Patent Description:
Patent Literature <NUM> discloses a printing device including a thermal head, a head pressing mechanism, and a head moving mechanism. The thermal head is supported by a holding member. The head pressing mechanism includes a rotation shaft, a transmission member, a roller, a drive portion, and the like. The rotation shaft extending in a left-right direction is rotatable about an axis of the rotation shaft. The transmission member is provided at both ends of the rotation shaft in the left-right direction. The transmission member pivots about the rotation shaft by a driving force of the drive portion. The roller is fixed to a front side of the transmission member. The roller moves downward due to the pivoting of the transmission member to press the thermal head downward from above. The head moving mechanism includes a linear bush. The linear bush is connected to the thermal head. As the linear bush slides on the rotation shaft, the thermal head moves in the left-right direction.

Patent Literature <NUM> discloses the preamble of claim <NUM>.

In the above printing device, the linear bush connected to the thermal head moves on the rotation shaft, and thus a movable range of the thermal head in the left-right direction is limited to a range between both end portions of the rotation shaft where the transmission member is disposed. Therefore, there is a possibility that the printing device cannot increase the movable range of the thermal head.

An object of the present invention is to provide a printing device capable of increasing a movable range of a thermal head.

A printing device according to a first aspect of the present invention includes: a thermal head; a rotation shaft extending in an axial direction and rotatably supported; a rotation drive portion configured to rotate the rotation shaft; a pivot member connected to the rotation shaft and configured to pivot integrally with the rotation shaft about the rotation shaft; a first support portion configured to support the thermal head to be movable in an up-down direction intersecting the axial direction; a second support portion configured to support the first support portion to be movable parallel to the axial direction; a biasing means configured to bias the thermal head upward; a first pivot shaft supported by the pivot member, extending parallel to the axial direction, located below the rotation shaft, and configured to pivot integrally with the pivot member about the rotation shaft; a support member supported by the first pivot shaft to be movable along the first pivot shaft and to be pivotable about the first pivot shaft, the support member including an upper end portion located above the rotation shaft, a lower end portion located below the rotation shaft, and an intermediate portion located between the upper end portion and the lower end portion; a pressing portion provided on the lower end portion of the support member and configured to press the thermal head downward; and a movement drive portion configured to drive the first support portion in the axial direction.

In the printing device according to the first aspect, the rotation shaft and a first rotation shaft are separately provided. Therefore, the printing device can move the thermal head without limiting a movable range of the thermal head in the axial direction, as compared with a case where the thermal head is provided on the rotation shaft, moves in the axial direction on the rotation shaft, and is pressed downward by rotation of the rotation shaft. Therefore, the printing device can increase a movable range of the thermal head.

In the first aspect, the printing device may include a second pivot shaft supported by the pivot member, extending parallel to the axial direction, located above the rotation shaft, and configured to pivot integrally with the pivot member about the rotation shaft, and a sliding member provided on the upper end portion of the support member, configured to come into contact with the second pivot shaft, and configured to slide along the axial direction.

In the first aspect, the printing device may include a sensor configured to detect a rotational position of the rotation shaft. The printing device can accurately detect a position of the thermal head in the up-down direction by detecting the rotational position of the rotation shaft with the sensor.

In the first aspect, the printing device may include the rotation drive portion including a motor, a cam provided on a drive shaft of the motor, the drive shaft extending parallel to the axial direction, and a plate-shaped member including one end portion connected to the cam and an other end portion fixed to the rotation shaft. The cam rotates in accordance with rotation of the motor. The rotation of the cam causes the one end portion of the plate-shaped member to move in the up-down direction together with the cam. Therefore, the other end portion of the plate-shaped member moves following the movement of the plate-shaped member. The rotation shaft rotates due to the movement of the other end portion of the plate-shaped member. In the printing device, the rotation drive portion can be implemented by the motor, the cam, and the plate-shaped member at low cost.

In the first aspect, the printing device may include a head holding member configured to hold the thermal head from above, in which the first support portion may be configured to support the head holding member to be movable manner in the up-down direction, and the pressing portion of the support member may press the head holding member from above to below. The pressing portion can press the thermal head downward via the head holding member.

In the first aspect, the thermal head may be attachable to and detachable from the head holding member and may include an engaged portion protruding to one side in the axial direction, and the head holding member may include a third support portion having an insertion hole, penetrating in the axial direction, through which the engaged portion is insertable in a case where the thermal head is mounted to the head holding member, and an engaging member configured to engage with the engaged portion in a state where the engaged portion is inserted through the insertion hole of the third support portion. The thermal head is attachable to and detachable from the head holding member. The head holding member can reliably fix the thermal head by engaging the engaging portion with the engaged portion in a state where the engaged portion is inserted through the insertion hole of the third support portion. Therefore, a user can easily replace the head.

A printing device according to a second aspect of the present invention includes: a thermal head; a rotation shaft extending in an axial direction and supported rotatably around an axis of the rotation shaft; a rotation drive portion configured to rotate the rotation shaft; a pivot member connected to the rotation shaft and configured to pivot integrally with the rotation shaft about the rotation shaft; a first support portion configured to support the thermal head to be movable on one side in an intersecting direction with respect to the pivot member, the intersecting direction intersecting with the predetermined axial direction; a second support portion configured to support the first support portion to be movable parallel to the axial direction; a biasing means configured to bias the thermal head to an other side in the intersecting direction; a first pivot shaft supported by the pivot member, extending parallel to the axial direction, located on the one side in the intersecting direction than the rotation shaft, and configured to pivot integrally with the pivot member about the rotation shaft; a support member supported to be movable along the first pivot shaft and to be pivotable about the first pivot shaft, the support member including a first end portion located on the other side in the intersecting direction than the rotation shaft, a second end portion located on the one side than the rotation shaft, and an intermediate portion located between the first end portion and the second end portion; a pressing portion provided on the second end portion of the support member and configured to press the thermal head toward the one side in the intersecting direction; and a movement drive portion configured to drive the first support portion in the axial direction.

In the printing device according to the second aspect, the rotation shaft and the first pivot shaft are separately provided. Therefore, the printing device can move the thermal head without limiting a movable range of the thermal head in the axial direction, as compared with a case where the thermal head is provided on the rotation shaft, moves in the axial direction on the rotation shaft, and is pressed downward due rotation of the rotation shaft. Therefore, the printing device can increase a movable range of the thermal head.

A printing device <NUM> according to the present invention will be described with reference to the drawings. In the following description, left and right, front and rear, and up and down indicated by arrows in the drawings are used.

The printing device <NUM> shown in <FIG> is a thermal transfer printing device. The printing device <NUM> performs printing on a printing medium conveyed by an external device that is not shown. An example of the external device is a packaging machine that conveys a packaging material. For example, the printing device <NUM> is incorporated in a conveyance line along which the packaging material is conveyed by a platen of the packaging machine. A cassette <NUM> that supports an ink ribbon that is not shown is mounted to the printing device <NUM>. The printing device <NUM> feeds out the ink ribbon from the mounted cassette <NUM>. The printing is performed on the packaging material by heating the ink ribbon with a plurality of heating elements linearly arranged in a front-rear direction of a thermal head <NUM> (see <FIG> and <FIG>).

As shown in <FIG>, the printing device <NUM> has a substantially rectangular parallelepiped shape. The printing device <NUM> includes a main body <NUM> and the cassette <NUM>. The cassette <NUM> is detachably mounted to the main body <NUM> from a front side. The main body <NUM> includes a base plate <NUM> and housings <NUM> and <NUM>. As shown in <FIG>, the base plate <NUM> has a substantially rectangular plate shape. The housing <NUM> is provided at a rear side with respect to the base plate <NUM> (see <FIG>). The housing <NUM> is formed with a rectangular opening that opens forward. The base plate <NUM> is fitted into the opening of the housing <NUM> from the front side. The housing <NUM> covers peripheries of motors 72A and <NUM> (see <FIG>) which are provided at a rear side with respect to the base plate <NUM>, a cassette motor (not shown), a control board, and the like.

As shown in <FIG> and <FIG>, the housing <NUM> is provided at a front side with respect to the base plate <NUM>. The housing <NUM> is formed with a rectangular opening that opens to a front side of the housing <NUM>. The opening at the front side of the housing <NUM> is covered with a cassette base <NUM>, which will be described later, in a state where the cassette <NUM> is mounted to the printing device <NUM>. Therefore, a lower side of the housing <NUM> is formed with an opening that opens downward. In <FIG>, the housing <NUM> is omitted.

As shown in <FIG>, a front surface of the base plate <NUM> is provided with a supply roll bearing portion <NUM>, a take-up roll bearing portion <NUM>, a support shaft <NUM>, a bearing portion <NUM>, a head moving mechanism <NUM>, a head unit <NUM>, and the like.

The supply roll bearing portion <NUM> is provided on an upper side with respect to a center of the base plate <NUM> in an up-down direction and on a left side with respect to a center of the base plate <NUM> in a left-right direction. The take-up roll bearing portion <NUM> is provided on the upper side with respect to the center of the base plate <NUM> in the up-down direction and on a right side with respect to the center of the base plate <NUM> in the left-right direction. The supply roll bearing portion <NUM> and the take-up roll bearing portion <NUM> each have a columnar shape (see <FIG>), and are arranged in the left-right direction. The supply roll bearing portion <NUM> and the take-up roll bearing portion <NUM> are each rotated by driving of the cassette motor that is not shown provided at the rear side with respect to the base plate <NUM>.

The support shaft <NUM> is provided on a lower right corner of the base plate <NUM>. The support shaft <NUM> is formed in a columnar shape protruding forward. The bearing portion <NUM> is provided on a lower left corner of the base plate <NUM>. The bearing portion <NUM> has a columnar shape. The bearing portion <NUM> has a recessed portion recessed rearward. A columnar support portion <NUM> extends from the vicinity of the supply roll bearing portion <NUM> toward the front side of the base plate <NUM>. The support portion <NUM> is provided with a through hole <NUM>. The through hole <NUM> extends forward from a mounting portion provided on the base plate <NUM>. The head moving mechanism <NUM> and the head unit <NUM> will be described later.

As shown in <FIG> and <FIG>, the cassette <NUM> includes the cassette base <NUM>, a handle <NUM>, a protruding portion <NUM>, a supply roll shaft <NUM>, a take-up roll shaft <NUM>, and guide rollers <NUM> and <NUM>. The cassette base <NUM> is a base portion having substantially square plate-shape. A front surface 41A and a rear surface 41B of the cassette base <NUM> have substantially the same shape as that of the opening at the front side of the housing <NUM> of the printing device <NUM>.

The handle <NUM> is provided on a center of the front surface 41A of the cassette base <NUM> over upper and lower sides (see <FIG>). A user grips the handle <NUM> of the cassette <NUM> on which the ink ribbon is supported, and slides the handle <NUM> rearward from a state of being disposed on a front side of the main body <NUM>. Accordingly, the cassette <NUM> is inserted into the housing <NUM> through the opening at the front side of the housing <NUM>.

In a case where the cassette <NUM> is mounted to the main body portion <NUM>, the protruding portion <NUM> of the cassette <NUM> is engaged with the through hole <NUM> from the front. The user releases the engagement between the through hole <NUM> and the protruding portion <NUM> by pushing a release button <NUM> (see <FIG> and <FIG>) while gripping the handle <NUM>. Accordingly, the user can remove the cassette <NUM> from the housing <NUM>.

The supply roll shaft <NUM> is provided on an upper side with respect to a center of the rear surface 41B in an up-down direction and on a left side with respect to a center of the rear surface 41B in a left-right direction. The take-up roll shaft <NUM> is provided on the upper side with respect to the center of the rear surface 41B in the up-down direction and on a right side with respect to the center of the rear surface 41B in the left-right direction. The supply roll shaft <NUM> and the take-up roll shaft <NUM> are arranged in the left-right direction. The guide roller <NUM> is provided on a lower left corner of the rear surface 41B. The guide roller <NUM> is provided on a lower right corner of the rear surface 41B.

A cylindrical spool to which one end of the ink ribbon is connected is mounted to the take-up roll shaft <NUM>. An unused ink ribbon is wound into a roll around the spool. A cylindrical spool to which the other end of the ink ribbon is connected is mounted to the supply roll shaft <NUM>. The ink ribbon extending over the supply roll shaft <NUM> and the take-up roll shaft <NUM> is stretched between the guide roller <NUM> and the guide roller <NUM>.

In a case where the cassette <NUM> is mounted to the main body <NUM>, rear end portions of the supply roll shaft <NUM>, the take-up roll shaft <NUM>, the guide roller <NUM>, and the guide roller <NUM> (see <FIG>) of the cassette <NUM> can be engaged with the supply roll bearing portion <NUM>, the take-up roll bearing portion <NUM>, the bearing portion <NUM>, and the support shaft <NUM>, respectively. Specifically, the rear end portion of the supply roll shaft <NUM> is engaged with the supply roll bearing portion <NUM> (see <FIG>). The rear end portion of the take-up roll shaft <NUM> is engaged with the take-up roll bearing portion <NUM> (see <FIG>). An engaging portion 45A on a rear end of the guide roller <NUM> is engaged with the recessed portion of the bearing portion <NUM> (see <FIG>). The support shaft <NUM> (see <FIG>) is inserted into and engaged with the guide roller <NUM>.

For example, the ink ribbon fed out from the spool mounted to the supply roll shaft <NUM> is conveyed obliquely downward to the left toward the guide roller <NUM>. The ink ribbon comes into contact with a rotational body of the guide roller <NUM> to change its direction, and is conveyed rightward toward the guide roller <NUM>. The ink ribbon comes into contact with a rotational body of the guide roller <NUM> to change its direction, and is conveyed obliquely upward to the left toward the spool mounted to the take-up roll shaft <NUM>. In a case where the supply roll shaft <NUM> and the take-up roll shaft <NUM> are rotated by the cassette motor, the ink ribbon is fed out from a ribbon roll and taken up by the spool of the take-up roll shaft <NUM>. In accordance with the conveyance of the ink ribbon, the rotational bodies of the guide rollers <NUM> and <NUM> rotate.

The head moving mechanism <NUM> and the head unit <NUM> will be described with reference to <FIG>. The head moving mechanism <NUM> is a mechanism for moving the head unit <NUM> including the thermal head <NUM> in the left-right direction and the up-down direction. The head moving mechanism <NUM> is provided below the center of the base plate <NUM> (see <FIG>). The head moving mechanism <NUM> includes a head holding mechanism <NUM>, a head left-right moving mechanism <NUM>, and a head pressing mechanism <NUM>.

As shown in <FIG>, the head holding mechanism <NUM> holds the head unit <NUM>. The head holding mechanism <NUM> includes a guide rail <NUM>, a guide member <NUM>, a support portion <NUM>, a head support portion 48A, an engaging member 48B, springs <NUM>, and the like.

The guide rail <NUM> extends in the left-right direction and is fixed to a lower side of the base plate <NUM>. The guide member <NUM> has a substantially rectangular parallelepiped shape. The guide member <NUM> has a recessed portion that is not shown on a rear surface of the guide member <NUM>. The recessed portion is provided across the rear surface in the left-right direction. The recessed portion of the guide member <NUM> is engaged with the guide rail <NUM> to be movable in the left-right direction.

As shown in <FIG>, the support portion <NUM> is formed in a substantially rectangular parallelepiped shape extending in the up-down direction. A rear side of a lower end portion of the support portion <NUM> is fixed to the guide member <NUM>. The support portion <NUM> is fixed to the guide member <NUM>, and thus is movable in the left-right direction together with the guide member <NUM>. A front side of the support portion <NUM> has a pair of left and right groove portions that is not shown extending in the up-down direction.

As shown in <FIG>, the head support portion 48A is formed in a substantially rectangular parallelepiped shape extending in a front-rear direction. A rear end portion of the head support portion 48A is engaged with the pair of left and right groove portions of the support portion <NUM> to be slidable in the up-down direction. The rear end portion of the head support portion 48A includes a pair of pins <NUM> protruding in left and right directions, respectively. The head support portion 48A has an insertion hole <NUM> (see <FIG>) at a central portion of the head support portion 48A in the front-rear direction. The insertion hole <NUM> penetrates the head support portion 48A in the left-right direction. The engaging member 48B extending in the front-rear direction is formed in an inverted U-shape in a front view. A rear end portion of the engaging member 48B is pivotally supported by the pair of left and right pins <NUM> (see <FIG> and <FIG>). Therefore, the engaging member 48B is pivotable about an axis of the pair of left and right pins <NUM> (see <FIG>).

On a front side with respect to a center of the engaging member 48B in the front-rear direction, bifurcated claw portions 481R and <NUM> protruding downward from end portions in the left-right direction are provided (see <FIG> and <FIG>). As shown in <FIG>, the right bifurcated claw portion 481R is engaged with a right end portion of a protruding portion 68A of the head unit <NUM>, which will be described later, to sandwich the right end portion in the front-rear direction. The left bifurcated claw portion <NUM> (see <FIG> and <FIG>) is engaged with a left end portion of the protruding portion 68A in the front-rear direction. Hereinafter, the engagement of the left and right bifurcated claw portions 481R and <NUM> with the right end portion and the left end portion of the protruding portion 68A, respectively, is also referred to as "engagement of the engaging member 48B with the protruding portion 68A".

As shown in <FIG>, the head unit <NUM> includes a head fixing portion <NUM> and the thermal head <NUM>. The head fixing portion <NUM> is formed in a triangular prism shape extending in the front-rear direction. A right surface of the head fixing portion <NUM> faces the left bifurcated claw portion <NUM>. A lower surface of the head fixing portion <NUM> faces obliquely downward to the left.

The protruding portion 68A formed in a rod shape protrudes rightward from the right surface of the head fixing portion <NUM>. The protruding portion 68A is inserted through the insertion hole <NUM> (see <FIG>) of the head support portion 48A. The right end portion of the protruding portion 68A protrudes to a right side with respect to a right surface of the head support portion 48A. The head fixing portion <NUM> is fixed to the head holding mechanism <NUM> by engaging the engaging member 48B with the protruding portion 68A. In this case, the left bifurcated claw portion <NUM> is disposed between the head fixing portion <NUM> and the head support portion 48A. The right surface of the head fixing portion <NUM> and a left surface of the bifurcated claw portion <NUM> are in contact with each other, and thus a position of the head fixing portion <NUM> in the left-right direction is fixed. The protruding portion 68A is inserted through the insertion hole <NUM>, and thus front, rear, upper, and lower positions of the head fixing portion <NUM> are fixed.

The thermal head <NUM> is fixed to the head fixing portion <NUM> with bolts that is not shown in a state where the lower surface of the head fixing portion <NUM> is in contact with an upper surface of the thermal head <NUM>. Therefore, the thermal head <NUM> is held to be movable in an up-down direction while maintaining a predetermined angle. The thermal head <NUM> is exposed from the opening at the lower side of the housing <NUM>.

As shown in <FIG>, <FIG>, and <FIG>, a movement drive portion <NUM> of the head left-right moving mechanism <NUM> includes the motor 72A, pulleys 72R and <NUM>, a belt 72B, and the like. The motor 72A is provided on the rear side with respect to the base plate <NUM> and on a rear side with respect to a right end portion of the guide rail <NUM>. A shaft of the motor 72A extends forward. The pulley 72R is provided on the shaft of the motor 72A. The pulley 72R rotates together with rotation of the shaft of the motor 72A. The pulley <NUM> is rotatably provided on the front side and a left end portion with respect to the base plate <NUM>. The pulley <NUM> is disposed at the same height as the shaft of the motor 72A in the up-down direction, that is, at the same height as the pulley 72R.

The belt 72B has an annular shape. The belt 72B is stretched over the pulleys <NUM> and 72R. The belt 72B rotates with rotation of the pulleys <NUM> and 72R. An upper end portion of the support portion <NUM> is fixed to a lower side of the belt 72B (see <FIG> and <FIG>). The head holding mechanism <NUM> is provided on the support portion <NUM>, and thus the head holding mechanism <NUM> moves in the left-right direction in accordance with the rotation of the belt 72B. The head holding mechanism <NUM> holds the thermal head <NUM>, and thus the thermal head <NUM> is also movable in the left-right direction.

The head pressing mechanism <NUM> includes a rotation shaft <NUM>, a pair of shaft support portions <NUM>, a pair of pivot members <NUM>, a sliding shaft <NUM>, a pressing shaft <NUM>, an L-shaped member <NUM>, the springs <NUM>, a rotation drive portion <NUM>, a sensor <NUM>, and the like. The rotation shaft <NUM> extends in the left-right direction. The pair of shaft support portions <NUM> are separated from each other in the left-right direction. The left shaft support portion <NUM> rotatably supports a left end portion of the rotation shaft <NUM>. The right shaft support portion <NUM> rotatably supports a right end portion of the rotation shaft <NUM>. The pair of shaft support portions <NUM> are arranged above the support portion <NUM>. The pair of shaft support portions <NUM> are fixed to an upper side of the base plate <NUM>. The rotation shaft <NUM> rotates in a state of being fixed by the pair of shaft support portions <NUM>.

The pair of pivot members <NUM> are separated from each other in the left-right direction. Each of the pair of pivot members <NUM> is formed in a plate shape extending in the up-down direction. The left pivot member <NUM> is disposed on a right side of the left shaft support portion <NUM>. The right pivot member <NUM> is disposed on a left side of the right shaft support portion <NUM>. Each of the pair of pivot members <NUM> has a through hole <NUM> (see <FIG>), at a substantially center of each of the pair of pivot members <NUM>, penetrating in the left-right direction. The rotation shaft <NUM> is fixed in a state of being inserted through the through hole <NUM>. The pair of pivot members <NUM> pivot integrally with the rotation shaft <NUM> around the rotation shaft <NUM>.

The sliding shaft <NUM> extends in the left-right direction. A left end of the sliding shaft <NUM> is fixed to an upper end portion of the left pivot member <NUM>. A right end of the sliding shaft <NUM> is fixed to an upper end portion of the right pivot member <NUM>. The sliding shaft <NUM> is provided above the rotation shaft <NUM>. The pressing shaft <NUM> extends in the left-right direction. A left end of the pressing shaft <NUM> is fixed to a lower end portion of the left pivot member <NUM>. A right end of the pressing shaft <NUM> is fixed to a lower end portion of the right pivot member <NUM>. The pressing shaft <NUM> is provided below the rotation shaft <NUM>. The sliding shaft <NUM> and the pressing shaft <NUM> pivot integrally with the rotation shaft <NUM> around the rotation shaft <NUM>.

As shown in <FIG>, the L-shaped member <NUM> is formed in an inverted L-shape in a right side view. The L-shaped member <NUM> includes a central portion 18C, an upper end portion 18U, and a front end portion 18F. The upper end portion 18U extends upward from an upper portion of the central portion 18C. The front end portion 18F extends forward from a front portion of the central portion 18C. The central portion 18C is pivotally supported by the pressing shaft <NUM> to be movable in the left-right direction along the pressing shaft <NUM> and pivotable about the pressing shaft <NUM>. The front portion of the central portion 18C includes a pair of pins <NUM> protruding in left and right directions, respectively.

As shown in <FIG> and <FIG>, the upper end portion 18U of the L-shaped member <NUM> is located above the rotation shaft <NUM>. The upper end portion 18U is provided with a shaft portion 19A (see <FIG>) extending upward. The shaft portion 19A rotatably supports a sliding roller <NUM>. The sliding roller <NUM> comes into contact with the sliding shaft <NUM> from the front and slides in the left-right direction.

A pressing roller <NUM> is provided on a lower side of the front end portion 18F of the L-shaped member <NUM>. The pressing roller <NUM> includes a shaft portion 23A, a right wheel portion 23R, and a left wheel portion <NUM>. The shaft portion 23A extends in the left-right direction and is pivotally supported on the lower side of the front end portion 18F of the L-shaped member <NUM>. The right wheel portion 23R is formed in a substantially circular shape in a side view, and is fixed to a right end of the shaft portion 23A. The left wheel portion <NUM> is formed in a substantially circular shape in a side view, and is fixed to a left side of the shaft portion 23A. The right wheel portion 23R and the left wheel portion <NUM> rotate about the shaft portion 23A. The pressing roller <NUM> is in contact, to be slidable, with an upper surface of the engaging member 48B of the head holding mechanism <NUM>. The right wheel portion 23R and the left wheel portion <NUM> of the pressing roller <NUM> sandwich a front end portion of the engaging member 48B in the left-right direction. Therefore, the L-shaped member <NUM> moves in the left-right direction in conjunction with movement of the head unit <NUM> in the left-right direction.

As shown in <FIG> and <FIG>, a pair of springs <NUM> are separated from each other in the left-right direction. An upper end portion of the right spring <NUM> is attached to the right pin <NUM> of the L-shaped member <NUM> (see <FIG> and <FIG>). A lower end portion of the right spring <NUM> is attached to the right pin <NUM> of the head support portion 48A. An upper end portion of the left spring <NUM> is attached to the left pin <NUM> of the L-shaped member <NUM> (see <FIG>). A lower end portion of the left spring <NUM> is attached to the pin <NUM> of the head support portion 48A. The pair of left and right springs <NUM> bias the head unit <NUM> upward. In this case, the thermal head <NUM> is disposed at a retracted position (see <FIG> and <FIG>) separated from the ink ribbon.

The rotation drive portion <NUM> includes a motor <NUM>, a cam support portion <NUM>, a cam follower 77A, a plate spring <NUM>, and the like (see <FIG> and <FIG>). The motor <NUM> is disposed on the rear side with respect to the base plate <NUM> and on a left side with respect to the motor 72A. The cam support portion <NUM> is a substantially rectangular plate member extending in the up-down and front-rear directions. One end portion of the cam support portion <NUM> is fixed to a drive shaft 76A of the motor <NUM> extending parallel to the left-right direction. The cam follower 77A is provided on the other end portion of the cam support portion <NUM>. The cam follower 77A is formed in a substantially columnar shape extending in the left-right direction. The cam follower 77A rotates around the drive shaft 76A together with the cam support portion <NUM>. A rear end portion 78R of the plate spring <NUM> is connected to the cam follower 77A. A front end portion 78F of the plate spring <NUM> is fastened to the rotation shaft <NUM> from below with a bolt 11A.

The sensor <NUM> includes a magnetic member 58A and a Hall sensor 58B (see <FIG> and <FIG>). The magnetic member 58A is attached to a left end portion of the rotation shaft <NUM>. The Hall sensor 58B is provided in the housing <NUM>. The Hall sensor 58B faces a left side of the magnetic member 58A. The Hall sensor 58B detects a change in a magnetic flux density of the magnetic member 58A that changes in accordance with the rotation of the rotation shaft <NUM>. The Hall sensor 58B detects a rotational position of the rotation shaft <NUM> based on the detected change in the magnetic flux density.

The pressing for the thermal head <NUM> will be described. In the printing device <NUM>, the cam follower 77A rotates about the drive shaft 76A in accordance with rotation of the motor <NUM>. As the cam follower 77A rotates, the rear end portion 78R of the plate spring <NUM> moves in the up-down direction together with the cam follower 77A of the cam support portion <NUM> (see <FIG> and <FIG>). Accordingly, an inclination angle of the plate spring <NUM> about the rotation shaft <NUM> changes. That is, in a case where the cam follower 77A moves downward due to the rotation of the cam support portion <NUM> (see <FIG>), the inclination angle of the plate spring <NUM> from the front end portion 78F to the rear end portion 78R increases. In a case where the cam follower 77A moves upward due to the rotation of the cam support portion <NUM> (see <FIG>), the inclination angle of the plate spring <NUM> from the front end portion 78F to the rear end portion 78R becomes small. As the inclination angle changes, a position of the front end portion 78F changes. Accordingly, the rotation shaft <NUM> rotates.

In a case where the drive shaft 76A of the motor <NUM> moves in a clockwise direction in a right side view (see <FIG>), the cam support portion <NUM> rotates in the clockwise direction in the right side view. In a case where the cam follower 77A moves downward, the inclination angle of the plate spring <NUM> increases. At this time, the front end portion 78F moves forward and upward. The rotation shaft <NUM> rotates in the clockwise direction in the right side view. Accordingly, the pivot member <NUM> pivots about the rotation shaft <NUM> in the clockwise direction in the right side view. Therefore, the sliding shaft <NUM> pivots clockwise in the right side view together with the pivot member <NUM>. At this time, the L-shaped member <NUM> moves the thermal head <NUM> upward with a biasing force of the pair of left and right springs <NUM>. Therefore, the thermal head <NUM> is disposed at the retracted position where the thermal head <NUM> is separated from the ink ribbon.

In a case where the motor <NUM> moves in a counterclockwise direction in the right side view from a state shown in <FIG> (see <FIG>), the cam follower 77A rotates in the counterclockwise direction in the right side view. When the cam follower 77A moves upward, the inclination angle of the plate spring <NUM> decreases. At this time, the front end portion 78F moves rearward and downward. In this case, the rotation shaft <NUM> rotates in the counterclockwise direction in the right side view. Accordingly, the pivot member <NUM> pivots about the rotation shaft <NUM> in the counterclockwise direction in the right side view. Therefore, the sliding shaft <NUM> rotates counterclockwise in the right side view about an axis of the rotation shaft <NUM>. At this time, the sliding roller <NUM> of the L-shaped member <NUM> pivots counterclockwise in the right side view about the rotation shaft <NUM> together with the sliding shaft <NUM>.

In a case where the sliding roller <NUM> pivots counterclockwise in the right side view, the L-shaped member <NUM> pivots counterclockwise in the right side view about the pressing shaft <NUM>. Therefore, the pressing roller <NUM> provided on the front end portion 18F moves downward while pivoting about the pressing shaft <NUM> in the counterclockwise direction in the right side view. Due to the downward movement of the pressing roller <NUM>, the engaging member 48B of the head holding mechanism <NUM> is pressed downward against the upward biasing force of the springs <NUM>. At this time, the head support portion 48A slides downward with respect to the support portion <NUM> together with the head unit <NUM>. Therefore, the head unit <NUM> is pressed downward. Accordingly, the thermal head <NUM> moves to a printing position where printing can be performed on the printing medium (see <FIG> and <FIG>).

At the time of performing the printing, the ink ribbon is fed out from the ribbon roll of the supply roll shaft <NUM> and conveyed in the cassette <NUM>. The fed ink ribbon moves between the guide roller <NUM> and the guide roller <NUM>. The thermal head <NUM> is moved up, down, left, and right by the head moving mechanism <NUM> to move from the retracted position (see <FIG> and <FIG>) to the printing position (see <FIG> and <FIG>). The thermal head <NUM> at the printing position heats a portion of the fed ink ribbon stretched between the guide roller <NUM> and the guide roller <NUM>. In a case where an ink of the ink ribbon is heated, the ink is transferred to a packaging material disposed on a lower side with respect to the printing device <NUM> by the platen of the packaging machine that is not shown. The heated ink ribbon is taken up by the spool of the take-up roll shaft <NUM>.

As described above, the thermal head <NUM> moves in the up-down direction in conjunction with the rotation of the rotation shaft <NUM>. The printing device <NUM> can detect the rotational position of the rotation shaft <NUM> by the sensor <NUM>. That is, the rotational position of the rotation shaft <NUM> and a position of the thermal head <NUM> in the up-down direction correspond to each other, and thus the printing device <NUM> can specify the position of the thermal head <NUM> in the up-down direction from a detection result of the rotational position of the rotation shaft <NUM>. For example, in a case where a surface of the platen comes into contact with a lower surface of the thermal head <NUM>, the printing device <NUM> can detect the position of the thermal head <NUM> in the up-down direction as a position of the platen in the up-down direction.

Replacement of the head unit <NUM> will be described with reference to <FIG> and <FIG>. At the time of replacing the head unit <NUM>, the user operates the printing device <NUM> to move the head unit <NUM> upward using the head pressing mechanism <NUM>. Accordingly, the thermal head <NUM> is moved to the retracted position. The user pivots the engaging member 48B counterclockwise in the right side view about the axis of the pins <NUM>. Accordingly, the engagement of the engaging member 48B with the protruding portion 68A is released (see <FIG>). At this time, the user moves the head unit <NUM> leftward. Accordingly, the user can remove the head unit <NUM> from the head holding mechanism <NUM>.

Next, the user inserts a protruding portion 68A of a new head unit <NUM> through the insertion hole <NUM> of the head support portion 48A. The user pivots the engaging member 48B clockwise in the right side view to engage the engaging member 48B with the protruding portion 68A inserted through the insertion hole <NUM>. Accordingly, the replacement of the head unit <NUM> by the user is completed.

As described above, in the printing device <NUM>, the rotation shaft <NUM> and the pressing shaft <NUM> are separately provided. Therefore, the printing device <NUM> can move the thermal head <NUM> without limiting a movable range of the thermal head <NUM> in the left-right direction, as compared with a case where the thermal head <NUM> is provided on the rotation shaft <NUM>, moves in the left-right direction on the rotation shaft <NUM>, and is pressed downward due to the rotation of the rotation shaft <NUM>. Therefore, the printing device <NUM> can increase a movable range of the thermal head <NUM>.

The sensor <NUM> can detect the rotational position of the rotation shaft <NUM>. Therefore, the printing device <NUM> can accurately detect the position of the thermal head <NUM> in the up-down direction by detecting the rotational position of the rotation shaft <NUM> by the sensor <NUM>.

The rotation drive portion <NUM> includes the motor <NUM>, the cam support portion <NUM>, the cam follower 77A, and the plate spring <NUM>. The cam support portion <NUM> is provided on the drive shaft 76A of the motor <NUM> extending parallel to the left-right direction. The rear end portion 78R of the plate spring <NUM> is connected to the cam follower 77A, and the front end portion 78F of the plate spring <NUM> is fixed to the rotation shaft <NUM>. In the printing device <NUM>, the cam follower 77A rotates in accordance with the rotation of the motor <NUM>. As the cam follower 77A rotates, the rear end portion 78R of the plate spring <NUM> moves in the up-down direction together with the cam follower 77A. Therefore, the front end portion 78F of the plate spring <NUM> moves the rotation shaft <NUM> in a direction in which the rotation shaft <NUM> rotates, in accordance with the inclination angle of the plate spring <NUM>. Therefore, the rotation shaft <NUM> can rotate. In the printing device <NUM>, the rotation drive portion <NUM> can be implemented by the motor <NUM>, the cam follower 77A, and the plate spring <NUM> at low cost.

The head holding mechanism <NUM> holds the thermal head <NUM> from above. The support portion <NUM> supports the head holding mechanism <NUM> to be movable in the up-down direction. The pressing roller <NUM> presses the head holding mechanism <NUM> from above to below. Therefore, the pressing roller <NUM> can press the thermal head <NUM> downward via the head holding mechanism <NUM>.

The thermal head <NUM> is detachably attached to the head holding mechanism <NUM>. The thermal head <NUM> includes the protruding portion 68A protruding rightward. The head holding mechanism <NUM> includes the head support portion 48A and the engaging member 48B. The head support portion 48A has the insertion hole <NUM> penetrating in the left-right direction through which the protruding portion 68A is allowed to be inserted in a case where the thermal head <NUM> is mounted to the head holding mechanism <NUM>. The engaging member 48B is engaged with the protruding portion 68A in a state where the protruding portion 68A is inserted through the insertion hole <NUM> of the head support portion 48A. In the printing device <NUM>, the thermal head <NUM> is detachably attached to the head holding mechanism <NUM>. In the head holding mechanism <NUM>, the engaging member 48B is engaged with the protruding portion 68A in a state where the protruding portion 68A is inserted through the insertion hole <NUM> of the head support portion 48A. Therefore, the thermal head <NUM> can be reliably fixed. Therefore, the user can easily replace the thermal head <NUM>.

The present invention is not limited to the above embodiment, and various modifications are possible. The support portion <NUM> may directly hold the thermal head <NUM> to be movable in the up-down direction without using the head holding mechanism <NUM>. In this case, the head unit <NUM> may not include the head fixing portion <NUM>. The head unit <NUM> may be non-replaceable. The L-shaped member <NUM> has an L-shape, but may be a member extending in an up-down direction. Only one of the pair of springs <NUM> may be provided. Instead of the sliding roller <NUM>, a member that slides along the sliding shaft <NUM> may be provided. Instead of the pressing roller <NUM>, a member capable of pressing the thermal head <NUM> may be provided. This member has a structure that converts a force for pivoting the sliding shaft <NUM> into a force for pressing the head unit <NUM> downward.

The sensor <NUM> is not limited to the magnetic member 58A and the Hall sensor 58B. For example, the rotational position of the motor <NUM> may be detected by an encoder, and the position of the thermal head <NUM> may be detected using information on the rotational position of the motor <NUM>.

The rotation drive portion <NUM> is implemented by the motor <NUM>, the cam follower 77A, and the plate spring <NUM>, but may be configured to rotate the rotation shaft <NUM> with a gear or the like. In such a case, a movable distance of the head in the left-right direction can also be set to be wide regardless of a length of the rotation shaft <NUM>, the gear, and the like. The plate spring <NUM> may be a plate.

The configuration of the head holding mechanism <NUM> is not limited to the above configuration, and may be any configuration as long as the thermal head <NUM> can be pressed downward.

The head holding mechanism <NUM> is engaged with the protruding portion 68A with the left and right bifurcated claw portions <NUM> and 481R, but may be engaged with the protruding portion 68A with one side alone. The head holding mechanism <NUM> may be engaged with the protruding portion 68A by being fixed to a tip end portion of the protruding portion 68A with a nut or the like. In an example, a form in which the printing device <NUM> is installed and used to perform printing on a lower surface has been described, but a printing surface can be freely changed by changing an installation form. For example, it is also possible to use the printing device <NUM> in such a manner that the printing device <NUM> is installed sideways and performs printing on a side surface (vertical surface).

Claim 1:
A printing device (<NUM>) comprising:
a thermal head (<NUM>);
a rotation shaft (<NUM>) extending in an axial direction and rotatably supported;
a rotation drive portion (<NUM>) configured to rotate the rotation shaft;
a pivot member (<NUM>) connected to the rotation shaft and configured to pivot integrally with the rotation shaft about the rotation shaft;
a first support portion (<NUM>) configured to support the thermal head to be movable in an up-down direction intersecting the axial direction;
a second support portion (<NUM>, <NUM>) configured to support the first support portion to be movable parallel to the axial direction;
a biasing means (<NUM>) configured to bias the thermal head upward; and
a movement drive portion (<NUM>) configured to drive the first support portion in the axial direction,
characterized in that the printing device further comprises:
a first pivot shaft (<NUM>) supported by the pivot member, extending parallel to the axial direction, located below the rotation shaft, and configured to pivot integrally with the pivot member about the rotation shaft;
a support member (<NUM>) supported by the first pivot shaft to be movable along the first pivot shaft and to be pivotable about the first pivot shaft, the support member including an upper end portion located above the rotation shaft, a lower end portion located below the rotation shaft, and an intermediate portion located between the upper end portion and the lower end portion; and
a pressing portion (<NUM>) provided on the lower end portion of the support member and configured to press the thermal head downward.