JP2011011552A - Recording medium guiding device, recording device, and liquid jetting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper guiding device which prevents head friction of a paper distal end and reducing unevenness of PG upon recording of a second surface even when a warped state is formed on the print paper after recording of a first surface.SOLUTION: The recording medium (paper) guiding device guides the paper so that the second surface faces a recording head 100 by curving and reversing the paper so that the first surface of the paper P on which recording has been carried out is inside. The paper guiding device includes a conveyance time control means which controls the time Tfrom the end of the recording onto the first surface until the paper distal end reaches a first drive roller 28, which conveys the paper P to the recording head 100, and a first driven roller 29 upon recording of the second surface. The conveyance time control means sets the time Tto be shorter if the ink discharge amount in the region that has a length Lfrom the paper rear end upon recording of the first surface is small. Meanwhile, if the ink discharge amount is larger, the time Tis set longer.

Description

In order to perform recording on the second surface of the recording medium recorded on the first surface, the present invention curves the recording medium recorded on the first surface with the first surface inward. The present invention relates to a recording medium guide device to be reversed and a recording device including the same. The present invention also relates to a liquid ejecting apparatus.
Here, the liquid ejecting apparatus uses an ink jet recording head, and is not limited to a recording apparatus such as a printer, a copying machine, and a facsimile machine that discharges ink from the recording head to perform recording on a recording medium. And a device that ejects a liquid corresponding to the application from a liquid ejecting head corresponding to the ink jet recording head to an ejected medium corresponding to a recording medium, and adheres the liquid to the ejected medium. .
In addition to the recording head, as a liquid ejecting head, a color material ejecting head used for manufacturing a color filter such as a liquid crystal display, and an electrode material (conductive paste) used for forming an electrode such as an organic EL display or a surface emitting display (FED) Examples thereof include an ejection head, a bioorganic matter ejection head used for biochip production, and a sample ejection head as a precision pipette.

An example of a recording apparatus represented by a facsimile, a printer, or the like is an ink jet printer. Among them, there is an apparatus configured to execute recording on both sides of a printing sheet as an example of a recording medium.
In such an ink jet printer capable of double-sided recording, after recording on the first surface of the printing paper, the printing paper is curved and reversed, and the second surface opposite to the first surface is the ink jet recording head. A paper guide device that guides and conveys the printing paper is provided so as to face each other.

  Here, if the printing paper is immediately entered into the curved inversion path after recording on the first surface, there arises a problem that the recording surface is soiled by the first surface coming into contact with the curved inversion path. This is particularly noticeable when recording is performed on printing paper having poor ink drying characteristics (which requires a long drying time). As a prior art for solving such a problem, Patent Document 1 discloses a time (hereinafter referred to as “waiting time”) from the end of recording on the first surface (front surface) to the start of recording on the second surface (back surface). ) Is determined in accordance with the type of printing paper. If the waiting time is set uniformly according to the type of printing paper, a uniform waiting time is required regardless of whether the printing duty is high or the printing duty is low. That is, in the case where the print duty is high and the case where the print duty is low, the latter may require a shorter waiting time. A technique for variably setting the waiting time is disclosed.

Japanese Patent Laid-Open No. 06-134982 JP 2003-48311 A

  By the way, when ink jet recording is performed on the first surface, the printing paper tends to be warped like a ridge so that the printing paper absorbs ink and swells to form a convex shape with the first surface up. The present inventor has found that. That is, when the deformed printing paper is curved and reversed by the paper guiding device and the second surface faces the ink jet recording head, the printing paper rubs against the ink jet recording head or the ink jet recording head It has been found that the distance to the surface (paper gap: PG) becomes non-uniform and the recording quality may be degraded.

  More specifically, such inconvenience is caused by the fact that the leading edge of the paper during the second surface recording is from the first roller pair provided on the upstream side of the inkjet recording head to the second roller pair provided on the downstream side of the inkjet recording head. Occurs until it reaches. This is because, when the printing paper is nipped by the first roller pair and the second roller pair, the posture is restricted, so that head rubbing or the like hardly occurs, but the paper is nipped by the first roller pair. However, when the sheet is not nipped by the second roller pair, the leading edge of the sheet is in an unrestrained state, and head rubbing or the like is likely to occur. Therefore, in order to start recording on the second surface, the leading edge of the paper does not reach the second roller pair in a state where the paper is cued, so that the head rubbing and PG non-uniformity described above occur. Occurs and the recording quality decreases.

  However, in the technique disclosed in Patent Document 1 or Patent Document 2 described above, the time from the end of the first side recording to the start of the second side recording is simply set to be variable depending on the type of printing paper or the print duty. Therefore, it has not been possible to completely prevent the recording quality from being deteriorated due to head rubbing at the front end of the paper or PG change during the second side recording as described above.

  Therefore, the present invention has been made in view of such a situation, and the problem is that even if a warped state is formed on the printing paper after the first side recording, the head rubbing at the front end of the paper is caused during the second side recording. It is an object of the present invention to provide a paper guide device that can prevent PG non-uniformity while preventing it.

In order to solve the above-described problems, a recording medium guide apparatus according to a first aspect of the present invention provides a first surface on which recording is performed by an ink jet recording head that performs recording by discharging ink onto a recording medium. And a curved reversal path for curving and reversing the recording medium with the first surface facing inward so that the second surface on the opposite side faces the ink jet recording head, and recording on which recording has been performed on the first surface Conveying means for conveying the recording medium so that the medium reaches the upstream side of the ink jet recording head via the curved reversal path with the trailing edge at the time of recording on the first surface as the leading edge; and the conveying means By controlling the driving of the recording medium, the leading edge of the recording medium at the time of the second surface recording is provided on the upstream side of the ink jet recording head from the end of the recording of the first surface, and the recording medium is nipped and rotated. And a conveying time control means for controlling the time T _w before reaching the first roller pair for conveying a recording medium to the downstream side by the Rukoto, the transfer time control means, when the first surface recording ink ejection amount in the area of length L ₁ from the recording medium the trailing end, or the recording duty, or in accordance with recording data, characterized in that it is configured so as to set the time T _w.

According to the above aspect, the second surface is inkjet-recorded via the curve reversal path in which the rear end of the recording medium on which recording is performed on the first surface is the leading end and the first surface is inward and the curve is reversed. The recording medium guide device for guiding and transporting the recording medium so as to face the head performs the second surface recording on the first roller pair provided on the upstream side of the ink jet recording head from the end of the first surface recording. tip when is a transport time control means for controlling the time T _w to reach. That is, the time T _w is the "first surface recording end from the time until the second surface recording start time" is not less different properties, recorded from the end, the second surface of the first surface The time until the leading edge of the recording medium reaches the first roller pair.

Then, the conveyance time control means, the ink discharge amount in the length L ₁ of the region from the recording medium the trailing end (hereinafter referred to as "recording medium rear area") at the first surface recording, or recording duty, Alternatively, since the time _Tw is set according to the recording data, when the leading edge of the recording medium at the time of the second surface recording advances downstream from the first roller pair, the time Tw is set. It is possible to prevent problems such as the tip of the recording medium rubbing against the ink jet recording head or the PG becoming extremely non-uniform.

That is, the trailing edge of the recording medium at the time of recording on the first surface is the leading edge of the recording medium at the time of recording on the second surface. Therefore, the state of the leading edge of the recording medium at the time of recording on the second surface is This is determined by the amount of ink absorbed at the rear end of the recording medium during surface recording. Therefore, in view of this, the time _Tw is set according to the ink absorption amount (that is, the ink discharge amount, recording duty, or recording data) at the trailing edge of the recording medium at the time of recording on the first side. As described above, it is possible to prevent problems such as the tip of the recording medium rubbing with the ink jet recording head or the PG becoming extremely nonuniform during the second surface recording.

Moreover, the time T _w is dependent on the ink absorption amount of the recording medium rear area when the first surface recording, not dependent on the ink absorbing quantity of the region other than the recording medium rear area. Thus, for example, at most ink absorption amount of the first surface as a whole, the less ink absorption amount of the recording medium rear area when the first surface recording, the time T _w is be short, whereby Throughput can be optimized.

The recording medium guide device according to the second aspect of the present invention, in the first aspect, the length L _1, from the first roller pair, is arranged downstream of the ink jet recording head, the recording characterized in that by rotating and nipping the recording medium made at the second roller pair to the path length L ₂ or more for conveying a recording medium to the downstream side.
According to the above embodiment, the length of the first surface of the recording medium the trailing end region of the recording (the sub-scanning direction length) L ₁ is, from the first pair of rollers, arranged downstream of the ink jet recording head first since 2 rollers to the path length L ₂ or more, the most head rubbing occurs easily region at the time of recording the execution of the second surface, i.e. the second roller from the distal end of the second surface of the first roller pair The time _Tw is set in consideration of all the existing ink absorption amount (ink absorption amount of the first surface) in the region until reaching the pair. Accordingly, it is possible to more reliably prevent problems such as the tip of the recording medium rubbing against the ink jet recording head or the PG being significantly non-uniform during the second surface recording.

The third recording medium guide apparatus according to an aspect of the present invention, in the above aspect 2, wherein a length L _1, for detecting passage of the recording medium provided on the upstream side of the first roller pair the The path length L ₃ from the recording medium passage detection means to the second roller pair is characterized in that
According to the above-described embodiment, the length L _1, the path length L from the recording medium passage detection means for detecting passage of the recording medium provided on the upstream side of the first roller pair to the second pair of rollers because it is _3, by using the recording medium passage detection means, at the time of the first surface recording, the ink discharge amount of the recording medium rear end region, or the recording duty, or be obtained recording data easily it can.

The recording medium guide apparatus according to a fourth aspect of the present invention is characterized in that, in any of the first to third aspects, the time _Tw is further set according to the type of the recording medium. And
According to the above aspect, in addition to the ink discharge amount, the recording duty, or the recording data of the recording medium rear end area at the time of the first surface recording, the time _Tw is further the type (thickness, material) of the recording medium. from being set in accordance with the like), it is possible to set the time T _w better.

According to a fifth aspect of the present invention, there is provided a recording apparatus configured to execute recording on both sides of a recording medium, wherein the recording medium guide apparatus according to any one of the first to fourth aspects is provided. It is characterized by having.
According to the above aspect, in the recording apparatus, it is possible to obtain the same effect as any of the first to fourth aspects described above.

A recording medium guide apparatus according to a sixth aspect of the present invention includes a liquid ejecting head that ejects liquid onto the ejected medium, and a first side opposite to the first surface on which the liquid is ejected by the liquid ejecting head. A curved reversing path for curving and reversing the medium to be ejected with the first surface facing inward so that two surfaces face the liquid ejecting head, and a medium to be ejected on which the liquid is ejected on the first surface, A transport unit that transports the ejection medium so as to reach the upstream side of the liquid ejecting head via the curved reversing path with the rear end during the first surface liquid ejecting as a leading end, and drive control of the transport unit As a result, the tip of the ejection medium at the time of the second surface liquid ejection is provided on the upstream side of the liquid ejection head from the end of the first surface liquid ejection, and the nip and rotation of the ejection medium are performed. Downstream medium to be ejected A conveying time control means for controlling the time T _w until it reaches the first pair of rollers feed, wherein the conveying time control means, the length L from the injection medium rear during the first surface liquid jet _The time _Tw is set according to the liquid ejection amount, the liquid ejection density, or the liquid ejection data in _one region.

1 is an external perspective view of a printer according to the present invention. 1 is a schematic side sectional view of a printer according to the present invention. FIG. 2 is a plan view of a main part of the printer according to the invention. FIG. 3 is a block diagram of a control unit of the printer according to the present invention. FIG. The side view of the paper conveyance path | route from a paper detector to a 2nd drive roller. FIG. 4 is a diagram illustrating a recording area at the trailing edge of a sheet. The flowchart which shows the operation | movement content at the time of double-sided recording. It is a figure which shows 1st Example of waiting time setting. It is a figure which shows 2nd Example of waiting time setting. It is a figure which shows 3rd Example of waiting time setting. It is a figure which shows 4th Example of waiting time setting. It is a figure which shows 5th Example of waiting time setting. It is a figure which shows 6th Example of waiting time setting. It is a figure which shows 7th Example of waiting time setting. It is a figure which shows 8th Example of waiting time setting.

Hereinafter, one embodiment of the present invention will be described.
1. Inkjet printer schematic configuration
2. Detailed configuration of paper reversing unit
3. Setting the waiting time for recording on the 2nd page
A description will be given in this order with reference to the drawings.
<1. General configuration of inkjet printer>
Hereinafter, a schematic configuration of an ink jet printer (hereinafter referred to as “printer”) 1 as an embodiment of “recording apparatus” and “liquid ejecting apparatus” according to the present invention will be described with reference to FIGS. 1 is an external perspective view of the printer 1, FIG. 2 is a schematic side sectional view of the printer 1, FIG. 3 is a plan view of the main part of the printer 1, and FIG. 4 is a block diagram of the control unit 160 of the printer 1.

  In FIG. 1, ink droplets as an example of “liquid” are ejected onto printing paper (mainly cut sheet paper: hereinafter referred to as “paper P”) as an example of “recording medium” and “ejection medium”. The printer 1 that performs recording is configured such that an apparatus main body 1a and an optional paper feeding unit (hereinafter referred to as "OPT unit") 3 can be connected to the apparatus main body 1a. The apparatus main body 1a has a paper feed section, a recording section, a paper discharge section, and the like (details will be described later). On the other hand, the OPT unit 3 supplies set sheets P one by one toward the upper apparatus main body 1a. A paper feed unit (not shown) for paper is provided.

  This printer 1 has a paper feed tray 200 in the apparatus main body 1a and a paper feed tray 300 in the OPT unit 3, and a large number of sheets P (500 sheets in this embodiment) are placed in both paper feed trays. It can be set in a stacked state. On the apparatus main body 1a side, a manual paper feed port 202 capable of manually feeding paper P of an arbitrary size is provided above the paper feed tray 200. Further, on the OPT unit 3 side, the paper feed tray 300 is provided so as to be detachable from the OPT unit 3, and the paper P can be set while being detached from the OPT unit 3.

  Next, the printer 1 has a face-down (hereinafter abbreviated as “Fd”) sheet discharge port 500 for discharging the recorded sheet P toward the front side of the apparatus at the upper part of the apparatus main body 1a. On the contrary, it has a face-up (hereinafter abbreviated as “Fu”) paper discharge port 600 for discharging toward the rear side of the apparatus. On the Fd paper discharge port 500 side, a cover 150 is provided that can be opened toward the front side of the apparatus by rotating about a rotation axis provided on the front side of the apparatus.

  FIG. 1 shows a state in which the cover 150 is opened. In the opened state, the cover 150 functions as a paper discharge stacker that stacks the paper P discharged from the Fd paper discharge port 500. In the closed state, the external appearance of the upper part of the apparatus is configured and the function of preventing entry of dust and the like into the apparatus is achieved. Further, on the Fu paper discharge port 600 side, a paper discharge stacker 601 is provided in an inclined posture, and the paper P discharged from the Fu paper discharge port 600 is sequentially stacked on the paper discharge stacker 601 in an inclined posture. The

  Next, the paper transport path of the printer 1 will be outlined with reference to FIG. The printer 1 conveys the sheet P obliquely from the lower front side of the apparatus toward the upper rear side of the apparatus, performs ink jet recording on the sheet P on the inclined conveyance path, and obliquely upwards (forwards) the recorded sheet P. Side (Fd paper discharge port 500)) or rear side (Fu paper discharge port 600)). In addition, the printer 1 reverses the paper P on which ink-jet recording has been performed on the front surface and transports it to the recording unit with the back surface facing up in order to perform ink-jet recording on both the front and back surfaces of the paper P. It has a reversal path.

More specifically, the paper conveyance path of the printer 1 includes a paper feeding unit 2, a recording unit 11, a face-down (Fd) discharge unit 5, a face-up (Fu) discharge unit 6, and a paper reversing unit 4. Generally composed. Although not shown in FIG. 2, a paper feeding unit that feeds paper to the recording unit 11 is further added by mounting the above-described OPT unit 3 below the paper feeding unit 2. A roller 61 and a roller 62 in FIG. 2 are for feeding the paper P from the OPT unit 3 to the apparatus main body 1a.
Hereinafter, each configuration of the paper transport path will be described. In the following, the upstream side of the paper transport path is simply referred to as “upstream side”, and the downstream side of the paper transport path is simply referred to as “downstream side”.

[Paper Feed Unit 2]
The paper feed unit 2 includes a hopper 203, a manual feed tray 201, a pickup roller 25, a paper feed roller 21, and a reverse roller 23. The hopper 203 supports a plurality of sheets P set in the sheet feeding tray 200 (FIG. 1) in a stacked state, and swings about the rotation shaft 203a, thereby causing the sheets P to be picked up by the pickup roller 25. Press contact. The pickup roller 25 has an outer peripheral surface made of a high friction material (for example, a rubber material), and presses the paper P and rotates to feed the uppermost paper P to the paper feeding roller 21 and the reverse roller 23 on the downstream side. . Note that a manual feed tray 201 having an edge guide 201 a is provided above the hopper 203, and the paper P set on the manual feed tray 201 is also sent downstream by the pickup roller 25.

The paper feed roller 21 and the reverse roller 23 are formed of a high friction material on the outer peripheral surface, and the paper feed roller 21 is rotationally driven in a rotational direction (counterclockwise direction in FIG. 2) for feeding the paper P downstream. On the other hand, the reverse roller 23 is rotationally driven in a rotational direction (counterclockwise in FIG. 2) that returns the paper P to the upstream side. The uppermost sheet P delivered from the hopper 203 by the pickup roller 25 is nipped between the sheet feeding roller 21 and the reverse roller 23, and the sheet feeding roller 21 rotates to cause the first drive on the downstream side. It is fed to the roller 28. The reverse roller 23 is provided so as to be able to switch between a state in which it is pressed against the paper feed roller 21 (the state shown in FIG. 2) and a state in which it is separated (not shown). It fulfills the function of separating the uppermost sheet P on the hopper 203 to be printed from the next and subsequent sheets P that are to be double fed. At this time, the reverse roller 23 rotates in a direction to return the paper P to the upstream side, thereby reliably ensuring that the next and subsequent paper P to be fed is fed at the nip point between the paper feed roller 21 and the reverse roller 23. stop. On the other hand, after the leading edge of the sheet P is nipped between the first driving roller 28 and the first driven roller 29, the conveying operation of the sheet P by the first driving roller 28 is not hindered, that is, a conveying load (back tension). ) Is separated from the paper feed roller 21.
In the following, for a roller pair that applies a conveyance force to the paper P, a conveyance load (mainly a force that tries to pull the paper P) applied to the paper P on the upstream side of the roller pair is referred to as “back tension”. Conversely, the conveyance load applied to the paper P on the downstream side (mainly, the force that pushes the paper P back from the downstream side to the upstream side) is referred to as “front tension”.

[Recording unit 11]
The recording unit 11 provided on the downstream side of the paper feeding unit 2 includes a paper detector 70 as a “recording medium passage detection unit”, a first driving roller 28 and a first driven roller 29 (hereinafter referred to as this as necessary). The roller pair is referred to as “first roller pair”), the inkjet recording head (hereinafter referred to as “recording head”) 100 as an example of the “liquid ejecting head”, the platen 65, the second drive roller 32, and the second A driven roller 33 (hereinafter referred to as “second roller pair” if necessary), an auxiliary roller 35, a third drive roller 36, and a third driven roller 37 (hereinafter referred to as “roller pair as necessary”). (Referred to as “third roller pair”).

  The first drive roller 28 is rotationally driven by a drive motor (not shown), and the first driven roller 29 is in contact with the first drive roller 28 and driven to rotate. In the present embodiment, two first driven rollers 29 are supported on the downstream side (upper side in FIG. 3) of the driven roller holder 26 as shown in FIG. 3, and the driven roller holder 26 is in the main scanning direction (see FIG. 3). 4 in the horizontal direction of 3). Here, the rotation center of the first driven roller 29 is arranged downstream of the rotation center of the first drive roller 28 in the conveying direction, so that the tangent line at the nip point between both rollers faces the platen 65. Has been. Accordingly, the sheet P that has passed through the first roller pair is pressed against the platen 65 and is prevented from being lifted from the platen 65. A pressing member 82 that presses the paper P toward the platen 65 is provided in the vicinity of the downstream side of the first driven roller 29 in one driven roller holder 26. The pressing member 82 functions to prevent the sheet P from lifting from the platen 65, which will be described in detail later.

  A paper detector 70 including a sensor 72 and a lever 71 that detects passage of the paper P is provided on the upstream side of the first roller. The lever 71 is provided so as to be able to swing in the clockwise direction and the counterclockwise direction with the swinging shaft 71a as a center when the conveyance path of the paper P is viewed from the side. One end extending from the swing shaft 71a is formed so as to be able to protrude on the transport path of the paper P, and is pushed away when the front end of the paper P passes, whereby the lever 71 swings about the swing shaft 71a. To do. The lever 71 is urged in a direction in which one end contacting the paper P protrudes on the transport path of the paper P by a coil spring (not shown).

  The end of the lever 71 opposite to the end that contacts the paper P is formed so that its tip can enter a gap (not shown) provided in the sensor 72 as shown. Here, the sensor 72 has a light emitting part (not shown) and a light receiving part (not shown), and radiated light from the light emitting part to the light receiving part can be blocked by the tip of the end extending from the lever 71. Thus, the lever 71 rotates to detect the passage of the front end or the rear end of the paper P.

  Next, on the downstream side of the first roller pair, the recording head 100 is provided on the upper side of the paper conveyance path, and the platen 65 is provided on the lower side of the paper conveyance path so as to face the recording head 100. Here, the sheet conveyance path in the recording unit 11 has an inclination angle as illustrated, and in the present embodiment, the sheet conveyance path is configured to have an inclination angle of about 60 ° with respect to the horizontal plane. . Accordingly, the platen 65 and the recording head 100 are provided in an inclined posture as illustrated. The recording head 100 is provided below the carriage 101, and the carriage 101 is provided so as to pass through a carriage guide shaft 103 extending in the main scanning direction (front and back direction in FIG. 2), and is guided by the carriage guide shaft 103. Receiving power from a driving means (not shown) reciprocates in the main scanning direction.

In the platen 65, a platen surface (a surface facing the recording head 100 in the platen 65) 65c protrudes toward the recording head 100 and extends in the sub-scanning direction (vertical direction in FIG. 3) as shown in FIG. Ribs 65a and second ribs 65b (hereinafter collectively referred to as “ribs” as appropriate) are formed at predetermined intervals in the main scanning direction, and the sheet P has a distance from the recording head 100 by the ribs. Be regulated. The platen 65 is formed with a long hole 65e extending in the main scanning direction. The long hole 65e is provided to more appropriately detect the size (width dimension) of the paper P. That is, an optical sensor (not shown) that detects a reflection component of light emitted toward the platen 65 is provided on the surface of the carriage 101 that faces the platen 65, and the reflectance between the paper P and the platen 65 is provided. By using the difference, the width dimension of the paper P can be detected. However, when the paper P and the platen 65 are the same color, the width dimension of the paper P cannot be detected appropriately. Therefore, in the present embodiment, the radiated light is radiated toward the long hole 65e, thereby making it possible to detect the width dimension of the paper P more accurately.
Note that the rib is divided into the upstream side and the downstream side by the elongated hole 65e, so that the first rib 65a located near the downstream side of the first drive roller 28 and the downstream side of the first rib 65a are located. The second rib 65b constitutes a rib for supporting the paper P.

  In addition, an auxiliary rib 65d extending in the sub-scanning direction is provided between two adjacent ribs, and the protruding height from the platen surface 65c is lower than that of the rib 65b. Therefore, the valley portion of the cock ring formed on the paper P is supported by the auxiliary rib 65d between the two adjacent ribs, and the degree of depression of the valley portion is reduced and the PG is made uniform. Further, it is possible to prevent the recording quality from being deteriorated, and the valley portion does not come into contact with the platen surface 65c contaminated by the scattering of the ink mist. Therefore, the surface opposite to the recording surface can be prevented from being stained. .

  Next, when the sheet P is lifted from the platen 65 in the recording unit 11, the recording quality deteriorates due to the sheet P rubbing against the recording head 100 or the distance from the recording head 100 (paper gap: PG). To do. In particular, in the present embodiment, the sheet reversing unit 4 is configured to be able to record the sheet P on the second surface by curving and reversing the sheet P recorded on the first surface. There is a case where the sheet P on which the recording is performed tends to be warped in a bowl shape so that the sheet P is convex with the first side facing up. In this case, when the second surface and the recording head 100 face each other, the side edge or the tip of the second surface is lifted from the platen 65, which may cause head rubbing or PG change. Therefore, in order to prevent the sheet P from being lifted from the platen 65, a pressing member 82 is provided. The pressing member 82 is provided so as to be swingable when viewed from the side of the paper transport path, and is configured to press the paper P toward the platen 65 by an urging means (not shown). Therefore, the undulating shape in the main scanning direction is formed by the pressing member 82 and the first rib 65a, and the side end portion is curved (curled) toward the platen surface 65c. This improves the apparent rigidity of the paper P, prevents head rubbing and PG changes, and prevents the recording quality from deteriorating.

  Next, returning to FIG. 2, the carriage 101 is not mounted with an ink cartridge in this embodiment, and an ink tube (not shown in FIG. 2) is displayed from the ink cartridge 105 mounted on the ink cartridge mounting frame 110. Ink is supplied to the recording head 100 via the. Each color ink cartridge 105 is mounted with an IC chip 107 that holds information about each ink cartridge. The IC chip 107 has a built-in storage device that stores fixed information such as ink color, as well as fluctuation information such as the remaining amount of ink. Each IC chip 107 is connected to a receiving antenna (not shown). On the other hand, a carriage 101 that reciprocates in the main scanning direction has a transmitting antenna (not shown) that transmits a radio signal to the receiving antenna. The antenna substrate 109 provided with () is erected substantially vertically.

  The antenna substrate 109 is opposed to the IC chip 107 of one ink cartridge 105 among a plurality of ink cartridges 105 arranged in the main scanning direction when the carriage 101 moves in the main scanning direction. To do. By communicating with the IC chip 107, various information stored in the IC chip 107 can be transmitted to a control unit of the printer 1 (not shown).

  Next, a second roller pair is provided on the downstream side of the recording head 100, and the paper P on which recording has been performed by the recording head 100 is conveyed downstream by the rotation of the second roller pair. Further, an auxiliary roller 35 is provided on the upstream side of the second roller pair, thereby further preventing the sheet P from being lifted from the platen 65. The second driven roller 33 and the auxiliary roller 35 are in contact with the recording surface of the paper P on which the ink droplets are ejected. Therefore, the second driven roller 33 and the auxiliary roller 35 are toothed to make point contact with the recording surface to prevent ink transfer and white spots. It is composed of rollers.

  Here, as shown in FIG. 3, the second roller pair is arranged such that the arrangement position in the main scanning direction coincides with the rib formation position. In addition, among the plurality of auxiliary rollers 35, the auxiliary roller indicated by the reference numeral 35 c is positioned so as to be approximately in the middle of two adjacent ribs and is in contact with the recording surface of the paper P. The contact point is provided so as to be located slightly below the top of the rib (that is, overlaps with the rib as viewed from the side of the sheet conveyance path). Therefore, when the paper P swells by absorbing ink droplets, the stretched portion escapes between two adjacent ribs, and as a result, a regular wavy state (cockling) is formed on the paper P. Is done. That is, a cock ring is formed which has a crest at the rib position and a trough at the auxiliary roller 35c, thereby making the distance between the paper P and the recording head 100 extremely uneven, or between the rib and the rib. Thus, the problem that the paper P is lifted and rubbed against the recording head 100 is prevented. In addition, the apparent rigidity in the transport direction is increased by the formation of the cock ring, and even if the front tension is generated, the effect that the paper P does not easily lift (is difficult to bend) in the recording head 100 can be obtained. .

  Next, a third roller pair including a third drive roller 36 and a third driven roller 37 is provided downstream of the second roller pair. The third roller pair functions to assist the sheet conveying force exerted by the upstream second roller pair to reliably convey the recorded sheet P to the downstream side, and between the second roller pair. By forming a curved posture on the paper P, the paper P is smoothly bent and reversed.

[Face Down (Fd) Discharge Unit 5]
Next, the Fd discharge unit 5 provided on the downstream side of the recording unit 11 includes a bending roller 37, an Fd discharge drive roller 41, and an Fd discharge driven roller 43, and the recording of the paper P on which recording has been performed. By reversing the curve with the surface facing inward, the paper P is discharged with the recording surface down.
More specifically, on the downstream side of the third roller pair, the sheet P conveyed from the recording unit 11 by the third roller pair is switched to either the face-down (Fd) discharge path or the face-up (Fu) discharge path. An Fd / Fu switching member 503 is provided. The Fd discharge route is a paper discharge route for discharging the paper P from the Fd paper discharge port 500 (FIG. 1), and the Fu discharge route is a paper discharge route for discharging from the Fu paper discharge port 600 (FIG. 1).

  The Fd / Fu switching member 503 switches the traveling direction of the paper P sent from the recording unit 11 to the downstream side by swinging about the swing shaft 503a. The Fd / Fu switching member 503 is provided outside the curve reversal path in the Fd discharge path, and the sheet P is curved and reversed by the curved surface 503b.

  FIG. 2 shows a state in which the Fd / Fu switching member 503 switches the traveling direction of the paper P sent from the recording unit 11 to the downstream side to the Fd discharge path. The leading edge of the paper P sent from the recording unit 11 to the downstream side comes into contact with a smooth curved surface 503 b formed on the Fd / Fu switching member 503. The leading edge of the sheet P advances while contacting the curved surface 503b and the guide member 505 provided on the downstream side of the curved surface 503b, and is eventually nipped by the Fd discharge driving roller 41 and the Fd discharge driven roller 43, By rotation, the paper is discharged from the Fd paper discharge port 500 (FIG. 1) toward the front of the apparatus (the direction indicated by the arrow “Fd”).

  Note that the stack lever 509 is disposed near the side edge position of the paper P (in this embodiment, the side edge positions of the A4 size and B5 size) at the paper discharge port 500. The stack lever 509 is attached so as to be swingable about the rotation shaft 41 a of the Fd discharge driving roller 41, and functions to hold down the paper P discharged from the Fd paper discharge port 500 from above.

  When the paper P is discharged through the Fd discharge path, the paper P is bent into a substantially U shape with the recording surface inside and discharged. Accordingly, when the paper is discharged while proceeding through the Fd discharge path, the sheets P stacked on the paper discharge stacker 150 (FIG. 1) are stacked in order in the page order, which is convenient for the user. improves.

[Face-up (Fu) discharge unit 6]
The Fu discharge section 6 provided downstream of the recording section 11 and at the rear portion (right side in FIG. 2) of the apparatus main body 1a includes a Fu discharge drive roller 45, a Fu discharge driven roller 47, and a Fu auxiliary roller 49. I have. When the paper P is discharged through the Fu discharge path, the Fd / Fu switching member 503 swings clockwise from the state shown in FIG. 2 (not shown). As a result, a sheet conveyance path is formed in which the sheet P sent from the recording unit 11 to the downstream side proceeds straight and obliquely upward, and the sheet P sent from the recording unit 11 to the downstream side is connected to the Fu discharge drive roller 45 and Fu. The paper is nipped by the discharge driven roller 47 and is discharged from the Fu paper discharge port 600 (see FIG. 1) toward the rear of the apparatus (in the direction indicated by the arrow “Fu”) by the rotation of the Fu discharge driving roller 45.

  When the sheet P is discharged through the Fu discharge path, the sheet P is not formed in a curved state, and is discharged substantially straight from the recording unit 11 with the recording surface up. Therefore, by using the above Fu discharge path, it is possible to record easily and appropriately discharge even thick paper and stiff paper.

[Paper Inversion Section 4]
Returning to FIG. 1, the sheet reversing unit 4 provided at the rear portion of the printer 1 includes a roller group constituting the Fu discharge driving roller 45 and the Fu discharge unit 6 such as the Fu discharge driven roller 47 described above, and further includes a guide. A driving roller 51, a movable guide driven roller 52, a feed driving roller 53 and a feed driven roller 54, a curve reversing portion driving roller 55, a curve reversing portion driven roller 57, and a reversing path forming roller 59; Yes. The sheet reversing unit 4 records the sheet P so that the unrecorded surface (second surface) and the recording head 100 face each other by reversing the curve of the sheet P with the recorded surface (first surface) inside. Guide to section 11 again.

  That is, as shown in FIG. 5, the sheet reversing unit 4 presses the rear end portion of the sheet P that has traveled through the Fu discharge path so as to be substantially along the vertical direction, and the Fu discharge drive roller 45 and the guide drive roller. By rotating and driving 51 in the counterclockwise direction in the drawing, the paper P is drawn into the paper reversing unit 4 without being completely discharged in the direction indicated by the reference symbol Fu (the direction indicated by the reference symbol R).

  Then, the sheet P is fed to the downstream side by the feed driving roller 53 and the feed driven roller 54, and the sheet reversing section is formed by reversing the sheet P by the curve reversing path portion formed by the reversing path forming roller 59 and the guide member 413. The drive roller 55 and the curved reversing portion driven roller 57 feed the paper P further downstream. The sheet P sent in this way has the second surface facing the recording head 100, whereby double-sided recording on the sheet P is executed. In this embodiment, the sheet P that has passed through the sheet reversing unit 4 passes through the above-described Fu discharge path (Fu discharge unit 6) and is discharged in the direction indicated by Fu.

[Control unit 160]
The control unit 160 of the printer 1 as the “transport time control unit” is configured to be able to transmit and receive data to and from the host computer 700 that transmits recording data to the printer 1, and is an interface unit with the host computer 700 ( (Hereinafter referred to as “IF”) 161, ASIC 162, RAM 163, PROM 164, EEPROM 165, CPU 166, timer IC 167, DC unit 168, PF motor driver 169, CR motor driver 171, and head driver 170.

  The CPU 166 performs arithmetic processing for executing the control program of the printer 1 and other necessary arithmetic processing, and the timer IC 167 causes the CPU 166 to generate periodic interrupt signals necessary for various processing. The ASIC 162 controls recording resolution, a driving waveform of the recording head 100, and the like based on print data transmitted from the host computer 700 via the IF 161. The RAM 163 is used as a work area for the ASIC 162 and the CPU 166 and a primary storage area for other data. The PROM 164 and the EEPROM 165 store control programs (firmware) necessary for controlling the printer 1 and data necessary for processing. Has been.

  The PF (paper feed) motor driver 169 controls the driving of the PF motor 172 under the control of the DC unit 168, so that a plurality of driving objects, that is, the first driving roller 28, the second driving roller 32, and the third driving roller 36 are controlled. , The drive roller group R as “conveying means” including the Fd discharge drive roller 41, the Fu discharge drive roller 45, the guide drive roller 51, the feed drive roller 53, and the curve reversal unit drive roller 55 is rotated. The CR motor driver 171 drives the CR motor 180 under the control of the DC unit 168 to reciprocate the carriage 101 in the main scanning direction, or stop and hold the carriage 101. The head driver 170 drives and controls the recording head 100 according to the print data transmitted from the host computer 700 under the control of the CPU 166.

  In the CPU 166 and the DC unit 168, the detection signal from the paper detector 70 that detects the start and end of the conveyed paper P and the output from the rotary encoder 174 that detects the rotation amount of the first drive roller 28 are detected. A signal and an output signal from the linear encoder 173 that detects the absolute position of the carriage 101 in the main scanning direction are given.

The rotary encoder 174 is attached to a gear (not shown) that transmits power from the PF motor 172 to the first drive roller 28, and has a disk-like scale (not shown) having a number of slits (not shown) on the outer periphery. A light-emitting unit that emits light with respect to the slit, and a detection unit (not shown) that includes a light-receiving unit that receives the light that has passed through the slit. The detection unit outputs a rising signal and a falling signal formed by light passing through the slit. The control unit 160 receives the output signal from the rotary encoder 174 as described above, thereby calculating the rotation amount and rotation speed of the drive roller group R, thereby calculating the conveyance amount of the paper P. In addition, the target control can be executed.
The above is the overall configuration of the printer 1.

<Detailed Configuration of Paper Reversing Unit 4>
Next, a more detailed configuration of the sheet reversing unit 4 will be described with reference to FIG. 5 and other drawings as appropriate. Here, FIG. 5 is a schematic side sectional view of the sheet reversing unit 4. In FIG. 5, on the downstream side of the third drive roller 36, there is provided a Fu / R first switching member 401 that pivotally supports the movable guide driven roller 52 made of a toothed roller so as to be freely rotatable. A Fu / R second switching member 405 is provided at a position facing the first switching member 401. The Fu / R first switching member 401 is provided so as to be swingable around a swing center (not shown), and the movable guide driven roller 52 is separated from the guide drive roller 51 (not shown), and the guide drive roller The state in contact with 51 (the state shown in FIG. 5) can be changed by a drive mechanism (not shown). The Fu / R second switching member 405 is provided so as to be swingable about the rotation center of the Fu discharge drive roller 45, and is substantially perpendicular to an inclined posture (not shown) (state shown in FIG. 5). And can be changed by a drive mechanism (not shown).

With the above configuration, the sheet P travels along the Fu discharge path, and after the trailing edge of the sheet P (the trailing edge during the first surface recording) passes through the guide member 501, the rotation direction of the PF motor 172 (FIG. 4) is changed. Switch. Accordingly, the Fu / R first switching member 401 and the Fu / R second switching member 405 are in the state shown in FIG. 5, and the rear end portion of the sheet P is the guide driving roller 51 and the movable guide driven roller 52. The Fu discharge drive roller 45 is switched from normal rotation to reverse rotation, and the sheet P receives the conveying force of the Fu discharge drive roller 45 and the guide drive roller 51 and receives the rear end of the sheet P (first surface recording). Proceed vertically downward with the trailing edge of the hour as the leading edge.
Note that the paper P traveling through the paper reversing unit 4 has a traveling direction opposite to that during recording on the first side. That is, the side that was the leading edge during recording on the first surface is the trailing edge side, and the side that was the trailing edge is the leading edge side. R) '' and the rear end side to ``
It is described as “paper P rear end (R)”.

Subsequently, when the leading end (R) of the paper P further advances downstream in FIG. 5, the rotationally driven feed disposed downstream of the guide driving roller 51 and on the second surface (unrecorded surface) side. The leading end (R) of the sheet P is nipped by the driving roller 53 and the feed driven roller 54 disposed on the first surface (recorded surface) side, which is driven to rotate in contact therewith, and further proceeds downstream. Here, the feed drive roller 53 that is rotationally driven on the second surface side is disposed, so that the recording quality of the first surface is prevented from deteriorating. Further, since the feed driven roller 54 in contact with the first surface is a toothed roller having teeth on the outer periphery, problems such as ink whitening and transfer can be prevented.

  Further, as shown in FIG. 3, the feed driving roller 53 (and the feed driven roller 54) is aligned with the positions of the ribs 65a and 65b formed on the platen 65, that is, in the cockling state formed on the paper P. Arranged according to the period. Accordingly, an excessive force is not applied to the paper P, and the paper P can be appropriately sent downstream in a natural state.

  Next, on the downstream side of the feed drive roller 53, a large-diameter reverse path forming roller 59 is provided inside the curved reversal portion, and the outer peripheral surface 59a of the reverse path forming roller 59 and the curved reversal portion A curved portion of the curved inversion path is formed by the concave curved surface 413a of the guide member 413 provided on the outside. Here, the reverse path forming roller 59 is a roller having a smooth outer peripheral surface 59a, and is provided so as to be driven to rotate.

  This is due to the following reason. That is, in order to invert the first surface on which ink jet recording has already been performed in order to make the second surface face the recording head 100, the first surface is in contact with the first surface. There is a risk of scratching one surface. In particular, when performing high-quality color ink jet recording, it is easily noticeable, and there is a risk of causing whitening or transfer of ink.

Further, in a state where the leading end (R) of the paper P is not nipped between the first driving roller 28 and the first driven roller 29, the paper P receives the driving force of the feed driving roller 53, and the concave curved surface outside the curved reversal portion. Proceeding downstream in contact with 413a. However, the leading edge (R) of the paper P is the first drive roller 28.
And the first driven roller 29, the leading end (R) of the paper P is pulled by the pair of rollers, so that it is in strong contact with the inside of the curved reversal portion, and the recording quality of the first surface is further reduced. Easy to invite. However, as described above, the reversing path forming roller 59 inside the curved reversing portion is driven to rotate, thereby preventing the recording quality of the first surface from being deteriorated. In addition, the outer peripheral surface 59a is smooth, and this also prevents deterioration in recording quality.

  Incidentally, a plurality of reverse path forming rollers 59 are provided in the width direction of the paper P, but as shown in FIG. 3, the reverse path forming rollers 59 are provided at substantially intermediate positions of the ribs 65 a formed on the platen 65. This is because the paper P has a regular cockling state in which the rib 65a portion is a crest and the recording portion auxiliary roller 35b is a trough as described above, but such a cockling state is formed. When the curved sheet P is bent and reversed, the crest portion is strongly in contact with the inside of the bent portion and the recording quality is likely to deteriorate. Accordingly, the reverse path forming roller 59 is disposed in the valley portion of the cockling state on the first surface where recording has already been performed, thereby preventing strong contact with the reverse path forming roller 59 on the first surface. The recording quality is prevented from being deteriorated.

Subsequently, on the side facing the reverse path forming roller 59, a curved reversing portion driving roller 55 that is rotationally driven is provided, and between the reverse path forming rollers 59 (intermediate position), the curved reversing portion driving roller. A curved reversing portion driven roller 57 that rotates in contact with 55 is provided in a state of being biased toward the bending reversing portion drive roller 55 by a biasing means (not shown). The paper P sent by the upstream feed driving roller 53 and the feed driven roller 54 is further nipped by the leading end (R) of the paper P by the curved reversing portion driving roller 55 and the curved reversing portion driven roller 57. Proceed downstream.

Here, the curve reversing unit driven roller 57 is provided so as to be lightly in contact with the curve reversing unit driving roller 55 by an urging means (not shown) as described above, and is in a state of being in contact with the curve reversing unit driving roller 55 and a state of being separated therefrom. It is provided so that it can be taken. On the other hand, the leading end (R) of the paper P is later nipped between the first drive roller 28 and the first driven roller 29 and conveyed to the recording head 100, but is caused by the first drive roller 28 and the first driven roller 29. The conveyance force of the paper P is stronger than that of other roller pairs. Accordingly, when the leading end (R) of the sheet P is nipped between the first drive roller 28 and the first driven roller 29, the leading end (R) of the sheet P is pulled, so that the curved reversing portion driven roller 57 is urged. It separates from the curve inversion part drive roller 55 against the urging force.

Here, the reverse path forming roller 59 is provided so as to be displaceable in a direction orthogonal to the rotation axis direction without providing the curved reverse part driven roller 57, and the reverse path forming roller 59 is directly connected to the curved reverse part drive roller 55. It is also possible to configure so as to contact. However, in this case, when the leading edge (R) of the paper P is pulled, the reverse path forming roller 59 is displaced, the shape of the curved reverse path changes, and there is a problem that a stable transport operation of the paper P cannot be realized. . However, in this embodiment, the reversing path forming roller 59 is provided so as not to be displaced in a direction orthogonal to the rotation axis direction, and a curved reversing portion driven roller 57 is separately provided, thereby reversing the paper P in a curved manner. Since it is configured to be conveyed while being nipped with the part drive roller 55, the curve reversal path is kept constant and stable while appropriately protecting the first surface (recorded surface). It is possible to realize the transporting operation of the paper P.

Further, the curved reversing portion driven roller 57 is not a toothed roller, but a roller having a smooth surface that is in surface contact with the paper P. This is because the curved reversing portion driven roller 57 is provided with the paper P inside the curved reversing path, so that the leading end (R) of the paper P is nipped between the first driving roller 28 and the first driven roller 29 as described above. This is because the first surface may come into strong contact with the curved reversing portion driven roller 57 to reduce the recording quality. Further, the curved reversing portion drive roller 55 that is driven to rotate is in contact with the unrecorded surface (second surface), and the curved reversing portion driven roller 57 that is driven to rotate is in contact with the recorded surface (first surface). No rotational driving force is applied to the first surface, and this also protects the first surface. That is, if a roller (for example, a rubber roller) that is driven to rotate comes into contact with the first surface, scratches or the like may be imparted and the recording quality of the first surface may be degraded.

  As shown in FIG. 3, the curved reversing portion driven rollers 57 are arranged near the positions on both sides of the paper P, and the number of the curved reversing portion driven rollers arranged therebetween may be minimized. Is preferred. In the present embodiment, the curved reversing portion driven rollers indicated by reference numerals 57a and 57d are positioned at both ends of the A4 size paper P, and the curved reversing portion driven rollers indicated by reference numerals 57b and 57d are provided on both sides of the B5 size paper P. Located at the end. Further, the curved reversing portion driven roller indicated by reference numeral 57 c is positioned between the curved reversing portion driven rollers disposed on both side ends of the paper P. As a result, even if a tendency of warping occurs on both side edges due to recording on the first surface of the paper P, the both side edges are nipped by the curve reversing part driving roller 55 and the curve reversing part driven roller 57. In addition to reducing the tendency to warp, the paper P can be smoothly transported to the downstream side, and the transport load when transporting the paper P by the first driving roller 28 and the first driven roller 29 on the downstream side is reduced. And good recording results can be obtained.

  By the way, the curved reversing portion is provided with a driven roller (curved reversing portion driven roller 57) that comes into surface contact with the side that contacts the already recorded surface (first surface). On the side in contact with the first surface, a toothed roller (guide driven roller 54) having teeth on the outer periphery and in point contact with the first surface is provided. In this way, a toothed roller is used in the linear path portion and a surface contact roller is used in the curved reversal path portion, so that the upstream linear path portion, i.e., the portion where ink droplets may not be dried is used. While preventing problems such as white spots and transfer, the curved reversal part on the downstream side, that is, the part where the drying of ink droplets has progressed, and the part that touches more strongly due to the curving reversal, prevents damage to the recorded surface and records quality. Can be prevented.

Subsequently, when the leading edge (R) of the paper P further moves downstream, the lever 71 of the paper detector 70 is pushed away, whereby the paper detector 70 detects the passage of the leading edge (R) of the paper P. At this point
Since the first drive roller 28 is driven to rotate in a direction to return the paper P to the upstream side, the rotation direction of the PF motor 167 is switched when the paper detector 70 detects the passage of the front end (R) of the paper P. . As a result, the leading edge (R) of the sheet P is nipped between the first drive roller 28 and the first driven roller 29. When the leading edge (R) of the sheet P is slightly cueed from the first driving roller 28 and the first driven roller 29 (for example, about 3 mm), the rotation direction of the PF motor 167 is switched to change the first driving roller 28. Is driven reversely to discharge the leading edge (R) of the paper P to the upstream side of the first drive roller 28 and the first driven roller 29. At this time, the bending reversing unit driving roller 55 is temporarily stopped due to the action of a driving mechanism (not shown), so that the paper P is restrained by the bending reversing unit driving roller 55 and the bending reversing unit driven roller 57. The leading edge (R) of the sheet P is discharged, and the skew of the sheet (skew) is corrected (skewing of the biting discharge type).

<Setting the waiting time for recording on the second side>
Next, the setting of the waiting time for recording on the second surface will be described in detail with reference to FIGS. Here, FIG. 6 is a side view of the paper conveyance path from the paper detector 70 to the second drive roller 32, FIG. 7 is a diagram for explaining the recording area at the trailing edge of the paper during the first surface recording, and FIG. FIG. 9 to FIG. 16 are flowcharts showing the operation contents at the time of double-sided recording, and FIGS. 9 to 16 are diagrams showing the setting contents of the waiting time for recording on the second side. In FIG. 7, for the sake of simplicity, the inclined paper conveyance path is drawn horizontally, but in actuality, the inclined paper conveyance path is as shown in FIG.

Here, the necessity of waiting time for recording on the second surface will be described. As described above, when ink jet recording is performed on the first surface of the paper P, the paper P is warped in a bowl shape so as to have a convex shape with the first surface up by absorbing ink and swelling. It is easy to become. If the second surface faces the recording head 100 in this state, the leading edge (R) of the paper P and the side edge of the paper may rub against the recording head 100, or the PG may be non-uniform, leading to a decrease in recording quality. . Therefore, the waiting time for recording on the second surface, more particularly in this embodiment the time T _w until the paper P tip from the time of the first surface recording end (R) reaches the first drive roller 28 By adjusting, the degree of deformation (warping) of the paper P described above is reduced. After that, by conveying the leading end (R) of the sheet P to the downstream side of the first drive roller 28, there is a problem that the sheet P and the recording head 100 at the time of the second surface recording are rubbed and the PG becomes extremely uneven. To prevent. That is, the above-mentioned time T _w according to the present invention, not just a time for waiting for the drying of the ink on the first surface, the degree of the deformation of the sheet P is deformed by absorbing the ink, significant at the second surface recording This is the time for waiting for the effect to be reduced to such an extent that it does not have an adverse effect (deterioration in recording quality due to head rubbing or PG nonuniformity).

It will be specifically described how to set the time T _w. In addition, the setting method of time Tw _demonstrated below is an example, and is not limited to this.
7, the region indicated by symbol A ₁ is the area at the first surface recording, code F, together with a sheet trailing end at the time of the first surface recording, shows a paper leading edge at the second surface recording . Therefore, as indicated by the arrows in the figure, the upper direction is the transport direction during the first surface recording, and the lower direction is the transport direction during the second surface recording. A region indicated by symbol A ₂ indicates a region of the length L ₁ from the trailing edge of the sheet F at the first surface recording. Further, reference numeral D _w represents the width of the paper P.

When recording is performed on the second surface after recording on the first surface of such a sheet P, the rear end at the time of recording on the first surface indicated by the symbol F becomes the leading edge, and the first drive as shown in FIG. The roller 28 and the first driven roller 29 are conveyed below the recording head 100. Therefore, the more the ink absorption in the region A _2, becomes significant degree of deformation of the sheet P in the first surface recording is completed, the smaller the ink absorption amount in the region A ₂ Conversely, the first surface recording is completed The degree of deformation of the paper P is reduced. Therefore, by setting the time T _w according to the ink absorption amount in the region A _2, while minimizing a decrease in throughput, the head rubbing prevention and PG of the sheet P at the time of the second surface recording (particularly the tip) It becomes possible to reduce the change.

Next, in this embodiment, the length L ₁ of the area A ₂ is the path length L ₃ shown in FIG. 6, that is, the transport path length from the paper detector 70 to the second roller pair. This is due to the following reason. First, the length _{L 1} of the region _{A 2,} it is desirable that the path length _{L 2} than shown in FIG. That is, the leading edge (R) of the sheet P causes the head rubbing or the like at the time of recording on the second side when the leading edge (R) of the sheet P is located between the first driving roller 28 and the second driving roller 32. thus corresponds to the path length L ₂ showing the meantime conveying path length in other words, some of the ink absorption in the region of the sheet P rear at the first surface recording, paper P tip (R during the second surface recording This is because it greatly affects the rubbing of the head.

Then, the above use the path length L ₃ as the length L ₁ of the region A ₂ in a possible first path length L ₃ in is the path length L ₂ or is the existing components in the second by using the paper detector 70, can be paper P rear paper detector 70 at the time of the first surface recording ask the amount of ink discharged from the through until the first surface recording end, i.e. the area a ₂ This is because the ink absorption amount can be easily obtained without providing any special component.

The following describes the timing of adjusting the time T _w with reference to FIG. In FIG. 8, when recording data is received from the host computer 700 (step S101), recording on the first surface is started (step S102). Next, when the trailing edge of the paper passes the paper detector 70 during the first side recording (step S103: affirmative branch), the ink ejection amount starts to be counted (step S104). Here, the ink discharge amount can be calculated by using a known method, for example, by multiplying the number of ink droplet discharges by a pre-measured weight per ink droplet. This is disclosed in Japanese Patent Laid-Open No. 2000-218817. Note ink ejection amount obtained here (milligrams: mg) is the amount of ink ejected in the area A ₂ shown in FIG.

Next, when the recording on the first surface is completed (step S105: affirmative branch), the sheet P that has been subjected to the sheet reversing operation, that is, the recording on the first surface, is drawn into the sheet reversing unit 4 as described above. Then, the paper reversing unit 4 conveys the paper with the side that was the rear edge when recording on the first surface as the front edge. And the point (R) of the paper P is indicated by a symbol S in FIG.
5 (Yes in step S107), the conveyance operation is temporarily interrupted (step S108), and when the time T has elapsed, the conveyance operation is started again (positive branch in step S109, step S110). ). Time T in step S109 is, (hereinafter referred to as "waiting time T") is the time for adjusting the above-mentioned time T _w. Then, after resuming the conveying operation, the above-described biting-out discharge type skew removal is performed (step S111), recording on the second surface is started (step S112), and the recording on the second surface is completed. A discharging operation is performed (Yes in step S113, step S114).

Thus, in the present embodiment, the time T _w until the paper P tip from the first surface recording is completed (R) reaches the first driving roller 28, the paper P tip (R) is the S point of Fig. 5 The waiting time T at the time of arrival is adjusted so as to set the optimum time. However, the waiting time T may be set at another point, or the sheet transport operation may be interrupted. without, it may be configured so as to adjust the time T _w by adjusting the paper transport speed.

The waiting time T is set as follows in the present embodiment. In the present embodiment, the waiting time T is set by the control unit 160 (FIG. 4) according to a predetermined condition in accordance with the ink discharge amount. _It functions as a conveyance time control means for controlling _w .

FIG. 9 shows a first embodiment for setting the waiting time T. In FIG. In the upper table, the symbol Q is obtained by dividing the ink discharge amount M _f (mg) in the area A ₂ of FIG. 7 by the paper width D _w (inch), that is, ink per unit width (1 inch) in the area A 2. Discharge amount. Hereinafter, this ink discharge amount is referred to as “reference ink discharge amount Q”. Further, the symbol _Qc is a predetermined constant ink discharge amount (threshold) (details will be described later), the symbol T is the waiting time (sec), and the symbol _Tc is a predetermined constant. (The details will be described later). Further, the symbol DR indicates a waiting time set by the user. Here, the waiting time DR by the user setting is a waiting time that can be arbitrarily set by the user on the printer driver 710 (FIG. 4) operating in the host computer 700, that is, the user can add an arbitrary waiting time DR. It can be done.

When the waiting time DR user settings (with user setting) if it is set will be described as an example, when the reference ink discharge amount Q is equal to or higher than the threshold Q _c (region indicated by circled numeral A) waits The time T is set to T _c + DR. When the time T is less than the threshold value Q _c (region indicated by a circled symbol B), the waiting time T is set to 0 + DR.

Here, the threshold value Q _c and waiting time T _c is the ink ejection amount and latency determined by experiment, when the reference ink discharge amount Q of the threshold Q _c, at least the waiting time latency T _Tc means that no head rubbing or the like occurs during the second surface recording. Therefore, it is desirable to change the threshold value _Qc and the waiting time _Tc according to the type and resolution of the paper P. In particular, when the paper P is a thick coated paper or the like, deformation (warping) due to ink swelling. Therefore, the waiting time _Tc can be set short. The threshold value Q _c and the waiting time T _c may be stored in a storage unit (eg, EEPROM 165) of the control unit 160, or may be held by the printer driver 710 of the host computer 700.

In the case where the waiting time DR set by the user is not set (no user configuration), the waiting time T when the reference ink discharge amount Q is equal to or greater than the threshold Q _c as shown in the table T _c, and the waiting time T is zero when the reference ink discharge amount Q is less than the threshold value Q _c.

FIG. 10 shows a second embodiment of setting the waiting time T. All the other symbols except the symbol Z in the figure are the same as those described in the first embodiment (hereinafter, the same applies to the third and subsequent embodiments), and the waiting time T is the same as that of the first embodiment in the region A. is there. However, in the area B, the waiting time T is set to the variable Z + DR (when user setting is present). That is, the reference ink discharge quantity Q when less than the threshold value Q _c, in proportion to the reference ink discharge amount Q, is intended to vary the waiting time T. Therefore, the variable Z is a straight line connecting 0 and T _c + DR as shown in the figure, and the equation representing this is as shown in the figure. As described above, since the waiting time T is changed according to the ratio of the reference ink discharge amount Q, it is possible to more reliably prevent head rubbing or the like during the second surface recording.

FIG. 11 shows a third embodiment of setting the waiting time T. In FIG. 11, a symbol _Qv is a threshold value of the ink discharge amount calculated (changes) each time according to a given condition, and a symbol _Tv is calculated (changes) each time according to a given condition. It is waiting time. More specifically, the type of paper P (thickness, material, etc.) by the like and printing resolution, even the reference ink discharge amount Q is equal to or more than the threshold value Q _c as described in Example 1, the waiting time T, again In some cases, it may be shorter than the waiting time _Tc shown in the first embodiment. That is, when the paper type and the printing resolution are different from the threshold value Q _c and the waiting time T _c obtained under certain conditions such as the paper type and the printing resolution, for example, when a thicker paper P is used. In other words, even when the ink discharge amount is the same, the degree of deformation generated in the paper P due to the absorption of the ink is small, so that the waiting time T can be shortened. In this case, by changing the threshold value and the waiting time according to the conditions such as the paper type and the printing resolution, it is possible to eliminate the useless waiting time and optimize (shorten) the throughput. Specifically, whether the waiting time _{T v} with the threshold _{Q v} is set higher than the threshold _{Q c} is the same as the waiting time _{T c,} or the threshold _{Q v} is the same as the threshold value _{Q c} as, shorten the waiting time _{T v} than waiting _{T c,} or to shorten the waiting time _{T v} than waiting _{T c} with higher setting than the threshold _{Q c} the threshold _{Q v} as shown in FIG. 11 I can think of three ways.

Incidentally, determined by the threshold _{Q v} variables m27 × 0.01 in the present embodiment As shown, the waiting time _{T v} is determined by the variable m22 × 0.01 in the present embodiment As shown in the figure. The variable m27 and the variable m22 are numerical values designated for each print job by the printer driver 710 (FIG. 4), and are calculated when the control unit 160 of the printer 1 receives print data from the host computer 700. Can do.

By the above, the region in the example shown in FIG. 11, showing when the latency DR set by the user is set, the reference ink discharge amount Q is in the calculated threshold Q _v or more in the case (circled A ), The waiting time T is set to T _v + DR. When the waiting time T is smaller than the threshold value Q _v (regions indicated by circled symbols B and C), the waiting time T is set to 0 + DR. In addition, when the waiting time DR by a user setting is not set, since it is as showing in figure, description is abbreviate | omitted.

FIG. 12 shows a fourth embodiment of setting the waiting time T. In this embodiment, the waiting time T of the areas A and C is the same as that of the first embodiment, but the waiting time of the area B is set to a variable Z + DR (when user setting is present). That is, the reference ink discharge amount Q is in the case and not less than the threshold value Q _c threshold Q _v smaller, in proportion to the reference ink discharge amount Q, is intended to vary the waiting time T. Therefore, the variable Z is a straight line connecting 0 and T _v + DR as shown in the figure, and the equation representing this is as shown in the figure. As described above, since the waiting time T is changed according to the ratio of the reference ink discharge amount Q, it is possible to more reliably prevent head rubbing or the like during the second surface recording. In addition, when the waiting time DR by a user setting is not set, since it is as showing in figure, description is abbreviate | omitted.

FIG. 13 shows a fifth embodiment for setting the waiting time T. In FIG. This embodiment also reference ink discharge amount Q is equal to or less than the threshold value Q _c as described in Example 1, inadequate zero as the waiting time T is Example 1, i.e., a certain waiting time An embodiment suitable for the paper P as required is shown. That is, when the paper type, the printing resolution, and the like are different from the threshold value Q _c and the waiting time T _c obtained under certain conditions such as the paper type and the printing resolution, for example, when the thinner paper P is used. In some cases, even if the ink discharge amount is the same, the degree of deformation generated in the paper P due to the absorption of ink is large, or a long time is required until the degree of deformation is reduced. In this case, therefore, the less space B from Q _c reference ink discharge amount Q is not more Q _v or more, as shown in this embodiment, by providing a constant waiting time different from the first embodiment, the second The head rubbing or the like during surface recording is surely prevented.

In the present embodiment, when the reference ink discharge amount Q is equal to or greater than Q _c (region A), but the waiting time T is set to the same T _c as in Example 1, the degree of deformation caused by absorption of ink In view of the remarkable properties, it is also effective to further increase the waiting time T in the region A. In addition, when the waiting time DR by a user setting is not set, since it is as showing in figure, description is abbreviate | omitted.

FIG. 14 shows a sixth embodiment of setting the waiting time T. In this embodiment, the waiting time T for the areas A and C is the same as that of the fifth embodiment, but the waiting time for the area B is set to a variable Z + DR (when user setting is present). Variable Z becomes a straight line connecting the T _v and T _{c +} DR As shown, the equation is as shown in FIG representative thereof. As described above, since the waiting time T is changed according to the ratio of the reference ink discharge amount Q, it is possible to more reliably prevent head rubbing or the like during the second surface recording. In addition, when the waiting time DR by a user setting is not set, since it is as showing in figure, description is abbreviate | omitted.

FIG. 15 shows a seventh embodiment for setting the waiting time T. FIG. This embodiment also reference ink discharge amount Q is equal to or less than the threshold value Q _c as described in Example 1 is unsuitable waiting time T is zero as in Example 1, further examples 1 An embodiment suitable for the paper P that is insufficient even in the waiting time _Tc is shown. That is, it is suitable for the paper P that requires a longer time until the degree of deformation is greater than the paper P to which the fifth embodiment is applied or the degree of deformation is reduced. Therefore, in this case, by longer than the waiting time T _c latency T _v and sets the threshold value Q _v as illustrated below the threshold Q _c, etc. rubbing head at the second surface recording Can be prevented. In addition, when the waiting time DR by a user setting is not set, since it is as showing in figure, description is abbreviate | omitted.

FIG. 16 shows an eighth embodiment for setting the waiting time T. FIG. In this embodiment, the waiting time T for the areas A and B is the same as that in the seventh embodiment, but the waiting time for the area C is set to a variable Z + DR (when user setting is present). As shown in the figure, the variable Z is a straight line connecting 0 and T _V + DR, and the equation representing this is as shown in the figure. As described above, since the waiting time T is changed according to the ratio of the reference ink discharge amount Q, it is possible to more reliably prevent head rubbing or the like during the second surface recording. In addition, when the waiting time DR by a user setting is not set, since it is as showing in figure, description is abbreviate | omitted.

Above in Examples 1 to 8 described, as a parameter representing some ink absorption in the region A ₂ shown in FIG. 7, is used the amount of ink discharged from the recording head 100 (liquid discharge amount), for example, recording duty (liquid ejection density) and in the region a _2, image data may be used shading, etc. (liquid ejection data) can be determined from the images. Further, as the sub-scanning direction length L ₁ of the region A _2, in the present embodiment is used the path length L ₃ from the paper detector 70 to the second driving roller 32 is not limited to this, for example, FIG. it may be used a path length L ₂ shown in 7.

DESCRIPTION OF SYMBOLS 1 Inkjet printer, 1a apparatus main body, 2 paper supply part, 3 option paper supply unit, 4 inversion part, 5 face down (Fd) discharge part, 6 face up (Fu) discharge part, 11 recording part, 28 1st drive roller , 29 First driven roller, 32 Second drive roller, 33 Second driven roller, 35 Auxiliary roller, 36 Third drive roller, 37 Third driven roller, 65 Platen, 70 Paper detector, 100 Inkjet recording head, 160 Control , 500 Fd outlet, 600 Fu outlet, 700 Host computer, P Printing paper

Claims (6)

The first surface is placed on the inner side so that the second surface opposite to the first surface on which recording is performed by the ink jet recording head that performs recording by discharging ink onto the recording medium. And a curve reversal path for reversing the recording medium,
The recording medium on which recording has been performed on the first surface reaches the upstream side of the inkjet recording head via the curved reversal path with the trailing edge at the time of recording on the first surface as the leading edge. Conveying means for conveying the recording medium;
By driving and controlling the conveying means, the leading edge of the recording medium at the time of the second surface recording is provided on the upstream side of the ink jet recording head from the end of the first surface recording, and nips the recording medium and and a conveying time control means for controlling the time T _w before reaching the first roller pair for conveying a recording medium to the downstream side by the rotation,
The transfer time control means, the ink discharge amount in the region of the length L ₁ from the recording medium the trailing end of the time of the first surface recording, or recording duty, or in accordance with the recording data, as for setting the time T _w Configured to,
A recording medium guide device characterized by the above. According to claim 1, wherein a length L _1, from the first roller pair, is arranged downstream of the ink jet recording head, the recording medium by and rotate nipping the recording medium made of record is the path length L ₂ or more to the second pair of rollers conveyed downstream,
A recording medium guide device characterized by the above. _{3. The} path length L _{3 according to} claim 2, wherein the length L ₁ is provided upstream of the first roller pair and detects a passage of the recording medium from a recording medium passage detection unit to the second roller pair. Is,
A recording medium guide device characterized by the above. In any one of claims 1 to 3, wherein the time T _w is set further according to the type of the recording medium,
A recording medium guide device characterized by the above. A recording apparatus configured to be able to execute recording on both surfaces of a recording medium, comprising the recording medium guide device according to any one of claims 1 to 4.
A recording apparatus. A liquid ejecting head for ejecting liquid onto the ejected medium;
A curve that inverts the medium to be ejected with the first surface inward so that a second surface opposite to the first surface on which liquid is ejected by the liquid ejecting head faces the liquid ejecting head. An inversion path,
The ejected medium on which the liquid is ejected on the first surface reaches the upstream side of the liquid ejecting head via the curved inversion path with the rear end at the time of the first surface liquid ejecting as a leading end. Conveying means for conveying the ejection medium to
By controlling the transporting means, the tip of the medium to be ejected at the time of the second surface liquid ejection is provided on the upstream side of the liquid ejecting head from the end of the first surface liquid ejection, and the medium to be ejected is nipped. and a conveying time control means for controlling the time T _w before reaching the first roller pair for conveying a jet medium to the downstream side by to and rotates,
The transfer time control means, the liquid discharge amount in the area of length L ₁ from the injection medium rear during the first surface liquid jet or liquid jet density, or in accordance with the liquid ejection data, the time T _w Configured to set,
A liquid ejecting apparatus.

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