transport direction is stopped (S7). In the process of S7, the CPU 61 stops the drive of the transport motor 73, thereby stopping the reverse rotation of the platen roller 12.

[0080] The CPU 61 starts transporting the medium 6 downstream in the transport direction (S9). In the process of S9, the CPU 61 drives the transport motor 73 to start the platen roller 12 rotating in the forward direction. The CPU 61 prints on the label 7 of the medium 6 using the thermal head 11 (S11).

[0081] The CPU 61 determines whether printing on the medium 6 is complete (S13). If the CPU 61 determines that printing on the medium 6 is not complete (S13: NO), it returns to processing S13. If the CPU 61 determines that printing on the medium 6 is complete (S13: YES), it stops the downstream transport of the medium 6 in the transport direction (S15). In processing S15, the CPU 61 stops the forward rotation of the platen roller 12 by stopping the drive of the transport motor 73.

[0082] The CPU 61 cuts the medium 6 (S17). In the process of S17, the CPU 61 drives the cutting motor 74 to cut the medium 6 with the cutter 40. The CPU 61 then finishes the main process.

[0083] As described above, the printer 1 comprises a case 20, a cover 3, a thermal head 11, a platen roller 12, and a laser sensor 50. The case 20 has a storage space 10 for housing the medium 6. The cover 3 opens and closes the storage space 10. The thermal head 11 is positioned in the case 20 and prints on the medium 6. The platen roller 12 transports the medium 6 between itself and the thermal head 11. The laser sensor 50 detects the marks 8 and is used to position the medium 6. The platen roller 12 and the laser sensor 50 are located on the same side of the case 20 and the cover 3. Compared to the case where the laser sensor 50 is located on a different side from the platen roller 12, the printer 1 can shorten the distance between the laser sensor 50 and the platen roller 12 in the transport direction. Therefore, the printer 1 can efficiently position the medium 6.

[0084] In printer 1, the platen roller 12 and the laser sensor 50 are located in the cover 3. Compared to the case 20 which has a housing space 10, the cover 3 makes it easier to secure space for the platen roller 12 and the laser sensor 50. Therefore, printer 1 can more easily shorten the distance in the transport direction between the laser sensor 50 and the platen roller 12. Thus, printer 1 can efficiently position the media 6.

[0085] In printer 1, the cover 3 has a holder 33. The holder 33 rotatably supports the platen roller 12. The holder 33 includes a side wall 39. In a side view, the side wall 39 covers a portion of the side surface of the platen roller 12. The laser sensor 50 is located on the opposite side of the platen roller 12, with the side wall 39 in between, and is in contact with the side wall 39. With a simple configuration, printer 1 can shorten the distance between the laser sensor 50 and the platen roller 12 in the transport direction. Therefore, printer 1 can efficiently position the media 6.

[0086] In printer 1, the laser sensor 50 is positioned on the transport path 24 in the transport direction. Printer 1 can more easily shorten the distance between the laser sensor 50 and the platen roller 12 in the transport direction. Therefore, printer 1 can efficiently position the media 6.

[0087] In printer 1, the laser sensor 50 is positioned closer to the platen roller 12 than to the storage space 10 on the transport path 24. Printer 1 can more easily shorten the distance between the laser sensor 50 and the platen roller 12 in the transport direction. Therefore, printer 1 can efficiently position the media 6.

[0088] In printer 1, the distance L1 in the transport direction from the laser sensor 50 to the platen roller 12 is shorter than the distance L2 in the transport direction from the downstream end of the label 7 to the mark 8. With the thermal head 11 and the platen roller 12 sandwiching the medium 6, printer 1 can shorten the distance in the transport direction between the laser sensor 50 and the platen roller 12. Therefore, printer 1 can efficiently position the medium 6.

[0089] In printer 1, the case 20 has an inclined wall 25. The inclined wall 25 is positioned downstream of the storage space 10 in the transport direction. When the cover 3 is in the closed position, the inclined wall 25 faces the inclined wall 37 of the cover 3 with a gap between them. The gap between the inclined wall 25 and the inclined wall 37 is the transport path 24 through which the medium 6 is transported. In printer 1, a portion of the transport path 24 is defined by the cover 3 for opening and closing the storage space 10. Therefore, printer 1 can transport the medium 6 with a simple configuration.

[0090] In printer 1, the laser sensor 50 has a light-emitting element 53 and a light-receiving element 54. The light-emitting element 53 irradiates infrared laser light toward the conveyed medium 6. The light-receiving element 54 receives the reflected infrared laser light reflected by the medium 6. The light-emitting element 53 and the light-receiving element 54 are arranged in the left-right direction, which is the width direction of the medium 6. Compared to the case where the light-emitting element 53 and the light-receiving element 54 are not arranged in the width direction of the medium 6, printer 1 can reduce the size of the element section 52 in the conveying direction. Therefore, printer 1 can more easily shorten the distance between the laser sensor 50 and the platen roller 12 in the conveying direction. Thus, printer 1 can efficiently position the medium 6.

[0091] In printer 1, the laser sensor 50 is positioned to the right of the center line C of the media 6. The laser sensor 50 can detect marks 8 that are positioned off-center from the widthwise center of the media 6.

[0092] In printer 1, the laser sensor 50 detects the downstream end of the mark 8 in the transport direction. Based on the downstream end of the mark 8 in the transport direction detected by the laser sensor 50, the CPU 61 controls the timing of heating of the multiple heating elements 19. In printer 1, because the laser sensor 50 detects the downstream end of the mark 8 in the transport direction, the distance between the laser sensor 50 and the platen roller 12 in the transport direction can be shortened. Therefore, printer 1 can efficiently position the medium 6 and shorten the time until printing is completed.

[0093] In printer 1, when the CPU 61 starts printing on the medium 6, the platen roller 12 causes the medium 6 to be transported upstream in the transport direction (S1). The CPU 61 detects the downstream end of the mark 8 while transporting the medium 6 upstream in the transport direction (S3). The CPU 61 positions the label 7 while transporting the medium 6 upstream in the transport direction (S5). The CPU 61 causes the platen roller 12 to transport the medium 6 downstream in the transport direction (S9). The CPU 61 prints on the label 7 while transporting the medium 6 (S11). For example, the CPU 61 may detect the upstream end of the mark 8. In this case, the CPU 61 first detects the upstream end of the mark 8 while transporting the medium 6 downstream in the transport direction. The CPU 61 then positions the label 7 while transporting the medium 6 upstream in the transport direction with the platen roller 12. The CPU 61 then prints on the label 7 while transporting the medium 6 downstream in the transport direction. Thus, since the rotation of the platen roller 12 is reversed when detecting the upstream end of mark 8 and when positioning the label 7, the CPU 61 needs to stop the drive of the transport motor 73 once. On the other hand, the CPU 61 detects the downstream end of mark 8 using the laser sensor 50. While the platen roller 12 transports the medium 6 upstream in the transport direction, the CPU 61 detects the downstream end of mark 8 and positions the label 7. In this way, the CPU 61 detects the downstream end of mark 8 and positions the label 7 without stopping the drive of the transport motor 73. Therefore, the printer 1 can efficiently position the medium 6 and shorten the time until printing is completed.

[0094] The present invention can be modified in various ways from the above embodiments. The various modifications described below can be combined in any way, as long as they do not create contradictions.

[0095] As shown in Figure 9, the printer 1 further includes a filter 59. The filter 59 transmits infrared laser light and blocks the transmission of visible light. Hereinafter, the direction in which the light-emitting element 53 irradiates the infrared laser light toward the medium 6 will be referred to as the irradiation direction.

[0096] The holder 33's housing 34 further has a protrusion 58. The protrusion 58 projects inward into the hole 38 from the end of the inclined wall 37 in the direction of illumination. The protrusion 58 covers a portion of the hole 38.

[0097] The filter 59 is positioned on the protruding portion 58. In the irradiation direction, the filter 59 is located between the laser sensor 50 and the transported medium 6. The filter 59 is in contact with the element portion 52 of the laser sensor 50.

[0098] In the modified printer 1, the filter 59 is positioned between the laser sensor 50 and the transported medium 6, thereby suppressing dust from adhering to the laser sensor 50. Dust is generated, for example, by friction when the backing paper 60 is transported.

[0099] Furthermore, since the filter 59 blocks the transmission of visible light, the printer 1 can prevent false detection of the mark 8 due to visible light entering, for example, from the output port 22.

[0100] Furthermore, since the filter 59 is in contact with the element portion 52 of the laser sensor 50, the printer 1 can suppress false detection of the mark 8 by infrared laser light reflected from the surface of the filter 59.

[0101] Other variations will be described. The thermal head 11 is not limited to being located in the case 20, and the platen roller 12 and laser sensor 50 are not limited to being located in the cover 3. The thermal head 11 may be located in the cover 3, and the platen roller 12 and laser sensor 50 may be located in the case 20.

[0102] The laser sensor 50 only needs to be positioned upstream of the platen roller 12 in the transport direction and does not need to be in contact with the rear surface of the side wall 39. In this case, the holder 33's casing 34 does not need to include the side wall 39.

[0103] The laser sensor 50 is not limited to being positioned on the transport path 24 in the transport direction. The laser sensor 50 may be positioned closer to the storage space 10 than the platen roller 12 in the transport path 24.

[0104] The transport path 24 does not necessarily have to be defined by the inclined wall 25 of the case 20 and the inclined wall 37 of the cover 3. For example, the case 20 may have a wall that is vertically opposite to the inclined wall 25, and the transport path 24 may be the gap between the inclined wall 25 and that wall.

[0105] In the above embodiment, the light-emitting element 53 and the light-receiving element 54 are arranged in the left-right direction, but they may also be arranged in the front-back direction. The laser sensor 50 is not limited to a reflective type sensor. The laser sensor 50 may also be a transmissive type sensor in which the light-receiving element 54 is located on the opposite side of the medium 6 from the light-emitting element 53.

[0106] The light-emitting element 53 only needs to emit laser light and is not limited to emitting infrared laser light. For example, the light-emitting element 53 may emit a visible light laser. The light-emitting element 53 is not limited to a VCSEL element and may be, for example, an end-face emitting semiconductor laser element.

[0107] The light-receiving element 54 only needs to output a current of a magnitude corresponding to the amount of light received, and is not limited to a phototransistor element. The light-receiving element 54 may be, for example, a photodiode element.

[0108] The form of Mark 8 may be changed as appropriate. The color of Mark 8 is not limited to black and may be changed as appropriate depending on the color of the backing paper 60 or the color of the label 7. For example, if the color of the backing paper 60 is black, Mark 8 may be white.

[0109] In the above embodiment, the laser sensor 50 detected the mark 8 attached to the backing paper 60, but the object detected by the laser sensor 50 is not limited to the mark 8. For example, the laser sensor 50 may detect a hole that penetrates the backing paper 60 in the thickness direction of the backing paper 60. In this case, the laser sensor 50 is preferably a through-type sensor, but it may also be a reflective type sensor. The laser sensor 50 may also detect the label 7, the edge of the medium 6, etc. The laser sensor 50 may be positioned to coincide with the center line C of the medium 6.

[0110] The configuration of printer 1 may be changed as appropriate. The transport motor 73 does not have to be a stepping motor; for example, it may be a brushless DC motor. The CPU 61 may be connected to an encoder that detects the rotational position of the rotation axis of the transport motor 73.

[0111] The cutting motor 74 does not have to be a stepping motor; for example, it could be a brushless DC motor. The CPU 61 may be connected to an encoder that detects the rotational position of the rotation axis of the cutting motor 74.

[0112] In the above embodiment, the cutter 40 may have a support base instead of a fixed blade 41. In this case, the cutter 40 contacts the support base to cut the medium 6. The printer 1 does not need to have a cutter 40. The printer 1 does not need to have an input unit 27.

[0113] The medium 6 does not have to be wound. In this case, the storage space 10 may contain, for example, fanfold paper in which the medium 6 is folded. The medium 6 may also be cut paper. The medium 6 may have a plastic sheet instead of a backing board 60.

[0114] The medium 6 does not necessarily have a label 7. In this case, the medium 6 is preferably a thermal medium printed by the thermal head 11. The shapes of the medium 6 and the label 7 may be changed as appropriate.

[0115] The printer 1 may use, for example, a microcomputer, ASIC (Application Specific Integrated Circuits), FPGA (Field Programmable Gate Array), etc., for control instead of the CPU 61. The main processing may be distributed using multiple CPUs 61, or it may be processed by combining the CPU 61 with an ASIC, etc.

[0116] Non-temporary storage media such as ROM 62 and storage device 64 can be any storage medium capable of retaining information regardless of the period for which the information is stored. Non-temporary storage media do not necessarily have to include temporary storage media (e.g., transmitted signals). Programs for executing the main processing may be downloaded from a server connected to a network (i.e., transmitted as a transmission signal) and stored in storage device 64, etc. In this case, the programs may be stored on a non-temporary storage medium such as an HDD provided on the server.

[0117] Mark 8 is an example of the "detected part" of the present invention. The left-right direction is an example of the "axial direction" and "width direction" of the present invention. The side wall 39 is an example of the "holder wall" of the present invention. Label 7 is an example of the "printed area" of the present invention. The inclined wall 25 is an example of the "case wall" of the present invention. CPU 61 is an example of the "control unit" of the present invention.

[0118] 1 Printer 3 Cover 10 Enclosure 11 Thermal head 12 Platen roller 20 Case 50 Laser sensor

Claims

A case having a containment space for accommodating a medium having a detection unit, A cover for opening and closing the aforementioned storage space, A thermal head, which is placed in either the case or the cover, and prints on the medium, A platen roller is positioned in either the case or the cover, and transports the medium between itself and the thermal head, A laser sensor is positioned upstream of the platen roller in the transport direction of the medium in either the case or the cover, and detects the part to be detected by irradiating laser light toward the medium being transported by the platen roller. A printer characterized by having the following features. 　 The thermal head is placed in the case. The printer according to claim 1, characterized in that the platen roller and the laser sensor are arranged in the cover. 　 The cover has a holder that rotatably supports the platen roller and includes a holder wall that covers a portion of the side surface of the platen roller when viewed from the axial direction of the platen roller. The laser sensor is located on the opposite side of the platen roller from the holder wall and is in contact with the wall. The printer according to claim 2, characterized by the following: 　 The medium is transported along the transport path between the containment space and the platen roller. The printer according to claim 1, characterized in that the laser sensor is arranged on the transport path in the transport direction. 　 The printer according to claim 4, characterized in that the laser sensor is positioned closer to the platen roller than the storage space in the transport path. 　 The medium has a printable area on which printing is performed by the thermal head, The printer according to claim 1, characterized in that the distance in the transport direction from the laser sensor to the platen roller is shorter than the distance in the transport direction from the downstream end in the transport direction in the area to be printed to the detection unit. 　 The case has a case wall extending in the transport direction, which is positioned downstream of the storage space in the transport direction and faces the cover with a gap between them when the cover is closed to the storage space. The printer according to claim 4, characterized in that the transport path is the gap. 　 The aforementioned laser sensor is A light-emitting element that emits the laser light toward the medium being transported, A light-receiving element is arranged in the width direction of the medium, alongside the light-emitting element, and receives reflected light from the laser light reflected by the medium. A printer according to any one of claims 1 to 7, characterized by having [a certain feature]. 　 The printer according to any one of claims 1 to 7, characterized in that the laser sensor is positioned offset in the width direction from the center of the medium in the width direction. 　 The printer according to any one of claims 1 to 7, further comprising a filter that allows the laser light to pass through, which is disposed between the laser sensor and the medium conveyed by the platen roller in the direction of irradiation of the laser light. 　 The aforementioned laser light is infrared laser light, The printer according to claim 10, characterized in that the filter blocks visible light. 　 The printer according to claim 10, characterized in that the filter is in contact with the laser sensor. 　 Further equipped with a control unit, The laser sensor detects the downstream end of the detected part in the transport direction, The control unit controls the printing of the medium based on the downstream end of the detected part in the transport direction detected by the laser sensor. A printer according to any one of claims 1 to 7, characterized by the following: 　 The medium has a printable area on which printing is performed by the thermal head, The control unit, when the thermal head starts printing on the medium, The platen roller transports the medium upstream in the transport direction to detect the downstream end of the detected part in the transport direction and to position the printed area in the transport direction. The platen roller conveys the medium downstream in the conveying direction, and the thermal head prints on the area to be printed. The printer according to claim 13, characterized by the following:

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