JP2015189533A - Medium conveying device and printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a medium conveying device and a printer capable of suppressing a decrease in detection accuracy of a conveyance amount of a medium.SOLUTION: A printer comprises: a conveyance unit for conveying continuous paper P; an imaging unit 30 for imaging the undersurface of the continuous paper P conveyed by the conveyance unit; and a control unit for detecting a conveyance amount of the continuous paper P conveyed by the conveyance unit on the basis of an image picked up by the imaging unit 30, and controlling the conveyance unit based on the conveyance amount of the continuous paper P. The imaging unit 30 comprises: an object side lens 34 for imaging the undersurface of the continuous paper P; a translucent member 32 disposed above the object side lens 34 for preventing a foreign matter from adhering to the object side lens 34; and a lens barrel cover 40 for supporting the continuous paper P at an upper side of the translucent member 32. The focal point of the object side lens 34 is positioned above an upper surface 32a of the translucent member 32.

Description

  The present invention relates to a medium conveying apparatus and a printing apparatus including the apparatus.

  As a medium transport device for transporting a medium such as paper, an image capturing unit is provided in a medium support unit that supports the medium, and the texture of the lower surface of the medium passing over the medium support unit is captured by the image capturing unit. 2. Description of the Related Art There is known a medium conveying apparatus that detects a medium conveying amount based on the medium. In this medium transport 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. In addition, a light-transmitting member is provided in the opening, while allowing light to pass therethrough, and suppressing entry of foreign matters such as paper dust and dust in the imaging unit.

  As such a medium transport apparatus, for example, the medium transport apparatus of Patent Document 1 moves a template of a rectangular area set in advance in an image captured last time on the image captured this time in order to detect the transport amount of the medium. However, a template matching process is performed to find a position where the degree of similarity is maximized. That is, the medium conveyance device of Patent Document 1 calculates the distance in the conveyance direction between the position of the template in the image captured last time and the position of the template matched in the image captured this time as the medium conveyance amount.

  In addition, as shown in FIG. 4 of the same document, the medium transport device of Patent Document 1 is such that the upper surface and the support surface of the translucent member arranged in the opening of the medium support unit are flush with each other, and the imaging unit. The focal position of is aligned with the support surface. That is, the focus position of the imaging unit is adjusted to be the upper surface of the translucent member.

JP 2013-119439 A

  According to the medium transport device of Patent Document 1, since the focal position of the imaging unit is coincident with the upper surface of the translucent member, when a foreign object adheres to the upper surface of the translucent member, the focal position of the imaging unit matches the foreign object. End up. As a result, the imaging unit clearly captures the foreign matter, and the influence of the foreign matter on the textured image of the lower surface of the imaged medium increases. For this reason, when performing the template matching process, the medium transport apparatus of Patent Document 1 sets the position of the template different from the position of the template to be matched in the image captured this time as the position having the maximum similarity, and the incorrect template. There is a possibility that the transport amount of the medium may be calculated based on the position. For this reason, there is a possibility that the accuracy of detection of the transport amount of the medium is lowered.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a medium transport device capable of suppressing a decrease in detection accuracy of the transport amount of the medium and a printing apparatus including the same. is there.

Hereinafter, means for solving the above-described problems and the effects thereof will be described.
A medium transport apparatus that solves the above-described problem is imaged by a transport unit that transports a medium, an image capturing unit that captures an image of the medium transported by the transport unit from one side in a front-back direction of the medium, and the image capturing unit. A control unit that detects a transport amount of the medium transported by the transport unit based on the image and controls the transport unit based on the transport amount of the medium, and the imaging unit includes an optical member, A translucent member that is disposed on the other side of the optical member in the front and back direction of the medium and that transmits light for medium imaging by the imaging unit, and the translucent member are fixed, and the translucent member in the front and back direction of the medium is fixed. A support member that supports the medium on the other side of the optical member, and the focal position of the optical member is closer to the other side than the surface of the other side of the translucent member in the front and back direction of the medium. To position.

  According to the above configuration, even if a foreign object adheres to the other surface of the translucent member in the front and back direction of the medium, the foreign object is positioned on one side in the front and back direction of the medium from the focal position of the optical member. Thereby, in the front and back direction of the medium, the foreign matter adhering to the other side surface of the translucent member does not coincide with the focal position of the optical member. The image is not clearly captured. For this reason, the influence of the foreign material with respect to the image imaged by the imaging unit is reduced. Accordingly, it is possible to suppress a decrease in the detection accuracy of the conveyance amount of the medium based on the image of the imaging unit.

  Moreover, in the said medium conveyance apparatus, it has a support surface which supports the said medium conveyed by the said conveyance part, and the medium in which the several recessed part dented from the said support surface to the said one side in the front and back direction of the said medium was formed It is preferable that an opening for the imaging unit to image the medium is formed in the recess, and the translucent member is disposed in the opening.

  According to the above configuration, the translucent member is disposed in the concave portion recessed from the support surface to one side in the front and back direction of the medium on the support surface of the medium support portion. Therefore, when the medium is bent and deformed on the support surface, it is possible to support the portion of the medium located on the arrangement region of the translucent member by displacing it to one side of the support surface in the front and back direction of the medium. It is. Therefore, even when the bending deformation portion of the medium is located on the translucent member, the bending deformation portion is suppressed from floating from the support surface.

  The medium transporting apparatus may further include a suction part for adsorbing the medium to the support surface, and the suction part may be formed in the recess so as to communicate with the suction part. 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, when the suction part sucks air existing in the space between the light-transmitting member and the medium through the suction hole, the light is transmitted onto the other surface of the light-transmitting member in the front and back direction of the medium. An air flow from the member toward the suction hole is formed. For this reason, when a foreign substance adheres to the other side surface of the translucent member in the front and back direction of the medium, the foreign object can be removed from the other side surface of the translucent member in the front and back direction of the medium.

  Further, in the medium transport apparatus, the support member has a pair of wall portions that are inserted through the opening portion and project further to the other side than the bottom surface of the recess in the front and back direction of the medium. The wall portion is formed so as to sandwich both sides of the translucent member in the width direction of the medium, which is a direction orthogonal to the conveyance direction of the medium, and the suction holes are the pair of wall portions in the conveyance direction of the medium It is preferably formed at a position different from that of the pair of wall portions in the width direction of the medium.

  According to the above configuration, when the end of the medium in the transport direction passes over the suction hole or the translucent member, the medium and the recess are formed from the opening in the transport direction formed by the end of the medium in the transport direction and the recess. Air is introduced into the space formed between the two. 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 on the other side of the translucent member in the front and back direction of the medium. Thereby, when the foreign material has adhered to the translucent member, a foreign material moves toward a conveyance direction with the said airflow. Therefore, foreign matters can be removed from the translucent member.

  Further, in the medium transporting apparatus, the support member supports the medium from a position on the other side of the surface of the light transmitting member with respect to the other surface of the light transmitting member in a front-back direction of the medium. It is preferably set within the range up to the surface.

  According to the above configuration, when the focal position of the optical member coincides with the support surface, the optical member is the medium when the medium passing through the translucent member is hardly bent from the support surface toward one side in the front and back direction of the medium. The optical member can be focused on the surface on one side in the front and back direction. For this reason, the medium can be clearly imaged.

  In the front and back direction of the medium, when the focal position of the optical member is located on the other side of the light transmitting member and on the one side of the support surface, the medium is directed from the support surface to the front and back sides of the medium. A medium in a state of being bent and deformed on one side of the image can be clearly imaged.

  A printing apparatus that solves the above problem includes the medium conveying apparatus and a printing unit that performs printing on the medium.

(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.

Hereinafter, an embodiment in which a printing 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 printing apparatus is an example of a medium conveying apparatus that conveys a continuous sheet P of a long sheet that is an example of a medium. And a jetting unit 17 that is an example of a printing unit that performs printing by jetting ink onto the continuous paper P transported by the transporting 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 transport device 12, a medium support unit 20 that supports the continuous paper P is disposed at a position facing the ejection unit 17 across the transport 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. Based on the image from the imaging unit 30, the control unit 18 controls the transport amount of the continuous paper P by a known method as described in Patent Document 1, for example.

  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 disposed 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 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 2nd recessed part 26 is made into the opening shape which can receive the ink injected to the continuous paper P from the injection part 17 (refer FIG. 1). 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. . In the present embodiment, the front and back directions of the medium are defined by the upper surface (front surface) and the lower surface (back surface) of the continuous paper P at the position where the imaging unit 30 is provided in the transport device 12. The front and back direction of the medium is a direction along the vertical direction Z.

  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 space formed by the accommodating portion 31a and the lens barrel cover 40, a light irradiation portion 33 that irradiates light to 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.

  An object side lens 34 which is an example of an optical member positioned on the upper side (medium support unit 20 side) in the lens barrel 31, and an example of an optical member positioned on the lower side (control unit 18 side) than the object side lens 34. And an aperture 36 positioned between the object side lens 34 and the image side lens 35 are housed. 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 upper surface 32a of 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.

  The translucent member 32 is disposed at the upstream end of the first recess 24A in the transport direction Y. The translucent member 32 is disposed such that the upper surface 32a is below the bottom surface 24a of the first recess 24B. The width dimension of the translucent member 32 is ½ or more of the width dimension of the first recess 24A.

  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. The optical axis direction, which is the direction along the optical axis of the object side lens 34, is parallel to the vertical direction Z.

  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 the cockling, which is a phenomenon in which the continuous paper P swells in the width direction X due to swelling, occurs, 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 1st recessed part 24A, 24B, the upper surface of a pair of 1st wall part 41, the upper surface of the 2nd wall part 42, and the bending part of the injection part 17 side (upper) of the continuous paper P to support walls 27A-27C Is adsorbed, and 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.
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 this region. As a result, it tends to float from the support surface 20a.

  On the other hand, 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. For this reason, if the imaging unit 30 captures the lower surface of the continuous paper P conveyed to the region having the constant width, 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 continuous paper P can be clearly imaged. Therefore, 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 having the constant width, and the translucent member 32 is disposed in the opening 24b. preferable. In the present embodiment, an opening 24b is formed at the upstream end in the transport direction Y of the first recess 24A as this constant width region. At the upstream end in the transport direction Y of the first recess 24A, the continuous paper P is adsorbed to the support surface 20a by the first recess 24 and the second recess 26 as shown in FIG. For this reason, the lower surface of the continuous paper P is less likely to float upward from the support surface 20a. Therefore, the imaging unit 30 can clearly capture the texture of the lower surface of the continuous paper P.

  And the upper surface 32a of the translucent member 32 is located below the support surface 20a. For this reason, in the up-down direction Z, the focal position of the object side lens 34 and the upper surface 32a of the translucent member 32 are different positions. Thereby, even if foreign matter such as paper dust of the continuous paper P adheres to the upper surface 32a of the translucent member 32, the object side lens 34 is not focused on the foreign matter. For this reason, even if a foreign object appears in the captured image, the texture of the lower surface of the continuous paper P becomes a clear image, and the foreign object becomes an unclear image, so the influence of the foreign object on the captured image is reduced.

According to the printer 11 of the present embodiment, the following effects can be obtained.
(1) Since the upper surface 32a of the translucent member 32 is positioned below the focal position of the object side lens 34, even if foreign matter adheres to the upper surface 32a of the translucent member 32, the foreign matter on the captured image Since the influence is small, it is possible to suppress detection of an incorrect template position during the template matching process for detecting the carry amount. Therefore, it is possible to suppress a decrease in detection accuracy of the conveyance amount of the continuous paper P by the control unit 18.

  (2) 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, it is possible to suppress contact between the continuous paper P and the ejection unit 17 in the constant width region.

  (3) A suction hole 23 is formed on the downstream side in the transport direction Y of the translucent member 32 in the first recess 24A. Since the suction fan 28 sucks the air between the continuous paper P and the first recess 24A through the suction hole 23, 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.

  (4) When the rear end portion of the continuous paper P in the transport direction Y passes over the translucent 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. The air is introduced into the space formed between the continuous paper P and the first recess 24 from the opening formed in the transport direction Y formed by. 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.

  (5) 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 operator cleans the upper surface 32 a of the translucent member 32 with a cleaning member such as a brush or a cotton swab, thereby removing foreign matters such as paper dust attached to the upper surface 32 a of the 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 operator 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 conveyance direction Y described in (4) passes over the suction hole 23 formed in the first recess 24 generates airflow 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 the airflow.

  (6) 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.

  (7) 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, 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.

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 of the continuous paper P in the transport direction Y passes over 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 of the continuous paper P Air is introduced into the space formed between the continuous paper P and the first recesses 24A, 24B from the opening portion opened in the transport direction Y formed by the first recesses 24A, 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 over the translucent member 32 or the suction hole 23 on the downstream side in the transport direction Y of the first recesses 24A and 24B, 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 the above-described embodiment, at least one of the first wall portion 41, the second wall portion 42, and the third wall portion 43 is the range of the medium support portion 20 within a range in which the continuous paper P can be supported by the wall portions 41 to 43. It may be positioned below the support surface 20a.

-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 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 first recesses 24A and 24B may be omitted. In this case, the opening 24b is formed in the support surface 20a. The translucent member 32 is disposed below the support surface 20 a of the medium support unit 20, that is, below the focal position of the object side lens 34.

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 texture of the lower surface of the continuous paper P can be clearly imaged.

  The printing apparatus is not limited to a printer having only a printing function, and may be a multifunction machine. Furthermore, the printing apparatus is not limited to a serial printer, and may be a line printer or a page printer.

The printing apparatus (medium conveying 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.

  In the above embodiment, liquid other than ink may be ejected from the ejecting unit 17 onto the continuous paper P as a minute amount of liquid droplets. The liquid state includes those having a tail in a granular shape, a tear shape, and 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.

  The medium conveying device is not limited to being provided in the printing device, and may be provided in a processing device that performs processing other than printing. A medium other than continuous paper may be conveyed. For example, the medium conveying device may be adopted as a drying device that conveys the inside of a dryer to dry the medium. In addition, the medium conveying device may be employed in a surface treatment apparatus that performs surface treatment such as coating or surface modification treatment on the medium. Further, a medium conveying device may be employed in a processing device that performs punching processing on a medium. Furthermore, the medium conveying apparatus may be applied to a plating apparatus that performs electroless plating on a medium. The medium transport device may be applied to a circuit forming apparatus that prints a circuit on a tape-shaped substrate. The medium conveying device may be employed in a measuring device that acquires measured values such as the thickness and surface roughness of the medium. Further, a medium conveying device may be employed in an inspection device that inspects a medium.

  DESCRIPTION OF SYMBOLS 11 ... Printer as an example of a printing apparatus, 12 ... Conveyance apparatus as an example of a medium conveyance apparatus, 13 ... Paper feed roller pair as an example of a conveyance part, 17 ... Ejection part as an example of a printing part, 18 ... Control part , 20 ... medium support part, 20a ... support surface, 23 ... suction hole, 24, 24A, 24B ... first recess as an example of recess, 24a ... bottom surface, 24b ... opening, 28 ... suction as an example of suction part Fan 30, imaging unit, 32 translucent member, 32 a upper surface as the other surface of the translucent member, 33 object side lens as an example of optical member, 34 image side lens as an example of optical member 40 ... A lens barrel cover as an example of a support member, 41 ... a first wall portion as an example of a pair of wall portions, 41a, 42a, 43a ... an upper surface as an example of a surface on which the support member supports a medium, P ... Ream as an example of media Paper, X ... width direction, Y ... conveyance direction, the vertical direction as an example of front and back direction of the Z ... medium.

Claims (6)

A transport unit for transporting the medium;
An imaging unit that images the medium conveyed by the conveyance unit from one side in a front-back direction of the medium;
A control unit that detects a transport amount of the medium transported by the transport unit based on an image captured by the imaging unit, and controls the transport unit based on the transport amount of the medium;
The imaging unit
An optical member;
A translucent member that is disposed on the other side of the optical member in the front and back direction of the medium, and transmits light for medium imaging by the imaging unit;
The translucent member is fixed, and includes a support member that supports the medium on the other side of the translucent member in the front and back direction of the medium.
The medium conveyance device, wherein the focal position of the optical member is located on the other side in the front and back direction of the medium with respect to the other side surface of the translucent member. It has a support surface that supports the medium transported by the transport unit, and includes a medium support portion in which a plurality of recesses that are recessed from the support surface to the one side in the front and back direction of the medium are formed.
An opening for the imaging unit to image the medium is formed in the recess,
The medium conveying apparatus according to claim 1, wherein the light transmissive member is disposed in the opening. 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 medium conveying apparatus according to claim 2, wherein the suction unit sucks a portion of the medium facing the light-transmissive member toward the bottom surface side of the concave portion by sucking through the suction hole. The support member has a pair of wall portions that are inserted through the opening and project to the other side of the bottom surface of the recess in the front and back direction of the medium.
The pair of wall portions are formed so as to sandwich both sides of the translucent member in the width direction of the medium, which is a direction orthogonal to the conveyance direction of the medium,
The medium according to claim 3, wherein the suction hole 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 of the medium. Conveying device. The focal position of the optical member is set in a range from the position on the other side to the surface on which the support member supports the medium with respect to the other surface of the translucent member in the front and back direction of the medium. The medium carrying device according to any one of claims 1 to 4. The medium conveying device according to any one of claims 1 to 5,
And a printing unit that performs printing on the medium.