JP4645661B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus, and more particularly, to an image forming apparatus including a print head that has a print unit that comes into contact with an ink sheet and can print an image on a sheet.

  2. Description of the Related Art Conventionally, there has been known an image forming apparatus that includes a printing unit that includes a printing unit that contacts an ink sheet and that can print an image on a sheet (see, for example, Patent Documents 1 to 4).

  In Patent Document 1, a thermal head (printing head) having a heating element, a protective cover that is positioned upstream of the heating element in the transport direction of the ink ribbon and that guides the ink sheet, and a transport direction rather than the heating element. And a single sheet guide for guiding the ink sheet, and a thermal transfer recording apparatus is disclosed. The ink sheet of this thermal transfer recording apparatus is configured to be conveyed while being in contact with a protective cover disposed on the upstream side in the conveying direction with respect to the heating element and a sheet guide disposed on the downstream side. In the thermal transfer recording apparatus according to Patent Document 1, the heating element is provided along the width direction of the ink sheet, and the contact surface of the sheet guide with the ink sheet is more ink at the center of the heating element in the line direction than the peripheral part. By projecting in a stepwise manner downstream in the sheet conveying direction, the ink sheet is configured to remove slack.

  Further, in Patent Document 2, a line thermal head in which a plurality of heating elements are formed, one ribbon guide disposed upstream of the line thermal head in the ink ribbon transport direction, and downstream of the line thermal head. There is disclosed a thermal transfer printer with one release plate disposed on the side. The peeling plate is provided with a ribbon sliding surface that is in sliding contact with the ink ribbon. The ink ribbon of this thermal transfer printer is conveyed while being in sliding contact with a ribbon guide disposed on the upstream side of the line thermal head and a ribbon sliding portion provided on a peeling plate disposed on the downstream side of the line thermal head. It is configured as follows.

  Further, in Patent Document 3 described above, a print head that performs printing using an ink ribbon and an ink ribbon are pressed from above at one location on each of an upstream side and a downstream side in the transport direction of the ink ribbon. A printing apparatus including a ribbon guide for guiding a conveyance path is disclosed.

  Further, in Patent Document 4, a recording head that performs printing using a toner sheet and an upstream side in the conveying direction of the toner sheet (ink sheet) are provided, and the toner sheet is guided around the outer periphery together with paper. An image forming apparatus including one guide member and a platen roll that performs printing by partially winding and adhering a toner sheet around a sheet together with a sheet and sandwiching the recording sheet with a recording head at a predetermined recording position is disclosed. . In the image forming apparatus according to Patent Document 4, the toner sheet is configured to be wound around the outer periphery of the platen roll in a state where the paper is sandwiched, and to be conveyed together with the paper to a predetermined recording position.

JP-A-9-123494 JP 2006-240091 A Japanese Patent No. 3491790 JP-A-11-198472

  However, in the thermal transfer recording apparatus described in Patent Document 1, it is possible to remove the slack of the ink sheet, while being located upstream of the heating element in the conveyance direction and guiding the ink sheet, When the ink sheet is conveyed between the body and the ink sheet, the ink sheet may be vibrated. In this case, the ink sheet is wrinkled due to the vibration of the ink sheet.

  Further, in the thermal transfer printer described in Patent Document 2, the ink ribbon is conveyed while being slidably contacted with a ribbon guide disposed on the upstream side in the conveyance direction with respect to the line thermal head. Ink ribbon vibration may occur between the head and the ink ribbon as it is transported. In this case, there is a problem that wrinkles occur in the ink ribbon due to vibration of the ink ribbon.

  Further, in the printing apparatus described in Patent Document 3, since the ink ribbon is conveyed while being pressed by the ribbon guide on the upstream side in the conveyance direction, the ribbon guide is pressed on the upstream side in the conveyance direction of the ink ribbon from the print head. When the ink ribbon is transported between the print head and the print head, the ink ribbon may vibrate. In this case, the ink ribbon may be wrinkled due to the vibration of the ink ribbon. is there.

  In the image forming apparatus described in Patent Document 4, since the toner sheet is wound around the outer periphery of the platen roll with the paper sandwiched, the vibration of the paper during conveyance is transmitted to the toner sheet. Therefore, there is a problem that wrinkles occur in the toner sheet due to the vibration of the toner sheet transmitted from the paper when the paper and the toner sheet are conveyed.

  The present invention has been made to solve the above-described problems, and one object of the present invention is to prevent generation of wrinkles in the ink sheet due to vibration of the ink sheet caused by the conveyance of the ink sheet. An image forming apparatus capable of being suppressed is provided.

Means for Solving the Problems and Effects of the Invention

An image forming apparatus according to an aspect of the present invention includes an ink sheet that is transported together with a sheet at the time of printing, a print head that is in contact with the transported ink sheet, and capable of printing an image on the sheet, and the print head Is positioned upstream of the ink sheet conveyance direction, is positioned between the first guide portion for guiding the ink sheet to the print head, and between the print portion and the first guide portion of the print head, and is in contact with the ink sheet. And a second guide portion, and the first guide portion includes a support portion that contacts the surface of the print head on the print portion side and supports the print head .

  In the image forming apparatus according to this aspect, as described above, the first guide unit that is positioned upstream of the print head in the ink sheet conveyance direction and guides the ink sheet to the print head, and the print unit of the print head And the first guide portion, and the second guide portion that contacts the ink sheet is provided, so that the printing portion and the first guide portion of the print head are conveyed along with the conveyance of the ink sheet during printing. The vibration generated between the ink sheet and the second guide portion can be suppressed. Thereby, since vibration of the ink sheet is suppressed, generation of wrinkles of the ink sheet due to vibration of the ink sheet can be suppressed.

  In the image forming apparatus according to the above aspect, the second guide unit is preferably configured to contact the ink sheet over substantially the entire width in a direction intersecting the ink sheet conveyance direction. With this configuration, since the second guide portion abuts over substantially the entire width of the conveyed ink sheet, vibration can be suppressed over substantially the entire width of the ink sheet. Occurrence of wrinkles can be suppressed.

  In the image forming apparatus according to the above aspect, the second guide portion is preferably provided so as to abut against the ink sheet in the vicinity of the print portion of the print head and to protrude from the print head toward the ink sheet. Yes. If comprised in this way, an ink sheet can be immediately sent to a printing part in the state from which the vibration was removed, when the 2nd guide part contact | abuts in the vicinity of a printing part.

  In the image forming apparatus according to the above aspect, the contact surface of the second guide portion with the ink sheet is preferably formed in a curved surface having a rounded cross-sectional shape along the transport direction of the ink sheet. ing. According to this structure, the ink sheet can contact the second guide portion with a rounded curved contact surface along the transport direction, so that the ink sheet slides when the ink sheet is transported. It is possible to suppress the surface from being scratched.

  The image forming apparatus according to the above aspect preferably includes a protrusion protruding from the print head toward the ink sheet and a surface layer formed of a material having a lower coefficient of friction than the protrusion. According to this structure, the surface layer constituting the contact surface between the second guide portion and the ink sheet is formed of a material having a lower coefficient of friction than the protruding portion, so that the ink sheet and the second ink sheet when the ink sheet is transported are formed. 2 The surface of the ink sheet can be further prevented from being scratched by sliding with the surface layer of the guide portion.

  In the image forming apparatus according to the above aspect, the third guide is preferably located on the downstream side of the print head in the ink sheet conveyance direction and abuts the ink sheet in the vicinity of the print head and guides the ink sheet. The unit is further provided. According to this configuration, the ink sheet and the third guide portion abut on the downstream side of the printing unit, so that not only the upstream side before printing but also the downstream side ink sheet after printing is conveyed. The state can be stabilized. Accordingly, it is possible to suppress the influence of the disturbance in the conveyance state of the ink sheet on the downstream side in the conveyance direction from reaching the vicinity of the printing unit that performs printing, and it is possible to improve the print quality.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings.

  FIG. 1 is an exploded perspective view showing the overall configuration of a sublimation printer according to an embodiment of the present invention. FIG. 2 is a perspective view of the sublimation printer according to the embodiment of the present invention shown in FIG. FIG. 3 is a perspective view showing an appearance of the sublimation printer according to the embodiment of the present invention shown in FIG. 4 to 14 are diagrams for explaining the details of the sublimation printer according to the embodiment of the present invention shown in FIG. First, the structure of a sublimation printer 100 according to an embodiment of the present invention will be described with reference to FIGS. In the present embodiment, a case where the present invention is applied to a sublimation printer which is an example of an image forming apparatus will be described.

  As shown in FIG. 1, the apparatus main body 90 of the sublimation printer 100 according to the embodiment of the present invention is disposed so as to face the metal chassis 1, the print head 2 for performing printing, and the print head 2. Platen roller 3 (see FIG. 4), metal feed roller 4 (see FIG. 4), metal presser roller 5 (see FIG. 4) for pressing the feed roller 4 with a predetermined pressing force, and metal A support rod 6 made of paper, head portion pressing members 7 and 8 for pressing the upper part of the print head 2 with a predetermined pressing force, and a drive gear 9 made of resin are provided. Further, the apparatus main body 90 of the sublimation printer 100 further includes a feed roller gear 10 (see FIG. 6), a resin-made lower paper guide 11a, a resin-made upper paper guide 11b (see FIG. 4), and a rubber-made product. Paper feed roller 12, paper feed roller gear 13 (see FIG. 2), rubber paper discharge roller 14, paper discharge roller gear 15 (see FIG. 2), take-up reel 16 (see FIG. 2), and motor bracket 17 (see FIG. 2), a stepping motor 18 (see FIG. 2) for conveying the paper 60, a stepping motor 19 (see FIG. 2) serving as a drive source when the print head 2 is rotated, and swinging The movable rocking gear 20 (see FIG. 5), a plurality of intermediate gears 21 to 24 (see FIG. 5), and a cartridge support portion 25 that supports the ink sheet cartridge 50 in which the ink sheet 51 is accommodated. . Further, as shown in FIG. 3, the apparatus main body 90 is configured to be disposed inside the resin casing 26. Further, in the sublimation printer 100 according to the present embodiment, as shown in FIG. 3, the ink sheet cartridge 50 and the paper feed cassette 70 for storing the paper 60 supplied to the apparatus main body 90 can be attached to and detached from the apparatus main body 90. It is attached to.

  Further, as shown in FIG. 1, the chassis 1 has one side surface 1a, the other side surface 1b, and a bottom surface 1c arranged so as to face each other. Further, the above-described motor bracket 17 (see FIG. 2) is attached to one side surface 1a of the chassis 1. A cartridge insertion hole 1 d for inserting the ink sheet cartridge 50 is provided on the other side surface 1 b facing the one side surface 1 a of the chassis 1. Further, as shown in FIG. 1, a support hole 1e for rotatably supporting a support bar 6 to which head portion pressing members 7 and 8 are attached is provided on one side surface 1a and the other side surface 1b of the chassis 1, respectively. It has been. Further, as shown in FIG. 4, paper sensors 27a and 27b for detecting the front end portion 60a and the rear end portion 60b of the paper 60 at the time of printing are provided on the bottom surface 1c of the chassis 1.

  As shown in FIG. 1, the two platen roller bearings 3a are respectively attached to one side surface 1a and the other side surface 1b of the chassis 1, and the platen roller 3 (see FIG. 4) is attached to the two platen roller bearings 3a. Reference) is rotatably supported. Further, as shown in FIG. 5, the feed roller 4 has a feed roller gear insertion portion 4 a that is inserted into the feed roller gear 10. The feed roller 4 is configured to be rotatably supported by a feed roller bearing (not shown) attached to the chassis 1. The pressing roller 5 (see FIG. 4) is configured to be rotatably supported by a pressing roller bearing (not shown). Further, as shown in FIG. 4, the feed roller 4 and the pressing roller 5 are rotated in a state where the paper 60 is sandwiched therebetween, thereby feeding the paper 60 in the paper feeding direction (arrow T1 direction) or the paper discharging direction (arrow). U1 direction). Further, as shown in FIG. 3, the paper feed roller 12 has a function of conveying the paper 60 stored in the paper feed cassette 70 (see FIG. 1) into the chassis 1. Further, as shown in FIG. 3, the paper discharge roller 14 has a function of conveying the paper 60 after printing to the outside of the chassis 1.

  Moreover, as shown in FIG. 2, the support part 6a is provided in the one and other edge part of the support bar 6, respectively. Then, as shown in FIG. 2, one support portion 6a and the other support portion 6a of the support rod 6 are rotatably inserted into the support hole 1e on one side surface 1a of the chassis 1 and the support hole 1e on the other side surface 1b, respectively. It is configured to be. Further, as shown in FIG. 2, head portion pressing members 7 and 8 are attached to the inside of the one end and the other end of the support rod 6 without spinning around the support rod 6, respectively.

  Further, as shown in FIG. 1, the head portion pressing member 7 is integrally formed with a pressing portion 7a and a gear portion 7b. As shown in FIG. 2, the head portion pressing member 8 is integrally formed with a pressing portion 8 a and a protruding portion 8 b that protrudes in the direction in which the support bar 6 extends.

  The head pressing members 7 and 8 are each formed with an insertion hole, and the insertion holes are fitted in the vicinity of both ends of the support bar 6. Thereby, it is comprised so that the support bar 6 and the head part press member 8 can be rotated with rotation of the head part press member 7. FIG. Further, as shown in FIGS. 1 and 2, the head pressing members 7 and 8 are disposed on the one side surface 1a and the other side surface 1b side of the chassis 1, respectively.

  As shown in FIGS. 1 and 4, the print head 2 includes a support shaft 2a, a head portion 2b arranged to face the platen roller 3 (see FIG. 4), a support shaft 2a, and a head portion 2b. Are connected to each other, an aluminum heat dissipating part 2d for dissipating heat from the head part 2b during printing, and a printing part 2e provided on the lower surface of the head part 2b. In addition, an ink sheet guide portion 2 i is provided in the vicinity of the print portion 2 e of the print head 2 so as to protrude from the head portion 2 b of the print head 2 toward the ink sheet 51. The ink sheet guide portion 2i is an example of the “second guide portion” in the present invention.

  Here, as shown in FIG. 8, a resin paper guide member 28 is attached to the print head 2 as a separate member from below from the head portion 2 b. Also, as shown in FIG. 4, the paper guide member 28 is rotated in the direction of the arrow P1 together with the print head 2 at the start of printing, and is stopped at a predetermined position, thereby being conveyed to the apparatus main body 90 in the direction of the arrow T1. The front end portion 60 a of the paper 60 to be printed has a role of regulating the transport direction after passing between the print head 2 and the platen roller 3. Specifically, as shown in FIG. 4, after the front end portion 60 a of the paper 60 passes between the print head 2 and the platen roller 3 in a substantially horizontal direction, the lower surface of the paper guide portion 28 a of the paper guide member 28. It is possible to suppress the front end portion 60a of the paper 60 from entering the inside of a supply bobbin storage portion 54a of the ink sheet cartridge 50, which will be described later, by being guided obliquely downward while being in contact with the ink.

  Further, as shown in FIG. 8, the resin-made paper guide member 28 is provided at the front end portion of the paper guide portion 28a, the rib 28b for supporting the lower surface of the head portion 2b of the print head 2, and the paper guide portion 28a. A vertical wall 28c provided at the rear end and extending upward from the vertical wall 28c in an obliquely upward direction, and a plurality of hooks 28e (this embodiment) for attaching the paper guide member 28 to the heat radiating member 2d of the print head 2 A mounting portion 28d having three locations in the form is integrally formed. As shown in FIG. 8, the paper guide member 28 dissipates heat by engaging the hooks 28e with the notches 2f (two places) and 2g (one place) provided in the heat dissipating part 2d of the print head 2. It is configured to be attached to the portion 2d.

  In this embodiment, as shown in FIG. 8, the ink sheet guide portion 28f is provided at the rear end portion (lower end portion of the vertical wall 28c) of the paper guide portion 28a to which the paper guide portion 28a and the vertical wall 28c are connected. Is provided in the width direction of the paper guide portion 28a (the arrow X direction in FIG. 10). As shown in FIG. 10, the ink sheet guide portion 28f has a width W1 larger than the width W2 of the ink sheet 51. Therefore, when the printing is started, the print head 2 contacts the ink sheet 51 from above in the arrow Y direction. When contacting, it is comprised so that it may contact | abut with the full width of the ink sheet 51. FIG. The ink sheet guide portion 28f is an example of the “first guide portion” in the present invention.

  In the present embodiment, as shown in FIG. 11, the ink sheet guide portion 28f provided at the rear end portion of the paper guide portion 28a is positioned upstream of the print head 2 in the transport direction (arrow A direction). The contact portion 28g is in contact with the ink sheet 51. The contact portion 28g of the ink sheet guide 28f is along the transport direction of the ink sheet 51 (the direction of arrow A in the drawing) so that the ink sheet 51 transported along with the printing operation can smoothly contact. The shape is formed to have a round shape. Therefore, as shown in FIG. 11, the ink sheet 51 at the time of printing is the ink of the paper guide member 28 immediately upstream from the supply bobbin 52 (see FIG. 4) and upstream in the transport direction (arrow A direction). The sheet guide portion 28f is configured to be guided toward the print portion 2e of the print head 2 by changing the conveyance direction (arrow A direction) from a diagonally downward direction to a substantially horizontal direction.

  Further, as shown in FIG. 8, the paper guide member 28 has ribs 28h (three locations in the present embodiment) for securing the bonding strength between the paper guide portion 28a and the vertical wall 28c, after the paper guide portion 28a. It is provided inside the end. Further, as shown in FIG. 8, when the paper guide member 28 is attached to the print head 2, fixing portions 28i and 28j for positioning and fixing in the width direction (arrow X direction) are provided on the left and right sides, respectively. It has been.

  Further, as shown in FIG. 6, the print unit 2e of the head unit 2b is provided with a plurality of heating elements 29 (outer shape is indicated by broken lines) along the width direction of the head unit 2b (the arrow X direction in the figure). It has been. As shown in FIG. 10, the printing unit 2 e provided with the heat generating element 29 (see the alternate long and short dash line in FIG. 10) has a width W <b> 2 that is larger than the width W <b> 1 of the ink sheet 51. It is provided so that it can contact | abut over. As shown in FIG. 4, the print head 2 has a vertical direction (in the direction of the arrow P1 and the arrow Q1) about a pair of support shafts 2a attached to the inner side of the one side surface 1a and the other side surface 1b of the chassis 1, respectively. In a direction).

  In the present embodiment, as shown in FIG. 11, the print unit 2 e of the head unit 2 b includes a heating element 29, a ceramic heating element fixing member 2 m that fixes the heating element 29, and the heating element 29. And a resin substrate 2n having a wiring pattern connected to the substrate. The heating element 29 and the wiring pattern of the board 2n are connected by wiring provided on the surface of the heating element fixing member 2m. And the protrusion part 2k which functions as a protective film of a wiring is provided so that this wiring may be covered while it consists of an insulating resin material.

  In the present embodiment, the protruding portion 2k formed of this resin material is formed so as to protrude downward from the head portion 2b, as shown in FIG. A surface layer 21 is provided on the surface of the protruding portion 2k (in the drawing, the lower surface of the protruding portion 2k) so as to cover the entire surface of the protruding portion 2k. A sheet guide portion 2i is configured. That is, the protruding portion 2k of the ink sheet guide portion 2i functions as a protective film for the wiring connecting the heating element 29 and the substrate 2n, and functions as a part of the ink sheet guide portion 2i that contacts the ink sheet 51. And has both functions.

  Further, in the present embodiment, the surface layer 21 forming the contact portion 2j of the ink sheet guide portion 2i is rounded along the transport direction (arrow A direction) of the ink sheet 51 as shown in FIG. It is formed in a curved surface shape having a cross-sectional shape, and is formed so as to contact the ink sheet 51 during printing. As a result, the ink sheet 51 can come into contact with the ink sheet guide portion 2i with the rounded curved surface layer 21 along the transport direction, so that the ink sheet 51 slides when the ink sheet 51 is transported. It is comprised so that it can suppress that the surface is damaged.

  Here, in the present embodiment, the ink sheet guide portion 2i is provided between the print portion 2e of the print head 2 and the ink sheet guide portion 28f. The distance L1 between the contact portion 2j of the ink sheet guide portion 2i and the heating element 29 of the print portion 2e is greater than the distance L2 between the contact portion 28g of the ink sheet guide portion 28f and the ink sheet guide portion 2i. Also have a small distance. That is, the ink sheet guide portion 2 i is configured to contact the ink sheet 51 in the vicinity of the print portion 2 e of the print head 2. Further, the ink sheet guide portion 2i is provided in the vicinity of the heating element 29 so as to extend along the width direction of the head portion 2b (the arrow X direction in FIG. 9). Here, as shown in FIG. 10, the width W <b> 1 of the ink sheet guide portion 2 i (see the broken line in FIG. 10) is configured to be larger than the width W <b> 2 of the ink sheet 51. Thereby, when the head 2 contacts the ink sheet 51 from above in the arrow Y direction during printing, the contact portion 2j of the ink sheet guide 2i intersects the transport direction of the ink sheet 51 (arrow X direction). It is comprised so that it may contact | abut over the full width.

  In the present embodiment, the ink sheet guide portion 2i is formed so as to protrude downward from the heating element 29 of the printing portion 2e, as shown in FIG. Therefore, at the time of printing, immediately after the ink sheet 51 is sent out from the supply bobbin 52 (see FIG. 4), the ink sheet guide portion 28f of the paper guide member 28 causes the conveyance direction (winding direction (arrow A direction)) to be inclined. The ink is guided toward the printing portion 2e of the print head 2 while changing from the lower direction to the substantially horizontal direction. The ink sheet 51 is configured to be guided to the heating element 29 of the printing unit 2e while being in contact with the contact part 2j of the ink sheet guide part 2i. At this time, the vibration generated between the ink sheet guide portion 28 f and the heating element 29 accompanying the conveyance of the ink sheet 51 is suppressed by the ink sheet guide portion 2 i coming into contact with the ink sheet 51 in the vicinity of the heating element 29. To do. As a result, the ink sheet 51 is prevented from wrinkling at the contact portion between the ink sheet 51 and the heating element 29 and the platen roller 3.

  Here, in the present embodiment, as shown in FIG. 11, the surface layer 21 covering the entire surface of the protruding portion 2k of the ink sheet guide portion 2i has a heat resistance and has a lower coefficient of friction than the protruding portion 2k. It is formed by. Accordingly, since the surface layer 21 has a lower coefficient of friction than the protruding portion 2k, when the ink sheet 51 comes into contact with the surface layer 21 forming the contact surface of the ink sheet guide portion 2i during conveyance, The surface of the ink sheet 51 is prevented from being scratched by sliding with the surface layer 2l. Further, in the present embodiment, since the surface layer 21 has heat resistance, it is possible to prevent the ink sheet guide portion 2i from being melted or deformed even when the periphery of the heating element 29 becomes high temperature during printing.

  In the present embodiment, as shown in FIG. 8, an engagement member 30 made of sheet metal is attached to the upper surface of the heat radiating portion 2 d of the print head 2 with screws 31. Further, as shown in FIG. 8, the engagement member 30 is engaged with the notch 30a and the protrusion 8b (see FIG. 4) of the head pressing member 8 (see FIG. 4) to engage the print head 2 (see FIG. 8). 4), the fixing portion 30c fixed to the upper surface of the portion corresponding to the head portion 2b of the heat radiating portion 2d, and the fixing portion on the front surface portion 2h side of the print head 2. A connecting portion 30d bent and extended substantially downward in the vertical direction from 30c, and an ink sheet guide portion 30e arranged to extend from the connecting portion 30d along the width direction of the print head 2 (the arrow X direction in the drawing). Are integrally provided. The ink sheet guide portion 30e is an example of the “third guide portion” in the present invention.

  Further, the ink sheet guide portion 30e is provided in the width direction (arrow X direction) of the print head 2 as shown in FIG. As shown in FIG. 9, the ink sheet guide portion 30e has a width W1 larger than the width W2 (see FIG. 10) of the ink sheet 51, and the abutting portion 30f is applied with the full width of the ink sheet 51 during printing. It is configured to touch. Further, as shown in FIG. 11, the ink sheet guide portion 30 e is disposed downstream of the print head 2 in the transport direction of the ink sheet 51 (arrow A direction). The distance L3 between the contact portion 30f of the ink sheet guide portion 30e and the heating element 29 of the printing portion 2e is substantially equal to the distance L1 between the contact portion 2j of the ink sheet guide portion 2i and the heating element 29. It is configured to have the same length. Accordingly, the contact portion 30f of the ink sheet guide portion 30e is configured to contact the ink sheet 51 in the vicinity of the print head 2.

  In the present embodiment, as shown in FIG. 11, the contact portion 30f of the ink sheet guide portion 30e that contacts the ink sheet 51 from above during printing is formed by folding the sheet metal member substantially 180 degrees. In addition, the shape of the contact portion 30f along the transport direction of the ink sheet 51 (the direction of the arrow A in the figure) is U-shaped so that the ink sheet 51 can smoothly contact. Is formed. Therefore, as shown in FIG. 11, the ink sheet 51 at the time of printing is supplied from the supply bobbin 52 (see FIG. 4), and immediately after passing through the print portion 2e of the print head 2 in the direction of arrow A, the ink sheet guide portion. By the contact part 30f of 30e, it is comprised so that a conveyance direction (winding direction) may be changed to the diagonally upward direction from a substantially horizontal direction, and it winds up by the winding bobbin 53 (refer FIG. 4). As a result, as shown in FIG. 11, the ink sheet guide portion 30e is immediately after being transferred by the printing portion 2e of the print head 2, and the downstream side of the print head 2 in the transport direction (arrow A direction) of the ink sheet 51. In the vicinity, the ink sheet 51 and the contact portion 30f of the ink sheet guide portion 30e come into contact with each other, thereby stabilizing the conveyance state of the ink sheet 51 and moving toward the take-up bobbin 53 (see FIG. 4). It is formed so that it can be guided.

  Further, as shown in FIG. 8, a first spring fixing portion 30 g and a second spring fixing portion 30 h are integrally provided in a region located above the head portion 2 b of the engaging member 30. The first spring fixing portion 30g and the second spring fixing portion 30h include a first torsion coil spring 32 and a second torsion coil spring 33 for urging the head portion 2b toward the platen roller 3 (see FIG. 11). They are arranged in regions corresponding to the head pressing members 7 and 8 (see FIG. 7), respectively. As shown in FIG. 8, the first torsion coil spring 32 and the second torsion coil spring 33 are fixed to the first spring fixing portion 30g and the second spring fixing portion 30h of the engaging member 30, respectively. Further, as shown in FIG. 8, the first spring fixing portion 30g of the engaging member 30 is provided with a locking portion 30i and a protruding portion 30j. Further, as shown in FIG. 8, the second spring fixing portion 30h of the engaging member 30 is provided with a locking portion 30k and a protruding portion 30l.

  Further, as shown in FIG. 8, the first torsion coil spring 32 is configured such that when the head portion pressing member 7 (see FIG. 7) rotates downward, the pressing portion 7a (see FIG. 7) of the head portion pressing member 7 (see FIG. 7). One end 32a that is pressed by (see FIG. 1), and the other end that transmits the urging force generated by pressing the one end 32a to the upper surface (upper part) of the head portion 2b via the fixed portion 30c. 32b. As shown in FIGS. 7 and 8, the second torsion coil spring 33 presses the head pressing member 8 (see FIG. 7) when the head pressing member 8 (see FIG. 7) rotates downward. One end portion 33a pressed by the portion 8b (see FIG. 7) and the urging force generated by pressing the one end portion 33a are transmitted to the upper surface (upper portion) of the head portion 2b via the fixed portion 30c. And the other end 33b. Therefore, as shown in FIG. 6 and FIG. 7, the printing portion 2e of the head portion 2b is moved to the platen roller by the urging force of the first torsion coil spring 32 and the second torsion coil spring 33 transmitted to the upper surface (upper portion) of the head portion 2b. It is configured to be able to be pressed to the 3 side with a predetermined pressing force.

  As shown in FIGS. 7 and 8, one end 32a of the first torsion coil spring 32 is locked to the locking portion 30i of the engaging member 30, and the other end 32b is connected to the engaging member. It is being fixed to 30 protrusion part 30j. As shown in FIGS. 7 and 8, one end 33a of the second torsion coil spring 33 is locked to the locking portion 30k of the engaging member 30, and the other end 33b is locked to the engaging member. It is fixed to 30 protrusions 30l.

  Further, as shown in FIG. 4, when the head portion pressing member 8 is rotated upward (in the direction of the arrow Q2), the protrusion portion 8b of the head portion pressing member 8 and the notch portion 30a of the engaging portion 30b are engaged. By doing so, the head portion 2b is also configured to rotate upward (in the direction of arrow P2). As a result, as shown in FIG. 4, when the head portion pressing member 8 rotates upward (in the direction of the arrow Q <b> 2), the head portion 2 b pressed by the platen roller 3 is separated upward from the platen roller 3. It is configured.

  6 and 7, the drive gear 9 and the intermediate gear 34 (see FIG. 7) transmit the driving force of the stepping motor 19 (see FIG. 2) to the head portion pressing members 7 and 8, It is provided to rotate the head pressing members 7 and 8. The drive gear 9 is attached to the inside of the one side surface 1 a of the chassis 1. Further, as shown in FIG. 7, the intermediate gear 34 and the stepping motor 19 are attached to the outside on the one side surface 1 a side of the chassis 1 via the motor bracket 17. Further, as shown in FIG. 7, the small-diameter gear portion 9 a of the drive gear 9 is engaged with the gear portion 7 b of the head portion pressing member 7, and the large-diameter gear portion 9 b of the drive gear 9 is connected to the intermediate gear 34. The small-diameter gear 34a is meshed. Further, the large-diameter gear 34b of the intermediate gear 34 is meshed with the motor gear 35 of the stepping motor 19, as shown in FIG. As a result, the driving force of the stepping motor 19 can be transmitted to the head pressing members 7 and 8 via the intermediate gear 34 and the driving gear 9.

  As shown in FIG. 5, a motor gear 36 is attached to the shaft portion of the stepping motor 18 attached to the motor bracket 17. Further, the stepping motor 18 has a function as a drive source for driving the gear portion 16 a of the take-up reel 16, the paper feed roller gear 13, the paper discharge roller gear 15, and the feed roller gear 10.

  4 and 5, the take-up reel 16 is a take-up bobbin disposed inside a take-up bobbin storage portion 54b (see FIG. 4) of an ink sheet cartridge 50 (see FIG. 4) described later. By engaging with 53 (see FIG. 4), the ink sheet 51 (see FIG. 4) wound around the take-up bobbin 53 is wound up. Further, as shown in FIG. 5, the gear portion 16 a of the take-up reel 16 is arranged so as to mesh with the swinging gear 20 swinging.

  Further, as shown in FIG. 4, the lower sheet guide 11 a is installed in the vicinity of the feed roller 4 and the pressing roller 5. The upper paper guide 11b is attached to the upper part of the lower paper guide 11a. The upper paper guide 11b guides the paper 60 to the feeding path to the printing unit so that the paper 60 passes the lower surface side during paper feeding, and discharges the paper 60 so as to pass the upper surface side when paper is ejected. It is configured to be able to guide the paper path.

  Moreover, the housing | casing 26 contains the cover members 26a and 26b and the pushbutton switch 26c, as shown in FIG. Further, as shown in FIG. 3, the lid members 26 a and 26 b are provided on the outer side of the housing 26 so as to be rotatable around the lower end portion. Further, as shown in FIG. 3, the lid member 26 a of the housing 26 is provided so as to be openable and closable for mounting the paper feed cassette 70 on the apparatus main body 90. In the state in which the paper feed cassette 70 is removed, the lid member 26a is closed to prevent dust and the like from entering the apparatus main body 90. Further, as shown in FIG. 3, the lid member 26 b of the housing 26 is provided so as to be openable and closable for mounting the ink sheet cartridge 50 to the apparatus main body 90. In addition, except when the ink sheet cartridge 50 is attached / detached, the lid member 26b is closed to prevent dust and the like from entering the apparatus main body 90. Further, the push button switch 26c of the housing 26 is provided as an operation button when the user starts printing, as shown in FIG.

  As shown in FIG. 1, the ink sheet cartridge 50 includes a supply bobbin 52 for supplying the ink sheet 51 and a take-up bobbin 53 for winding the supplied ink sheet 51 in the arrow A direction. ing. Further, as shown in FIG. 1, the cartridge case 54 constituting the ink sheet cartridge 50 includes a supply bobbin storage portion 54a that rotatably stores the supply bobbin 52 and a winding bobbin 53 that rotatably stores the take-up bobbin 53. The intake bobbin storage part 54b is composed of a pair of connection parts 54c and 54d that connect the supply bobbin storage part 54a and the take-up bobbin storage part 54b with a predetermined distance therebetween. 1 and 4, when the supply bobbin 52 and the take-up bobbin 53 are stored in the supply bobbin storage 54a and the take-up bobbin storage 54b, respectively, the supply bobbin 52 and the take-up bobbin The ink sheet 51 wound around 53 is exposed to the outside between a predetermined distance between the supply bobbin storage portion 54a and the take-up bobbin storage portion 54b. The ink sheet 51 is configured by sequentially connecting three color ink sheets, a Y (yellow) ink sheet, an M (magenta) ink sheet, and a C (cyan) ink sheet. A compression coil spring (not shown) is provided in each of the supply bobbin storage portion 54a and the take-up bobbin storage portion 54b of the ink sheet cartridge 50. With this compression coil spring, the ink sheet cartridge 50 is always urged in the direction of taking out the ink sheet cartridge 50 (in the direction of arrow B in FIG. 1) while being attached to the apparatus main body 90.

  12 to 14 are diagrams for explaining the printing operation of the sublimation printer according to the embodiment of the present invention shown in FIG. Next, with reference to FIGS. 3 to 7 and FIGS. 11 to 14, the printing operation of the sublimation printer 100 according to the present embodiment will be described.

  First, in the state before the start of printing, as shown in FIG. 12, the head portion 2 b of the print head 2 is held at a position spaced upward from the platen roller 3. Further, in this case, the head portion 2b is engaged with the engaging portion 30b (strictly, the notch portion 30a) of the engaging member 30 in which the protruding portion 8b of the head portion pressing member 8 is provided above the head portion 2b. As a result, the rotation of the head portion 2b in the direction of the arrow P1 is suppressed.

  When the user presses the push button switch 26c (see FIG. 3) to start the printing operation, as shown in FIG. 13, the stepping motor 19 (see FIG. 6) is driven and the stepping motor 19 (see FIG. 6). The driving force of the intermediate gear 34 (see FIG. 7) is pressed through the large-diameter gear 34b (see FIG. 7), the small-diameter gear 34a (see FIG. 7), and the drive gear 9 (see FIG. 7). By being transmitted to the gear portion 7b (see FIG. 7) of the member 7 (see FIG. 7), the head portion pressing member 7 (see FIG. 7) is rotated in the arrow Q1 direction with the support rod 6 as a fulcrum. At this time, since the head portion pressing members 7 and 8 (see FIG. 7) do not rotate freely with respect to the support rod 6, the head portion pressing member 8 also moves in the direction of the arrow Q1 together with the head portion pressing member 7 (see FIG. 7). It is rotated. Then, the protrusion 8b of the head pressing member 8 rotates in the direction of the arrow Q1, so that the head 2b whose rotation in the direction of the arrow P1 is suppressed by the protrusion 8b rotates in the direction of the arrow P1. Thereby, from the state shown in FIG. 12, as shown in FIG. 4, the head portion 2b starts to gradually descend from a position spaced upward from the platen roller 3, and moves toward the platen roller 3 side (press side). The movement is started.

  Further, as the print head 2 rotates in the direction of arrow P1, the paper 60 is conveyed (feeded) in the direction of arrow T1 from the state shown in FIG. As shown in FIG. 13, cueing of the paper 60 is performed by the paper sensors 27a and 27b for detecting the front end portion 60a and the rear end portion 60b.

  Here, as shown in FIG. 4, after the front end 60a of the paper 60 passes between the print head 2 and the platen roller 3 in a substantially horizontal direction, it contacts the lower surface of the paper guide 28a of the paper guide member 28. The front end portion 60a of the sheet 60 is prevented from entering the inside of the supply bobbin storage portion 54a of the ink sheet cartridge 50 by being guided obliquely downward while in contact with the upper portion of the sheet sensor 27b in the direction of the arrow T1. pass.

  When feeding paper, as shown in FIG. 5, as the stepping motor 18 is driven, the motor gear 36 attached to the stepping motor 18 rotates in the direction of the arrow C3 and passes through the intermediate gears 21 and 22. The feed roller gear 10 rotates in the arrow C1 direction. Thereby, the feed roller 4 rotates in the arrow C1 direction. Further, the paper feed roller gear 13 and the paper feed roller 12 rotate in the direction of arrow C4 via the intermediate gears 23 and 24. Thus, the paper 60 (see FIG. 4) is conveyed in the paper feeding direction (the direction of arrow T1 in FIG. 4). At this time, the swingable rocking gear 20 (see FIG. 5) is not meshed with the gear 16a (see FIG. 5) of the take-up reel 16 (see FIG. 5), and the take-up reel 16 (see FIG. 5). ) Gear 16a (see FIG. 5) does not rotate. As a result, the ink sheet 51 wound around the supply bobbin 52 (see FIG. 4) is not taken up by the take-up bobbin 53 during paper feeding.

  Then, as shown in FIG. 13, after the cueing of the paper 60 is completed, the print head 2 is moved to a position to press the ink sheet 51 and the paper 60, and the head portion pressing members 7 and 8 are further moved in the direction of the arrow Q1. Is rotated. Accordingly, as shown in FIG. 7, the one end portion 32 a of the first torsion coil spring 32 attached to the first spring fixing portion 30 g of the engaging member 30 is pressed by the pressing portion 7 a of the head portion pressing member 7. . Further, the one end portion 33 a of the second torsion coil spring 33 attached to the second spring fixing portion 30 h of the engaging member 30 is pressed by the pressing portion 8 a of the head portion pressing member 8. At this time, an urging force is generated in the first torsion coil springs 32 and 33, and the urging force is applied to the upper portion of the head portion 2 b via the other end portions 32 b and 33 b of the first torsion coil spring 32 and the second torsion coil spring 33. Is transmitted to. As a result, as shown in FIG. 13, the printing unit 2 e of the head unit 2 b is pressed against the platen roller 3 via the ink sheet 51 (Y color ink sheet) and the paper 60.

  Here, in the present embodiment, as shown in FIG. 11, when the head portion 2b of the print head 2 rotates and contacts the ink sheet 51 in the arrow Y direction from above, the ink sheet guide portion 28f Then, contact with the ink sheet 51 is started on the upstream side in the conveyance direction (arrow A direction) of the ink sheet 51. As shown in FIG. 11, immediately after the ink sheet 51 is sent from the supply bobbin 52 (see FIG. 13), the ink sheet 51 is pulled obliquely downward by the ink sheet guide portion 28f of the paper guide member 28, and the ink sheet 51 Along the surface of the sheet guide portion 28f, the conveyance direction (winding direction) is changed from an obliquely downward direction to a substantially horizontal direction for conveyance. Then, the ink sheet 51 that has passed through the ink sheet guide portion 28f comes into contact with the ink sheet guide portion 2i disposed in the vicinity of the heating element 29 provided in the print portion 2e of the print head 2, as shown in FIG. . As shown in FIG. 11, the ink sheet guide portion 2i is formed so as to protrude downward from the heating element 29 of the printing portion 2e, so that it is substantially between the ink sheet guide portion 28f and the ink sheet guide portion 2i. The ink sheet 51 transported in the horizontal direction is transported toward the heating element 29 of the printing unit 2e along the surface of the ink sheet guide unit 2i. At this time, as the ink sheet 51 is transported, the vertical vibration of the ink sheet 51 between the heating element 29 of the printing unit 2e and the ink sheet guide unit 28f occurs in the vicinity of the printing unit 2e. The ink sheet guide portion 2i and the ink sheet 51 that are disposed are in contact with each other to be suppressed. For this reason, the ink sheet 51 is guided to the heating element 29 in a state where vibration is suppressed between the ink sheet guide portion 2 i and the heating element 29.

  As shown in FIG. 11, the heating element 29 of the printing unit 2 e generates heat, so that the ink on the ink sheet 51 (Y color ink sheet) is melted and sublimated, and the ink is transferred to the paper 60.

  Further, as shown in FIG. 5, as the stepping motor 18 is driven, the motor gear 36 attached to the stepping motor 18 rotates in the direction of arrow D3, and the feed roller gear 10 is interposed via the intermediate gears 21 and 22. Rotates in the direction of arrow D1. As a result, as shown in FIG. 13, the feed roller 4 is rotated in the direction of arrow D1 in FIG. 5 with the rotation of the feed roller gear 10 (see FIG. 5). It is conveyed in the direction (arrow U1 direction). Further, as shown in FIG. 5, the swingable swing gear 20 is swung in a direction (arrow D2 direction) that meshes with the gear portion 16a of the take-up reel 16, and the gear portion 16a of the take-up reel 16 is swung. Is engaged. As a result, the gear portion 16 a of the take-up reel 16 is rotated in the direction of arrow D 4, so that the ink sheet 51 wound around the supply bobbin 52 (see FIG. 13) is taken up on the take-up bobbin 53. In this way, as shown in FIG. 13, the paper 60 and the ink sheet 51 are both conveyed in the paper discharge direction (the direction of the arrow U1), and the ink of the ink sheet 51 (Y color ink sheet) is continuously supplied to the paper. 60.

  In this embodiment, as shown in FIG. 11, when the ink sheet 51 immediately after the ink is transferred to the paper 60 is conveyed in the arrow A direction, the ink sheet 51 is provided in the vicinity of the print head 2. Further, the conveying direction is changed from the substantially horizontal direction to the obliquely upward direction by the contact portion 30f of the ink sheet guide portion 30e, and the ink sheet guide portion 30e is wound by the winding bobbin 53 (see FIG. 13). At this time, the ink sheet 51 and the ink sheet guide portion 30e are brought into contact with each other over the entire width (see FIG. 9), so that the ink sheet 51 is wound on the downstream side in the conveying direction (arrow A direction) of the heating element 29. A change in the conveyance state of the ink sheet 51 due to a change in tensile force for winding around the bobbin 53 (see FIG. 13) or an extension of the ink sheet 51 due to heat is suppressed.

  Next, when printing of the Y (yellow) ink sheet is completed, the stepping motor 19 (see FIG. 5) is driven, and the driving force of the stepping motor 19 is changed to the intermediate gear 34 (see FIG. 7) and the driving gear. 9 (see FIG. 7) is transmitted to the gear portion 7b (see FIG. 7) of the head portion pressing member 7. Then, as shown in FIG. 14, the head portion pressing member 7 (see FIG. 7) is rotated in the arrow Q2 direction about the support bar 6. At this time, since the head portion pressing members 7 and 8 (see FIG. 7) do not idle with respect to the support rod 6, the head portion pressing member 8 is also rotated in the direction of the arrow Q2. Then, when the protrusion 8b of the head pressing member 8 is rotated in the direction of the arrow Q2, the engagement member 30 of the print head 2 engaged with the protrusion 8b by the protrusion 8b of the head pressing member 8 is engaged. The joining portion 30b (strictly, the cutout portion 30a is shown) is lifted upward, and the head portion 2b of the print head 2 is rotated in the direction of arrow P2. As a result, the head portion 2 b of the print head 2 is moved to a position separated from the platen roller 3.

  Then, as shown in FIG. 5, as the stepping motor 18 is driven, the motor gear 36 attached to the stepping motor 18 is rotated in the direction of the arrow C3 and is fed via the intermediate gears 21 and 22. The roller gear 10 is rotated in the direction of arrow C1. Accordingly, as shown in FIG. 14, the feed roller 4 is rotated in the direction of the arrow C1 in accordance with the rotation of the feed roller gear 10 (see FIG. 5), so that the paper 60 is fed in the paper feed direction (arrow T1). The paper 60 is cueed by the paper sensors 27a and 27b. Further, the swingable swing gear 20 (see FIG. 5) swings in a direction away from the gear portion 16a of the take-up reel 16 (see FIG. 5) (in the direction of arrow C2 in FIG. 5). Accordingly, the ink sheet 51 wound around the supply bobbin 52 is not taken up by the take-up bobbin 53 and only the paper 60 is conveyed in the paper feeding direction.

  Thereafter, with respect to the M color (magenta) ink sheet and the C color (cyan) ink sheet, the same operation as the printing operation when printing the Y color (yellow color) ink sheet shown in FIGS. Is repeated.

  In the present embodiment, the M (magenta) ink sheet and the C (cyan) ink sheet of the ink sheet 51 (see FIG. 13) are respectively wound by the winding bobbin 53 (see FIG. 13). However, when printing is repeated on the paper 60 (see FIG. 13), as shown in FIG. 11, the ink sheet 51 is conveyed while being in contact with the ink sheet guide portion 28f and the ink sheet guide portion 2i. The generated vibration is suppressed and guided to the heating element 29 of the printing unit 2e. Then, when the heating element 29 of the printing unit 2 e generates heat, the ink of the ink sheet 51 (M color ink sheet and C color ink sheet) is melted and sublimated, and the ink is transferred to the paper 60.

  In the present embodiment, as shown in FIG. 11, as the Y color ink is transferred to the paper 60, the M color ink and the C color ink of the ink sheet 51 are respectively transferred to the paper 60 while the arrows are transferred. Even when the ink sheet 51 is conveyed in the A direction, the ink sheet 51 is brought into contact with the abutting portion 30f of the ink sheet guide portion 30e provided in the vicinity of the front surface portion 2h of the print head 2, thereby changing the conveying direction from the substantially horizontal direction. The ink sheet 51 is taken up by the take-up bobbin 53 (see FIG. 14) while being changed obliquely upward and stabilizing the transport state of the ink sheet 51 on the downstream side of the printing unit 2e.

  When the printing of the ink sheets 51 of all colors is completed, the paper 60 is conveyed in the paper discharge direction (the direction of the arrow U1 in FIG. 14) and discharged outside the apparatus main body 90. Then, as shown in FIG. 12, the head portion 2b of the print head 2 is rotated in the direction of the arrow P2 to a position spaced upward with respect to the platen roller 3, and the printing operation on the paper 60 is completed.

  In the present embodiment, as described above, the ink sheet guide unit is located upstream of the print head 2 in the transport direction of the ink sheet 51 (the direction of arrow A in FIG. 11) and guides the ink sheet 51 to the print head 2. 28f and an ink sheet guide portion 2i that is located between the print portion 2e of the print head 2 and the ink sheet guide portion 28f and that abuts against the ink sheet 51, so that the ink sheet 51 The vibration generated between the printing part 2e of the print head 2 and the ink sheet guide part 28f accompanying the conveyance can be suppressed by the contact of the ink sheet 51 and the ink sheet guide part 2i. Thereby, since vibration of the ink sheet 51 is suppressed, generation of wrinkles of the ink sheet 51 due to vibration of the ink sheet 51 can be suppressed.

  Further, in the present embodiment, the ink sheet guide portion 2i is configured to abut on the ink sheet 51 over substantially the entire width in the direction intersecting with the transport direction of the ink sheet 51 (the direction of arrow A in FIG. 11). Since the ink sheet guide portion 2i abuts over substantially the entire width of the conveyed ink sheet 51, vibration can be suppressed over substantially the entire width of the ink sheet 51. Occurrence can be suppressed.

  Further, in the present embodiment, the ink sheet guide portion 2 i is provided so as to contact the ink sheet 51 in the vicinity of the printing portion 2 e of the print head 2 and to protrude from the print head 2 toward the ink sheet 51. When the sheet guide portion 2i abuts in the vicinity of the printing portion 2e, the ink sheet 51 can be immediately fed to the printing portion 2e while the vibration is removed.

  Further, in the present embodiment, the contact surface of the ink sheet guide portion 2i with the ink sheet 51 is a curved surface having a rounded cross-sectional shape along the conveyance direction of the ink sheet 51 (arrow A direction, see FIG. 11). By forming the ink sheet 51, the ink sheet 51 can contact the ink sheet guide portion 2i with a rounded curved contact surface along the transport direction (the direction of arrow A in FIG. 11). It is possible to prevent the surface of the ink sheet 51 from being scratched by sliding during conveyance of the sheet 51.

  In the present embodiment, the ink sheet guide portion 2i includes a protrusion 2k protruding from the print head 2 toward the ink sheet 51, and a surface layer 2l formed of a material having a lower friction coefficient than the protrusion 2k. By forming the surface layer 21 that constitutes the contact surface between the ink sheet guide part 2i and the ink sheet 51 with a material having a lower friction coefficient than the protruding part 2k, the ink sheet 51 It is possible to further suppress the surface of the ink sheet 51 from being scratched by sliding between the ink sheet 51 and the surface layer 21 of the ink sheet guide portion 2i during the conveyance of the ink sheet.

  In the present embodiment, the ink sheet 51 is positioned downstream of the print head 2 in the transport direction of the ink sheet 51 (in the direction of arrow A in FIG. 11), and in contact with the ink sheet 51 in the vicinity of the print head 2. By further comprising an ink sheet guide part 30e for guiding, the ink sheet 51 and the ink sheet guide part 30e abut on the downstream side of the printing part 2e, so that not only the upstream side before printing but also the upstream side before printing is performed. The transport state of the downstream ink sheet 51 after printing can be stabilized. Thereby, it is possible to suppress the influence of the disturbance in the conveyance state of the ink sheet 51 on the downstream side in the conveyance direction from reaching the vicinity of the printing unit 2e that performs printing, so that the print quality can be improved.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  For example, in the above-described embodiment, an example in which the present invention is applied to a sublimation type printer as an example of an image forming apparatus has been described. However, the present invention is not limited to this, and includes a printing unit that abuts on an ink sheet. Any image forming apparatus provided with a print head capable of printing can be applied to image forming apparatuses other than sublimation printers.

  In the above embodiment, the example in which the ink sheet guide portion 2i is provided so as to protrude from the head portion 2b of the ink head 2 has been described. However, the present invention is not limited thereto, and the ink sheet guide portion is separated from the head portion. It is not necessary to project. For example, by separately providing an ink sheet guide portion composed of a rotatable roller in the vicinity of the print portion of the print head, the ink sheet guide portion comes into contact with the ink sheet in the vicinity of the heating element of the print portion. It may be configured.

  Further, in the above embodiment, the example in which the protruding portion 2k constituting the ink sheet guide portion 2i is provided so as to function as an insulating protective film that covers the wiring of the heating element 29 has been shown. Not only this but the protrusion part of an ink sheet guide part does not need to have insulation. Further, it does not have to function as a protective film for the wiring. In this case, the wiring connected to the heating element may be insulated by a member having an insulating property separately.

  Moreover, in the said embodiment, although the surface layer 21 of the ink sheet guide part 2i showed the example formed with the polyimide resin which has heat resistance and a friction coefficient lower than the protrusion part 2k, this invention shows this. Not limited to this, the surface layer may be formed of a resin material other than polyimide resin or a metal material. The surface layer may be formed of a material having a friction coefficient lower than that of the protruding portion so that the surface of the ink sheet 51 can be prevented from being scratched by sliding during conveyance.

1 is an exploded perspective view showing an overall configuration of a sublimation printer according to an embodiment of the present invention. FIG. 2 is a perspective view of a sublimation printer according to the embodiment illustrated in FIG. 1. FIG. 2 is a perspective view illustrating an overall configuration of the sublimation printer according to the embodiment illustrated in FIG. 1. It is sectional drawing which showed the internal structure of the sublimation type printer by one Embodiment shown in FIG. It is the figure which showed the arrangement position of the gear of the sublimation type printer by one Embodiment shown in FIG. FIG. 2 is a top view of the sublimation printer according to the embodiment illustrated in FIG. 1. It is a front view of the sublimation type printer by one Embodiment shown in FIG. FIG. 2 is a perspective view showing a detailed structure of a print head of the sublimation type printer according to the embodiment shown in FIG. 1. FIG. 2 is a bottom view of the print head of the sublimation printer according to the embodiment shown in FIG. 1. FIG. 2 is a diagram illustrating a positional relationship between a print head and an ink sheet of the sublimation printer according to the embodiment illustrated in FIG. 1. FIG. 2 is an enlarged view of the vicinity of a paper guide member when a print head of a sublimation printer according to the embodiment shown in FIG. 1 presses a platen roller. It is a figure for demonstrating the printing operation | movement of the sublimation type printer by one Embodiment shown in FIG. It is a figure for demonstrating the printing operation | movement of the sublimation type printer by one Embodiment shown in FIG. It is a figure for demonstrating the printing operation | movement of the sublimation type printer by one Embodiment shown in FIG.

Explanation of symbols

2 Print head 2e Print section 2i Ink sheet guide section (second guide section)
2k Protruding part 2l Surface layer 28f Ink sheet guide part (first guide part)
30e Ink sheet guide part (third guide part)
51 Ink sheet 60 Paper 100 Sublimation printer (image forming apparatus)

Claims (6)

An ink sheet conveyed with the paper during printing;
A print head that has a print portion that contacts the conveyed ink sheet, and is capable of printing an image on the paper;
A first guide portion that is located upstream of the print head in the transport direction of the ink sheet and guides the ink sheet to the print head;
A second guide portion that is positioned between the print portion and the first guide portion of the print head and contacts the ink sheet ;
The image forming apparatus, wherein the first guide portion includes a support portion that contacts the surface of the print head on the print portion side and supports the print head .   2. The image forming apparatus according to claim 1, wherein the second guide unit is configured to contact the ink sheet over substantially the entire width in a direction intersecting with a conveyance direction of the ink sheet.   The said 2nd guide part is provided so that it may contact | abut to the said ink sheet in the vicinity of the said printing part of the said print head, and may protrude toward the said ink sheet from the said print head. Image forming apparatus.   The contact surface of the second guide part with the ink sheet is formed in a curved surface having a rounded cross-sectional shape along the transport direction of the ink sheet. The image forming apparatus described in the item.   The said 2nd guide part contains the protrusion part which protrudes toward the said ink sheet from the said print head, and the surface layer formed with the material which has a lower coefficient of friction than the said protrusion part. The image forming apparatus according to claim 1.   6. The apparatus further comprises a third guide portion that is located downstream of the print head in the transport direction of the ink sheet, contacts the ink sheet in the vicinity of the print head, and guides the ink sheet. The image forming apparatus according to any one of the above.

Images