Patent Publication Number: US-11396193-B2

Title: Label printer and label printer control method

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2020-004633, filed on Jan. 15, 2020, the entire contents of which are incorporated herein by reference. 
     FIELD 
     Embodiments described herein relate generally to a label printer and a label printer control program. 
     BACKGROUND 
     A label printer issues a label by executing printing on labels attached to a label mount, a backing sheet or the like. Such a label mount, backing sheet, or the like may be in the form a roll or the like. If a sensor detects a label that has been peeled off from a label mount while in a continuous label issuing mode, the printing operation can be stopped to prevent accidental entanglement, loss, or the like of the peeled-off label. After the temporary halt in the printing operation, a user generally must press one or more buttons to perform a position adjustment feeding to adjust a position of the labels or the label mount being fed for printing and then instruct the printer to resume the printing operation. 
     In such a label printer, however, even in a case where the possibility of accidental label entanglement is low (for example, in a case where a label has been totally peeled off and is not present on a label mount), the printing operation is stopped irrespective of a peel-off state or the degree of peel-off of a label. This causes a frequent interruption of the label printing whenever a label peel-off, whether partial or total, is detected, and a user has to adjust the feeding position, spending extra time and effort every time the label printing comes to an unexpected halt. 
     Hence, there is a need for a label printer and a label printer control program that can determine suitability of continuation of a printing operation depending on a peel-off state of a label from a mount. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  depicts a label printer in a perspective view according to an embodiment. 
         FIG. 2  depicts an internal configuration of a label printer in a cross-sectional view according to an embodiment. 
         FIG. 3  is a block diagram of a configuration of a label printer according to an embodiment. 
         FIG. 4  depicts an example case of a “no peel-off” state according to an embodiment. 
         FIGS. 5A, 5B, and 5C  depict example outputs of sensors at three positions along a width direction of the mount according to an embodiment. 
         FIG. 6  depicts an example case of a “partial peel-off” state according to an embodiment. 
         FIGS. 7A, 7B, and 7C  depict example outputs of sensors at three positions along a width direction of a label mount. 
         FIG. 8  depicts an example case of a “partial peel-off” state according to an embodiment. 
         FIGS. 9A, 9B, and 9C  depict of example outputs of sensors at three positions along a width direction of a label mount. 
         FIG. 10  depicts an example case of a “total peel-off” state according to an embodiment. 
         FIGS. 11A, 11B, and 11C  depict example outputs of sensors at three positions along a width direction of a label. 
         FIG. 12  is a flowchart of an operation of a label printer according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     In general, according to an embodiment, a label printer for printing labels attached to a mount is provided. The label printer includes a detection unit configured to detect a peel-off state of a label to be printed, and a printing unit configured to control printing of labels on the mount according to the detected peel-off state of the label to be printed. The printing unit is configured to advance the mount to a next label on the mount if the detected peel-off state of a label is total peel-off. When the detected peel-off state is partial peel-off, the printing unit is configured to not print on the label. 
     Hereinafter, embodiments of a label printer, a label printer control method, and a label printer control program will be described with reference to the accompanying drawings. These example embodiments are non-limiting with respect to the present disclosure. 
       FIG. 1  depicts a label printer  1  according to one embodiment. As illustrated in  FIG. 1 , the label printer  1  includes a left case  2  and a right case  8 . The right case  8  is connected to the right side of the left case  2  by hinges  7 . A front panel  3  of the left case  2  includes a display unit  4  and an operation unit  5 . The display unit  4  comprises, for example, a liquid crystal display with a backlight unit. Other types of a display device may be used. The operation unit  5  includes a plurality of operation buttons  6 . 
     The right case  8  opens by rotation of the hinges  7  to expose the inside of a printer housing that comprises the left and right cases  2  and  8 . As shown in  FIG. 2 , in the printer housing, the label printer  1  includes a label paper  20  that is wound in a roll shape, an ink ribbon  30  that bridges over two shafts, and a printing unit  23  that executes printing on the ink ribbon  30 . The label printer  1  according to the present embodiment allows easy access to the internal components by the hinge rotation to widely open the housing such that replacement or maintenance of, for example, the ink ribbon  30  or the label paper  20  can be smoothly done. A label issuing port  10  is provided in a front panel  9  of the right case  8 . The label printer  1  issues a printed label from the label issuing port  10 . 
       FIG. 2  is a schematic cross-sectional view illustrating an internal configuration of the label printer  1  according to one embodiment. As illustrated in  FIG. 2 , besides the label paper  20 , the ink ribbon  30 , and the printing unit  23 , the label printer  1  includes, in the housing, a paper holding unit  21 , a paper conveying unit  22 , a frame  26 , and an ink ribbon supply device  27 . The label printer  1  also includes sensors  50  on a conveyance path  24  between the paper conveying unit  22  and the printing unit  23  in the housing. 
     The paper holding unit  21  is a shaft that winds and holds the label paper  20  in a roll shape. The label paper  20  is drawn from the paper holding unit  21  along the paper conveying unit  22  and is printed by the printing unit  23 . The printed label paper  20  is discharged from the label issuing port  10 . The label paper  20  has a plurality of labels attached in a row to a label mount, for example. 
     The paper conveying unit  22  includes a paper conveying roller  41 , a pinch roller  42 , a frame  43 , a support unit  44 , and a plate spring  45 . The pinch roller  42  is rotatable and supported by the support unit  44 . The paper conveying roller  41  and the pinch roller  42  abut against each other via the label paper  20  that is being conveyed therebetween along the conveyance path  24 . The paper conveying roller  41  is rotatable and attached to the frame  26  and is driven to rotate by a driving structure, a driver, or the like (not separately depicted). 
     The support unit  44  is pivotable and attached to the frame  43 . One end of the plate spring  45  is attached to the frame  43 , and another end of the plate spring  45  abuts against the pinch roller  42 . The pinch roller  42  is configured to be biased toward the plate spring  45  and to abut against the paper conveying roller  41 . 
     The conveyance path  24  of the label paper  20  starts from a position where the label paper  20  is drawn from the paper holding unit  21 . The conveyance path  24  passes through a position where the pinch roller  42  and the paper conveying roller  41  abut against each other in the paper conveying unit  22 . Further, the conveyance path  24  passes through a position where a print head  32  and a platen  31  of the printing unit  23  abut against each other and ends at the label issuing port  10 . 
     In the conveyance path  24 , a label peeling plate  25  is also provided downstream of the printing unit  23  in a conveying direction. The label peeling plate  25  bends the label paper  20  while being conveyed along the conveyance path and peels off a label from a label mount. The peeled off mount is wound around a winding shaft (not separately depicted), and the label peeled off from the mount is issued from the label issuing port  10 . 
     The printing unit  23  includes the platen  31  and the print head  32 . The print head  32  may be, for example, a line thermal printer. The configuration of the print head  32  corresponds to a print method of the label printer  1 . For example, in the case of a dot impact printer, a dot impact print head  32  is used. The platen  31  is rotatable and attached to the frame  26  and is driven to rotate by a driving unit, a driver, or the like (not separately depicted). 
     The print head  32  is fixed to a head holding unit  33  that is rotatable and attached to a frame (not separately depicted). 
     The ink ribbon supply device  27  includes a ribbon holding shaft  35 , a ribbon winding shaft  36 , a ribbon end sensor  34 , and a guide frame  37 . The ribbon holding shaft  35  winds the unused, new ink ribbon  30  in a roll shape. The ink ribbon supply device  27  also includes a guide roller  38  at an end portion of the guide frame  37  on the ribbon holding shaft  35  side. The guide roller  38  guides the ink ribbon  30  drawn from the ribbon holding shaft  35 . The guide roller  38  is rotatably disposed in the guide frame  37 . 
     The ink ribbon  30  before printing abuts against the guide roller  38 , passes through a detection target region of the ribbon end sensor  34 , reaches a position where the print head  32  and the platen  31  abut against each other, and is transferred onto the label paper  20  by the print head  32 . The printed ink ribbon  30  abuts against an end portion  39  of the guide frame  37  on the ribbon winding shaft  36  side and is wound and recovered by the ribbon winding shaft  36 . 
     A conveyance path  28  of the ink ribbon  30  starts from a position where the ink ribbon  30  is drawn from the ribbon holding shaft  35  and passes through a position where the ink ribbon  30  abuts against the guide roller  38  of the guide frame  37 . The conveyance path  28  passes through the detection target region of the ribbon end sensor  34  and a position (that is, a print position) where the print head  32  and the platen  31  abut against each other in this order. Further, the conveyance path  28  passes through a position where the ink ribbon  30  abuts against the end portion  39  of the guide frame  37  and ends at a position where the ink ribbon  30  is wound around the ribbon winding shaft  36 . 
     The ribbon end sensor  34  detects a ribbon end, that is, a leading end portion of the ink ribbon  30 . As illustrated in  FIG. 2 , the ribbon end sensor  34  is disposed on the conveyance path  28  between the printing unit  23  and the ribbon holding shaft  35 . In one embodiment, the ribbon end sensor  34  may be provided along the conveyance path  28  of the ink ribbon  30  and is provided between the guide roller  38  and the printing unit  23  in the conveyance path  28 . In another embodiment, the ribbon end sensor  34  may be provided between the guide roller  38  and a position where the print head  32  and the platen  31  abut against each other (that is, a print position or an ink/image transfer position) in the printing unit  23 . 
     In the case where the guide frame  37  does not have the guide roller  38 , the ribbon end sensor  34  may be provided between the end portion of the guide frame  37  on the ribbon holding shaft  35  side and the position where the print head  32  and the platen  31  abut against each other. 
     As the ribbon end sensor  34 , an optical sensor that optically detects the ink ribbon  30  may be used. As another example of the ribbon end sensor  34 , a reflected light sensor including a light emitting element and a light receiving element may be used. As still another example of the ribbon end sensor  34 , a sensor that mechanically detects the ink ribbon  30  may be used. Examples of the ribbon end sensor  34  are not limited to these. 
     The sensors  50  are, for example, a plurality of transmission sensors arranged in a width direction of the label mount or the label of the label paper  20 . Each of the sensors  50  detects light transmitted through the label paper  20  and outputs a signal of an increase or decrease in transmitted light intensity depending on the conveyance of the label paper  20 . In one embodiment, each of the sensors  50  comprises a pair of a light emitting unit  50   a  and a light receiving unit  50   b . The light emitting unit  50   a  emits light to the label and the mount. The light receiving unit  50   b  receives light that is emitted from the light emitting unit  50   a  and transmits through the label and the mount and outputs an electrical signal that changes depending on the intensity of the received light (that is transmitted light intensity). 
     In the present embodiment, for convenience of description, the sensors  50  are provided at three positions at regular intervals in the width direction of the mount of the label paper  20 . This configuration is merely exemplary, and the number of the sensors  50  is not limited so long as there is at least one sensor  50 . In the present embodiment, each sensor  50  is fixedly positioned. In another embodiment, the sensor  50  may be configured to be movable in the width direction. In the present embodiment, each sensor  50  is a transmission sensor as one example. Other examples of the sensor  50  include but not limited to a reflective sensor. 
       FIG. 3  is a block diagram illustrating a part of the configuration of the label printer  1  according to one embodiment. As illustrated in  FIG. 3 , the label printer  1  includes a CPU  61 , a ROM  62 , and a RAM  63 . The CPU  61  is connected to a communication interface (I/F)  64 , a display controller  65 , an operation unit controller  66 , a head driver  67 , motor drivers  68 ,  69 ,  71 , and  72 , and the ribbon end sensor  34  via a bus or an interface. 
     The display unit  4  is connected to the display controller  65 . The operation unit  5  is connected to the operation unit controller  66 . The print head  32  is connected to the head driver  67 . The print head  32  includes heating elements provided in a line in a direction perpendicular to the conveying direction of the label paper  20 . The head driver  67  switches between ON and OFF of energization of the heating elements of the print head  32  based on print data and thermally transfers a print image to the label paper  20 . 
     A platen motor  81  that drives the platen  31  of the printing unit  23  to rotate is connected to the motor driver  68 . A conveyance motor  82  that drives the paper conveying roller  41  of the paper conveying unit  22  to rotate is connected to the motor driver  69 . A feed motor  83  that drives the ribbon holding shaft  35  to rotate is connected to the motor driver  71 . A winding motor  84  that drives the ribbon winding shaft  36  to rotate is connected to the motor driver  72 . The configuration of each of the motors is not limited so long as each motor performs the necessary function for the label printer  1  to perform the label printing. Examples of the motor include but not limited to a stepping motor. 
     The ROM  62  stores a program or programs (hereinafter collectively referred to as a program) to be executed by the CPU  61  or the like of the label printer  1  and various data upon the execution of the program. The RAM  63  is a memory for loading that temporarily stores the program and the data upon the program execution. The communication I/F  64  connects the label printer  1  with a host computer (not separately depicted) and controls data communication between the label printer  1  and the host computer. The host computer transmits print data, a print command, or the like to the RAM  63  via the communication I/F  64 . In another instance, the print data may be input via the operation unit  5 . 
     In one instance, the program is provided by being incorporated into the ROM  62  or the like in advance. In another instance, the program may be provided by being recorded in a non-transitory computer-readable recording medium such as a CD-ROM, a flexible disk (FD), a CD-R, or a Digital Versatile Disk (DVD) in a file format that is installable to and executable by a computer or the label printer  1 . 
     In still another instance, the program may be stored in a computer connected to a network such as the Internet in advance and may be downloaded from the computer via the network for use by the label printer  1 . The program may be provided or distributed by a network such as the Internet. 
     As illustrated in  FIG. 3 , the program to be executed by the CPU  61  of the label printer  1  according to the present embodiment has a module configuration including a print control unit  52 , a detection control unit  51 , and a motor control unit  53 . The CPU  61  (or a processor) reads the program from a storage medium such as the ROM  62  and loads the respective units of the program to a main memory such as the RAM  63 . As a result, the detection control unit  51 , the print control unit  52 , the motor control unit  53  are generated on the main memory. 
     The detection control unit  51  is an example of a detection unit configured to detect a peel-off state of a label from a label mount before the print control unit  52  performs a printing process. The detection control unit  51  detects whether the label on the label mount of the print paper  20  that is about to be conveyed to the printing unit  23  ( FIG. 2 ) is in a “no peel-off” state, or in a “partial peel-off” state, or in a “total peel-off” state, based on the electrical signals output from the sensors  50 . 
       FIG. 4  depicts an example case where the peel-off state of a label  55  from a mount  56  indicates “no peel-off” according to one embodiment. An arrow indicates the conveying direction of the mount  56  along the conveyance path  24  in the label printer  1 , and A, B, and C indicate three positions of the sensors  50  provided in the width direction of the mount  56 , respectively. The same shall be applied to  FIGS. 6, 8, and 10 . 
       FIGS. 5A, 5B, and 5C  depict example output signals from the sensors  50  provided at the three positions A, B, and C in  FIG. 4 . In each of the graphs, an increase or decrease in the output signal of each sensor  50  corresponds to an increase or decrease in transmitted light intensity. The same applies for the depictions in  FIGS. 7A-7C, 9A-9C, and 11A-11C . 
     In the example of  FIG. 4 , the label  55  does not have any portion thereof peeled off from the mount  56 . In this case, as illustrated in  FIGS. 5A-5C , the output signal of each of the sensors  50  increases at a trailing edge portion  54   b  of a label  54 , that is a previous label located immediately before the label  55  on the mount  56 , and decreases at a leading edge portion  55   a  of the label  55 . The output signal shows a maximum value at a center portion Q of a gap portion between the label  54  and the label  55  where only the mount  56  is present. The portion of the output signal curve including the maximum value will be referred to as a peak P of the output signal. A portion indicated by symbol S in  FIG. 5  is a threshold S. The threshold S is a value used by the detection control unit  51  to recognize an edge such as the leading edge portion  55   a  or a trailing edge portion  55   b  of the label  55  and may be set to an arbitrary value. 
     In consideration of the fact that the transmitted light intensity rapidly increases at a position where the label  55  changes to the mount  56  on the label paper  20  and rapidly decreases at a position where the mount  56  changes to the label  55  on the label paper  20 , the detection control unit  51  detects the leading edge portion  55   a  and the trailing edge portion  55   b  of the label  55  at each of the positions A, B, and C based on the output of each of the sensors  50  and determines the peel-off state based on the detection result. 
     The detection control unit  51  determines a position where the output of each of the sensors  50  increases passing the threshold S as the trailing edge portion  54   b  of the label  54  at each of the positions A, B, and C. The detection control unit  51  determines a position where the output of each of the sensors  50  decreases passing the threshold S as the leading edge portion  55   a  of the label  55 . The trailing edge portion  54   b  of the label  54  and the leading edge portion  55   a  of the label  55  are, respectively, the start and end of the gap portion between the label  54  and the label  55  on the mount  56  exists. 
     The detection control unit  51  detects the peel-off state of the label  55  based on the length of a period where the output of each of the sensors  50  falls below the threshold S after the peak P. For example, based on the output curve of each sensor  50  as shown in  FIG. 5 , the detection control unit  51  determines that there is no peeled-off portion present in the label  55  and that the peel-off state of the label  55  is “no peel-off” because the length of the period where the output signal of each of the sensors  50  falls below the threshold S is equal to a predetermined period T 2 . The period T 2  may be set in advance corresponding to a length of one label in the conveyance direction. 
       FIG. 6  depicts an example case where the peel-off state of the label  55  from the mount  56  is “partial peel-off” according to one embodiment. A broken line virtually indicates a part of the label  55  that has been peeled off.  FIGS. 7A -&amp;C depicts example output signals of the sensors  50  at the three positions A, B, and C in  FIG. 6 . 
     As illustrated in  FIG. 6 , the label  55  is in a state where a part of the leading edge portion  55   a  has been peeled off. The peeled-off part exists at a position corresponding to the sensor positions B and C. In this case, as illustrated in  FIG. 7A-7C , the output signal decreases below the threshold S in order of the sensor  50  at the position A, the sensor  50  at the position B, and the sensor  50  at the position C according to a change in the position of the leading edge portion  55   a  of the label  55  caused by the partial peel-off. 
     The detection control unit  51  then determines that there is a partially peeled-off portion present in the label  55  and that the peel-off state of the label  55  is “partial peel-off” because there is a period in the output curve that falls below the threshold S after the peak S for less than the predetermined period T 2  such as T 3  and T 4 . The detection control unit  51  may further determine that the partially peeled-off portion exists in a part of the leading edge portion  55   a  of the label  55  on the sensor position C side because the lengths of the periods where the outputs L of the sensors  50  at the respective positions A, B, and C fall below the threshold S after the peak P satisfy a predetermined time-duration relation of T 2 &gt;T 3 &gt;T 4 , where T 4  of the output curve of the sensor  50  at the position C is the shortest period. 
       FIG. 8  depicts another example case where the peel-off state of the label  55  from the mount  56  is “partial peel-off” according to one embodiment. A broken line in  FIG. 8  virtually indicates a part of the label  55  that has been peeled off.  FIG. 9  depicts graphs of the example outputs L of the sensors  50  that are provided at positions A, B, and C in  FIG. 8 . 
     As illustrated in  FIG. 8 , the label  55  is in a state where there are two parts thereof peeled off from the mount  56 : a first peeled-off part is of the leading edge portion  55   a  at a position corresponding to the sensor positions B and C; and a second peeled-off part is of the trailing edge portion  55   b  at a position corresponding to the sensor position A. 
     In this case, as illustrated in  FIGS. 9A-C , the output decreases below the threshold S in order of the sensor  50  at the position A, the sensor  50  at the position B, and the sensor  50  at the position C according to a change in the position of the leading edge portion  55   a  of the label  55  caused by a partial peel-off. Subsequently, the output increases above the threshold S in order of the sensor  50  at the position A and the sensors  50  at the respective positions B and C according to a change in the position of the trailing edge portion  55   b  of the label  55  caused by the second partial peel-off. 
     The detection control unit  51  then determines that there is at least one partially peeled-off portion present in the label  55  and that the peel-off state of the label  55  is “partial peel-off” because there is a period in the output curve that falls below the threshold S after the peak S for less than the predetermined period T 2  such as T 3  and T 4 . The detection control unit  51  may further determine that two partially peeled-off portions exist in a part of the leading edge portion  55   a  of the label  55  on the sensor position C side and also in a part of the trailing edge portion  55   b  of the label  55  on the sensor position A side because the detection control unit  51  identifies the following conditions in the respective output curves: the timings at which the outputs of the sensors  50  at the respective positions A, B, and C fall below the threshold S are in order of A, B, and C; the timing at which the output of the sensor  50  at the position A exceeds the threshold S after passing the peak P is faster than those of the output curves of the sensors at the position B and C; the timings at which the outputs L of the sensors  50  at the respective positions B and C exceed the threshold S after passing the peak P are substantially the same with one another; and the lengths of the periods where the outputs L of the sensors  50  at the respective positions A, B, and C fall below the threshold S satisfy a predetermined time-duration relation of T 2 &gt;T 5 , T 3 , and T 4 . 
       FIG. 10  is a diagram of an example case where the peel-off state of the label  55  from the mount  56  indicates “total peel-off” according to one embodiment. A broken line region  57  in  FIG. 10  indicates the previous position of the label  55  that has been peeled off from the mount  56 .  FIG. 11A-11C  depicts example outputs of the sensors  50  that are provided at the three positions A, B, and C in  FIG. 10 . 
     As illustrated in  FIG. 10 , the label  55  has been totally peeled off from the mount  56 . In this case, as illustrated in  FIG. 11A-11C , since the label  55  is not present on the mount  56 , the output of each of the sensors  50  at the three positions A, B, and C stays at a constant value that exceeds the threshold S after the peak P for a period T 6 . The period T 6  is, for example, a predetermined period from detection of a trailing edge portion  54   b  of a previous label  54 , that is a label located immediately before the totally peeled-off label  55  on the mount  56 , to detection of a leading edge portion  58   a  of a next label  58 , that is the label located immediately after the missing (totally peeled-off) label  55  on the mount  56 . 
     The detection control unit  51  then determines that the label  55  is totally peeled off and that the peel-off state of the label  55  is “total peel-off” because the output of each of the sensors  50  at the three positions A, B, and C stays at the constant value exceeding the threshold S after the peak P for the period T 6  or more. 
     In one embodiment, if the leading edge portion  55   a  and the trailing edge portion  55   b  of the label  55  are not detected at any of the sensor positions A, B, and C for a section of the label paper  20  corresponding to an N number of labels, the detection control unit  51  may also determine a state where an N number of labels in a row are not present on the label mount. 
     Referring back to  FIG. 3 , the print control unit  52  is an example of a printing unit configured to control an operation of the print head  32  via the head driver  67  and to transfer the print data to the label paper  20  when the print data is input via the communication I/F  64  or the operation unit controller  66 . 
     The print control unit  52  executes the printing process in at least one of a “label issue peel-off mode” and a “label issue continuous mode” according to one embodiment. The “label issue peel-off mode” is an operation mode where printed labels are individually issued from a label issuing port (such as the label issuing port  10  in  FIG. 2 ) after being peeled off from a label mount by a peeling unit. The “label issue continuous mode” is an operation mode where labels are to be continuously printed for a target number of labels, which, for example, has been set by a user, and are issued together with the label mount (that is, in an unpeeled state), without a separate peeling operation of each label after printing like in the label issue peel-off mode. 
     The print control unit  52  may further control the printing process in an “automatic feed mode” according to one embodiment. When the “automatic feed mode” is selected, the print control unit  52  determines suitability for the continuance of the printing operation depending on the peel-off state detected by the detection control unit  51  and then controls the label printing operation based on the determination result. For example, in the “automatic feed mode” operation, if the peel-off state detected by the detection control unit  51  is a total peel-off state where a label is entirely missing from an expected position on the mount (label paper  20 ), the label paper  20  is automatically fed to another printing position for the next printable label while skipping the printing attempt on a label-missing region, and this process is continued until a total target number of labels are printed and issued. During the automatic feed mode, the function of the label issue continuous mode, which allows the printing unit to continuously execute printing for the target number of labels, is maintained. 
     If the detection control unit  51  detects peel-off of at least a part of the label from the mount, the print control unit  52  controls printing according to the peel-off state detected by the detection control unit  51 . In the automatic feed mode, when the detection control unit  51  determines that the peel-off state is “no peel-off”, the print control unit  52  executes printing on the labels, and, when the detection control unit  51  determines that the peel-off state is “partial peel-off”, the print control unit  52  stops printing on the labels and outputs an error message. However, in the “automatic feed mode,” when the detection control unit  51  determines the “total peel-off” state, the print control unit  52  automatically conveys or feeds the label mount corresponding to the position of the totally peeled off label without attempting printing thereon and then returns to continuously executing printing on the labels after the position of the totally peeled off label. 
     The print control unit  52  can shift to the automatic feed mode by a specific operation executed during the label issue continuous mode. 
     The motor control unit  53  is an example of a printing unit and controls the rotation of the platen motor  81  via the motor driver  68 . The motor control unit  53  also controls the rotation of the conveyance motor  82  via the motor driver  69 . Further, the motor control unit  53  controls the rotation of the feed motor  83  via the motor driver  71 . Still further, the motor control unit  53  controls the rotation of the winding motor  84  via the motor driver  72 . 
     When the “automatic feed mode” is selected, the motor control unit  53  controls the conveying operation of the mount according to the peel-off state determined by the detection control unit  51 . For example, in the “automatic feed mode,” when the detection control unit  51  determines the “total peel-off” state, the motor control unit  53  automatically conveys the mount past the position corresponding to the totally peeled-off label in order to execute label printing without unnecessary delay. In the example illustrated in  FIG. 10 , when the detection control unit  51  determines the “total peel-off” state of the label  55 , the motor control unit  53  automatically conveys the mount past the position corresponding to the label  55  in order to speedily execute printing on the label  54  (positioned before the peeled off label  55 ) and the next label  58  (positioned after the peeled off label  55 ). 
       FIG. 12  is a flowchart of a printing operation of the label printer  1  according to one embodiment. 
     First, the print control unit  52  receives an instruction to shift to the automatic feed mode (ACT  1 ). The instruction is input via the communication I/F  64  or the operation unit  5 . The instruction to shift to the automatic feed mode may be executed, for example, by a specific operation (for example, long-pressing, simultaneous pressing of multiple buttons, or rapidly repeated pressing) on a button or buttons of the operation unit  5  or the like when peel-off of a label in an estimated printing range is verified by visual inspection of a user before executing continuous label printing in the label issue continuous mode. 
     The print control unit  52  shifts to the automatic feed mode in response to the instruction to shift to the automatic feed mode (ACT  2 ). The print control unit  52  receives an input of print data and the target number of labels to be printed from the communication I/F  64  or the operation unit  5  (ACT  3 ). 
     The detection control unit  51  detects a peel-off state of the label that is about to be conveyed to a printing position (ACT  4 ). When the detection control unit  51  determines that the peel-off state is “no peel-off” for the label about to be printed (ACT  4 : no peel-off), the print control unit  52  then proceeds to execute the printing process on the label (ACT  5   a ). When the detection control unit  51  determines that the peel-off state for the label about to be printed is “partial peel-off” (ACT  4 : partial peel-off), the print control unit  52  stops the printing process on the label (ACT  5   b ) and outputs an error message. 
     When the detection control unit  51  determines that the peel-off state for the label about to be printed is “total peel-off” (ACT  4 : total peel-off), the motor control unit  53  is configured to execute an automatic feed, that is, the motor control unit  53  automatically advances or feeds the mount past the mount position corresponding to the totally peeled-off label without printing thereto. The next label on the mount (assuming the peel-off state for such a label is detected as “no peel-off”) can then be printed without substantial delay (ACT  5   c ). 
     The print control unit  52  can execute printing on the next label after the peeled off label (ACT  5   a ). 
     The print control unit  52  determines whether the number of printed labels reaches the number of labels to be printed that has been input or designated in ACT  3  (ACT  6 ). When the print control unit  52  determines that the number of printed labels has reached the designated number of labels to be printed, the print control unit  52  ends the printing process in the “label issue continuous mode” (Yes in ACT  6 ). If the print control unit  52  determines that the number of printed labels has not reached the designated number of labels to be printed (No in ACT  6 ), the print control unit  52  repeatedly executes the processes from ACT  4  to ACT  6 . 
     According to one or more embodiments, the label printer  1  executes printing on each of a plurality of labels attached to a continuous mount, such as a label roll or the like. The label printer  1  includes the detection control unit  51  as a detection unit or a detector and the print control unit  52  as a printing unit. The detection control unit  51  is configured to detect a peel-off state of a label  55  from the mount  56  before attempting a printing on the label  55 . The print control unit  52  is configured to control printing according to the peel-off state detected by the detection control unit  51  such as if the detection control unit  51  detects a peel-off or a partial peel-off of the label  55 , printing can be stopped or skipped. For example, when the detection control unit  51  does not detect a peel-off of the label  55  from the mount  56 , the print control unit  52  executes printing on the label  55  normally, but when the detection control unit  51  detects a partial peel-off of the label  55  from the mount  56 , the print control unit  52  stops/skips the printing on the label  55 . Furthermore, when the detection control unit  51  detects a total peel-off of the label  55  from the mount  56 , the printing unit automatically advances the mount  56  past the position corresponding to the totally peeled off label  55  so near continuous printing on the labels before and after the missing, peeled off label can be performed. 
     Accordingly, in the label printer  1  according to at least one of the embodiments, the print control unit  52  can determine suitability for continuance of the printing operation depending on the peel-off state detected by the detection control unit  51  and can control the printing operation on the labels based on the determination result. That is, when a label is totally missing from a position on the mount, such as with a total peel-off, the mount can be automatically fed so that the next printable label moves to the printing position while printing on a label-missing region is skipped, and the printing process can be continued without interruption until a target number of labels are issued. This way, when the total label peel-off is detected, stopping the printing operation, and then requiring the user to manually press a button to execute the position adjustment feeding process before resuming the printing operation are not necessary. Consequently, the number of times the printing operation is interrupted can be reduced, and the throughput in the label issuing process can be improved. In addition, the frequency of the position adjustment feeding caused by the operation of stopping printing can be reduced, and the operating load on the user can be reduced. 
     MODIFICATION EXAMPLE 1 
     In one embodiment, the automatic feed mode is shifted to from the label issue continuous mode. In a modified example, the automatic feed mode may be shifted to from the label issue peel-off mode. 
     MODIFICATION EXAMPLE 2 
     In one embodiment, when it is determined that the peel-off state is a partial peel-off, the printing process is stopped, and an error message is output for preventing the entanglement of a label within the printer. In a modified example, the mount corresponding to the label that has been determined to be in the partial peel-off state may still be automatically conveyed even though the printing process for the particular partially peeled label is skipped. Thus, printing on the labels before and after the partially peeled label can be performed without substantial delay. 
     MODIFICATION EXAMPLE 3 
     In one embodiment, the peel-off state is determined based on the length of the period for which the output falls below the threshold S after the peak P or the length of the period where the output exceeds the threshold S after the peak P. In a modified example, the peel-off state may be determined by comparing the timing at which the output of each of the sensors  50  increases above the threshold S (that is, the timing at which the trailing edge portion  55   b  of the label  55  is detected) and the timing at which the output of each of the sensors  50  decreases below the threshold S (that is, the timing at which the leading edge portion  55   a  of the label  55  is detected). 
     While certain embodiments have been described, these embodiments have been presented by way of example only and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.