JP6287464B2 - Liquid ejector - Google Patents

Description

  The present invention relates to a liquid ejecting apparatus that ejects liquid onto a medium such as paper.

  As a liquid ejecting apparatus that ejects liquid such as ink onto a medium such as paper from an ejecting unit, an imaging unit is provided in a medium supporting unit that supports the medium, and the texture of the lower surface of the medium that passes over the medium supporting unit by the imaging unit is provided. A liquid ejecting apparatus that captures an image and detects the transport amount of a medium based on the captured image is known. In such a liquid ejecting apparatus, an opening for irradiating light from the imaging unit toward the lower surface of the medium is formed on the support surface of the medium support unit (see, for example, Patent Document 1).

  Further, in such a liquid ejecting apparatus, when a large amount of liquid is ejected from the ejecting unit to the medium, for example, during solid printing, the medium swells by absorbing the large amount of liquid, and the medium becomes medium after printing. A so-called cockling that undulates against the support surface of the support portion may occur.

In such a case, the portion of the medium that is bent and deformed in the direction of rising from the support surface due to the cockling phenomenon may come into contact with the ejection unit.
Therefore, in such a liquid ejecting apparatus, as shown in FIG. 9, a plurality of recesses 102 are formed on the support surface 101 of the medium support unit 100, and the support surface 101 includes a bottom region of a part of the recesses 102. Suction holes 103 are formed at a plurality of locations. Then, a medium is adsorbed to the support surface 101 side by driving a suction fan (not shown) communicating with each suction hole 103.

JP 2013-119439 A

  By the way, in the conventional liquid ejecting apparatus, as shown in FIG. 9, the translucent member 110 of the imaging unit is disposed between the plurality of recesses 102 in the width direction of the medium support unit 100. That is, on the support surface 101 of the medium support unit 100, the arrangement region of the translucent member 110 and the region having a constant width extending downstream from the arrangement region in the medium conveyance direction are regions where the recess 102 is not formed. Yes. Therefore, in this constant width region, the medium cannot be supported by being displaced from the support surface 101 in a direction away from the ejecting unit, and the medium is bent and deformed in the direction of rising from the support surface 101 due to the cockling phenomenon. In the case where there is, there is still a possibility that the portion is brought into contact with the injection portion.

  The present invention has been made in view of the above circumstances, and its purpose is in the case where a translucent member that transmits light for medium imaging by the imaging unit is disposed on the support surface of the medium support unit facing the ejection unit. An object of the present invention is to provide a liquid ejecting apparatus capable of reducing the possibility that the bent deformation portion of the medium on the translucent member is in contact with the injection portion even when the bent deformation portion of the medium is located.

Hereinafter, means for solving the above-described problems and the effects thereof will be described.
A liquid ejecting apparatus that solves the above problems includes a transport unit that transports a medium, an ejecting unit that ejects liquid onto the medium transported by the transport unit, and the ejected unit that transports the medium transported by the transport unit. A medium support portion having a support surface that can be supported so as to face each other, and a plurality of concave portions that are recessed in a direction away from the ejection portion on the support surface, and the ejection portion based on the support surface An image pickup unit that is disposed on the opposite side and picks up an image of a surface of the medium that is opposite to the surface facing the ejection unit, an opening is formed in the recess, and the medium formed by the image pickup unit is formed in the opening A translucent member that transmits imaging light is disposed.

  According to the above configuration, the translucent member that transmits the light for medium imaging by the imaging unit is disposed in the concave portion that is recessed in the direction away from the ejection unit from the support surface on the support surface of the medium support unit. For this reason, when the medium is bent and deformed on the support surface, it is possible to support the medium by displacing a portion of the medium that is located on the arrangement region of the translucent member in a direction away from the ejecting unit with respect to the support surface. . Therefore, even when the bending deformation portion of the medium is positioned on the light transmitting member, the possibility that the bending deformation portion contacts the ejection unit can be reduced.

  Further, in the liquid ejecting apparatus, the imaging unit includes a support member to which the translucent member is fixed and supports the medium, and the support member includes a wall portion that is inserted through the opening. It is preferable that the support wall protrudes to the injection unit side from a surface of the translucent member facing the injection unit and constitutes at least a part of the peripheral wall of the recess.

  By forming the opening in the recess, when a part of the peripheral wall of the recess is cut out by the opening, the medium cannot be supported by the part of the cut-out recess. For this reason, when the medium is bent and deformed, the amount of bending of the medium in a direction away from the ejecting portion increases in a part of the recess where the peripheral wall is cut off. For this reason, the liquid is ejected from the ejecting unit onto a medium having a large amount of bending, and the accuracy of the liquid landing position is lowered.

  According to the above configuration, even when a part of the peripheral wall of the recess is cut out by the opening due to the opening formed in the recess, the wall of the support member supports the medium instead of the peripheral wall cut out of the recess. . For this reason, the amount by which the medium bends in the direction away from the ejection unit is reduced. Accordingly, it is possible to suppress a decrease in accuracy of the liquid landing position.

  In the liquid ejecting apparatus, it is preferable that a height dimension between the bottom surface of the recess and a surface of the wall portion supporting the medium is equal to a height dimension between the bottom surface of the recess and the support surface. .

  According to the above configuration, the surface of the wall portion of the support member and the support surface of the medium support portion are prevented from forming a step in the medium transport direction. For this reason, it is suppressed that a medium is caught by a level | step difference. Therefore, the medium is transported smoothly.

  The liquid ejecting apparatus may further include a suction unit for adsorbing the medium to the support surface, and the recess may be formed with a suction hole communicating with the suction unit. It is preferable that the portion of the medium facing the light transmissive member is sucked to the bottom surface side of the concave portion.

  According to the above configuration, since the suction part sucks air existing in the space between the translucent member and the medium through the suction hole, the suction from the translucent member on the surface of the translucent member that faces the ejection part. An air flow toward the hole is formed. For this reason, when a foreign material adheres to the surface of the translucent member that faces the ejection portion, the foreign material can be removed from the translucent member by the airflow.

  Further, in the liquid ejecting apparatus, the imaging unit includes a support member to which the translucent member is fixed and supports the medium, and the support member is inserted through the opening and has a peripheral wall of the recess. The wall portion protrudes from the bottom surface of the concave portion toward the ejection portion side, extends in the medium conveyance direction, and is perpendicular to the medium conveyance direction. A pair of wall portions formed so as to sandwich both sides of the translucent member in a certain width direction, and the suction hole formed in the concave portion is a position different from the pair of wall portions in the conveyance direction of the medium Preferably, it is formed between the pair of wall portions in the width direction.

  According to the above configuration, when the end in the transport direction of the medium passes through the suction hole or the light transmitting member formed in the recess, the opening in the transport direction formed by the end in the transport direction of the medium and the recess. Then, air is introduced into a space formed between the medium and the recess. For this reason, the airflow of a conveyance direction generate | occur | produces in the space formed between the medium and the recessed part. This airflow is guided by the pair of wall portions so as to pass on the surface of the light transmitting member on the ejection portion side. Thereby, when foreign matters, such as dust, are adhering to the translucent member, the foreign matters are moved in the transport direction by the air flow. Therefore, foreign matters can be removed from the translucent member.

(A) is a schematic block diagram of the inkjet type printer of one Embodiment, (b) is an enlarged view of the paper feed roller pair of (a) and its periphery. (A) is a plan view of a part of the medium support portion, and (b) is an enlarged view of the first recess and the second recess in (a). Sectional drawing of the 3-3 line of FIG. The enlarged view of the dashed-dotted line circle A of FIG. The perspective view of the 1st crevice and its circumference. FIG. 4 is a cross-sectional view of a part of a medium support unit. The top view of a part of medium support part. The top view of a part of medium support part of a modification. The top view of a part of conventional medium support part.

Hereinafter, an embodiment in which a liquid ejecting apparatus is embodied in an ink jet printer will be described with reference to the drawings.
As shown in FIG. 1A, an ink jet printer (hereinafter, “printer 11”) as an example of a liquid ejecting apparatus includes a transport device 12 that transports a continuous sheet P of a long sheet that is an example of a medium. And an ejection unit 17 that performs printing by ejecting ink, which is an example of a liquid, onto the continuous paper P conveyed by the conveyance device 12. Further, the printer 11 includes a control unit 18 that controls the transport device 12 and the ejection unit 17.

  The transport device 12 includes a feeding unit 14 that feeds the continuous paper P, and a winding unit 15 that winds the continuous paper P fed from the feeding unit 14 and printed by the ejecting unit 17. In FIG. 1, the feeding unit 14 is disposed at the right position on the upstream side in the transport direction Y (left direction in FIG. 1) of the continuous paper P, while the winding unit 15 is disposed at the left position on the downstream side. Has been.

  The ejection unit 17 is disposed at a position between the feeding unit 14 and the winding unit 15 so as to face the conveyance path of the continuous paper P. A plurality of nozzles 17 a for ejecting ink onto the continuous paper P are formed on the surface of the ejection unit 17 that faces the conveyance path of the continuous paper P.

  In the printer 11, a medium support unit 20 that supports the continuous paper P is disposed at a position facing the ejection unit 17 across the conveyance path of the continuous paper P. The medium support portion 20 has a bottomed square box shape in which a mouth portion 21 is formed on the lower surface side opposite to the ejection portion 17 side.

  A suction fan 28, which is an example of a suction unit that sucks air in the internal space 22 of the medium support unit 20, is provided on the lower surface of the medium support unit 20 so as to close the mouth 21. A surface of the medium support unit 20 that faces the ejection unit 17 is a horizontal support surface 20a that supports the conveyed continuous paper P. The medium support unit 20 is formed with a plurality of suction holes 23 for adsorbing the continuous paper P to the support surface 20a. Each suction hole 23 communicates with the internal space 22 of the medium support portion 20. According to such a configuration, the space between the continuous paper P and the medium support portion 20 is sucked through the internal space 22 and the suction holes 23 by sucking the mouth portion 21 as the suction port by the rotation of the suction fan 28. To negative pressure. Thereby, the suction force for adsorbing the continuous paper P to the support surface 20a is applied to the continuous paper P.

  An imaging unit 30 for detecting the transport amount of the continuous paper P in a non-contact manner is attached to the lower part of the medium support unit 20. The imaging unit 30 images the texture of the lower surface (non-printing surface) of the continuous paper P and transmits the image to the control unit 18 attached to the lower part of the imaging unit 30. The control unit 18 controls the transport amount of the continuous paper P by a known method based on the image from the imaging unit 30.

  The feeding section 14 is provided with a feeding shaft 14a that can be driven to rotate in the width direction X of the continuous paper P (direction orthogonal to the paper surface in FIG. 1), which is a direction orthogonal to the conveyance direction Y of the continuous paper P. . A continuous paper P is supported on the feeding shaft 14a so as to be integrally rotatable with the feeding shaft 14a in a state where the continuous paper P is wound in a roll shape in advance. When the feeding shaft 14a is rotationally driven, the continuous paper P is fed from the feeding shaft 14a toward the downstream side of the transport path.

  A pair of paper feed rollers 13 that is an example of a transport unit that guides the continuous paper P transported from the feed shaft 14a to the support surface 20a while sandwiching the continuous paper P is disposed below the feed shaft 14a. The paper feed roller pair 13 is arranged at a position adjacent to the upstream end of the medium support unit 20 in the transport direction Y in the transport direction Y. The pair of paper feed rollers 13 includes a paper feed roller 13a provided so as to be rotatable and a paper pressing roller 13b that is driven by the rotation of the paper feed roller 13a. As shown in FIG. 1B, the position where the continuous paper P is sandwiched between the paper supply roller 13 a and the paper pressing roller 13 b is located above the support surface 20 a of the medium support unit 20.

  As shown in FIG. 1A, a tension roller 16 for adjusting the tension of the printed region of the continuous paper P is arranged downstream of the support surface 20a in the transport direction Y on the transport path of the continuous paper P. Has been. A winding unit 15 is disposed on the downstream side of the tension roller 16 in the transport path of the continuous paper P.

  A winding shaft 15 a extending in the width direction X of the continuous paper P is provided in the winding unit 15 so as to be rotatable. When the take-up shaft 15a is driven to rotate, the printed continuous paper P conveyed from the tension roller 16 side is sequentially taken up by the take-up shaft 15a.

Next, a detailed configuration of the medium support unit 20 will be described with reference to FIGS. 2 and 3.
As shown in FIG. 2A, the medium support unit 20 includes a plurality of first recesses 24 that are an example of recesses that are open toward the ejection unit 17 (see FIG. 1) and are recessed downward from the support surface 20a. While recessed like the 1st recessed part 24, the some 2nd recessed part 26 which is an example of the recessed part from which a shape differs from the 1st recessed part 24 is formed. The upstream ends of the plurality of first recesses 24 and the plurality of second recesses 26 in the transport direction Y are formed at the upstream ends of the medium support unit 20 in the transport direction Y.

  As shown in FIG. 2A, the plurality of first recesses 24 and the plurality of second recesses 26 are formed in a printing region that is a region in which ink is ejected toward the continuous paper P by the ejecting unit 17 in the medium support unit 20. Has been. The plurality of first recesses 24 are formed so as to be arranged at a predetermined interval in the width direction X. On the other hand, the plurality of second recesses 26 are provided at one end serving as a reference (the right end in FIG. 2A) in accordance with the size in the width direction X of the plurality of types of continuous paper P scheduled to be used in the printer 11. They are formed at a plurality of locations at different distances in the width direction X from one formed second recess 26 (hereinafter also referred to as “second recess 26K”). In the width direction X, first recesses 24 are formed on both sides of each second recess 26 other than the second recess 26K.

  Further, between the first recesses 24 adjacent in the width direction X, a support wall 27A that forms a boundary of the first recesses 24 adjacent in the width direction X and supports the continuous paper P is formed. The support wall 27 </ b> A forms a part of the peripheral wall constituting the first recess 24 with the transport direction Y being the longitudinal direction. Further, a boundary between the first recess 24 and the second recess 26 adjacent in the width direction X is formed between the first recess 24 and the second recess 26 adjacent in the width direction X, and the continuous paper P is supported. A supporting wall 27B is formed. The support wall 27 </ b> B has the conveyance direction Y as a longitudinal direction, and forms a part of the peripheral wall constituting the first recess 24 and a part of the peripheral wall constituting the second recess 26. At the upstream end in the transport direction Y of all the first recesses 24 and all the second recesses 26, a support wall 27 </ b> C constituting the upstream end of the medium support unit 20 in the transport direction Y is formed. The support wall 27 </ b> C has a longitudinal direction in the width direction X, and constitutes a part of the peripheral wall constituting the first recess 24 and the second recess 26. The upper surface of the support wall 27 </ b> A, the upper surface of the support wall 27 </ b> B, and the upper surface of the support wall 27 </ b> C constitute a part of the support surface 20 a of the medium support unit 20.

  A rib 25 extending toward the downstream side in the transport direction Y is formed in the first recess 24. The rib 25 rises from the bottom surface 24a of the first recess 24 toward the injection unit 17 side. The height dimension from the bottom surface 24a of the first recess 24 to the upper surface of the rib 25 is the same as the height dimension from the bottom surface 24a of the first recess 24 to the support surface 20a. In this respect, the upper surface of the rib 25 is supported. A part of the surface 20a is formed. In the transport direction Y, the rib 25 extends from the upstream end of the first recess 24 in the transport direction Y toward the downstream side. The downstream end of the rib 25 is located upstream of the central portion of the first recess 24 in the transport direction Y. A suction hole 23 is formed in each first recess 24 on the downstream side of the rib 25 in the transport direction Y. For this reason, the first concave portion 24 communicates with the internal space 22 (see FIG. 1) of the medium support portion 20 through the suction hole 23.

  As shown in FIG. 2B, in the two first recesses 24 adjacent to each other in the width direction X, which are sandwiched between the two second recesses 26 in the width direction X, closer to the upstream side in the transport direction Y. An opening 24b is formed in the region. A part of the imaging unit 30 is inserted into the opening 24b from below. That is, the imaging unit 30 images the lower surface of the continuous paper P through the opening 24b. In the following description, the two first recesses 24 in which the opening 24b of the first recesses 24 is formed are referred to as “first recess 24A” and “first recess 24B”. The first recesses 24 </ b> A and 24 </ b> B have dimensions in the transport direction Y that are larger than those of the other first recesses 24 in the transport direction Y.

  On the other hand, the second concave portion 26 has an opening shape that can receive the ink ejected from the ejecting portion 17 (see FIG. 1) onto the continuous paper P. The second recess 26 has a width dimension that is a dimension in the width direction X slightly smaller than the width dimension of the first recess 24, and a dimension in the transport direction Y of the first recess 24 other than the first recesses 24 </ b> A and 24 </ b> B. An opening larger than the dimension in the transport direction Y is provided. In the following description, the second recess 26 adjacent to the first recess 24A in the width direction X is referred to as “second recess 26A”, and the second recess 26 adjacent to the first recess 24B in the width direction X is referred to as “second recess”. 2 recesses 26B ".

Next, a detailed configuration of the imaging unit 30 will be described with reference to FIGS.
As shown in FIG. 3, the imaging unit 30 includes a cylindrical lens barrel 31 that extends in the vertical direction Z. The lens barrel 31 is fixed to the medium support portion 20 by a screw 38 (see FIG. 2B) at an upper end portion thereof, and fixed to the control portion 18 having a housing by a screw (not shown) at a lower end portion thereof. .

  At the upper end of the lens barrel 31, an accommodating portion 31 a is formed in which the inner accommodating space extends in the transport direction Y. The housing portion 31a is a case body that is open at the top, and a lens barrel cover 40 that is an example of a support member is attached to the opening so as to be closed from above. The upper end portion of the lens barrel cover 40 is inserted into the opening 24b of the first recesses 24A and 24B. A colorless and transparent translucent member 32 is fixed to the upper part of the lens barrel cover 40 to allow light to pass therethrough while preventing entry of foreign matters such as dust into the imaging unit 30. In other words, the opening 24 b is blocked by the translucent member 32.

  In the accommodation space formed by the accommodation portion 31a and the lens barrel cover 40, a light irradiation portion 33 that irradiates light onto the lower surface of the continuous paper P is disposed. The light irradiation unit 33 is a light source such as a light emitting diode and a halogen lamp, and is configured by a light emitting diode (LED) in the present embodiment. The light irradiation unit 33 irradiates the continuous paper P with light from the lower surface side of the continuous paper P conveyed on the support surface 20a through the translucent member 32. In this case, the light irradiation unit 33 is arranged so that light is irradiated obliquely to the lower surface of the continuous paper P from the width direction X side.

  In the lens barrel 31, an object side lens 34 positioned on the upper side (medium support unit 20 side), an image side lens 35 positioned on the lower side (control unit 18 side) than the object side lens 34, and an object side lens A stop 36 positioned between the lens 34 and the image side lens 35 is accommodated. The object side lens 34 is, for example, a telecentric lens, and the light emitted from the light irradiation unit 33 and transmitted through the light transmitting member 32 is reflected by the lower surface of the continuous paper P and then passes through the light transmitting member 32 again. The reflected light incident in 31 is condensed. The diaphragm 36 narrows the light range by passing the light that has passed through the object side lens 34. The image side lens 35 is a telecentric lens, for example, and collects light that has passed through the aperture 36.

  An imaging element 37 having an imaging surface 37 a on which an image of the lower surface of the continuous paper P collected by the image side lens 35 is formed is provided at the lower end of the lens barrel 31 accommodated in the control unit 18. . The image sensor 37 is configured by a two-dimensional image sensor, for example. The image captured by the imaging unit 30 is output to a control circuit (not shown) for controlling the transport device 12 in the control unit 18.

  As shown in FIG. 4, the upper end portion of the lens barrel cover 40 is opposed to a pair of first wall portions 41 that are an example of a pair of wall portions that support the translucent member 32, and a pair of first wall portions 41. A second wall portion 42 formed at an interval in the width direction X and a third wall portion 43 that is a side wall connecting the first wall portion 41 and the second wall portion 42 are formed. In addition, the lens barrel cover 40 is formed at a position corresponding to the light irradiation unit 33 in the width direction X, and connects the lower portions of the first wall portion 41 and the second wall portion 42 to connect the upper wall of the lens barrel cover 40. A fourth wall portion 44 constituting a part is formed.

  As shown in FIGS. 4 and 5, the upper surface 41 a that is the upper end surface of the pair of first wall portions 41, the upper surface 42 a that is the upper end surface of the second wall portion 42, and the upper surface 43 a that is the upper end surface of the third wall portion 43. Is formed so as to have the same height in the vertical direction Z as the support surface 20a of the medium support portion 20. That is, the vertical dimension Z (height dimension Z1) from the bottom surface 24a of the first recess 24A to the top surfaces 41a to 43a is the vertical dimension Z (height) from the bottom surface 24a of the first recess 24A to the support surface 20a. Equal to dimension Z2). For this reason, the upper surfaces 41 a to 43 a support the continuous paper P when the continuous paper P is conveyed to the medium support unit 20. Further, the pair of first wall portions 41 protrudes above the upper surface 32a of the translucent member 32 (on the support surface 20a side). In other words, the translucent member 32 is located below the support surface 20a.

  “The height dimension Z1 from the bottom surface 24a of the first recess 24A to the top surfaces 41a to 43a is equal to the height dimension Z2 from the bottom surface 24a of the first recess 24A to the support surface 20a” means that the lens barrel 31 and the mirror This includes a range in which the height dimension Z1 and the height dimension Z2 are slightly shifted from each other due to processing errors and assembly errors of the tube cover 40. In short, it is sufficient that the height dimension Z1 is substantially equal to the height dimension Z2.

  As indicated by a broken line in FIG. 4, in order for the imaging unit 30 to clearly capture the lower surface of the continuous paper P, the focal position of the object side lens 34 in the vertical direction Z is set to the support surface 20a. That is, the focal position of the object side lens 34 is set above the upper surface 32 a of the translucent member 32. Note that when the continuous paper P is sucked by the suction fan 28, the portion of the continuous paper P that faces the translucent member 32 in the vertical direction Z may be slightly bent below the support surface 20 a. However, even if the lower surface of the continuous paper P is slightly below the support surface 20a and the lower surface of the continuous paper P is positioned below the focal position of the object-side lens 34, the object-side lens 34 If the distance between the focal position and the bottom surface Z of the continuous paper P is small, the imaging unit 30 can clearly capture the bottom surface of the continuous paper P.

  As shown in FIG. 5, in the pair of first wall portions 41, the transport direction Y is the longitudinal direction. The wall portions 41 </ b> A and 41 </ b> B, which are the pair of first wall portions 41, are formed at intervals so as to sandwich the translucent member 32 in the width direction X. Gaps are formed at both ends of the pair of first wall portions 41 in the transport direction Y. Between the pair of wall portions 41, between the translucent member 32 and the support wall 27C, a housing portion 45 is formed by the lens barrel cover 40 and the support wall 27C. The accommodating portion 45 is formed in a concave shape that opens upward and is recessed downward from the upper surface 32 a of the translucent member 32.

  Of the pair of first wall portions 41, the wall portion 41A on the second recessed portion 26A side is located in the first recessed portion 24A. This wall 41A is a substantially central portion in the width direction X between the support wall 27B serving as a boundary wall between the first recess 24A and the second recess 26A and the support wall 27A serving as a boundary wall between the first recesses 24A and 24B. Is located.

  Of the pair of first wall portions 41, the wall portion 41B on the second recess 26B side constitutes a part of the support wall 27A serving as a boundary wall between the first recesses 24A and 24B. The wall portion 41B is configured as an upstream end portion in the transport direction Y of the support wall 27A of the first recesses 24A and 24B.

  As for the 2nd wall part 42, the conveyance direction Y turns into a longitudinal direction. The second wall portion 42 is located at the center in the width direction X between the support wall 27A serving as the boundary wall between the first recesses 24A and 24B and the support wall 27B serving as the boundary wall between the first recess 24B and the second recess 26B. doing. The second wall portion 42 is formed at the upstream end portion of the medium support portion 20 in the transport direction Y.

  The third wall portion 43 is located in the first recess 24B. The third wall 43 has a longitudinal direction in the width direction X, and connects the upstream end of the wall 41B in the transport direction Y and the upstream end of the second wall 42 in the transport direction Y. A notch 24c is formed at the upstream end in the transport direction Y of the first recess 24 in which the third wall 43 is disposed. The third wall portion 43 is disposed at a position where the notch 24 c is formed in the first recess 24. And in this notch part 24c, the 3rd wall part 43 comprises some support walls 27C.

  The fourth wall portion 44 that is a part of the upper wall of the lens barrel cover 40 is formed as a plane parallel to a plane formed by the width direction X and the conveyance direction Y. The upper surface 44a of the fourth wall portion 44 is flush with the bottom surface 24a of the first recess 24B. And the 4th wall part 44 has covered a part of opening part 24b from the upper side.

  The suction hole 23 formed in the first recess 24 </ b> A is located between the pair of first wall portions 41 in the width direction X and is located downstream of the light transmitting member 32 in the transport direction Y. The suction hole 23 formed in the first recess 24B is located at the center of the first recess 24B in the width direction X, and is located downstream of the fourth wall 44 of the lens barrel cover 40 in the transport direction Y. Yes. The suction hole 23 of the first recess 24A is located upstream of the suction hole 23 of the first recess 24B in the transport direction Y.

  As described above, according to the configuration of the medium support portion 20 and the configuration of the pair of first wall portion 41, second wall portion 42, and third wall portion 43 of the lens barrel cover 40, the continuous paper P is printed. When cockling, which is a phenomenon that the continuous paper P swells in the width direction X due to swelling, the continuous paper P can be supported as shown in FIG.

  Specifically, in the first recess 24 and the second recess 26 other than the first recesses 24 </ b> A and 24 </ b> B, the suction fan 28 applies the continuous paper P to the upper surface of the support walls 27 </ b> A to 27 </ b> C and the upper surface of the rib 25 ( The upper bent portion is adsorbed, and the first concave portion 24 and the second concave portion 26 accommodate the bent portion on the support surface 20a side (lower side) of the continuous paper P. On the other hand, in the first recess 24A and the second recess 26, the upper surface of the pair of first wall portions 41, the upper surface of the second wall portion 42, and the support walls 27A to 27C on the ejection portion 17 side (upward) of the continuous paper P. The bent portions on the support surface 20a side (downward) of the continuous paper P are accommodated in the first recesses 24A and 24B. For this reason, it is suppressed that the continuous paper P floats to the injection part 17 side from the support surface 20a.

Next, the operation of the printer 11 will be described with reference to FIGS. 1 and 4 to 6.
As shown in FIG. 1B, the position of the continuous paper P sandwiched by the paper feed roller pair 13 is located above the support surface 20 a of the medium support unit 20. The continuous paper P conveyed to the support unit 20 enters the support surface 20a so as to intersect the support surface 20a. As a result, the continuous paper P is unlikely to float upward from the support surface 20a in a constant width region continuous from the upstream end in the transport direction Y intersecting the support surface 20a to the downstream side, and is directed to the downstream side of the region. As a result, it tends to float from the support surface 20a.

  On the other hand, as shown in FIG. 4, the imaging unit 30 is designed so that the focal position of the object-side lens 34 coincides with the support surface 20a on the premise that the continuous paper P is attracted and conveyed by the support surface 20a. Has been. For this reason, if the imaging unit 30 images the lower surface of the continuous paper P conveyed to the region, the lower surface of the continuous paper P and the focal position of the object side lens 34 are likely to coincide with each other. The texture of the lower surface of the image can be clearly imaged. Therefore, it is preferable that the opening 24b for irradiating the light from the light irradiation unit 33 toward the lower surface of the continuous paper P is formed in the region, and the translucent member 32 is disposed in the opening 24b.

  Further, the posture of the continuous paper P supported by the support surface 20a becomes less stable as the first concave portion 24 moves away from the paper feed roller pair 13 (see FIG. 1) on the downstream side. For this reason, it is preferable that the first concave portion 24 is as close as possible to the paper feed roller pair 13, that is, the first concave portion 24 is provided at the upstream end portion in the transport direction Y of the medium support portion 20.

  Therefore, in the present embodiment, as shown in FIG. 5, an opening 24b for imaging the lower surface of the continuous paper P by the imaging unit 30 is formed in the first recesses 24A and 24B, and a translucent member is formed in the opening 24b. 32 is arranged. According to this configuration, the first recesses 24A and 24B and the opening 24b are formed in an area having a constant width from the upstream end in the transport direction Y where the continuous paper P intersects the support surface 20a to the downstream. Can do. Therefore, the continuous paper P can be displaced downward and supported in this constant width region.

  However, since the dimension of the opening 24b in the width direction X is large, the first recesses 24A and 24B support the first recesses 24A and 24B as the boundary walls of the first recesses 24A and 24B in order to image the lower surface of the continuous paper P by the imaging unit 30. A part of the wall 27A and the ribs 25 of the first recesses 24A and 24B are cut off. For this reason, if a part of the support wall 27A and the rib 25 remain in this state, the continuous paper P may not be stably supported in the first recesses 24A and 24B.

  Therefore, as shown in FIG. 6, in this embodiment, the wall portions 41B of the pair of first wall portions 41 of the lens barrel cover 40 in the first recesses 24A and 24B are connected to the upstream end in the transport direction Y of the support wall 27A. Since the opening 24b is formed, the upper surface 41a of the wall 41B supports the continuous paper P even if a part of the support wall 27A is cut off.

  In addition, in the present embodiment, since the wall portion 41A and the second wall portion 42 of the first wall portion 41 are located at the substantially central portion in the width direction X of the first recess 24 and the upstream end portion in the transport direction Y, The wall portion 41 </ b> A and the second wall portion 42 have the same function as the rib 25. For this reason, the upper surface 41a of the wall portion 41A and the upper surface 42a of the second wall portion 42 support the continuous paper P.

  Thus, since the pair of wall portions 41 and the second wall portion 42 of the lens barrel cover 40 also functions to support the continuous paper P of the medium support portion 20, the translucent member 32 is arranged in the transport direction Y of the first recess 24. Even if it is disposed at the upstream end, a decrease in the function of supporting the continuous paper P is suppressed.

According to the printer 11 of the present embodiment, the following effects can be obtained.
(1) Since the opening 24b is formed in the first recesses 24A and 24B, and the translucent member 32 is disposed in the opening 24b, the first recess 24 including the first recesses 24A and 24B supports the medium. It can be formed in a constant width region that continues from the upstream end of the portion 20 to the downstream side. Therefore, in this region, even when there is a portion where the continuous paper P is bent and deformed in the direction (upward) from the support surface 20a due to the cockling phenomenon, the continuous paper P is bent and deformed downward by the first recesses 24A and 24B. Since it supports, it can suppress that the continuous paper P lifts from the support surface 20a. Therefore, the possibility that the continuous paper P contacts the ejection unit 17 in the region can be reduced.

  (2) Since the wall portion 41A of the first wall portion 41 of the lens barrel cover 40 has the same function as the support wall 27A, the first concave portion 24 and the second concave portion 26 are located upstream in the transport direction Y of the medium support portion 20. The first concave portion 24 and the second concave portion 26 can be formed at the end portions, that is, at positions adjacent to the paper feed roller pair 13. For this reason, the posture of the continuous paper P conveyed to the support surface 20a of the medium support unit 20 by the paper feed roller pair 13 is likely to be stabilized in the print region.

  (3) Since the wall portion 41B and the second wall portion 42 of the first wall portion 41 of the lens barrel cover 40 have the same function as the rib 25, the continuous paper is formed at the upstream end portion in the transport direction Y of the first recess 24A. P can be supported and the amount of downward deflection of the continuous paper P can be reduced.

  (4) Since the support surface 20a of the medium support portion 20 and the upper surfaces 41a to 43a of the wall portions 41 to 43 are formed flush, a step is formed between the support surface 20a and the upper surfaces 41a to 43a. Is suppressed. For this reason, when the continuous paper P is conveyed on the medium support part 20, it is suppressed that it catches on a level | step difference. Therefore, the continuous paper P is smoothly conveyed.

  (5) When the continuous paper P is conveyed on the pair of first wall portions 41 of the lens barrel cover 40, foreign matter such as paper dust of the continuous paper P may adhere to the translucent member 32. If the foreign matter adhering to the translucent member 32 appears in the image picked up by the image pickup unit 30, the detection accuracy of the transport amount of the continuous paper P may be lowered.

  Therefore, in the present embodiment, the suction hole 23 is formed in the first concave portion 24 </ b> A on the downstream side in the transport direction Y of the translucent member 32. The suction fan 28 (see FIG. 1) sucks the air between the continuous paper P and the first recess 24A through the suction hole 23, so that the continuous paper P facing the translucent member 32 is sucked. For this reason, an air flow toward the downstream side in the transport direction Y is formed between the pair of first wall portions 41. That is, on the upper surface 32 a of the translucent member 32, an air flow from the translucent member 32 toward the suction hole 23 is formed. Thereby, the foreign matter adhering to the upper surface 32 a of the translucent member 32 is sucked into the suction hole 23. Therefore, the foreign matter adhering to the upper surface 32a of the translucent member 32 is removed.

  (6) When the rear end portion of the continuous paper P in the transport direction Y passes over the light transmitting member 32 or the suction hole 23 formed in the first concave portion 24A, the rear end portion of the continuous paper P and the first concave portion 24 Air is introduced into the space formed between the continuous paper P and the first recess 24 through the opening formed in the transport direction Y. Thereby, in the space between the continuous paper P and the 1st recessed part 24, the airflow which goes to the downstream from the upstream of the conveyance direction Y generate | occur | produces. This air flow is guided onto the upper surface 32 a of the translucent member 32 by the pair of first wall portions 41 of the lens barrel cover 40 as indicated by the one-dot chain line arrow in FIG. 7. As a result, the airflow passes over the upper surface 32 a of the translucent member 32. For this reason, since the foreign material adhering to the upper surface 32a of the translucent member 32 moves to the downstream side of the conveyance direction Y by the said airflow, a foreign material is removed from the upper surface 32a of the translucent member 32.

  (7) Since the translucent member 32 is positioned below the support surface 20a of the medium support portion 20 and the upper surfaces 41a to 43a of the wall portions 41 to 43, the position of the lower surface of the continuous paper P, that is, the support surface 20a. And it is located below the focus of the object side lens 34 set to the position of the upper surfaces 41a to 43a. For this reason, even if a foreign substance adheres to the translucent member 32, the foreign substance is difficult to appear in the image captured by the imaging unit 30. Therefore, the detection error of the imaging unit 30 is less likely to occur due to the foreign matter adhering to the translucent member 32, so that the control unit 18 can accurately calculate the transport amount of the continuous paper P.

  (8) The pair of first wall portions 41 of the lens barrel cover 40 is not formed with side walls that connect the ends in the transport direction Y of the pair of first wall portions 41 in the width direction X. According to this configuration, the user cleans the upper surface 32 a of the translucent member 32 with a cleaning member such as a brush or a cotton swab, so that foreign matters such as paper dust attached to the upper surface 32 a of the translucent member 32 are translucent member 32. Rather than upstream and downstream in the transport direction Y. Moreover, since the accommodating part 45 (refer FIG. 5) is formed between the translucent member 32 and the medium support part 20, the user can also accommodate a foreign material in the accommodating part 45 with a cleaning member. For this reason, the translucent member 32 can be easily cleaned.

  In addition, the air flow generated when the rear end portion of the continuous paper P in the transport direction Y described in (6) passes over the suction hole 23 formed in the first recess 24 generates air currents between the pair of first wall portions 41. By passing through, it becomes easy to introduce airflow onto the upper surface 32a of the translucent member 32. For this reason, it becomes easy to remove the foreign matter adhering to the upper surface 32a of the translucent member 32 by airflow.

  (9) The width dimension that is the dimension in the width direction X of the support wall 27A that is the boundary wall between the first recesses 24A and 24B is smaller than the width dimension that is the dimension in the width direction X of the translucent member 32. For this reason, compared with the configuration in which the width dimension of the support wall 27A is larger than the width dimension of the translucent member 32, the continuous paper P is adjacent to a portion that is bent and deformed in the direction of rising from the support surface 20a due to the cockling phenomenon. It becomes easy to accommodate the downwardly deformed portion in the first recesses 24A and 24B. For this reason, it is possible to suppress the continuous paper P from being lifted from the support surface 20a.

In addition, you may change the said embodiment into another embodiment as follows.
In the above embodiment, two or more suction holes 23 may be formed in the first recess 24.

  -In above-mentioned embodiment, as shown in FIG. 8, the opening part 24b may be formed in the downstream rather than the upstream edge part of the conveyance direction Y of 1st recessed part 24A, 24B. In addition, the opening 24b may be formed in a portion where a part of the support wall 27A of the first recesses 24A and 24B is cut out. In this case, the translucent member 32 is disposed so as to straddle the first recesses 24A and 24B.

  As illustrated in FIG. 8, the opening 24 b may be formed on the downstream side in the transport direction Y of the first recesses 24 </ b> A and 24 </ b> B, and the suction holes 23 may be formed on both sides of the translucent member 32 in the transport direction Y. The positions of these suction holes 23 in the width direction X are equal to the positions between the pair of first wall portions 41 in the width direction X.

  According to this configuration, when the front end portion in the transport direction Y of the continuous paper P passes through the suction hole 23 or the translucent member 32 on the upstream side in the transport direction Y of the first recesses 24A and 24B, the front end portion of the continuous paper P And air is introduced into the space formed between the continuous paper P and the first recesses 24A and 24B from the opening portion opened in the transport direction Y formed by the first recesses 24A and 24B. Thereby, in the space between continuous paper P and 1st recessed part 24A, 24B, as shown with the dashed-dotted arrow in a figure, the airflow which goes to the upstream from the downstream of the conveyance direction Y generate | occur | produces. Since the air flow passes over the upper surface 32a of the translucent member 32, the foreign matter attached to the upper surface 32a moves toward the suction hole 23 on the upstream side in the transport direction Y of the first recesses 24A and 24B. Foreign matter is removed.

  Further, when the rear end portion of the continuous paper P in the transport direction Y passes through the light transmitting member 32 or the suction hole 23 on the downstream side in the transport direction Y of the first recesses 24A and 24B, the rear end portion of the continuous paper P and the first end portion Air is introduced into the space formed between the continuous paper P and the first recesses 24A and 24B from the opening formed in the transport direction Y formed by the first recesses 24A and 24B. Thereby, in the space between continuous paper P and 1st recessed part 24A, 24B, the airflow which goes to the downstream from the upstream of the conveyance direction Y generate | occur | produces. As the airflow passes over the upper surface 32a of the translucent member 32, foreign matter adhering to the upper surface 32a is similarly removed.

-In above-mentioned embodiment, the lens-barrel cover 40 may comprise the 1st recessed part 24A, 24B whole.
In the above embodiment, one of the pair of first wall portions 41 of the lens barrel cover 40 may be omitted.

In the above embodiment, the second wall portion 42 of the lens barrel cover 40 may form only a part of the rib 25.
In the above embodiment, the second wall portion 42 of the lens barrel cover 40 may be omitted.

In the above embodiment, the number of ribs 25 formed in the first recess 24 may be two or more. The plurality of ribs 25 are formed at intervals in the width direction X.
In the above embodiment, the rib 25 of the first recess 24 may be omitted.

  In the above embodiment, the first recess 24 </ b> A is configured as a communication portion that communicates the space on the paper feed roller pair 13 side with respect to the medium support portion 20 and the space between the first recess 24 </ b> A and the continuous paper P. You may form in the support wall 27C. Thereby, when the continuous paper P is conveyed, outside air is introduced into the space between the first concave portion 24A and the continuous paper P via the communication portion. For this reason, the airflow shown with the dashed-dotted arrow in FIG. 7 is likely to occur.

In the above embodiment, the focal position of the object side lens 34 may be set in a range above the upper surface 32 a of the translucent member 32 and below the support surface 20 a of the medium support unit 20.
According to this configuration, when the continuous paper P is sucked downward by the suction fan 28 through the suction hole 23, the continuous paper P bends downward in the first recess 24A. Since the imaging unit 30 images the lower surface of the continuous paper P on the first recess 24A, the imaging unit 30 images the continuous paper P bent downward. Therefore, according to this configuration, since the focal position of the object side lens 34 is set below the support surface 20a, it is possible to focus on the lower surface of the continuous paper P bent downward. Therefore, the lower surface of the continuous paper P can be imaged with high accuracy.

The liquid ejecting apparatus may be applied to a thermal jet printer or a solid inkjet printer.
The liquid ejecting apparatus may be applied to a serial printer, a line printer, or a page printer.

The liquid ejecting apparatus may have a configuration in which the winding unit 15 and the tension roller 16 are omitted.
The medium is not limited to continuous paper, and may be cut paper, resin film, metal foil, metal film, resin-metal composite film (laminate film), woven fabric, nonwoven fabric, ceramic sheet, and the like.

  The state of the liquid ejected as a minute amount of liquid droplets from the ejection unit 17 includes those that have a tail in a granular shape, a tear shape, or a thread shape. The liquid here may be any material that can be ejected from the ejection unit 17. For example, it may be in the state when the substance is in a liquid phase, and a liquid material having high or low viscosity, sol, gel water, other inorganic solvents, organic solvents, solutions, liquid materials such as liquid resins are used. Shall be included. Further, not only a liquid as one state of a substance but also a particle in which solid particles such as a pigment are dissolved, dispersed or mixed in a solvent is included. When the liquid is an ink, the ink includes various liquid compositions such as general water-based ink and oil-based ink, gel ink, and hot-melt ink.

  DESCRIPTION OF SYMBOLS 11 ... Printer as an example of a liquid ejecting apparatus, 13 ... Paper feed roller pair as an example of a conveyance part, 17 ... Ejection part, 20 ... Medium support part, 20a ... Support surface, 23 ... Suction hole, 24, 24A, 24B A first recess as an example of a recess, 24a ... a bottom surface, 24b ... an opening, 26, 26A, 26B ... a second recess as an example of a recess, 28 ... a suction fan as an example of a suction unit, 30 ... an imaging unit, 32... Translucent member, 32 a... Upper surface as an example of a surface of the translucent member that faces the injection portion, 40... Lens barrel cover as an example of a support member, 41... First wall as an example of a pair of wall portions 42 ... a second wall portion as an example of a wall portion, 43 ... a third wall portion as an example of a wall portion, 41a, 42a, 43a ... an upper surface as an example of a surface on which the wall portion supports a medium, 27A, 27B , 27C ... As an example of the peripheral wall of the recess Of the support wall, the continuous paper as an example of a P ... medium, X ... width direction, Y ... conveyance direction.

Claims (5)

A transport unit for transporting the medium;
An ejection unit that ejects liquid onto the medium conveyed by the conveyance unit;
A medium support section having a support surface capable of supporting the medium transported by the transport section so as to face the ejection section, and a plurality of recesses recessed in a direction away from the ejection section on the support surface. When,
An imaging unit that is disposed on the side opposite to the ejection unit with respect to the support surface, and that captures an image of a surface of the medium opposite to the surface facing the ejection unit;
A liquid ejecting apparatus, wherein an opening is formed in the recess, and a translucent member that transmits light for medium imaging by the imaging unit is disposed in the opening. The imaging unit has a support member to which the translucent member is fixed and supports the medium,
The support member has a wall portion inserted through the opening,
The liquid ejecting apparatus according to claim 1, wherein the wall portion protrudes toward the ejecting portion from a surface of the translucent member facing the ejecting portion and constitutes at least a part of a peripheral wall of the concave portion. The liquid ejecting apparatus according to claim 2, wherein a height dimension between the bottom surface of the recess and a surface on which the wall portion supports the medium is equal to a height dimension between the bottom surface of the recess and the support surface. A suction unit for adsorbing the medium to the support surface;
The recess is formed with a suction hole communicating with the suction part,
The liquid ejecting apparatus according to any one of claims 1 to 3, wherein the suction unit sucks a portion of the medium facing the translucent member toward the bottom surface of the concave portion by sucking through the suction hole. . The imaging unit has a support member to which the translucent member is fixed and supports the medium,
The support member has a wall portion that is inserted into the opening and forms a part of the peripheral wall of the recess,
The wall portion protrudes from the bottom surface of the concave portion toward the ejecting portion, extends in the medium transport direction, and sandwiches both sides of the translucent member in a width direction that is perpendicular to the medium transport direction. A pair of wall portions formed as follows:
5. The suction hole formed in the concave portion is formed at a position different from the pair of wall portions in the conveyance direction of the medium, and is formed between the pair of wall portions in the width direction. The liquid ejecting apparatus according to 1.