JP5093417B2 - Inkjet recording device - Google Patents

Description

  The present invention relates to an ink jet recording apparatus including a recording head that performs recording by discharging ink onto a recording medium, and more particularly to an ink jet recording apparatus that takes measures when the recording medium absorbs ink and deforms.

  Conventionally, in this type of ink jet recording apparatus, various inks are ejected from a recording head, and characters and figures are recorded on a recording medium such as paper (hereinafter referred to as paper) facing the recording head, and then a conveying roller Is known to discharge the paper out of the ink jet recording apparatus.

  For example, Patent Document 1 describes an ink jet recording apparatus that can adjust the interval between a recording head and a paper according to various paper sizes. According to this ink jet recording apparatus, since the interval between the recording head and the paper can be adjusted according to various paper sizes, even if the paper is deformed after recording, the paper does not contact the recording head. The possibility of soiling or scratching the recording surface of the paper is reduced. Patent Document 2 describes an ink jet recording apparatus that causes a recording head to wait for a predetermined time between forward scanning and multiple scanning of the recording head. According to this ink jet recording apparatus, between the forward scanning and the multiple scanning of the recording head, the recording head waits for a predetermined time, so that the ink is sufficiently fixed on the paper, and the recording surface of the paper is stained. Reduced. Further, Patent Document 3 describes an ink jet recording method that reduces deformation of a sheet even when a large amount of ink is ejected by forming scratches or holes in the sheet.

JP 2006-103278 (paragraph 0011, etc.) JP 7-47695 (paragraph 0022, FIG. 4, etc.) JP-A-7-329413 (paragraph 0009, etc., FIG. 5, etc.)

  Here, the relationship between the paper curl and the conveyance direction will be described with reference to FIG. FIG. 15 is an explanatory diagram for explaining the relationship between the paper curl and the fiber direction of the paper P. FIG. 15A is an explanatory diagram when the paper P is conveyed in the vertical direction, and FIG. FIG. 5 is an explanatory diagram when a sheet is conveyed in the horizontal direction. The fiber direction of the paper P is often aligned in almost one direction by the manufacturing process. When the surface of the paper P is absorbed by the ink ejected from the recording head 39, the paper P itself is curled. appear. In general, the paper P is easily curled in a direction perpendicular to the fiber direction, and has a larger amount of curl than a direction parallel to the fiber direction.

  On the other hand, the inkjet recording apparatus is generally provided with a conveyance roller 60 for conveying the paper P so as to extend in a direction perpendicular to the conveyance direction B of the paper P. Therefore, when the paper P is curled in a direction perpendicular to the transport direction B (see the left figure in FIG. 15A), the shape of the paper P is corrected by the pressing force of the transport roller, and the paper P is applied to the recording head 39. There is no contact (see the right figure in FIG. 15 (a)).

  However, when the paper P is curled in the transport direction (see the left figure in FIG. 15B), the correction by the transport roller does not work, the paper P contacts the recording head 39, and the paper P is smoothly transported. There was a problem that the recording surface of the paper P was soiled (see the right figure in FIG. 15B).

  This problem cannot be solved by adjusting the interval between the recording head and the paper according to the size of the paper P as in the case of the ink jet recording apparatus described in Patent Document 1, and is also described in Reference 2 If the recording head is kept waiting for a predetermined time uniformly as in the ink jet recording apparatus, it takes a long time to record, and further, scratches or holes are formed in the paper as in the ink jet recording method described in Patent Document 3. In this case, special paper is required, which is inconvenient for the user.

  The first object of the present invention is to pay attention to the fact that the amount of deformation of the paper P due to the ink absorption varies depending on the fiber direction of the paper P and the shape of the paper P. It is an object of the present invention to provide an ink jet recording apparatus that can perform smoothly and prevent the recording surface of the paper P from being stained.

  In addition, the second object of the present invention is to reduce the amount of deformation due to ink absorption of the paper P regardless of the fiber direction of the paper P and the shape of the paper P, to smoothly transport the paper P, and An object of the present invention is to provide an ink jet recording apparatus capable of preventing the recording surface of the paper P from being soiled.

[First Embodiment]
Hereinafter, a preferred first embodiment of the present invention will be described with reference to the accompanying drawings. An ink jet recording apparatus according to the present invention is mainly connected to a computer (external information device) (not shown), and an image or document is recorded on a recording medium based on print data including image data and document data transmitted from the computer. Is to be recorded. In addition, when an external device such as a digital camera is connected, image data output from the digital camera or the like is recorded on a recording medium, or various recording media such as a memory card are loaded, and the image recorded on the recording medium is recorded. It is also possible to record data or the like on a recording medium. When the inkjet recording apparatus is implemented as a multi-function apparatus, it is equipped with a plurality of paper feed cassettes and an automatic document feeder (ADF: Auto Document Feeder) even if it is a compact one such as a multifunction peripheral. It may be.

  The ink jet recording apparatus will be described below with reference to FIGS. FIG. 1 shows an external configuration of a multifunction machine 1 according to the first embodiment of the present invention. The multi-function device 1 is a multi-function device (MFD) having a printer unit 2 at the bottom and a scanner unit 3 at the top, and has a printer function, a scanner function, a copy function, and a facsimile function. The printer unit 2 of the multifunction machine 1 corresponds to the ink jet recording apparatus according to the present invention, and functions other than the printer function are arbitrary. Therefore, the present invention may be implemented as a single-function printer that does not have the scanner unit 3 and has no scanner function or copy function. In addition, an operation panel 4 for operating the printer unit 2 and the scanner unit 3 is provided on the upper front portion of the multifunction device 1. The operation panel 4 includes various operation buttons and a liquid crystal display unit. The multifunction device 1 operates based on an operation instruction from the operation panel 4.

  FIG. 2 is a partially enlarged cross-sectional view showing the main configuration of the printer unit 2. In FIG. 2, a paper feed cassette 20 as a mounting table can accommodate paper P as recording media of various sizes of A3 size or smaller. The paper P is fed from the paper feed cassette 20 to the inside of the printer unit 2 to record a desired image, and is discharged to the paper discharge tray 21.

  FIG. 3 is a plan view of the paper feed cassette 20. The paper feed cassette 20 includes a paper width guide 11 that is movable in a direction perpendicular to the transport direction and a paper rear end guide 12 that is movable in a direction parallel to the transport direction for aligning the edges of the paper P. The paper rear end guide 12 is provided with a paper sensor 13. The paper width guide 11 and the paper trailing edge guide 12 can move according to the shape of the paper P. At this time, the paper sensor 13 provided in the paper trailing edge guide 12 detects a dimension in a direction parallel to the conveyance direction of the paper P.

  As shown in FIG. 2, on the upper side of the paper feed cassette 20, a paper feed roller 25 is provided for separating the paper P placed on the paper feed cassette 20 one by one and feeding it to the paper transport path 23. ing. The paper feed roller 25 is pivotally supported at the tip of the paper feed arm 26. The paper feed roller 25 is rotated by the drive transmission mechanism 27 in which a plurality of gears are engaged to transmit the drive of the LF motor 71 (see FIG. 10).

  The paper feed arm 26 is arranged with a base shaft 26 a as a rotation shaft, and moves up and down so as to be able to contact and separate from the paper feed tray 20. The paper feeding arm 26 is rotated downward so as to come into contact with the paper feeding tray 20 by its own weight or urged by a spring or the like, and as shown in FIG. It is configured to be evacuable. When the paper feed arm 26 is rotated downward, the paper feed roller 25 pivotally supported at the tip thereof is pressed against the surface of the paper P on the paper feed tray 20. In this state, when the paper feed roller 25 rotates, the uppermost paper P is fed to the separation inclined plate 22 by the frictional force between the roller surface of the paper feed roller 25 and the paper P. The leading edge of the sheet P abuts against the separation inclined plate 22 and is guided upward, and is fed into the sheet conveying path 23.

  The sheet conveyance path 23 is configured by an outer guide surface and an inner guide surface that are opposed to each other at a predetermined interval, except for a portion where the image recording unit 24 and the like are disposed. For example, the sheet conveyance path 23 on the back side of the printer unit 2 is configured such that the outer guide surface is formed integrally with the frame of the printer unit 2 and the inner guide surface is fixed to the guide member 28 in the frame. . In the sheet conveyance path 23, particularly at a portion where the sheet conveyance path 23 is bent, the sheet conveyance path 23 is configured such that a plurality of conveyance rollers 29 as conveyance means expose the roller surface to the outer guide surface or the inner guide surface. Is provided so as to be rotatable with the width direction of the shaft as an axial direction. The paper P that contacts the guide surface is smoothly transported by the rotatable transport rollers 29 where the paper transport path 23 is bent.

  As shown in FIG. 2, an image recording unit 24 is provided in the paper transport path 23. The image recording unit 24 includes a carriage 38 that carries an ink jet recording head 39 and reciprocates in the main scanning direction. The ink jet recording head 39 includes cyan (C), magenta (M), yellow (Y), and ink through an ink tube 41 from an ink cartridge 40 (see FIG. 4) disposed independently of the ink jet recording head 39 in the printer unit 2. Each color ink of black (Bk) is supplied, and each ink is ejected as a minute ink droplet. While the carriage 38 is reciprocated, ink droplets are ejected from the ink jet recording head 39, whereby image recording is performed on the paper P conveyed on the platen 42.

  As shown in FIG. 2, a platen 42 is disposed to face the ink jet recording head 39. The platen 42 is disposed over the central portion of the reciprocating range of the carriage 38 through which the paper P passes. The width of the platen 42 is sufficiently larger than the maximum width of the transportable paper P, and both ends of the paper P always pass over the platen 42.

  FIG. 4 is a plan view showing the main configuration of the printer unit 2. As shown in FIG. 4, the ink cartridge 40 is mounted on a cartridge mounting portion 6 provided in a housing on the front side of the printer unit 2 and on the left side (right side in FIG. 4). As shown in FIG. 4, the cartridge mounting unit 6 is disposed separately from the carriage 38 on which the inkjet recording head 39 is mounted in the apparatus, and the ink cartridge 40 mounted on the cartridge mounting unit 6 through the ink tube 41. From this, ink is supplied to the inkjet recording head 39.

  FIG. 5 is a bottom view showing the nozzle forming surface of the ink jet recording head 39. The ink jet recording head 39 has nozzle ports 53 arranged on the lower surface thereof in the transport direction of the paper P for each color ink of C, M, Y, and Bk. Further, the pitch and number of the nozzle ports 53 in the transport direction are appropriately set in consideration of the resolution of the recorded image. It is also possible to increase or decrease the number of rows of nozzle ports 53 according to the number of types of color ink.

  Further, as shown in FIG. 5, a media sensor 31 is mounted on the lower surface of the ink jet recording head 38. The media sensor 31 includes a light emitting unit 32 made of a light emitting diode and a light receiving unit 33 made of an optical sensor. The light emitting unit 32 of the media sensor 31 is configured such that light is emitted toward the platen 42 and the light receiving unit 33 receives reflected light of the light.

  The color of the upper surface of the platen 42 is composed of a color having a reflectance different from that of the paper P, such as black. For example, when the paper P is not present, the light receiving unit 33 receives reflected light from the platen 42 having a low reflectance. Is detected, the detected value (AD value) of the media sensor 31 is a low value. On the other hand, when the sheet P exists, the light receiving unit 33 receives the reflected light from the sheet P having a high reflectance, so that the detection value (AD value) of the media sensor 31 is a high value. Therefore, the presence or absence of the paper P can be detected from the difference in the amount of reflected light received by the media sensor 31.

  Such a media sensor 31 is mounted on the ink jet recording head 39 on the upstream side in the conveyance direction of the paper P, and is reciprocated in the scanning direction by the carriage 38. By mounting the media sensor 31 on the ink jet recording head 39, it is not necessary to provide a carriage for scanning the media sensor 31 separately from the carriage 38 for scanning the ink jet recording head 39, so that the apparatus is downsized. There is an advantage that you can. Further, by arranging the media sensor 31 on the upstream side in the transport direction of the ink jet recording head 39, the right and left end positions of the paper P can be detected by the media sensor 31 before image recording is performed on the paper P.

  As shown in FIG. 4, maintenance units such as a purge mechanism 51 and a waste ink tray 84 are disposed outside the image recording range of the inkjet recording head 39. The purge mechanism 51 includes a cap 52 that covers the nozzle port 53 of the ink jet recording head 39, a pump mechanism that is connected to the ink jet recording head 39 through the cap 52, and the cap 52 that is in contact with and away from the nozzle port 53 of the ink jet recording head 39. The moving mechanism. In FIG. 4, the pump mechanism and the moving mechanism are omitted.

  When performing suction removal of bubbles or the like of the ink jet recording head 39, the carriage 38 is moved so that the ink jet recording head 39 is positioned on the cap 52. In this state, the cap 52 moves upward and the ink jet recording head 39 is moved. The nozzle port 53 (see FIG. 5) on the lower surface of the ink-jet head is in close contact with each other, and ink is sucked from the nozzle port 53 of the inkjet recording head 39 by a pump connected to the cap 52. The sucked defective ink is stored in the waste ink tray 84.

  As shown in FIG. 4, the pair of guide frames 43 and 44 are perpendicular to the transport direction of the paper P at a predetermined distance in the transport direction of the paper P (vertical direction in FIG. 4) above the paper transport path 23. It extends in the left-right direction in FIG. The carriage 38 is placed so as to be reciprocally slidable in a direction orthogonal to the conveyance direction of the paper P so as to straddle the guide frames 43 and 44. The guide frame 43 disposed on the upstream side in the conveyance direction of the sheet P is a flat plate whose length in the width direction of the sheet conveyance path 23 is longer than the reciprocating range of the carriage 38, and the upper surface of the guide frame 43 is The upstream end of the carriage 38 is slidably supported.

  The guide frame 44 disposed on the downstream side in the conveyance direction of the paper P is a flat plate having a length in the width direction of the paper conveyance path 23 that is substantially the same as that of the guide frame 43, and is downstream of the carriage 38. An edge portion 45 that supports the end portion is bent upward at a substantially right angle. The carriage 38 is slidably supported on the upper surface of the guide frame 44, and the edge 45 is held by a roller (not shown). Accordingly, the carriage 38 is slidably supported on the guide frames 43 and 44 and reciprocates in a direction perpendicular to the conveyance direction of the paper P with reference to the edge 45 of the guide frame 44. A sliding member for reducing friction is appropriately provided at a portion where the carriage 38 contacts the upper surfaces of the guide frames 43 and 44.

  A belt driving mechanism 46 is disposed on the upper surface of the guide frame 44. In the belt driving mechanism 46, an endless annular timing belt 49 having teeth on the inside is stretched between a driving pulley 47 and a driven pulley 48 provided near both ends in the width direction of the paper conveyance path 23. It will be. A driving force is input from the CR motor 73 (see FIG. 10) to the shaft of the driving pulley 47, and the timing belt 49 moves circumferentially as the driving pulley 47 rotates. In addition to the endless annular belt, the timing belt 49 may be one that fixes both ends of the endless belt to the carriage 38.

  The carriage 38 is fixed to the timing belt 49, and the carriage 38 reciprocates on the guide frames 43 and 44 with the edge 45 as a reference by the circumferential movement of the timing belt 49. An ink jet recording head 39 is mounted on such a carriage 38, and the ink jet recording head 39 can reciprocate with the width direction of the paper transport path 23 as the main scanning direction. An encoder strip 50 of the linear encoder 77 (see FIG. 10) is disposed along the edge 45. The linear encoder 77 detects the encoder strip 50 with a photo interrupter, and the reciprocation of the carriage 38 is controlled based on the detection signal of the linear encoder 77.

  Hereinafter, a mechanism for adjusting the gap (gap) between the first inkjet recording head 39 and the paper P of the present invention will be described. FIG. 6 is an exploded perspective view showing the configuration of the sliding member 86, the coil spring 87, and the gap adjusting member 88. The carriage 38 includes an inkjet recording head 39, a sliding member 86 that slides on the guide frames 43 and 44 to support the carriage 38 at a predetermined height, a coil spring 87 that elastically biases the sliding member 86 upward, A gap adjusting member 88 interposed between the carriage 38 and the sliding member 86 is provided. The sliding member 86, the coil spring 87, and the gap adjusting member 88 are assembled to both sides of the carriage 38 in the recording sheet conveyance direction corresponding to the guide frames 43 and 44.

  As shown in FIG. 6, the sliding member 86 includes a sliding contact plate 89 that is in sliding contact with the guide frames 43 and 44, and a foot portion 90 that extends from the sliding contact plate 89. The sliding contact plate 89 is a rectangular flat plate whose length in the short direction is substantially the same as the length in the short direction of the gap adjusting member 88, and is slid while its bottom surface is in contact with the guide frames 43 and 44. A pair of ridges 91 are formed on the upper surface of the slidable contact plate 89 along the edge in the longitudinal direction, and the pair of ridges 91 are in contact with the bottom surface of the gap adjusting member 88 evenly. The bottom surface of the plate 89 is positioned parallel to the top surfaces of the guide frames 43 and 44.

  The foot portion 90 extends from the approximate center of the upper surface of the sliding contact plate 89 in a direction substantially orthogonal to the upper surface. The foot portion 90 has a flat plate shape extending in the longitudinal direction of the sliding contact plate 89, and a guide groove 92 penetrating in the thickness direction of the flat plate shape is formed in the extending direction of the foot portion 90. It opens to the end (upper side in FIG. 6). A support rib (not shown) of the carriage 38 is fitted into the guide groove 92, and the sliding member 86 is supported so as to be movable along the guide groove 92. Locking portions 93 are formed on both sides of the extended end of the foot portion 90 so as to protrude outward in the longitudinal direction of the sliding contact plate 89. As shown in FIG. 6, the locking portion 93 is for locking the sliding contact plate 89 to the retaining plate 94. A through hole 95 for inserting the foot portion 90 is formed in the retaining plate 94. The width of the through hole 95 is narrower than between the outer edges of the pair of locking portions 93. The pair of locking portions 93 are elastically deformed by being pressed inward so as to narrow the width of the guide groove 92, inserted through the through-hole 95 of the retaining plate 94, and restored to the elastic state when the pressure is released. Then, it protrudes outward from the peripheral edge of the through hole 95. By this pair of locking portions 93, the sliding contact plate 89 is locked to the retaining plate 94 so that the foot portion 90 does not come out of the through hole 95.

  As shown in FIG. 6, the gap adjusting member 88 is an elongated rod-like flat plate, and a pair of adjusting portions 99 are formed in the longitudinal direction. The thickness of each adjustment portion 99 (vertical direction in FIG. 6) is changed in three steps in the sliding direction of the gap adjustment member 88. Specifically, the thinnest thin-walled portion 100, the middle middle-walled portion 101, and the thickest thick-walled portion 102 are formed adjacent to each other so that the thickness changes stepwise in one direction. Yes. The upper surfaces of the thin portion 100, the middle portion 101, and the thick portion 102 are horizontal surfaces, and the length in the longitudinal direction of each upper surface is slightly longer than the length in the longitudinal direction of the foot portion 90 of the sliding member 86. . In addition, inclined surfaces are formed at the boundaries of the upper surfaces of the thin-walled portion 100, the middle-walled portion 101, and the thick-walled portion 102, respectively, in order to moderate thickness changes.

  In each adjustment portion 99, a long hole 103 penetrating in the thickness direction across the thin wall portion 100, the middle wall portion 101, and the thick wall portion 102 is formed in the approximate center in the short direction of the gap adjustment member 88. The width of the long hole 103 in the short direction (perpendicular to the plane of the drawing in FIG. 6) is slightly wider than the thickness of the foot part 90 of the sliding member 86, and the foot part 90 penetrates the long hole 103. The extending end of the foot portion 90 penetrating through the long hole 103 is inserted into the through hole 97 of the carriage 38. Further, the support rib of the carriage 38 is fitted into the guide groove 92 of the foot 90. Then, as shown in FIG. 6, the locking portion 93 of the foot portion 90 is locked to the retaining plate 94.

  A coil spring 87 is interposed between the retaining plate 94 and the support member 96, and an upward elastic biasing force is applied to the retaining plate 94 by the coil spring 87. This elastic biasing force acts on the sliding member 86 via the retaining plate 94, and the sliding member 86 is elastically biased so as to be positioned on the uppermost side. Further, since the gap adjusting member 88 is interposed between the support rib of the carriage 38 and the sliding contact plate 89 of the sliding member 86, the sliding is made by the thickness of the adjusting portion 99 of the gap adjusting member 88. The moving member 86 is moved downward against the elastic biasing force. Since the elongated portion 103 is formed in the adjustment portion 99, the gap adjustment member 88 is slidable in a state where the foot portion 90 of the sliding member 86 is penetrated in the thickness direction. As the gap adjusting member 88 slides, the thickness of the adjusting portion 99 located between the support rib of the carriage 38 and the sliding contact plate 89 is changed, and the vertical direction of the sliding member 86 is changed by the change in thickness. The position of is changed.

  The positions of the gap adjusting members 88 on the upstream side and the downstream side in the conveyance direction of the paper P are linked with each other so that the sliding members 86 are held at a predetermined height. Each sliding member 86 is held at the same height at the sliding position that changes when both ends in the sliding direction are brought into contact with each other. Therefore, the carriage 38 is always maintained parallel to the upper surfaces of the guide frames 43 and 44, and the carriage 38 is moved up and down while the inkjet recording head 39 mounted on the carriage 38 is maintained horizontally. As a result, the gap between the ink jet recording head 39 and the paper P on the platen 42 is maintained horizontally in the image recording area, so that accurate image recording is realized. The number of sliding members 86 can be changed as appropriate.

  As described above, according to the printer unit 2 according to the present embodiment, the sliding contact plate 89 of the sliding member 86 that supports the carriage 38 on which the inkjet recording head 39 is mounted at a predetermined height on the guide frames 43 and 44, and the carriage 38. The height of the carriage 38 supported by the sliding member 86 is changed by interposing the gap adjusting member 88 therebetween and sliding the gap adjusting member 88. Therefore, the inkjet recording head 39 and the paper P are changed. And the gap can be adjusted.

  Hereinafter, the second gap adjusting mechanism of the present invention will be described. The printer unit related to the second gap adjustment mechanism has the same configuration as that of the printer unit 2 except that the configuration of the carriage is different. Accordingly, only the carriage 110 having a different configuration will be described for the second gap adjustment mechanism. In the following description, the same reference numerals as those of the printer unit 2 are the same members.

  FIG. 7 is a partial bottom view showing the configuration of the lower surface of the carriage 110. The rotating shaft 112 and the slider 113 are respectively assembled on the upstream side and the downstream side of the carriage main body 111 in the paper transport direction corresponding to the guide frames 43 and 44. In FIG. 7, the upstream side of the carriage 110 in the sheet conveyance direction is omitted. FIG. 8 is a perspective view showing the external configuration of the rotating shaft 112 and the slider 113. FIG. 9 is a side view of the rotating shaft 112 and the slider 113.

  As shown in FIG. 7, the carriage 110 includes a carriage main body 111 on which the inkjet recording head 39 is mounted, a rotary shaft 112 that slides on the guide frames 43 and 44 to support the carriage main body 111 at a predetermined height, and a rotary shaft. And a slider 113 for rotating 112.

  As shown in FIG. 7, the rotating shaft 112 supported by the carriage body 111 is supported so that any one of the sliding members 114, 115, 116 protrudes vertically below the carriage body 111. . The carriage body 111 is horizontally placed on the guide frames 43 and 44 by any one type of sliding contact members 114, 115, and 116 protruding vertically downward on the upstream side and the downstream side in the sheet conveyance direction of the carriage body 111. The carriage 110 is supported so that the sliding contact members 114, 115, 116 are slidably contacted with the guide frames 43, 44, and reciprocated as described above.

  As shown in FIG. 9, the three types of sliding contact members 114, 115, and 116 have different projecting widths outward in the radial direction of the rotating shaft 112. It is getting bigger. These three types of sliding contact members 114, 115, and 116 are provided in the circumferential direction so that the protruding width changes sequentially at both ends of the rotating shaft 112. Further, the sliding members 114, 115, 116 having the same type, that is, the same projecting width are arranged so that the positions in the circumferential direction coincide with each other at both ends of the rotating shaft 112.

  As shown in FIG. 8, a slider 113 is externally fitted at the approximate center of the rotating shaft 112 in the axial direction. The slider 113 is a cylindrical member that can slide in the axial direction along the outer peripheral surface of the rotating shaft 112. A pair of spiral engaging grooves 117 are formed in the cylindrical inner peripheral surface of the slider 113. A pair of engaging projections (not shown) project from the outer peripheral surface to the radially outer side at approximately the center in the axial direction of the rotating shaft 112. The engaging projection is engaged with the engaging groove 117, and the rotating shaft 112 and the slider 113 are engaged. When the slider 113 slides in the axial direction of the rotating shaft 112, the engaging convex portion moves along the engaging groove 117, and as a result, the rotating shaft 112 rotates. That is, the rotation of the rotary shaft 112 is transmitted to the slide of the slider 113 by the engagement groove 117 and the engagement projection.

  As shown in FIG. 8, an L-shaped projecting piece 119 projecting radially outward is provided on the outer peripheral surface of the slider 113. As shown in FIG. 7, the protruding piece 119 protrudes from the lower surface of the carriage body 111 in a state where the rotating shaft 112 and the slider 113 are assembled to the carriage body 111. When the carriage 110 is slid to a predetermined position on the guide frames 43 and 44, the projecting piece 119 comes into contact with a contact portion 120 formed by cutting out part of the guide frames 43 and 44, and further the carriage. By sliding 110, the slider 113 is slid in the axial direction of the rotating shaft 112.

  In the carriage 110 configured as described above, the control unit 64 (see FIG. 10) controls the reciprocation of the carriage 110 so that the slider 113 is brought into contact with the contact portion 120 and the rotational position of the rotary shaft 112 is changed. To do. As shown in FIG. 9, the slidable contact member 114 having the shortest distance R1 from the axial center of the rotating shaft 112 to the radially outer end surface is in slidable contact with the upper surface 121 of the guide frames 43 and 44, thereby Supported at the lowest height of the three stages. As a result, the gap between the ink jet recording head 39 and the recording medium becomes the narrowest and suitable for high resolution image recording.

  As described above, according to the second gap adjusting mechanism, the sliding contact members 114, 115, and 116 that support the carriage main body 111 on which the inkjet recording head 39 is mounted at a predetermined height on the guide frames 42 and 43 are arranged in the radial direction. A plurality of sliding members 114, 115, 115 having different projecting widths are arranged in parallel in the circumferential direction of the rotating shaft 112 as a plurality of members having different projecting widths to the outside, and the rotating shaft 112 is rotated by sliding the slider 113. Since any one of 116 is selected and the height of the carriage body 111 is changed, the gap between the inkjet recording head 39 and the paper P can be adjusted.

FIG. 10 is a block diagram illustrating a configuration of the control unit 64 of the printer unit 2. As shown in the figure, the control unit 64 is configured as a microcomputer mainly including a CPU (Central Processing Unit) 65, a ROM (Read Onli Memory) 66, and a RAM (Random Accsess Memory) 67, and an ASIC via a bus 69. (Application Specific Integrated Circuit) 70 is connected.

  The ROM 66 stores a program for controlling various operations of the printer unit 2. The RAM 67 is used as a storage area or a work area for temporarily recording various data used when the CPU 65 executes the program.

  The ASIC 70 generates a phase excitation signal and the like for energizing the LF (conveyance) motor 71 in accordance with a command from the CPU 65, applies the signal to the drive circuit 72 of the LF motor 71, and drives the drive signal via the drive circuit 72. The LF motor 71 is rotated by energizing the LF motor 71.

  The drive circuit 72 drives the LF motor 71 connected to the paper feed roller 25, the transport roller 60, the paper discharge roller 62, and the purge mechanism 51. The drive circuit 72 receives an output signal from the ASIC 70 and receives the LF motor 71. An electrical signal is generated for rotation. In response to the electrical signal, the LF motor 71 rotates, and the rotational force of the LF motor 71 is fed via a known drive mechanism including a gear, a drive shaft, and the like, through the paper feed roller 25, the transport roller 60, the paper discharge roller 62, And is transmitted to the purge mechanism 51.

  Further, the ASIC 70 generates a phase excitation signal and the like for energizing a CR (carriage) motor 73 in accordance with a command from the CPU 65, applies the signal to the drive circuit 74 of the CR motor 73, and passes through the drive circuit 74. The CR motor 73 is controlled to rotate by energizing the CR motor 73 with a drive signal.

  The drive circuit 74 drives the CR motor 73 connected to the carriage 38 and receives an output signal from the ASIC 70 to form an electrical signal for rotating the CR motor 73. The CR motor 73 rotates in response to the electrical signal, and the rotational force of the CR motor 73 is transmitted to the carriage 38 via the belt drive mechanism 46, whereby the carriage 38 is reciprocated. In this way, the reciprocation of the carriage 38 is controlled by the control unit 64.

  The drive circuit 75 selectively ejects ink from the inkjet recording head 39 to the paper P at a predetermined timing. The drive circuit 75 receives an output signal generated by the ASIC 70 based on a drive control procedure output from the CPU 65. The inkjet recording head 39 is driven and controlled.

  Connected to the ASIC 70 are a rotary encoder 76 for detecting the amount of rotation of the transport roller 60 and a linear encoder 77 for detecting the amount of movement of the carriage 38. Further, the ASIC 70 includes an operation panel 4 for instructing operation of the scanner unit 3 and the printer unit 2, a media sensor 31 for detecting the lateral dimension of the paper P mounted on the carriage 38, and a paper trailing edge guide of the paper feeding cassette. A paper sensor 13 for detecting the vertical dimension of the installed paper P is connected.

  Next, the printing process of the printer unit 2 having the above-described configuration will be described. FIG. 11 is a flowchart showing the printing process of the printer unit 2. In this printing process, a variable G representing a gap between the ink jet recording head 39 and the paper P is set to an initial value in an initial setting (step (hereinafter referred to as S) 31). In the initial setting, the variable G is set so that the gap is 2.0 mm. The variable I and variable T will be described later. Subsequently, the presence or absence of print data is determined (S32). If there is no print data (S32: No), the presence / absence of repeated print data is determined. If there is print data (S32: Yes), printing is started (S35). Subsequently, it is determined whether or not to end printing (S36). If not ended (S36: No), the process returns to the determination of the presence / absence of print data in this process, and the process is repeated. On the other hand, if printing is finished (S36: Yes), this process is finished.

  Here, the operation of the gap adjustment will be described in detail using the first gap adjustment mechanism. As shown in FIG. 4, the carriage 38 on which the ink jet recording head 39 is mounted is supported at a predetermined height on the guide frames 43 and 44 by a sliding member 86. In the first gap adjustment mechanism, as described above, the height of the carriage 38 is changed in three stages depending on the thickness of the adjustment portion 99 of the gap adjustment member 88.

  As shown in FIG. 6, in the first gap adjusting mechanism, it is assumed that the height of the carriage 38 is set to the middle height of three stages in a normal state. The middle height of the three stages is such that the middle portion 101 of the adjustment portion 99 of the gap adjustment member 88 is interposed between the support rib (not shown) of the carriage 38 and the sliding contact plate 89 of the sliding member 86. It is in a state. The gap when set to the middle height is 2.0 mm.

  When the variable G is changed in S4 to be described later, the control unit 64 reciprocates the carriage 38 to widen the gap so that the right end of the gap adjusting member 88 in the sliding direction is set to the right end of the guide frames 43 and 44. It is made to contact | abut to the formed contact part 106 (refer FIG. 4). When the carriage 38 is further moved in a state where one end (right side in FIG. 4) of the gap adjusting member 88 is in contact with the contact portion 106, one end of the gap adjusting member 88 is moved into the carriage 38. The slide position changes so as to be immersed. Accordingly, the thick portion 102 of the adjustment portion 99 of the gap adjustment member 88 is interposed between the support rib of the carriage 38 and the sliding contact plate 89 of the sliding member 86. In this state, the carriage 38 is maintained at the highest height in three stages by the sliding member 86. At this time, the gap is 2.8 mm.

  Further, when printing a high resolution image, the gap can be made smaller than usual. In this case, the control unit 64 rotates the CR motor 73 in a predetermined direction so as to move the carriage 38 to the side where the waste ink tray 84 is provided (left side in FIG. 4). The other end of the gap adjusting member 88 that protrudes outward from the carriage 38 when the carriage 38 slid on the guide frames 43 and 44 toward the waste ink tray 84 moves to the end of the guide frames 43 and 44. The part (the left side in FIG. 4) abuts against the abutting portion 107. When the carriage 38 is further moved in a state where the other end of the gap adjusting member 88 is in contact with the contact portion 107, the gap adjusting member 88 slides to the left in FIG. The slide position is changed so that the other end of the gap adjusting member 88 is immersed in the carriage 38. Thus, the thin portion 100 of the adjustment portion 99 of the gap adjustment member 88 is interposed between the support rib of the carriage 38 and the sliding contact plate 89 of the sliding member 86. The gap at this time is 1.6 mm.

  When it is detected that the paper P is in the horizontal direction with respect to the transport direction during the printing process shown in FIG. 11, the paper horizontal processing 1 shown in FIG. 12 is performed. FIG. 12 is a flowchart of the paper horizontal placement process 1. Hereinafter, an operation for detecting the placement direction of the paper P and a paper horizontal placement process will be described in order.

  First, an operation for detecting the loading direction of the paper P will be described. Table 1 is a table showing the paper size and the loading direction corresponding to the vertical and horizontal dimensions of the paper P. The paper sensor 13 shown in FIG. 3 detects the dimension (vertical dimension) of the paper P in the transport direction, and the media sensor 31 shown in FIG. 5 detects the dimension (horizontal dimension) in the direction perpendicular to the paper P transport direction. The As a result, when the horizontal dimension of the paper P is larger than the vertical dimension of the paper P, it is detected that the loading direction of the paper P is horizontal with respect to the transport direction. When the vertical and horizontal dimensions of the paper P are standard sizes as shown in Table 1, the paper size and the loading direction of the paper P are detected.

  For example, when it is detected that the vertical dimension is 210 mm and the horizontal dimension is 297 mm, as shown in Table 1, it is detected as A4 landscape orientation. As described above, the placement direction of the paper P is determined as a result of detecting the vertical and horizontal dimensions of the paper P by the paper sensor 13 and the media sensor 31. As described above, the paper sensor 13 and the media sensor 31 are detection units that detect the loading direction of the paper P.

  Next, the paper horizontal placement process 1 shown in FIG. 12 will be described. As described above, as a result of detecting the placement direction of the paper P by the paper sensor 13 and the media sensor 31, the paper horizontal placement process 1 determines whether or not the paper P is in the horizontal orientation (S2). If it is determined that the paper P is in landscape orientation, the variable G is changed so that the gap is 2.8 mm (S4). If it is determined that the paper P is not in landscape orientation, the gap is 2.0 mm. The variable G is returned to the initial value (S3). Thus, the paper horizontal placement process 1 is completed.

In this paper horizontal placement process 1, the gap is made wider when it is detected that the loading direction of the paper P is horizontal than when it is detected that the loading direction of the paper P is vertical. Therefore, even when the paper P is deformed horizontally in the transport direction (see FIG. 15B) and the reduction by the pressing force of the transport roller is difficult, the paper P and the inkjet recording head 39 are in contact with each other. However, it is possible to smoothly convey the paper P and prevent the recording surface of the paper P from being stained.
[Second Embodiment]
Hereinafter, a second preferred embodiment of the present invention will be described with reference to the accompanying drawings. The printer unit according to the second embodiment is provided in the printer unit of the first embodiment because it changes the amount of ink ejected from the inkjet recording head 39 according to the placement direction of the paper P. The gap adjusting mechanism may not be provided. In the following description, the same reference numerals as those of the printer unit 2 are the same members. Further, the method for detecting the loading direction of the paper P is the same as the method described in the first embodiment.

  A printing process of the printer unit according to the second embodiment will be described with reference to FIGS. 11 and 13. FIG. 13 is a flowchart of the paper horizontal placement process 2. The paper horizontal placement process 2 performs a process of reducing the amount of ink ejected from the ink jet recording head 39 when it is detected that the paper P is placed in the horizontal direction with respect to the transport direction.

  In the printing process shown in FIG. 11, the variable I representing the ink discharge amount from the ink jet recording head 39 is set to an initial value in the initial setting (S31). In the initial setting, the variable I is set so that the ink discharge amount becomes 10 pl. Subsequently, the presence or absence of print data is determined (S32). If there is no print data (S32: No), the presence / absence of repeated print data is determined. If there is print data (S32: Yes), printing is started (S35). Subsequently, it is determined whether or not to end printing (S36). If not ended (S36: No), the process returns to the determination of the presence / absence of print data in this process, and the process is repeated. On the other hand, if printing is finished (S36: Yes), this process is finished. In the control unit 64 (see FIG. 10), the drive circuit 75 receives the output signal generated in the ASIC 70 based on the drive control procedure output from the CPU 65, and drives and controls the inkjet recording head 39 to perform inkjet recording. A predetermined amount of ink is selectively ejected from the head 39 onto the paper P at a predetermined timing.

  Next, the paper horizontal placement process 2 shown in FIG. 13 will be described. In the paper horizontal placement process 2, it is determined whether or not the paper P is in landscape orientation (S12). When it is determined that the paper P is in landscape orientation (S12: Yes), the variable I representing the ink ejection amount is changed so that the ink ejection amount is half of the initial setting (S14), and the paper P is not in landscape orientation. If it is determined (S12: No), the variable I is returned to the initial value so that the ink discharge amount is 10 pl (S13). Thus, the paper horizontal placement process 2 is completed.

In this paper horizontal placement process 2, when it is detected that the placement direction of the paper P is horizontal, the ink discharge amount is less than when the paper P is detected to be vertical. To do. Accordingly, the paper P does not absorb more ink than necessary, and the paper P can be smoothly conveyed while minimizing deformation of the paper caused by the paper P absorbing ink.
[Third embodiment]
Hereinafter, a third preferred embodiment of the present invention will be described with reference to the accompanying drawings. The printer unit according to the third embodiment changes the waiting time between the forward and backward scans of the reciprocating scans of the carriages 38 and 110 according to the loading direction of the paper P. The gap adjusting mechanism provided in the printer unit may not be provided. In the following description, the same reference numerals as those of the printer unit 2 are the same members. Further, the method for detecting the loading direction of the paper P is the same as the method described in the first embodiment.

  A printing process of the printer unit according to the third embodiment will be described with reference to FIGS. 11 and 14. FIG. 14 is a flowchart of the paper horizontal placement process 3. In the paper horizontal placement process 3, when it is detected that the placement direction of the paper P is transverse to the transport direction, the waiting time between the forward and backward scans of the reciprocating scanning of the carriages 38 and 110 is increased. Perform the process.

  In the printing process shown in FIG. 11, in the initial setting, a variable T representing the waiting time between the forward scan and the backward scan of the reciprocating scan of the carriages 38 and 110 is set to an initial value (S31). In the initial setting, the variable I is set so that the waiting time is 0 sec. Subsequently, the presence or absence of print data is determined (S32). If there is no print data (S32: No), the presence / absence of repeated print data is determined. If there is print data (S32: Yes), printing is started (S35). Subsequently, it is determined whether or not to end printing (S36). If not ended (S36: No), the process returns to the determination of the presence / absence of print data in this process, and the process is repeated. On the other hand, if printing is finished (S36: Yes), this process is finished. In the control unit 64 (see FIG. 10), the drive circuit 74 receives an output signal from the ASIC 70 and forms an electrical signal for rotating the CR motor 73. In response to the electrical signal, the CR motor 73 rotates at a predetermined timing, and the rotational force of the CR motor 73 is transmitted to the carriage 38 via the belt driving mechanism 46, whereby the forward scan and the backward scan of the carriage 38 are performed. Wait for a predetermined time in between. In this way, the reciprocation of the carriage 38 is controlled by the control unit 64.

  Next, the paper horizontal placement process 3 shown in FIG. 13 will be described. In the paper horizontal placement process 3, it is determined whether or not the paper P is in the landscape orientation (S22). If it is determined that the paper P is in the landscape orientation (S22: Yes), the variable representing the waiting time of the carriage 38 so that the waiting time between the forward scanning and the double scanning of the carriages 38, 110 is 0.5 sec. When T is changed (S24) and it is determined that the paper P is not in landscape orientation (S22: No), the variable T is returned to the initial value (S23). Thus, the paper horizontal placement process 3 is completed.

  In this paper horizontal placement process 3, when it is detected that the placement direction of the paper P is horizontal, the waiting time is reduced compared to when it is detected that the placement direction of the paper P is vertical. . Accordingly, the paper P can sufficiently fix the absorbed ink, can minimize the deformation of the paper, smoothly transport the recording medium, and prevent the recording surface of the paper P from being stained. .

  Note that S2, S12, and S22 function as instruction means for instructing the paper placement direction, and S3, S4, S13. S14, S23, and S24 function as changing means.

  Although the present invention has been described based on the embodiments, the present invention is not limited to the above-described embodiments, and various modifications can be easily made without departing from the spirit of the present invention. It can be done. For example, in the above-described embodiment, the paper sensor 13 and the media sensor 31 detect that the paper P is in landscape orientation. However, the means for instructing the placement direction of the paper P is not limited to this method, and the user can directly instruct. Alternatively, a computer externally connected to the operation panel 4 and the printer unit 2 may be used. In this case, the operation panel 4 and the computer function as an instruction unit for instructing the placement direction of the paper P. Also, even if the user's instruction is wrong, the paper sensor 13 and the media sensor 31 can correctly detect the loading direction of the paper P and perform processing. Further, in the above-described embodiment, as a result of detecting that the loading direction of the sheet P is transverse to the transport direction, the sheet horizontal placement processes 1 to 3 are executed. Appropriate processing can be executed according to the paper loading direction, for example, the fiber direction of the paper.

1 is a perspective view illustrating an external configuration of a multifunction machine 1 according to a first gap adjustment mechanism of the present invention. 2 is an enlarged cross-sectional view showing a main configuration of a printer unit 2. FIG. 2 is a diagram illustrating a paper feed cassette 20 of the printer unit 2. FIG. 2 is an enlarged plan view showing a main configuration of a printer unit 2. FIG. 4 is a bottom view of the ink jet recording head 39. FIG. FIG. 6 is an exploded perspective view showing configurations of a sliding member 86, a coil spring 87, and a gap adjusting member 88. It is a partial bottom view showing the lower surface of carriage 110 concerning the 2nd gap adjustment mechanism of the present invention. FIG. 3 is a perspective view showing an external configuration of a rotary shaft 112 and a slider 113. 4 is a side view of a rotating shaft 112 and a slider 113. FIG. 3 is a block diagram showing a configuration of a control unit 64. FIG. It is a flowchart of a printing process. 10 is a flowchart of sheet lateral processing 1; 12 is a flowchart of sheet lateral processing 2. 10 is a flowchart of sheet lateral placement processing 3; FIG. 6 is an explanatory diagram illustrating a relationship between deformation of a sheet and a fiber direction of the sheet P.

2 Printer section (inkjet recording device)
13 Paper sensor 31 Media sensor 38, 110 Carriage 39 Inkjet recording head 43, 44 Guide frame 64 Control unit
86 Slide member 87 Coil spring 88 Gap adjustment member 89 Sliding contact plate 90 Foot 92 Guide groove 96 Support member 98 Support rib 99 Adjustment part 103 Slot 106, 107 Contact part 111 Carriage body 112 Rotating shaft 113 Slider (input member)
114, 115, 116 Sliding contact member 117 Engaging groove
120 Contact part

Claims (2)

A mounting table for mounting a rectangular recording medium having a long side and a short side shorter than the long side;
Conveying means for conveying the recording medium from the mounting table in the conveying direction;
A recording head for recording by discharging ink to the recording medium conveyed by the conveying means;
When the long side of the recording medium and the transport direction are orthogonal to each other, the interval between the recording head and the recording medium is wider than when the short side of the recording medium is orthogonal to the transport direction. an ink jet recording apparatus characterized by comprising: a control unit. A mounting table for mounting the recording medium;
Conveying means for conveying the recording medium from the mounting table in the conveying direction;
A recording head for performing recording by discharging ink to the recording medium conveyed by the conveying means;
When the fiber direction of the recording medium transported by the transport means and the transport direction are orthogonal to each other, the recording head and the recording medium are more aligned than when the fiber direction of the recording medium transported and the transport direction are along. An ink jet recording apparatus comprising: a control unit that widens the interval.

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