Patent Description:
Hitherto, there have been proposed various types of tape printing apparatus including cutting means for cutting an elongated roll sheet over an entire width of the roll sheet. An example of a printer with a cutter is described in <CIT>. That document discloses a cutter unit configured to cut a recording sheet to be advanced toward a forward side in an advancing direction, the cutter unit comprising: a fixed blade, which includes a fixed blade edge, and is provided on a first surface side of the recording sheet; a movable blade including: a movable blade edge opposed to the fixed blade edge in a cutting direction crossing the advancing direction; and a sliding surface, which is provided on a first side in the advancing direction, and is configured to be slid on the fixed blade; and a rack holder capable of reciprocating along the cutting direction, the rack holder including a movable blade holder configurable to support the movable blade. For example, there has been widely known a tape printing apparatus including cutting means for cutting a roll sheet over the entire width of the roll sheet by moving a movable blade in a reciprocating manner in a thickness direction of the roll sheet to slide the movable blade on a fixed blade. This tape printing apparatus can suitably cut the roll sheet through use of an urging member such as a presser bar spring for urging a sliding surface of the movable blade, which is to be slid on the fixed blade, to the fixed blade. For example, as the tape printing apparatus of this type, there has been known an apparatus including a pressing spring configured so as to allow the movable blade to freely reciprocate in a tape thickness direction under a state in which the movable blade is pressed to the fixed blade side.

However, in the movable blade of the tape printing apparatus described above, a surface (front surface) opposite to the sliding surface, which is slid on the fixed blade every time the movable blade is moved in a reciprocating manner, is slid on a part (recessed portion) of the fixed pressing spring, and hence a large sliding load is applied to the movable blade. Accordingly, there has been a problem in that a sliding portion of the movable blade is worn, which may result in shortening a lifetime of the movable blade or reducing durability of a cutting mechanism. Further, as a method of reducing the sliding load, a method of providing, for example, a lubricant or a sleeve between the pressing spring and the movable blade may be employed. However, there has been a problem in that such a method may complicate manufacturing steps, which may result in requiring more time and cost for manufacturing the tape printing apparatus.

Accordingly, in this technical field, there has been a demand for a cutter unit and a printer which are capable of cutting a recording sheet under a state in which a movable blade is pressed to a fixed blade side and reducing a sliding load on the movable blade.

According to one embodiment of the present invention, there is provided a cutter unit configured to cut a recording sheet to be advanced toward a forward side in an advancing direction, the cutter unit including: a fixed blade, which includes a fixed blade edge, and is provided on a first surface side of the recording sheet; a movable blade including: a movable blade edge opposed to the fixed blade edge in a cutting direction crossing the advancing direction; and a sliding surface, which is provided on a backward side in the advancing direction, and is configured to be slid on the fixed blade; and a rack holder capable of reciprocating along the cutting direction, the rack holder including: a movable blade holder configured to support the movable blade; and an urging member configured to urge the movable blade to the backward side in the advancing direction.

In the above-mentioned cutter unit according to the one embodiment of the present invention, the urging member may include: a first end to be brought into abutment against the movable blade holder; and a second end to be brought into abutment against the forward side of the movable blade in the advancing direction.

In the above-mentioned cutter unit according to the one embodiment of the present invention, the urging member may be a pressurizing spring.

In the above-mentioned cutter unit according to the one embodiment of the present invention, the movable blade edge of the movable blade may be formed into an inverted V shape extending from both ends toward a center portion of the movable blade edge.

In the above-mentioned cutter unit according to the one embodiment of the present invention, the urging member may be provided at a center portion of the movable blade.

In the above-mentioned cutter unit according to the one embodiment of the present invention, the movable blade holder may include a plurality of grooves that are formed in a front end surface of the movable blade holder on the forward side, and each may have an opening.

According to one embodiment of the present invention, there is provided a printer including: a recording sheet to be advanced toward a forward side in an advancing direction; and a cutter unit configured to cut the recording sheet, the cutter unit including: a fixed blade, which includes a fixed blade edge, and is provided on a first surface side of the recording sheet; a movable blade including: a movable blade edge opposed to the fixed blade edge in a cutting direction crossing the advancing direction; and a sliding surface, which is provided on a backward side in the advancing direction, and is configured to be slid on the fixed blade; and a rack holder capable of reciprocating along the cutting direction, the rack holder including: a movable blade holder configured to hold the movable blade; and an urging member configured to urge the movable blade to the backward side in the advancing direction.

One embodiment of the present invention is described by way of example only with reference to <FIG>. In the following embodiment, description is made of, as an example, a thermal printer that is employed in, for example, a cash register or a portable terminal device and is capable of perform printing on, for example, various kinds of labels, receipts, and tickets. Further, in the embodiment and a modification example described later, in some cases, corresponding components are denoted by the same reference symbols, and description thereof is omitted. In addition, in the following description, an expression for describing relative or absolute arrangement, such as "parallel", "orthogonal", "center", or "coaxial", refers to not only the arrangement in a strict sense but also a state of being relatively displaced with an angle or distance to the degree that falls within a tolerance or can provide the same function.

<FIG> is a front view for illustrating a thermal printer <NUM>. <FIG> is a side view for illustrating the thermal printer <NUM>. <FIG> is a sectional view for illustrating an internal configuration of the thermal printer <NUM>, showing a cross section taken along the line I-I of <FIG>. In the drawings, FR, RH, and UP represent a front side, a right side, and an upper side, respectively. As illustrated in <FIG>, the thermal printer <NUM> includes a casing <NUM>, a printing unit <NUM>, a cutter unit <NUM> (see <FIG> and <FIG>), and a recording sheet P.

As illustrated in <FIG>, the thermal printer <NUM> is a printer that performs printing on a print surface P1 (front surface) of the recording sheet P by a thermal head <NUM> while conveying the recording sheet P through rotation of a platen roller <NUM>, which is to be described later, under a state in which the platen roller <NUM> and the thermal head <NUM> sandwich the recording sheet P therebetween. The thermal printer <NUM> is installed on an installation surface G. In the following description of the casing <NUM> and the printing unit <NUM>, a direction perpendicular to the installation surface G is referred to as an up-and-down direction (the upper side is indicated by the arrow UP), and two directions orthogonal to the up-and-down direction are referred to as a front-and-back direction (the front side is indicated by the arrow FR) and a right-and-left direction (the right side is indicated by the arrow RH).

As illustrated in <FIG>, the recording sheet P is a recording sheet to be used for printing by the thermal printer <NUM>. The recording sheet P has the print surface P1 (front surface) formed on a front surface thereof, and has a back surface P2 formed on a side opposite to the print surface P1 in the up-and-down direction. The recording sheet P is rolled up around a tubular core R1 with the print surface P1 facing the front side in the up-and-down direction, and thus forms a roll portion R. The roll portion R may have a configuration without the core R1. A leading edge portion PA of the recording sheet P is drawn to the front side, and is inserted between the thermal head <NUM> and the platen roller <NUM>. The roll portion R is located inside a housing <NUM> on a rear side opposite to the front side. When an upper cover <NUM> is in an opened position, the roll portion R is removed from or loaded into the housing <NUM> through an upper end opening portion 20a of the housing <NUM>.

The casing <NUM> is formed into a box shape. Specifically, the casing <NUM> includes the housing <NUM> and the upper cover <NUM>.

The housing <NUM> is formed into a box shape including the upper end opening portion 20a formed in an upper portion of the housing <NUM>, and is installed on the installation surface G. The housing <NUM> has a size large enough to allow the printing unit <NUM>, the cutter unit <NUM>, and the recording sheet P to be accommodated therein.

The upper cover <NUM> opens and closes the upper end opening portion 20a of the housing <NUM>. Specifically, the upper cover <NUM> is formed into a box shape opened downward, and has the same shape as that of the housing <NUM> in plan view. When the upper cover <NUM> is in a closed position, the upper cover <NUM> is superposed on the housing <NUM> from the upper side to close the upper end opening portion 20a of the housing <NUM>. Further, at this time, a delivery slot <NUM> is formed between the housing <NUM> and the upper cover <NUM>. The delivery slot <NUM> allows communication between an inside and an outside of the casing <NUM>, and has a slit shape extending in the right-and-left direction. The delivery slot <NUM> allows the recording sheet P having been subjected to printing by the printing unit <NUM> to be delivered toward the front side. Meanwhile, when the upper cover <NUM> is in the opened position, the upper cover <NUM> is retreated from the upper side of the housing <NUM> to open the upper end opening portion 20a of the housing <NUM>.

As illustrated in <FIG>, the printing unit <NUM> includes the platen roller <NUM> and the thermal head <NUM>.

The platen roller <NUM> is a rubber roller extending in the right-and-left direction. The platen roller <NUM> is provided at a front end portion (portion closer to the delivery slot <NUM>) inside the housing <NUM>. The platen roller <NUM> is rotatable about an axis O1 extending along the right-and-left direction, and is rotated in accordance with a driving force of a driving motor (not shown) during conveyance of the recording sheet P.

The thermal head <NUM> is provided at a portion inside the upper cover <NUM> closer to the delivery slot <NUM>. The thermal head <NUM> includes a plurality of heating elements arrayed in line along the right-and-left direction. The thermal head <NUM> is fixed to a front end portion of the upper cover <NUM> with the heating elements facing downward.

The platen roller <NUM> and the thermal head <NUM> are opposed to each other in the up-and-down direction while sandwiching the recording sheet P therebetween. When the upper cover <NUM> is in the closed position, the thermal head <NUM> is held in close contact with the platen roller <NUM>. The recording sheet P is passed through between the platen roller <NUM> and the thermal head <NUM> in accordance with rotation of the platen roller <NUM>. Based on a signal output from a control board (not shown), a heating pattern of the heating elements of the thermal head <NUM> is controlled. Heat of the heating elements is transferred to the print surface P1 of the recording sheet P, and thus information (such as letters or figures) corresponding to the heating pattern is printed on the print surface P1.

<FIG> is a side view for illustrating a state in which a rack holder <NUM> of the thermal printer <NUM> includes a movable blade <NUM>. <FIG> is a side view for illustrating the movable blade <NUM>, a fixed blade <NUM>, and the rack holder <NUM> of the thermal printer <NUM> under a state in which the movable blade is moved away from the fixed blade toward a separation side B1 in a cutting direction B. <FIG> is a perspective view for illustrating the state illustrated in <FIG>. Further, <FIG> is a perspective view for illustrating a state in which a sliding plate <NUM> of the rack holder <NUM> is removed. <FIG> is a side view for illustrating the movable blade <NUM>, the fixed blade <NUM>, and the rack holder <NUM> of the thermal printer <NUM> under a state in which the movable blade performs cutting on a cutting side B2 in the cutting direction B. <FIG> is a perspective view for illustrating the state illustrated in <FIG>. As illustrated in <FIG>, the cutter unit <NUM> includes the fixed blade <NUM>, the movable blade <NUM>, the rack holder <NUM>, and a moving mechanism <NUM>.

In the following description of the cutter unit <NUM>, a direction in which the recording sheet P is to be conveyed is referred to as a conveying direction A (advancing direction). In the conveying direction A, a side toward which the recording sheet P is to be conveyed is referred to as a conveyance destination side (forward side) A1, and a side opposite to the conveyance destination side A1 is referred to as a conveyance source side (backward side) A2. Further, a direction of cutting the recording sheet P by the fixed blade <NUM> and the movable blade <NUM>, which is orthogonal to the conveying direction A, is referred to as the cutting direction B. In the cutting direction B, a side toward which the movable blade <NUM> is moved away from the fixed blade <NUM> is referred to as the separation side B1, and a side toward which the movable blade <NUM> is moved close to the fixed blade <NUM> to form a rift in the recording sheet P is referred to as the cutting side B2. In addition, a sheet width direction of the recording sheet P orthogonal to the conveying direction A and the cutting direction B is referred to as a width direction C. It is not always required that the cutting direction B be orthogonal to the conveying direction A, and it is only required that the cutting direction B match a direction of cutting the recording sheet P by the fixed blade <NUM> and the movable blade <NUM>.

In this embodiment, the conveying direction A substantially matches the front-and-back direction. The cutting direction B substantially matches the up-and-down direction. Further, the width direction C substantially matches the right-and-left direction. However, it is not always required that the conveying direction A match the front-and-back direction. It is not always required that the cutting direction B match the up-and-down direction. Further, it is not always required that the width direction C match the right-and-left direction.

As illustrated in <FIG>, <FIG>, <FIG>, the fixed blade <NUM> is arranged between the platen roller <NUM> and the delivery slot <NUM> in the housing <NUM>. Further, a surface (first surface) of the recording sheet P on the fixed blade <NUM> side is the back surface P2 of the recording sheet P. The fixed blade <NUM> is formed into a plate shape extending in the width direction C. The fixed blade <NUM> is fixed through predetermined means by a support portion (not shown) provided in the housing <NUM>. Further, the fixed blade <NUM> includes a fixed blade edge <NUM>.

The fixed blade edge <NUM> is a blade edge of the fixed blade <NUM> provided on the separation side B1 in the cutting direction B. The fixed blade edge <NUM> of the fixed blade <NUM> is slightly moved to the conveyance destination side A1 so that the fixed blade <NUM> is mounted in an inclined manner.

As illustrated in <FIG>, the movable blade <NUM> is arranged between the thermal head <NUM> and the delivery slot <NUM> in the upper cover <NUM>. Further, a surface of the recording sheet P on the movable blade <NUM> side is the print surface P1 of the recording sheet P. In addition, as illustrated in <FIG>, the movable blade <NUM> is arranged more on the conveyance destination side A1 than the fixed blade <NUM> in the conveying direction A when the movable blade <NUM> is slid on the fixed blade <NUM>. The movable blade <NUM> is formed into a plate shape extending in the width direction C. Further, the movable blade <NUM> is held by a movable blade holder <NUM> provided in the rack holder <NUM>. The movable blade <NUM> is moved in a reciprocating manner in the cutting direction B by the moving mechanism <NUM> through intermediation of the movable blade holder <NUM>. Accordingly, the movable blade <NUM> held by and integrated with the movable blade holder <NUM> is moved along with movement of the movable blade holder <NUM>. As illustrated in <FIG>, the movable blade <NUM> includes a movable blade edge <NUM>, a movable blade sliding surface <NUM> (sliding surface), an urging member abutment surface <NUM>, and insertion holes <NUM>.

The movable blade edge <NUM> is a blade edge of the movable blade <NUM> that forms a rift in the recording sheet P. The movable blade edge <NUM> is provided on the cutting side B2 of the movable blade <NUM> in the cutting direction B.

As illustrated in <FIG> and <FIG>, the movable blade edge <NUM> of the movable blade <NUM> is formed into an inverted V shape extending to the separation side B1 in the cutting direction B as extending from both ends toward a center of the movable blade edge <NUM> in the width direction C. A recessed portion <NUM> is formed in a center portion of the movable blade edge <NUM> of the movable blade <NUM> in the width direction C so as to be recessed to the separation side B1 with respect to the movable blade edge <NUM>.

A bottom of the recessed portion <NUM> is configured so as to be prevented from being brought into contact with the recording sheet P when the cutter unit <NUM> cuts the recording sheet P. With this configuration, when the cutter unit <NUM> cuts the recording sheet P, an uncut portion is formed in a portion of the recording sheet P opposed to the recessed portion <NUM> (so-called partial cut). In this embodiment, description is made of a configuration in which one recessed portion <NUM> is formed, and thus one uncut portion is formed (one uncut portion is left), but the present invention is not limited to this configuration. For example, a plurality of recessed portions <NUM> may be formed, and thus a plurality of uncut portions may be formed (a plurality of uncut portions may be left). The recessed portion <NUM> is not an essential component.

The movable blade sliding surface <NUM> (sliding surface) is a surface of the movable blade <NUM> on the conveyance source side A2, and is slid on the fixed blade edge <NUM> of the fixed blade <NUM>. The movable blade <NUM> causes the movable blade sliding surface <NUM> to slide on the fixed blade edge <NUM>. With this configuration, the movable blade <NUM> cuts the recording sheet P between the movable blade edge <NUM> and the fixed blade edge <NUM>. The fixed blade <NUM> including the fixed blade edge <NUM> is provided in an inclined manner in the cutter unit <NUM>. Accordingly, the fixed blade edge <NUM> is reliably brought into abutment against the movable blade sliding surface <NUM> of the movable blade <NUM>, and thus the recording sheet P can be cut accurately.

The urging member abutment surface <NUM> is a surface of the movable blade <NUM> on the conveyance destination side A1. The urging member abutment surface <NUM> is formed on a side opposite to the movable blade sliding surface <NUM> in the conveying direction A.

As illustrated in <FIG>, the insertion holes <NUM> are holes formed so as to allow the movable blade <NUM> to be held on the movable blade holder <NUM>. Two insertion holes <NUM> pass through the movable blade <NUM>, and are formed in positions closer to both end sides of the movable blade <NUM> in the width direction C. Through the insertion holes <NUM>, holding protruding portions 324p are inserted when the movable blade <NUM> is arranged so as to be superposed on a rear holding portion <NUM> of a movable blade holder main body <NUM> to be described later from the conveyance destination side A1 toward the conveyance source side A2. The insertion holes <NUM> are set to be slightly larger than the holding protruding portions 324p.

As illustrated in <FIG>, the rack holder <NUM> is arranged on the conveyance destination side A1 of the housing <NUM> and on the side of the print surface P1 of the recording sheet P. The rack holder <NUM> has a driving function of moving the movable blade <NUM> in a reciprocating manner for cutting the recording sheet P having been subjected to printing by the printing unit <NUM>, and a function of holding the movable blade <NUM>. The rack holder <NUM> includes a rack holder main body <NUM>, the movable blade holder <NUM>, and urging members <NUM>.

As illustrated in <FIG>, or <FIG>, the rack holder main body <NUM> includes a movable blade holder accommodating portion <NUM> and a moving mechanism mounting portion <NUM>.

The movable blade holder accommodating portion <NUM> is formed by both side walls <NUM>, the sliding plate <NUM> provided on the conveyance destination side A1, and an upper plate <NUM> provided on the conveyance source side A2. Further, the movable blade holder accommodating portion <NUM> defines a space S1 by the both side walls <NUM>, the sliding plate <NUM>, and the upper plate <NUM>.

The both side walls <NUM> are provided at both ends of the movable blade holder accommodating portion <NUM> in the width direction C, respectively. The both side walls <NUM> each include a plurality of hook portions 313a on the conveyance destination side A1, and hence the both side walls <NUM> can be hooked on the housing <NUM>. With this configuration, the rack holder <NUM> can be mounted to the housing <NUM>.

The sliding plate <NUM> is provided on the conveyance destination side A1 of the movable blade holder accommodating portion <NUM>. The sliding plate <NUM> includes a sliding surface 314f on the conveyance source side A2. A front end surface 321a of the movable blade holder main body <NUM> is slid on the sliding surface 314f when the movable blade holder <NUM> reciprocates along the cutting direction B. Further, the sliding plate <NUM> includes two guide holes 314q. The two guide holes 314q are formed in center portions of the sliding surface 314f in line in the cutting direction B, and pass through the sliding plate <NUM>. The two guide holes 314q are formed so as to have a larger length in the cutting direction B than that in the width direction C. With the two guide holes 314q, guide protruding portions 321p formed on the movable blade holder <NUM> are engaged. The guide holes 314q have a function of guiding the rack holder <NUM> so as to allow the rack holder <NUM> to move straight in the cutting direction B when the rack holder <NUM> is moved in a reciprocating manner in the cutting direction B. Further, through adjustment of the lengths of the guide holes 314q in the cutting direction B, movable ranges of the guide protruding portions 321p can be adjusted. Accordingly, the guide holes 314q can limit a movement range of the rack holder <NUM>. In addition, with the above-mentioned configuration, the guide holes 314q can eliminate a risk in that the movable blade <NUM> held in the rack holder <NUM> is moved beyond a reciprocating movable range. Further, an end portion of the sliding plate <NUM> on the cutting side B2 is curved toward the conveyance source side A2, and thus a slight opening, that is, an opening portion <NUM> is formed in the movable blade holder accommodating portion <NUM>. The opening portion <NUM> is set to have a width slightly larger than a width of the movable blade <NUM> in the conveying direction A so as to allow the movable blade <NUM> to reciprocate in the cutting direction B. The movement range of the rack holder <NUM> may be controlled with a configuration in which, in addition to the guide holes 314q, for example, a position sensor is provided in the movable blade holder accommodating portion <NUM>, and a movement position of the movable blade <NUM> is detected with the position sensor.

The upper plate <NUM> is provided on the separation side B1 of the movable blade holder accommodating portion <NUM>. The upper plate <NUM> includes a lower surface 315b on the cutting side B2.

As illustrated in <FIG>, <FIG>, the moving mechanism mounting portion <NUM> is a plate-like member to which the moving mechanism <NUM> can be mounted. The moving mechanism mounting portion <NUM> is provided on the lower surface 315b of the upper plate <NUM>. The moving mechanism mounting portion <NUM> extends along a horizontal plane defined by the conveying direction A and the cutting direction B.

As illustrated in <FIG>, the movable blade holder <NUM> is a holder that moves the movable blade <NUM> in a reciprocating manner in the cutting direction B while holding the movable blade <NUM>. The movable blade holder <NUM> includes the movable blade holder main body <NUM>, an urging member holding portion <NUM>, and a rack portion <NUM>. The movable blade holder <NUM> is accommodated in the space S1 defined in the movable blade holder accommodating portion <NUM>.

The movable blade holder main body <NUM> is a holder that holds the movable blade <NUM>. The movable blade holder main body <NUM> includes the two guide protruding portions 321p. The two guide protruding portions 321p are formed on the conveyance destination side A1 of the movable blade holder main body <NUM> and on the front end surface 321a, which is slid on the sliding plate <NUM>, and extend to the conveyance destination side A1. The guide protruding portions 321p are engaged with the guide holes 314q formed in the sliding plate <NUM>. The movable blade holder main body <NUM> causes the front end surface 321a to slide on the sliding surface 314f of the sliding plate <NUM>. In order to reduce a sliding load on the sliding plate <NUM>, a plurality of recessed portions <NUM> (grooves) each having an opening 321q are formed in the front end surface 321a. Further, the movable blade holder main body <NUM> includes the rear holding portion <NUM> on a rear side thereof.

The rear holding portion <NUM> is a plate-like member provided on the conveyance source side A2 of the movable blade holder main body <NUM> in the conveying direction A. The rear holding portion <NUM> overlaps the movable blade <NUM> provided on the conveyance destination side A1. The rear holding portion <NUM> has a function of holding the movable blade <NUM>. The rear holding portion <NUM> includes the two holding protruding portions 324p. The two holding protruding portions 324p are formed on the conveyance destination side A1 and on a surface that overlaps the movable blade <NUM>, and extend to the conveyance destination side A1.

As illustrated in <FIG>, the holding protruding portions 324p are set to be at substantially the same positions as those of the insertion holes <NUM> of the movable blade <NUM> in the width direction C. When the movable blade <NUM> is arranged from the conveyance destination side A1, the holding protruding portions 324p are inserted through the insertion holes <NUM> of the movable blade <NUM>. The holding protruding portions 324p slightly project from the insertion holes <NUM> to the conveyance destination side A1. With this configuration, the movable blade <NUM> is held on the movable blade holder main body <NUM>. Further, the holding protruding portions 324p are slightly smaller than the insertion holes <NUM> of the movable blade <NUM>. The holding protruding portions 324p are smaller than the insertion holes <NUM>, and thus can stably hold the movable blade <NUM> even in a case in which a position of the movable blade <NUM> is changed in the conveying direction A when the movable blade <NUM> is moved to the cutting side B2 and brought into abutment against the fixed blade <NUM>.

The urging member holding portion <NUM> is provided on the conveyance destination side A1 of the movable blade holder <NUM>. The urging member holding portion <NUM> is formed in a region from a lower end of the movable blade holder <NUM> to the cutting side B2, extends in the width direction C, and holds the urging members <NUM> to be described later. The urging member holding portion <NUM> includes a rear surface 322b on the conveyance source side A2. A first end <NUM> of each of the urging members <NUM> is brought into abutment against the rear surface 322b. Further, the rear surface 322b includes urging member holding protruding portions 322p extending to the conveyance source side A2. The urging member holding protruding portions 322p are formed at positions against which the first ends <NUM> of the urging members <NUM> are to be brought into abutment. In accordance with the number of the urging members <NUM>, the urging member holding protruding portions 322p of the same number are provided. The urging member holding protruding portions 322p are each set to have substantially the same size as a diameter of an inner periphery of each of the urging members <NUM> (pressurizing spring), and allow the urging members <NUM> to be fitted thereto. Accordingly, the urging member holding protruding portions 322p allow the urging members <NUM> to be easily mounted thereto without the need for, for example, an adhesive. The number of the urging member holding protruding portions 322p is not particularly limited. Further, the first end <NUM> of each of the urging members <NUM> may be fixed directly to the rear surface 322b without provision of the urging member holding protruding portions 322p, or the first end <NUM> may be fixed with, for example, an adhesive.

The rack portion <NUM> is provided on the conveyance source side A2 of the movable blade holder <NUM>. The rack portion <NUM> meshes with a second driving gear <NUM> of the moving mechanism <NUM> to be described later. When a rotational driving force in one direction is transmitted to the rack portion <NUM>, the rack portion <NUM> is moved in a reciprocating manner in the cutting direction B. Along with movement of the rack portion <NUM>, as well as the movable blade holder <NUM>, the movable blade <NUM> and the urging members <NUM> are moved in a reciprocating manner.

As illustrated in <FIG>, the moving mechanism <NUM> is driving means for moving the movable blade <NUM> in a reciprocating manner. The moving mechanism <NUM> is mounted to a predetermined position on one surface 312c of the moving mechanism mounting portion <NUM>. The moving mechanism <NUM> includes the driving motor (not shown), a first driving gear <NUM>, and the second driving gear <NUM>.

The driving motor gives the driving force to the first driving gear <NUM>. The driving force is transmitted to the first driving gear <NUM> by the driving motor, and thus the first driving gear <NUM> makes a rotary motion in a first rotation direction J1 in which the first driving gear <NUM> rotates in one direction, or in a second rotation direction J2 in which the first driving gear <NUM> rotates in a direction opposite to the first rotation direction J1. The second driving gear <NUM> is provided between the first driving gear <NUM> and the rack portion <NUM>. The second driving gear <NUM> meshes with the first driving gear <NUM> on the conveyance source side A2, and meshes with the rack portion <NUM> on the conveyance destination side A1. The rotational driving force is transmitted to the second driving gear <NUM> from the first driving gear <NUM>. When the first driving gear <NUM> rotates in the first rotation direction J1, the second driving gear <NUM> rotates in the second rotation direction J2 opposite to the rotation direction of the first driving gear <NUM>. When the first driving gear <NUM> rotates in the second rotation direction J2, the second driving gear <NUM> rotates in the first rotation direction J1 opposite to the rotation direction of the first driving gear <NUM>. When the second driving gear <NUM> rotates in the second rotation direction J2, the second driving gear <NUM> transmits the rotational driving force to the rack portion <NUM>, thereby moving the rack portion <NUM> to the cutting side B2 in the cutting direction B. When the second driving gear <NUM> rotates in the first rotation direction J1, the second driving gear <NUM> transmits the rotational driving force to the rack portion <NUM>, thereby moving the rack portion <NUM> to the separation side B1 in the cutting direction B.

With the above-mentioned configuration, the moving mechanism <NUM> moves the movable blade <NUM> in a reciprocating manner with respect to the recording sheet P through intermediation of the movable blade holder <NUM>, and causes the movable blade <NUM> and the fixed blade <NUM> to sandwich the recording sheet P therebetween, thereby forming a rift in the recording sheet P. In this embodiment, a movement range of the moving mechanism <NUM> is limited by the guide holes 314q and the guide protruding portions 321p described above. Accordingly, rotation ranges of the first driving gear <NUM> and the second driving gear <NUM> of the moving mechanism <NUM> are also limited. Owing to provision of the plurality of driving gears, the moving mechanism <NUM> can easily control an operation at the time of cutting, and can stabilize the cutting operation.

The urging members <NUM> always urge the movable blade <NUM> to the fixed blade <NUM>. As the urging members <NUM>, for example, pressurizing springs are used. In this embodiment, the urging members <NUM> include three pressurizing springs, and are arranged in the same line at substantially equal intervals in the width direction C. Further, the urging members <NUM> are arranged at such positions as to be prevented from overlapping the holding protruding portions 324p of the rear holding portion <NUM>. The urging members <NUM> always urge the movable blade <NUM> to the conveyance source side A2 in the conveying direction A. Accordingly, the fixed blade edge <NUM> is reliably brought into abutment against the movable blade sliding surface <NUM> of the movable blade <NUM>, and thus the recording sheet P can be cut accurately. The urging members <NUM> each include the first end <NUM> and a second end <NUM> along the conveying direction A.

The first end <NUM> is fitted and coupled to the urging member holding protruding portion 322p that is formed on the rear surface 322b of the urging member holding portion <NUM> provided on the conveyance source side A2 of the movable blade holder main body <NUM> and extends to the conveyance source side A2.

The second end <NUM> is brought into press contact with the urging member abutment surface <NUM> of the movable blade <NUM>. The urging members <NUM> are provided so as to always apply an urging force to the urging member abutment surface <NUM> of the movable blade <NUM> toward the conveyance source side A2 in the conveying direction A, and thus the urging members <NUM> are prevented from slipping off the rack holder <NUM>.

The urging members <NUM> are provided so as to apply the urging force to the movable blade <NUM> arranged more on the conveyance source side A2 than the urging members <NUM>. Regarding a position of each of the urging members <NUM>, it is desired that the urging member <NUM> be provided at a center of the movable blade <NUM> in the width direction C. With the arrangement at this position, each of the urging members <NUM> can reduce a risk in that a cutting failure occurs when the movable blade edge <NUM> of the movable blade <NUM> having an inverted V shape cuts the recording sheet P from both ends to a center of the recording sheet P. In this embodiment, three urging members <NUM> are used, but the number of the urging members <NUM> is not particularly limited. Further, it is not always required that the urging members <NUM> be the pressurizing springs, and it is only required that the urging members <NUM> (preferably always) apply the urging force to the movable blade <NUM> toward the conveyance source side A2. Further, a material, a size, a shape, or the number of the urging members <NUM> is selected as appropriate in accordance with, for example, application and a configuration of the cutter unit <NUM>.

Next, operations of the cutter unit <NUM> of the above-mentioned thermal printer <NUM> are described with reference to <FIG>, <FIG>.

<FIG> are views for illustrating the movable blade <NUM>, the fixed blade <NUM>, and the rack holder <NUM> of the thermal printer <NUM> under a state in which the movable blade is moved away from the fixed blade toward the separation side B1 in the cutting direction B. <FIG> are views for illustrating the movable blade <NUM>, the fixed blade <NUM>, and the rack holder <NUM> of the thermal printer <NUM> under a state in which the movable blade performs cutting on the cutting side B2 in the cutting direction B. First, as illustrated in <FIG>, the first driving gear <NUM> is rotated in the first rotation direction J1 by the driving force transmitted from the driving motor (not shown). When the first driving gear <NUM> rotates in the first rotation direction J1, the second driving gear <NUM>, which is provided on the conveyance destination side A1 and meshes with the first driving gear <NUM>, rotates in the second rotation direction J2 opposite to the rotation direction of the first driving gear <NUM>. The rack portion <NUM> provided in the movable blade holder <NUM> meshes with the second driving gear <NUM>. When the second driving gear <NUM> rotates in the second rotation direction J2, the rotational driving force is transmitted to the rack portion <NUM>, and thus the rack portion <NUM> is moved to the cutting side B2 in the cutting direction B. When the rack portion <NUM> is moved, the rack holder <NUM> is moved together with the rack portion <NUM>. The rack holder <NUM> holds the movable blade <NUM> through intermediation of the movable blade holder <NUM>, and hence moves the movable blade <NUM> to the cutting side B2 in the cutting direction B. When the movable blade <NUM> is moved to the cutting side B2 in the cutting direction B, the movable blade <NUM> can cut the recording sheet P between the movable blade edge <NUM> and the fixed blade edge <NUM>. The urging members <NUM> urge the movable blade <NUM>, and are moved to the cutting side B2 in the cutting direction B along with movement of the rack holder <NUM>. Accordingly, the urging members <NUM> can always urge the movable blade <NUM> without being slid on the urging member abutment surface <NUM> of the movable blade <NUM>.

Next, as illustrated in <FIG>, by the driving force transmitted from the driving motor (not shown), the first driving gear <NUM> is rotated in the second rotation direction J2. In this case, the second driving gear <NUM> rotates in the first rotation direction J1 opposite to the rotation direction of the first driving gear <NUM>. The rack portion <NUM> provided in the movable blade holder <NUM> meshes with the second driving gear <NUM>. When the second driving gear <NUM> rotates in the first rotation direction J1, the rotational driving force is transmitted to the rack portion <NUM>, and the rack portion <NUM> is moved to the separation side B1 in the cutting direction B. When the rack portion <NUM> is moved, the rack holder <NUM> is moved together with the rack portion <NUM>. The rack holder <NUM> holds the movable blade <NUM> through intermediation of the movable blade holder <NUM>. Accordingly, the movable blade <NUM> can be moved to the separation side B1 in the cutting direction B. The urging members <NUM> urge the movable blade <NUM>, and are moved to the separation side B1 in the cutting direction B along with movement of the rack holder <NUM>. Accordingly, the urging members <NUM> can always urge the movable blade <NUM> without being slid on the urging member abutment surface <NUM> of the movable blade <NUM>.

In this embodiment, the urging members <NUM> are provided in the rack holder <NUM>, and hence can always urge the movable blade <NUM>. Further, along with movement of the rack holder <NUM>, the movable blade <NUM> is moved in a reciprocating manner in the cutting direction B together with the urging members <NUM>. Accordingly, the movable blade <NUM> is not slid on the urging members <NUM>, thereby being capable of reducing the sliding load. Further, the movable blade <NUM> does not include a portion to be slid on the urging members <NUM>. With this configuration, the movable blade <NUM> can reduce a fear in that the movable blade <NUM> is worn due to sliding and generates, for example, abrasion powder.

Further, in this embodiment, the urging members <NUM> are each arranged at or towards the center of the movable blade <NUM> in the width direction C. When each of the urging members <NUM> is arranged at this position, each of the urging members <NUM> can reduce a risk in that a cutting failure occurs when the movable blade edge <NUM> of the movable blade <NUM> having an inverted V shape cuts the recording sheet P from the both ends to the center of the recording sheet P.

Further, in this embodiment, the front end surface 321a of the movable blade holder main body <NUM> includes the plurality of recessed portions <NUM> each having the opening 321q. Accordingly, when the movable blade holder main body <NUM> is slid on the sliding plate <NUM>, sliding portions can be reduced.

Further, in this embodiment, the guide holes 314q of the rack holder <NUM> have a function of guiding the rack holder <NUM> so as to allow the rack holder <NUM> to move straight in the cutting direction B when the rack holder <NUM> is moved in a reciprocating manner in the cutting direction B. Further, through adjustment of the lengths of the guide holes 314q in the cutting direction B, the movable ranges of the guide protruding portions 321p can be adjusted. Accordingly, the guide holes 314q can limit the movement range of the rack holder <NUM>. In addition, with the above-mentioned configuration, the guide holes 314q can reduce a fear in that the movable blade <NUM> held in the rack holder <NUM> is moved beyond the reciprocating movable range.

As described above, in the thermal printer <NUM> and the cutter unit <NUM> according to this embodiment, the movable blade <NUM> can cut the recording sheet P under a state of being pressed toward the fixed blade <NUM> side, thereby being capable of reducing the sliding load on the movable blade <NUM>.

The present invention is not limited by the one embodiment described above. Further, the components in the one embodiment encompass components easily conceived by a person skilled in the art, or substantially the same components, that is, so-called equivalents. In addition, the components disclosed in the one embodiment can be combined with each other as appropriate.

Hereinabove, the one embodiment of the present invention has been described in detail with reference to the accompanying drawings. However, specific structures of the present invention are not limited to the one embodiment and encompass design modifications and the like without departing from the scope of the claims. Further, the components described in the one embodiment described above and a modification example described below may be configured in combination with each other as appropriate.

For example, the printer according to the present invention is not limited to the thermal printer <NUM> illustrated in <FIG>, and is also applicable to printers having a variety of configurations.

Further, in the above-mentioned embodiment, the fixed blade <NUM> and the movable blade <NUM> are arranged under a state in which the first surface being the surface on the fixed blade <NUM> side is the back surface P2, and the surface on the movable blade <NUM> side is the print surface P1. However, in the present invention, the arrangement is not particularly limited to such arrangement. For example, the fixed blade <NUM> and the movable blade <NUM> may be arranged under a state in which the first surface being the surface on the fixed blade <NUM> side is the print surface P1, and the surface on the movable blade <NUM> side is the back surface P2.

Further, in the above-mentioned embodiment, the movable blade <NUM> is arranged more on the conveyance destination side A1 in the conveying direction A than the fixed blade <NUM> when being slid on the fixed blade <NUM>. However, in the movable blade of the present invention, for example, a part of the movable blade edge <NUM> may be arranged more on the conveyance source side A2 than the fixed blade <NUM>.

Further, for example, the urging member <NUM> that urges the movable blade <NUM> in the cutting direction B may be formed of an urging member other than the pressurizing spring (for example, a synthetic rubber or a plate spring). In addition, it is not always required that the urging member <NUM> urge the movable blade <NUM> to the fixed blade <NUM> in the conveying direction A. For example, the urging member <NUM> may be arranged more on the conveyance source side A2 than the movable blade <NUM>, and may be configured to always urge the movable blade <NUM> to the fixed blade <NUM> by pulling the movable blade <NUM>.

Further, in the above-mentioned embodiment, description is made of the thermal printer <NUM> of a so-called cross type in which the movable blade <NUM> crosses the fixed blade <NUM>, but the present invention is not limited thereto. The present invention is also applicable to printers having a variety of configurations in which the movable blade <NUM> is moved in a reciprocating manner to cut the recording sheet P.

Claim 1:
A cutter unit (<NUM>) configured to cut a recording sheet (P) to be advanced toward a forward side in an advancing direction, the cutter unit (<NUM>) comprising:
a fixed blade (<NUM>), which includes a fixed blade edge (<NUM>), and is provided on a first surface side of the recording sheet (P);
a movable blade (<NUM>) including:
a movable blade edge (<NUM>) opposed to the fixed blade edge (<NUM>) in a cutting direction crossing the advancing direction; and
a sliding surface (<NUM>), which is provided on a first side in the advancing direction, and is configured to be slid on the fixed blade (<NUM>); and
a rack holder (<NUM>) capable of reciprocating along the cutting direction, the rack holder (<NUM>) including:
a movable blade holder (<NUM>) configured to support the movable blade (<NUM>); and
an urging member (<NUM>) configured to urge the movable blade (<NUM>) to the first side in the advancing direction.