JP6403966B2 - Printer - Google Patents

Description

  The present invention relates to a print medium sensor unit, for example, a print medium sensor unit in a printer having a function of printing desired information such as characters, symbols, figures or barcodes on a print medium such as a label. It is.

  A printer that prints information such as characters, symbols, figures, or barcodes on a print medium such as a label is equipped with a sensor for detecting the position of the print medium.

  As this type of print medium detection sensor, the light signal from the light emitting element that has passed through the print medium is detected by the light receiving element, and the position of the print medium is detected based on the difference in local light transmittance of the print medium. A transmissive sensor, a reflective sensor that detects the position of a print medium based on black and white light signals reflected on the surface of the print medium, and the like are known.

  For example, Patent Document 1 discloses a print medium sensor unit in which a position detection sensor is accommodated in each of a pair of sensor mounting members arranged to face each other with a print medium conveyance path interposed therebetween. The print medium sensor unit is detachably attached to the print unit of the printer, and detects the position of the print medium conveyed to the print medium conveyance path.

JP 2005-178309 A

  The reflection type sensor for detecting the print medium placed in the print medium conveyance path (hereinafter also simply referred to as the conveyance path) of the printer detects the light from the light emitting element reflected by the surface of the print medium passing through the conveyance path by the light receiving element. Then, based on the change in the amount of light received by the light receiving element, the position of the label temporarily attached to the print medium is detected, or whether the leading edge or the trailing edge of the printing medium has passed is detected.

  That is, when the print medium passes through the conveyance path in which the reflective sensor is arranged, the light from the light emitting element is reflected by the surface of the print medium and enters the light receiving element, whereas the print medium enters the conveyance path. When there is no light, the amount of reflected light incident on the light receiving element is relatively reduced. Therefore, the reflection type sensor determines whether or not there is a print medium in the conveyance path based on the change in the amount of the two kinds of reflected light incident on the light receiving element. When it is determined that there is no print medium passing through the conveyance path, that is, when it is determined that the paper is out, the printing operation of the printer is stopped and a new print medium is replenished.

  However, when detecting the position of the print medium using such a reflective sensor, if the light reflectance of the surface of the print medium is low, the amount of light reflected by the surface of the print medium and entering the light receiving element is reduced. Since there is a small difference from the amount of light incident on the light receiving element when there is no print medium in the conveyance path, there may be a problem that it is erroneously determined that there is no print medium in the conveyance path.

  The present invention has been made from the above-described technical background, and an object of the present invention is to provide a technique capable of performing position detection with high accuracy even when various print media having different light reflectances are used. To do.

  In order to solve the above-described problem, the print medium sensor unit according to the first aspect of the present invention includes first and second sensor mounting members disposed opposite to each other across a print medium conveyance path through which the print medium passes, A reflective sensor housed in the first sensor mounting member and composed of a first light emitting element and a first light receiving element, and a second light emitting element housed in the first sensor mounting member and constituting one of the transmissive sensors A second light receiving element housed in the second sensor mounting member and constituting the other of the transmissive sensor, and a portion of the second sensor mounting member facing the reflective sensor, the first light emission And an opening through which light from the element passes.

  According to a second aspect of the present invention, there is provided the print medium sensor unit according to the first aspect, wherein the second sensor mounting member is disposed around the opening inside the second sensor mounting member through the opening. A light shielding member is provided to prevent light incident on the second light receiving element from entering the second light receiving element.

  According to a third aspect of the present invention, a printer includes the print medium sensor unit according to the first or second aspect.

  According to the first aspect of the present invention, the amount of light incident on the light receiving element is reduced when there is no print medium in the print medium conveyance path, and the difference between the amount of light reflected on the surface of the print medium and incident on the light receiving element is increased. Therefore, the print medium position detection accuracy is improved.

  According to the second aspect of the present invention, light from the first light emitting element that has entered the second sensor mounting member through the opening enters the second light receiving element of the transmissive sensor housed in the second sensor mounting member. Since this can be prevented, a decrease in position detection accuracy of the transmissive sensor is suppressed.

  According to the third aspect of the present invention, it is possible to realize a printer capable of performing accurate and quick printing even when a printing medium having a low light reflectance is used.

1 is an overall perspective view of the appearance of a printer according to an embodiment of the present invention. It is the perspective view which showed the inside of the printer. It is a side view of a printer. It is a perspective view which shows an example of a label continuous body. It is the perspective view which looked at the printing part of the printer from the front side. It is a side view of the printing part of a printer. It is the perspective view which looked at the printing part of the printer from the back side. (A) is the perspective view which looked at the printing part at the time of the closed state of the print head part of a printer from the front, (b) is the perspective view which looked at the printing part at the time of the open state of the print head part of the printer from the front. is there. It is the perspective view which extracted the printing head part of the printer and was seen from the lower side. It is a disassembled perspective view of the printing part of a printer. It is a perspective view of the support part of a printer. It is a perspective view of the sensor unit with which the printer is mounted. (A) is a side view along the longitudinal direction of the sensor unit in a closed state, (b) is a side view along the longitudinal direction of the sensor unit in an open state. It is a disassembled perspective view of a sensor unit. It is a fragmentary perspective view which shows the internal structure of a sensor unit. (A) is a perspective view which shows the lower surface of the front-end | tip part of an upper sensor attachment holder, (b) is a perspective view which shows the upper surface of the front-end | tip part of a lower sensor attachment holder. It is a schematic sectional drawing in alignment with the AA of FIG. It is a schematic sectional drawing of the front-end | tip part of a sensor unit. (A) is a perspective view of the upper sensor board accommodated in an upper sensor attachment holder, (b) is a perspective view of the lower sensor board accommodated in a lower sensor attachment holder. It is a principal part disassembled perspective view of the label press attached to a sensor unit. It is a perspective view which shows the method of mounting | wearing the support part of a printer with a sensor unit. It is a principal part perspective view which shows the state which inserted the front end side of the sensor unit in the notch of a label holding | suppressing. It is sectional drawing which shows the method of fixing a label press to a sensor unit. It is sectional drawing which shows the method of fixing a label press to a sensor unit.

  Hereinafter, an embodiment as an example of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.

  The printer of the present embodiment is a thermal transfer type label printer having a function of printing various information such as characters, symbols, figures or barcodes on a label temporarily attached to one surface of a label continuum (print medium). 1 has an appearance as shown in FIG.

  A front cover 2 on the front (front) of the label printer 1 is provided with an operation panel 3, a power switch 4, and an issue port 5. The operation panel 3 includes an LCD (Liquid Crystal Display) for displaying a message necessary for a printing operation, a plurality of keys for operating the label printer 1, and a plurality of LEDs (Light for indicating the operation state of the label printer 1). Emitting Diode) is arranged. An open cover 6 is attached to one side surface of the label printer 1 so as to be opened and closed vertically by two hinges 7, and the back (rear) of the label printer 1 is covered with a back cover 8. Yes.

  FIG. 2 is a perspective view of the inside of the label printer 1 as viewed obliquely from the front, and FIG. 3 is a side view showing the inside of the label printer 1.

  A paper supply unit 10 is disposed behind the label printer 1, and a printing unit 11 is disposed in front thereof. An ink ribbon unit 12 is disposed above the printing unit 11.

  The paper supply unit 10 is a component that supplies the label continuum P to the printing unit 11, and includes a support shaft 10a and a roll guide 10b installed at one end thereof. The support shaft 10a is a component that rotatably supports the label continuous body P wound in a roll shape. The roll guide 10b is a component that positions the label continuum P, and is movably installed along the axial direction of the support shaft 10a so that its position can be changed according to the width of the label continuum P. .

  As shown in FIG. 4, the label continuum P is a roll of a long mount 70 and a plurality of labels 71 temporarily attached to one surface (printed surface) of the mount 70 at a predetermined interval. It is a turn. The printing surface of the mount 70 is coated with a release agent such as silicone so that the label 71 can be easily peeled off. Further, on the other surface (back surface) of the mount 70, black eye marks 72 used for detecting the position of the label 71 are formed at predetermined intervals along the longitudinal direction of the mount 70.

  As shown in FIG. 3, one end of the label continuum P loaded in the paper supply unit 10 is fed out with the printed surface (the surface on which the label 71 shown in FIG. 4 is temporarily attached) facing upward. Then, it is conveyed from the vicinity of the inner bottom surface of the label printer 1 toward the bottom portion of the printing unit 11. In the following description, the direction in which the label continuum P is conveyed from the paper supply unit 10 to the printing unit 11 is referred to as a printing direction. Further, upstream in the transport direction refers to the upstream side in the printing direction, and downstream in the transport direction refers to the downstream side in the printing direction.

  As shown in FIGS. 2 and 3, the print unit 11 includes a print head unit 13, a support unit 14 disposed below the print head unit 13, and a damper unit 15 disposed behind the support unit 14.

  As will be described later, the print head unit 13 is installed inside the label printer 1 so as to be openable and closable with respect to the support unit 14. When the print head unit 13 is in a closed state with respect to the support unit 14, a paper passage route (print medium conveyance path) is formed between the print head unit 13 and the support unit 14. This sheet passing route communicates with an issue port 5 (see FIG. 1) provided in the front cover portion 2 in front of the label printer 1.

  A head lock lever 16 that maintains the closed state of the print head unit 13 is installed on the support unit 14 disposed below the print head unit 13. When the head lock lever 16 is manually tilted backward, the closed state of the print head unit 13 is released, the front portion of the print head unit 13 is lifted, and the print head unit 13 is opened. That is, the print head unit 13 moves in a direction away from the support unit 14.

  The damper portion 15 disposed behind the support portion 14 is a component that applies an appropriate label printing by applying tension to the label continuum P, and includes an outer damper 15a and an inner damper 15b. The outer damper 15a and the inner damper 15b are swingably installed so that tension can be applied to the label continuum P when the print head unit 13 is in the closed state.

  The ink ribbon unit 12 disposed above the printing unit 11 is a component that supplies and winds up the ink ribbon RB coated with printing ink. The ribbon unit 12 is disposed obliquely in front of the ribbon supply unit 12a. And a ribbon take-up portion 12b. The ribbon supply unit 12a is a component that rotatably supports the ink ribbon RB wound in a roll shape, and the ribbon take-up unit 12b is a component that winds and collects the printed ink ribbon RB. .

  When the ink ribbon RB is loaded into the ink ribbon unit 12, the print head unit 13 is opened with respect to the support unit 14, and then the ink ribbon RB pulled out from the ribbon supply unit 12a is transferred to the print head unit 13 and the later-described. The leading end portion of the ink ribbon RB is wound up by the ribbon winding portion 12b.

  When performing printing, the ink ribbon RB fed out from the ribbon supply unit 12 a and the label continuous body P fed out from the paper supply unit 10 are conveyed between the print head unit 13 and the support unit 14. After the printing process is performed on the label 71 of the label continuous body P, the label continuous body P is discharged to the outside from the issuing port 5 of the front cover portion 2, and the printed ink ribbon RB is transferred to the ribbon take-up portion 12b. Collected.

  FIG. 5 is an enlarged perspective view of the printing unit 11 as viewed obliquely from the front, FIG. 6 is a side view of the printing unit 11, FIG. 7 is a perspective view of the printing unit 11 as viewed from diagonally behind, and FIG. FIG. 8B is a perspective view of the printing unit 11 when the printing head unit 13 is in a closed state, and FIG. 8B shows the printing unit 11 when the printing head unit 13 is in an open state. FIG. 9 is a perspective view of the print head portion 13 as viewed obliquely from below, FIG. 10 is an exploded perspective view of the print head portion 13 and the support portion 14, and FIG. 11 is the direction opposite to FIG. It is a perspective view of the support part 14 seen from the back.

  As described above, the printing unit 11 includes the print head unit 13, the support unit 14 disposed below the print head unit 13, and the damper unit 15 disposed behind the support unit 14.

  As shown in FIGS. 6 and 7, the damper portion 15 includes an outer damper 15a and an inner damper 15b. The outer damper 15a extends obliquely downward from the front side to the rear side when the printing unit 11 is viewed from the side surface direction, and the rear part can swing up and down around the rotation axis S3 on the front side. In this state, it is supported by the damper support member 25. The coil spring 26 of the damper portion 15 shown in FIG. 7 is a member that restrains the outer damper 15a from going too far upward (rear side) and supports the outer damper 15a in a swingable state. On the other hand, the inner damper 15b extends obliquely downward from the rear side to the front side when the printing unit 11 is viewed from the side surface direction, and the front part can swing up and down about the rotation axis S4. In the state, it is supported by the rear part of the outer damper 15a.

  In the previous stage of paper passing, the paper contact portion of the inner damper 15b is arranged at a position lower than the paper contact portion of the outer damper 15a. That is, the paper contact portion of the inner damper 15 b is disposed in the middle in the height direction between the paper contact portion of the outer damper 15 a and the inner bottom surface 29 of the label printer 1. On the other hand, at the time of printing, the paper contact portion of the inner damper 15b is located on the downstream side of the transport of the label continuum P with respect to the paper contact portion of the outer damper 15a. That is, the paper contact portion of the inner damper 15b is disposed between the print head portion 13 and the paper contact portion of the outer damper 15a.

  As shown in FIG. 7, a pair of width adjustment guides 27 are installed below the outer damper 15a so as to be movable along the axial directions of the rotation axes S3 and S4. These width adjustment guides 27 are components that abut the both ends in the width direction of the label continuum P conveyed from the paper supply unit 10 and guide the conveyance of the label continuum P. Each of the pair of width adjustment guides 27 is connected to a guide operation unit 28 on the back side of the outer damper 15a. The guide operation unit 28 is a knob for moving the width adjustment guide unit 27 according to the width of the label continuum P and fixing the position of the width adjustment guide unit 27.

  The damper support member 25 that supports the outer damper 15a is supported in the label printer 1 in a state in which the rear portion is swingable in the vertical direction around the rotation axis S5 on the front side. The damper support member 25 is urged at a rear portion thereof in a direction of opening upward about the rotation shaft S5 (a direction in which the entire damper portion 15 is lifted) by a torsion spring 30 attached to the rotation shaft S5.

  As shown in FIGS. 7 and 9, the print head portion 13 of the print portion 11 is supported by the head support plate 17 in a state in which the front portion thereof can freely rotate (that is, open and close) in the vertical direction about the rotation axis S <b> 1. Has been. The print head unit 13 is urged in the opening direction by a torsion spring 21 mounted on the rotation shaft S <b> 1, and the lock claw 22 of the support unit 14 is engaged with the pin 20 below the print head unit 13. The closed state is maintained. When the head lock lever 16 is tilted to the right in FIG. 6, the lock claw 22 moves in the same direction in conjunction with it and comes off the pin 20. When the lock claw 22 is removed from the pin 20, the print head unit 13 is opened by the urging force of the torsion spring 21.

  As shown in FIGS. 8B and 9, a thermal head 18 that performs printing on the label 71 of the label continuum P is installed on the lower surface of the print head unit 13. The thermal head 18 includes a printing line 18L in which a plurality of heating resistors (not shown) that generate heat when energized are arranged along the width direction of the label continuum P. A pair of concave claws 19 are provided on the lower surface on the front side of the print head portion 13 so as to sandwich the thermal head 18, and the rear sides of the concave claws 19 are provided from both side surfaces of the print head portion 13. A pin 20 protruding outward is provided.

  As shown in FIG. 8A, when the print head unit 13 is closed, the concave claw 19 is fitted to the platen shaft 23 s of the platen roller 23 of the support unit 14 and the press provided on the print head unit 13. The printing surface of the thermal head 18 is pressed against the platen roller 23 below the apparatus (not shown), and the label continuum P is sandwiched between the thermal head 18 and the platen roller 23.

  As shown in FIG. 7, at one end of the platen shaft 23s of the platen roller 23, a gear G1 connected to the gear G4 through connection gears G2 and G3 is installed. Although not shown, the gear G1 is engaged with the rotation shaft of the stepping motor via a timing belt or the like.

  The platen roller 23 of the support unit 14 is a conveying unit that conveys the label continuum P supplied from the paper supply unit 10 to the issue port 5 (see FIG. 1) along the paper route, as shown in FIG. The shaft is fixed to the support frame 14a of the support portion 14 so as to be rotatable in both forward and reverse directions.

  The main body of the platen roller 23 is made of an elastic material such as an elongated cylindrical rubber. The platen shaft 23s of the platen roller 23 is formed of, for example, an elongated columnar metal, and both longitudinal ends thereof protrude from both ends of the main body of the platen roller 23 into the cylinder of the main body. Inserted and fixed.

  As shown in FIG. 10, a paper guide 24 that guides the conveyance of the label continuum P is installed on the upper surface of the support portion 14 on the upstream side of the platen roller 23 in the conveyance direction. The sheet guide 24 is installed in an inclined state so that the height of the upper surface thereof increases from the upstream in the transport direction toward the downstream in the transport direction.

  As shown in FIGS. 10 and 11, a label presser 40 and a sensor unit 41 are arranged above the paper guide 24. The label presser 40 is a member that prevents flapping of the label continuum P, and the label continuum P that has been transported to the upper surface of the paper guide 24 through the damper portion 15 is disposed between the lower surface of the label presser 40 and the paper guide 24. It is conveyed in the direction of the platen roller 23 through a gap with the upper surface.

  The sensor unit 41 is a container that accommodates a sensor (a transmissive sensor and a reflective sensor 49 described later) that detects the position of the continuous label P that has been conveyed to the upper surface of the paper guide 24, and supports the label presser 40. It also has a function as a member for positioning. As will be described later, the label presser 40 is fixed to the sensor unit 41 by the sensor unit lock lever 60, and the sensor unit 41 is manually attached to the support frame 14a of the support portion 14.

  FIG. 12 is a perspective view of the sensor unit 41, and FIGS. 13A and 13B are side views of the sensor unit 41.

  The housing of the sensor unit 41 includes an upper sensor mounting holder (second sensor mounting member) 42 and a lower sensor mounting holder (first sensor mounting member) 43 made of synthetic resin. The upper sensor mounting holder 42 and the lower sensor mounting holder 43 are rotatably connected to each other via a shaft support portion 44 on the rear end side (the left side in the drawing). When the right side in the figure is lifted upward with a finger or the like, as shown in FIG. 13B, the upper sensor mounting holder 42 rotates about the shaft support portion 44, and the tip portions of both are separated from each other. Further, when the finger or the like is released from the upper sensor mounting holder 42 in this state, the upper sensor mounting holder 42 rotates in the opposite direction due to its own weight, and stops in a state in which the tip portions of both approach each other (FIGS. 12 and 12). 13 (a)).

  As shown in FIG. 13A, a gap (Ga) is formed between the lower surface (bottom surface) of the upper sensor mounting holder 42 and the upper surface of the lower sensor mounting holder 43 at the distal end portion of the sensor unit 41. This gap (Ga) becomes a sheet passing route through which the label continuum P passes when the sensor unit 41 is mounted on the support portion 14 of the label printer 1.

  Upper guide grooves 52 for supporting the label presser 40 described above are provided on both side surfaces of the upper sensor mounting holder 42. In addition, a convex portion 54 for fixing the label presser 40 to a predetermined position of the sensor unit 41 is provided on one side surface of the upper sensor mounting holder 42. On the other hand, lower guide grooves 53 for mounting the sensor unit 41 to the support portion 14 are provided on both side surfaces of the lower sensor mounting holder 43.

  On the upper surface of the tip portion of the upper sensor mounting holder 42, there are provided a knob 33 and a concave recess 34 that are used when the sensor unit 41 is mounted on the support portion 14 of the label printer 1. In addition, on the bottom surface of the rear end portion of the lower sensor mounting holder 43, a sawtooth-shaped uneven groove 55 used for positioning the position detection sensor (transmission type sensor, reflection type sensor 49) and the label presser 40 is provided. As schematically shown in FIG. 13A, when the sensor unit 41 is mounted on the label printer 1, the leaf spring 31 attached to the support portion 14 is engaged with the concave and convex groove 55. Yes.

  14 is an exploded perspective view of the sensor unit 41, FIG. 15 is a partial perspective view showing the internal structure of the sensor unit 41, and FIG. 16A is a perspective view showing the lower surface of the tip portion of the upper sensor mounting holder 42. 16B is a perspective view showing the top surface of the tip portion of the lower sensor mounting holder 43, FIG. 17 is a schematic cross-sectional view taken along the line AA in FIG. 12, and FIG. FIG. 19A is a perspective view of the upper sensor substrate accommodated in the upper sensor mounting holder 42, and FIG. 19B is a perspective view of the lower sensor substrate accommodated in the lower sensor mounting holder 43. It is.

  As shown in FIG. 14, each of the upper sensor mounting holder 42 and the lower sensor mounting portion 43 has a structure that is divided into two in the left-right direction (the direction perpendicular to the longitudinal direction of the sensor unit 41). That is, the upper sensor attachment holder 42 is divided into an upper sensor attachment holder 42R and an upper sensor attachment holder 42L, and the lower sensor attachment holder 43 is divided into a lower sensor attachment holder 43R and a lower sensor attachment holder 43L. Further, the upper sensor mounting holder 42R and the upper sensor mounting holder 42L are integrally assembled by two screws 58, and the lower sensor mounting holder 43R and the lower sensor mounting holder 43L are integrally assembled by two screws 58.

  An upper sensor substrate 47 on which the light receiving element 45 and the connector 51a are mounted is detachably fitted in a fitting groove 42a provided on the inner wall of the upper sensor mounting holder 42. The light receiving element 45 and the connector 51 a are mounted on the lower surface of the upper sensor substrate 47. On the other hand, in the fitting groove 43a provided on the inner wall of the lower sensor mounting holder 43, the lower sensor substrate 48 on which the light emitting element 46, the reflective sensor 49 and the connector 51b are mounted is detachably fitted. The light emitting element 46, the reflective sensor 49, and the connector 51b are mounted on the upper surface of the lower sensor substrate 48.

  The light receiving element 45 mounted on the upper sensor substrate 47 and the light emitting element 46 mounted on the lower sensor substrate 48 constitute a transmissive sensor as a pair. The transmissive sensor is an optical signal from the light emitting element 46 that has passed through the label continuum P passing through the gap (Ga) between the lower surface of the upper sensor mounting holder 42 and the upper surface of the lower sensor mounting holder 43 shown in FIG. Is detected by the light receiving element 45, and the mounting position or the label position is detected based on the difference in light transmittance between the mounting sheet 70 and the label 71 shown in FIG.

  Openings 36 a and 36 b are provided above the light emitting element 46 at the tip of the lower sensor mounting holder 43. An opening 37 is provided on the lower surface of the upper sensor mounting holder 42 below the light receiving element 45 (a portion facing the opening 36a of the lower sensor mounting holder 43). Therefore, the optical signal from the light emitting element 46 mounted on the lower sensor substrate 48 reaches the light receiving element 45 mounted on the upper sensor substrate 47 through the openings 36a, 36b, and 37.

  Inside the reflective sensor 49 mounted on the lower sensor substrate 48, a light emitting element 49a and a light receiving element 49b are arranged side by side. Further, a light shielding plate 59 (see FIG. 18) is disposed between the light emitting element 49a and the light receiving element 49b so that light from the light emitting element 49a does not directly enter the light receiving element 49b.

  The reflective sensor 49 receives light from the light emitting element 49a reflected by the surface (lower surface) of the label continuum P passing through the gap (Ga) between the lower surface of the upper sensor mounting holder 42 and the upper surface of the lower sensor mounting holder 43. 49b, based on the change in the amount of light received by the light receiving element 49b, the position of the eye mark 72 of the mount 70 shown in FIG. 4 is detected, and whether the leading edge or the trailing edge of the label continuum P has passed is detected. To do.

  An opening 38 is provided at a location facing the reflective sensor 49 on the top surface of the tip portion of the lower sensor mounting holder 43. An opening 39 is provided on the lower surface of the upper sensor mounting holder 42 above the reflective sensor 49 (a portion facing the opening 38 of the lower sensor mounting holder 43). Further, a light shielding cover (light shielding member) 50 for preventing light from the light emitting element 49 a of the reflective sensor 49 from reaching the light receiving element 45 of the transmissive sensor is provided above the opening 39. Therefore, when there is no label continuum P in the gap (Ga) between the lower surface of the upper sensor mounting holder 42 and the upper surface of the lower sensor mounting holder 43, the light from the light emitting element 49a of the reflective sensor 49 passes through the openings 38 and 39. And reaches the wall surface of the light shielding cover 50.

  As described above, the sensor unit 41 includes two types of position detection sensors (a transmission type sensor and a reflection type sensor 49), and selectively selects these two types of position detection sensors according to the type of the label continuum P. It is configured to use. The light emitting element 46 of the transmissive sensor is made of, for example, a GaAs (gallium arsenide) infrared light emitting diode, and the light receiving element 45 is made of, for example, a silicon phototransistor. The light emitting element 49a of the reflective sensor 49 is made of, for example, a GaAs infrared light emitting diode, and the light receiving element 49b is made of, for example, a silicon phototransistor.

  As shown in FIG. 12, marks 35 a and 35 b indicating the positions of two types of sensors (a transmissive sensor and a reflective sensor 49) housed in the sensor unit 41 are formed on the upper surface of the tip portion of the upper sensor mounting holder 42. Is formed. That is, the mark 35 a is disposed immediately above the transmissive sensor (the light receiving element 45 and the light emitting element 46), and the mark 35 b is disposed immediately above the reflective sensor 49. Thereby, the positions of the two types of sensors can be easily confirmed from the outside of the sensor unit 41.

  Next, the operation and effect of the opening 39 provided above the reflective sensor 49 on the lower surface of the upper sensor mounting holder 42 will be described.

  As described above, the reflective sensor 49 is used to detect whether the label continuum P passes through the gap (Ga) between the lower surface of the upper sensor mounting holder 42 and the upper surface of the lower sensor mounting holder 43. That is, when the label continuum P passes through the gap (Ga), the light from the light emitting element 49a is reflected by the surface (lower surface) of the label continuum P and enters the light receiving element 49b. On the other hand, when the label continuum P is not present in the gap (Ga), the light from the light emitting element 49a reaches the wall surface of the light shielding cover 50 through the opening 39 on the lower surface of the upper sensor mounting holder 42, and is reflected by this wall surface. The incident light enters the light receiving element 49b.

  Therefore, the amount of reflected light incident on the light receiving element 49b when there is no label continuum P in the gap (Ga) is much smaller than when the label continuum P is in the gap (Ga). The reflection type sensor 49 determines whether or not there is the label continuum P in the gap (Ga) based on the change in the amount of the two kinds of reflected light incident on the light receiving element 49b. When it is determined that the label continuum P that has passed through the gap (Ga) has disappeared, that is, when it is determined that the sheet is out of paper, the printing operation of the label printer 1 is stopped, and FIGS. A new label continuum P is replenished to the paper supply unit 10 shown.

  Here, assuming that the opening 39 is not provided on the lower surface of the upper sensor mounting holder 42, when the label continuum P is not present in the gap (Ga), the light from the light emitting element 49a is reflected on the lower surface ( The light is reflected at the bottom surface and enters the light receiving element 49b. Therefore, the amount of reflected light incident on the light receiving element 49b at this time is larger than when the opening 39 is provided on the lower surface of the upper sensor mounting holder. In other words, when there is no opening 39 on the lower surface of the upper sensor mounting holder 42, the amount of reflected light incident on the light receiving element 49b is changed compared to the case where the opening 39 is provided, that is, the label continuum P is in the gap (Ga). The difference between the amount of reflected light incident on the light receiving element 49b when present and the amount of reflected light incident on the light receiving element 49b when there is no label continuum P in the gap (Ga) is reduced.

  However, if there is a small difference in the amount of reflected light incident on the light receiving element 49b when the gap continuity P has the label continuum P, it is reflected when, for example, the label continuum P having a low surface light reflectance is used. The mold sensor 49 malfunctions, causing a problem that it is erroneously determined that there is no label continuum P in the gap (Ga).

  Usually, the printer manufacturer sets a standard for the light reflectivity of the surface of the label continuum P so that such a problem does not occur. Therefore, the label continuum P conforming to the standard of the printer manufacturer is used. As long as such a defect is unlikely to occur.

  However, for example, when a printer manufactured in Japan is carried overseas and used, it is difficult to obtain a label continuum P that conforms to the printer manufacturer's standard, and a low surface light reflectance is used. In such a case, the above problem may occur. Further, even when the label continuum P conforming to the specifications of the printer manufacturer is used, the reflection type sensor 49 is caused by dust or paper dust accumulated on the surface of the reflection type sensor 49 disposed below the label continuum P. There is a possibility that the detection accuracy of 49 is lowered and the above-mentioned problem occurs.

  On the other hand, as in the label printer 1 of the present embodiment, an opening 39 is provided on the lower surface of the upper sensor mounting holder 42 so that light from the light emitting element 49a is inside the upper sensor mounting holder 42 (wall surface of the light shielding cover 50). In the case of reaching the upper limit, the distance from the light emitting element 49a to the reflecting surface becomes longer than in the case where there is no opening 39 on the lower surface of the upper sensor mounting holder. As a result, the amount of reflected light incident on the light receiving element 49b when the label continuum P is not present in the gap (Ga) is greatly reduced, so that the light receiving element 49b is present when the label continuum P is not present in the gap (Ga). The difference in the amount of light incident on the sensor increases, and the detection accuracy of the reflective sensor 49 improves.

  Thus, for example, even when a label continuum P having a low light reflectance on the surface is used, erroneous detection of the reflective sensor 49 is unlikely to occur, and therefore various label continuums P that deviate from the printer manufacturer's standard are used. Even in this case, it is possible to realize the label printer 1 that can perform accurate and quick printing.

  Also, even when a certain amount of dust or paper dust accumulates on the surface of the reflective sensor 49, it is difficult for false detection of the reflective sensor 49, so that the above-described effects are obtained and the surface of the reflective sensor 49 is cleaned. A label printer 1 with a low frequency can be realized.

  In the label printer 1 of the present embodiment, it is desirable to color the surface of the light shielding cover 50 provided above the opening 39 with black or a color close thereto. In this case, the light reflectance of the wall surface of the light shielding cover 50 is reduced, and the amount of light reaching the light receiving element 49b is small when there is no label continuum P in the gap (Ga). The accuracy is further improved. Further, the same effect can be obtained by applying a texture such as texture or grain to the wall surface of the light shielding cover 50 to reduce the light reflectance of the surface.

  In order to prevent dust and paper dust from adhering to the surfaces of the light emitting element 49a and the light receiving element 49b constituting the reflective sensor 49, the upper surface of the reflective sensor 49 is covered with a dustproof cover made of a transparent film. Although effective, in this case, it is desirable to place the dust cover as close to the reflective sensor 49 as possible. In this way, the amount of light reflected on the surface of the dustproof cover and reaching the light receiving element 49b is reduced, so that a decrease in detection accuracy of the reflective sensor 49 can be suppressed.

  Next, a method for attaching the label presser 40 to the sensor unit 41 of the above-described embodiment will be described.

  As shown in FIG. 20, the label presser 40 is formed of a synthetic resin molded body having a substantially rectangular planar shape, and a cutout 40 a into which the tip portion of the sensor unit 41 is inserted is provided on one side. . Further, a guide rail 40b to be inserted into upper guide grooves 52 (see FIG. 17) provided on both side surfaces of the sensor unit 41 is formed in a part of the notch 40a.

  A sensor unit lock lever (sensor displacement prevention mechanism) 60 formed separately from the label press 40 is attached to the label press 40. The sensor unit lock lever 60 is attached to the label presser 40 by fitting cylindrical pins 61 provided at both ends thereof into the pin holes 40 c of the label presser 40. The sensor unit lock lever 60 attached to the label presser 40 is rotatable in the vertical direction with the pin 61a fitted in the pin hole 40c of the label presser 40 as a fulcrum.

  When inserting the leading end portion of the sensor unit 41 into the notch 40a of the label presser 40, first, as shown in FIG. 21, the guide rail 14b of the support frame 14a is fitted into the lower guide groove 53 of the sensor unit 41, and the sensor unit is inserted. 41 is slid. As described above, since the knob 33 and the depression 34 are formed at the tip portion of the sensor unit 41 (see FIG. 12), when the sensor unit 41 is mounted on the support portion 14 of the label printer 1, the depression is formed. When the sensor unit 41 is slid while putting a finger or the like in 34 and sandwiching the knob 33, the sensor unit 41 can be mounted on the support portion 14 smoothly.

  Next, after the guide rail 40b of the label presser 40 is fitted into the upper guide groove 52 of the sensor unit 41, the sensor unit 41 is moved until the leading end of the sensor unit 41 contacts the innermost part of the notch 40a of the guide rail 40b. Slide (or label holder 40).

  FIG. 22 and FIG. 23 (a cross-sectional view taken along line BB in FIG. 22) show the state in which the tip portion of the sensor unit 41 is inserted into the notch 40a of the label presser 40 in this way.

  As shown in FIG. 23, when the leading end portion of the sensor unit 41 is inserted into the notch 40 a of the label presser 40, the sensor unit lock lever 60 of the label presser 40 is not in contact with the sensor unit 41. A concave portion 60b is formed on the surface of the sensor unit lock lever 60. When the sensor unit lock lever 60 and the sensor unit 41 are not in contact with each other, the concave portion 60b is provided on the side surface of the sensor unit 41. The convex portions 54 are at positions separated from each other.

  Next, as shown in FIG. 24, one end of the sensor unit lock lever 60 exposed to the outside of the label presser 40 is picked with a finger or the like, and this one end is directed upward (in the direction indicated by the arrow in the figure). Rotate. Thereby, the convex portion 54 of the sensor unit 41 is fitted into the concave portion 60 b of the sensor unit lock lever 60, so that the label presser 40 is securely fixed to the sensor unit 41. On the other hand, when releasing the fixation of the label presser 40 with respect to the sensor unit 41, one end of the sensor unit lock lever 60 may be rotated in a direction opposite to the direction shown in FIG.

  Thereafter, the sensor unit 41 is slid with respect to the support portion 14 in accordance with the size of the label continuum P and the position of the label 71 (see FIG. 4), so that the sensor for the label continuum P (transmission type sensor and reflection type sensor). 49) positioning is completed. When the sensor unit 41 is slid, it may be operated by pinching a knob 33 provided at the tip of the sensor unit 41 with a finger. Since the concave / convex groove 55 (see FIG. 13) with which the leaf spring 31 attached to the support portion 14 is engaged is provided on the bottom surface of the sensor unit 41, after the positioning of the sensor with respect to the label continuum P is completed. There is no fear that the position of the sensor with respect to the label continuum P is easily shifted.

  During the printing process, the thermal head 18 of the printing unit 11 is pressed against the platen roller 23 side, and the continuous plate P is rotated by rotating the platen roller 23 with the continuous label P inserted through the gap (Ga) of the sensor unit 41. Transport. Then, the print timing is determined based on the information detected by the sensors (the transmissive sensor and the reflective sensor 49), and the heating resistor of the print line 18L (see FIG. 9) is selected by the print signal transmitted to the thermal head 18. To generate heat. As a result, desired information such as characters, symbols, figures, barcodes, or the like is printed on the label of the label continuum P during the conveyance of the label continuum P. Labels on which various types of information are printed are used for various purposes such as packing tags, display of product information, details of packed items, price display, and component display.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the embodiment disclosed in this specification is an example in all respects and is limited to the disclosed technology. It should be considered not a thing. That is, the technical scope of the present invention should not be construed restrictively based on the description in the above-described embodiment, but should be construed according to the description of the scope of claims. All modifications are included without departing from the technical scope equivalent to the described technique and the gist of the claims.

  In the above description, the case where the present invention is applied to a sensor unit mounted on a thermal transfer label printer has been described. However, the printer is not limited to this and may be a thermal label printer. Moreover, although the thing wound in roll shape was illustrated as a label continuous body, the label continuous body of a fanfold (folding) specification may be sufficient.

DESCRIPTION OF SYMBOLS 1 Printer 10 Paper supply part 10a Support shaft 10b Roll guide part 11 Print part 13 Print head part 14 Support base 14a Support frame 14b Guide rail 15 Damper part 15a Outer damper 15b Inner damper 16 Head lock lever 17 Head support plate 18 Thermal head 18L Printing line 19 Concave claw 20 Pin 21 Torsion spring 22 Lock claw 23 Platen roller part 23a Platen shaft 24 Paper guide part 25 Damper support member 26 Coil spring 27 Width adjustment guide part 28 Guide operation part 30 Torsion spring 31 Leaf spring 33 Knob 34 Depression 35a 35b Marks 36a, 36b, 37, 38, 39 Opening 40 Label retainer 40a Notch 40b Guide rail 40c Pin hole 41 Sensor unit 42, 42L, 42R Upper sensor mounting holder 3, 43L, 43R Lower sensor mounting holders 42a, 43b Fitting groove 44 Shaft support 45 Light receiving element 46 Light emitting element 47 Upper sensor board 48 Lower sensor board 49 Reflective sensor 49a Light emitting element 49b Light receiving element 50 Light shielding cover 51a, 51b Connector 52 Upper guide groove 53 Lower guide groove 54 Convex part 55 Concave groove 56 Pin 57 Pin hole 58 Screw 59 Shading plate 60 Sensor unit lock lever 60a Pin 60b Concave part 70 Mount 71 Label 72 Eye mark Ga Clearance P Label continuum RB Ink ribbon G1, G5 Gear S1 Rotating shaft

Claims (4)

First and second sensor mounting members disposed opposite to each other across a print medium conveyance path through which the print medium passes;
A reflective sensor housed in the first sensor mounting member and composed of a first light emitting element and a first light receiving element;
A second light emitting element housed in the first sensor mounting member and constituting one of the transmissive sensors;
A second light receiving element that is housed in the second sensor mounting member and that constitutes the other of the transmissive sensors disposed apart from the print medium conveyance path ;
An opening provided at a position of the second sensor mounting member facing the reflective sensor, and through which light from the first light emitting element passes;
A light shielding cover that forms a concave space above the opening in the second sensor mounting member and prevents light emitted from the first light emitting element from entering the second light receiving element;
A part of the light shielding cover faces an incident path of light received by the second light receiving element from the second light emitting element . The printer according to claim 1, wherein a center position of the second light receiving element is disposed above an inner wall surface on an upper side of the light shielding cover. On the outer surface of the second sensor mounting member, a first mark indicating the position of the reflective sensor disposed at a position immediately above the reflective sensor, and the transmissive type disposed immediately above the transmissive sensor. The printer according to claim 1, wherein a second mark indicating a position of the sensor is formed. The printer according to claim 1, wherein the first light emitting element, the first light receiving element, and the second light emitting element are mounted on the same substrate.

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