Recording device and control method thereof

Abstract

To provide a technique advantageous for more suitably achieving double-sided printing.SOLUTION: A recording device includes: first conveyance means that conveys a recording medium; recording means that performs recording on a first surface of the recording medium conveyed by the first conveyance means and a second surface opposite to the first surface by discharging ink; second conveyance means that conveys the recording medium recorded by the recording means; and reverse conveyance means that reverses front and rear sides of the recording medium recorded on the first surface by the recording means and conveys the recording medium to the first conveyance means so as to perform recording on the second surface by the recording means. When the recording means performs recording on the second surface of the recording medium recorded on the first surface by the recording means by defining an end region on a conveyance direction upstream side when the recording means performs recording on the first surface as a first end region, the first conveyance means changes conveyance speed of the recording medium according to an ink discharge amount in the first end region.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a recording apparatus, particularly to a printer capable of double-sided printing. [Background technology]

[0002] 2. Description of the Related Art Recording devices, such as inkjet printers, are generally required to transport a recording medium (paper material such as a sheet) in an appropriate orientation to prevent misalignment of the recording position on the recording medium. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-245457 Summary of the Invention [Problem to be solved by the invention]

[0004] In the case of double-sided printing, where the front side of a recording medium is recorded and then the back side is recorded, the posture of the recording medium when recording the back side may change depending on the recording state of the front side, so further ingenuity is required to achieve more appropriate recording. Note that Patent Document 1 describes a platen structure that can suppress floating of the recording medium in a recording device, but does not recognize the above-mentioned problem in double-sided printing.

[0005] The present invention was made in response to the inventor's recognition of the above-mentioned problems, and aims to provide a technique that is advantageous for appropriately realizing double-sided printing. [Means for solving the problem]

[0006] One aspect of the present invention relates to a recording device, the recording device comprising: a first conveying means for conveying a recording medium; a recording means for ejecting ink onto a first surface of the recording medium conveyed by the first conveying means and onto a second surface opposite to the first surface, and a second conveying means for conveying the recording medium recorded by the recording means; a reversing conveying means for reversing the recording medium on which recording has been performed on the first side by the recording means, and conveying the recording medium to the first conveying means so that recording can be performed on the second side by the recording means, an end area on the upstream side in the transport direction when the recording means records on the first surface is defined as a first end area; When the recording means records on the second side of the recording medium recorded on the first side, the first transport means changes the transport speed of the recording medium according to the ink ejection amount in the first end area. It is characterized by: [Effects of the Invention]

[0007] According to the present invention, double-sided printing can be appropriately achieved. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing an example of the internal structure of a recording apparatus according to an embodiment. [Figure 2] FIG. 3 is a schematic cross-sectional view of the recording apparatus for explaining a transport path. [Figure 3] FIG. 1 is a block diagram showing an example of the system configuration of a recording apparatus. [Figure 4] FIG. 2 is a schematic side view showing the configuration of a recording unit of the recording apparatus. [Figure 5] 5A and 5B are schematic diagrams for explaining recording areas on the front and back sides of a sheet. [Figure 6] 10 is a flowchart showing an example of a recording control method. [Figure 7] 5A and 5B are schematic diagrams showing an example of a method for evaluating the amount of ink ejected in the rear end area of ​​the front surface. [Figure 8] 5A and 5B are schematic diagrams showing recording modes in normal mode and low-speed mode. [Figure 9] FIG. 10 is a diagram for explaining a waiting time until the start of recording. [Figure 10]6 is a timing chart for explaining the relative relationship between the changes in the sheet conveying speed and the scanning speed of the print head during one scanning print. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the claimed invention. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0010] First Embodiment <Overall configuration of the recording device> FIG. 1 is a perspective view showing an example of the internal structure of a recording device 50 according to the first embodiment. In this embodiment, the recording device 50 is an inkjet printer equipped with a recording head 5 that records by ejecting ink onto a recording medium. "Recording" here refers to forming an image using ink ejected onto a recording medium, and the concept of an image includes letters, numbers, symbols, figures, photographs, etc., as well as the spaces that may be formed between them. A typical example of a recording medium is paper, such as a cut sheet, which will be referred to simply as a sheet in the following description.

[0011] Here, to facilitate understanding of the device structure, the drawings show X, Y, and Z directions that intersect or are substantially perpendicular to one another (the same applies to other drawings described below). The X direction corresponds to the left-right direction or width direction, the Y direction corresponds to the front-rear direction or depth direction, and the Z direction corresponds to the up-down direction or height direction.

[0012] The recording device 50 further includes a paper feed roller 1, a first conveying roller 2, a pinch roller 3, a platen 4, a second conveying roller 6, spurs 7a and 7b, guide rails 8 and 9, a carriage 10, a recovery unit 11, a paper feed section 51, and a paper discharge section 52.

[0013] 2(a) and 2(b) are cross-sectional views illustrating the sheet transport path of the recording device 50. The recording device 50 further includes a sheet sensor 12, a relay roller 13, a leading edge detection sensor 91, and a code wheel 92.

[0014] Sheets are placed in the paper feed section 51, and if there are two or more sheets, they are stacked in the paper feed section 51. The paper feed roller 1 can receive the sheets placed in the paper feed section 51 one by one from the paper feed section 51 and supply them into the device main body.

[0015] The transport roller 2 is disposed upstream of the recording head 5 (the side along the sheet transport direction is referred to as the upstream side, and the opposite side is referred to as the downstream side), and is a drive roller that rotates by receiving power from a power source such as an electric motor. The transport roller 2 can transport a sheet supplied from a paper supply unit 51 by a paper supply roller 1 to the recording head 5. The pinch roller 3 is a driven roller that is disposed so as to abut against the transport roller 2, and pinches the supplied sheet together with the roller 2. In this way, the transport roller 2 and pinch roller 3 transport the supplied sheet to the recording head 5.

[0016] The platen 4 is disposed opposite the recording head 5 and supports the sheet to be recorded on from the side opposite the recording head 5 .

[0017] Here, the recording head 5 is mounted on a carriage 10 that is slidable in the X direction by guide rails 8 and 9. The carriage 10 receives power from a power source such as an electric motor and can move back and forth in the X direction along the guide rails 8 and 9, thereby causing the recording head 5 to scan in the X direction. During this scanning, the recording head 5 can perform recording on a sheet based on recording data. In this embodiment, an operation (intermittent conveyance) in which the conveyance roller 2 (and incidentally the conveyance roller 6) conveys the sheet by a predetermined amount to suppress the conveyance, and an operation (scanning recording) in which the recording head 5 records on the sheet by scanning while the conveyance is suppressed, are alternately performed. By repeating such intermittent conveyance and scan recording, recording is performed on the entire sheet. Such a recording head 5 is also referred to as a serial head, and the recording head 5, platen 4, and carriage 10 (and incidentally the guide rails 8 and 9) in this configuration may be collectively referred to as a recording unit.

[0018] The recovery unit 11 is disposed at the end of the movable range of the recording head 5 by the carriage 10, and can perform recovery processing of the recording head 5 outside the area where recording on a sheet is performed. An example of the recovery processing is a suction processing that removes air bubbles and thickened ink inside the recording head 5 by suction, thereby recovering the function of the recording head 5. The concept of function recovery also includes maintaining the function of the recording head 5, and for example, the recovery processing may be a process of preliminary ejection of ink from the recording head 5.

[0019] The leading edge detection sensor 91 is disposed upstream of the conveying roller 2 and can detect the leading edge of the sheet (the downstream edge of the sheet). A known mechanical or optical sensor can be used for the leading edge detection sensor 91. The code wheel 92 is provided as part of an encoder (not shown), and for example, an optical sensor detects the amount of rotation of the code wheel 92, thereby making it possible to calculate or identify the conveyance amount of the sheet. With this configuration, after the leading edge of the sheet is detected by the leading edge detection sensor 91, it is possible to calculate or identify the position of the leading edge of the sheet based on the detection result of the optical sensor.

[0020] <For single-sided printing> When recording is performed only on the front surface (one side or first side) of the sheet (so-called single-sided printing), the sheet on which recording has been completed by the recording head 5 is discharged directly to the paper discharge section 52 by the conveying rollers 6 described below, as shown in Figure 2(a).

[0021] A conveying roller 6, which is driven in the same manner as the conveying roller 2, and rotatable spurs 7a and 7b are arranged downstream of the recording head 5. The spurs 7a and 7b are grooved rollers configured to reduce the contact area with the sheet recorded by the recording head 5, and their rolling surfaces have, for example, an uneven shape. The spur 7a is arranged downstream of the spur 7b, and the conveying roller 6 is arranged opposite the spur 7a (see FIG. 4). The spur 7b is arranged between the recording head 5 and the conveying roller 6, and it restricts the sheet, which may lift off the platen 4 during recording, toward the platen 4, directing the conveying direction of the sheet to between the conveying roller 6 and the spur 7a. The conveying roller 6, in cooperation with the spur 7a, ejects the recorded sheet to the paper ejection unit 52.

[0022] The sheet sensor 12 is arranged to be able to detect whether or not a sheet to be conveyed has reached the conveying roller 2 (presence or absence of a sheet), and the drive control of the conveying rollers 2 and 6 can be performed based on the detection result of the sheet sensor 12. In the following description, the conveying roller 2 and the conveying roller 6 may be referred to as the upstream conveying roller 2 and the downstream conveying roller 6, respectively, for the sake of distinction.

[0023] The sheet whose front side has been recorded in this way is further conveyed by the downstream conveying roller 6 while being regulated by the spurs 7 a and 7 b , and is then discharged to the paper discharge unit 52 .

[0024] <For double-sided printing> On the other hand, when recording is also performed on the back side (other side or second side) of the sheet (in the case of so-called double-sided printing), the sheet is conveyed to relay rollers 13 by rotating conveying rollers 2 (and, incidentally, conveying rollers 6) in the reverse direction, as shown in Fig. 2(b). In this embodiment, another conveying path different from the conveying path from the paper feed rollers 1 to the upstream conveying rollers 2 is provided upstream of the conveying rollers 2 as a reverse conveying path, and relay rollers 13 are arranged on the reverse conveying path as part of a reverse conveying mechanism 53.

[0025] The sheet conveyed to the reversing conveying mechanism 53 is inverted on the reversing conveying path and conveyed again to the conveying rollers 2 by the relay rollers 13. That is, the reversing conveying mechanism 53 receives the sheet with the front side recorded from the upstream conveying rollers 2, inverts it, and conveys the inverted sheet to the upstream conveying rollers 2 by the relay rollers 13 so that the back side can be recorded by the recording head 5.

[0026] In this way, further recording is performed on the back side of the sheet that has been transported again to the recording head 5. The sheet, on which both the front and back sides have been recorded, is further transported by the downstream transport rollers 6 while being regulated by the spurs 7a and 7b, and is discharged to the paper discharge section 52. The sheet reverse transport path is not limited to the above configuration as long as it is formed so that the sheet with the printed surface returns to the recording unit. For example, the sheet from the reverse transport mechanism 53 may be transported to the recording unit by transport rollers other than the upstream transport rollers 2.

[0027] <System configuration> 3 is a block diagram showing an example of a system configuration for controlling the drive of each of the above-mentioned elements included in the recording device 50. The recording device 50 further includes an MPU 201, a ROM 202, a RAM 203, a carriage motor 204, a transport motor 205, a temperature sensor 206, a print head driver 207, a carriage motor driver 208, a transport motor driver 209, an operation display unit 211, and an I / F unit 213.

[0028] An MPU (Micro Processing Unit) 201 performs calculations for controlling the overall system drive of the recording device 50. A ROM (Read Only Memory) 202 stores programs and various parameters for executing recording. A RAM (Random Access Memory) 203 functions as a work memory.

[0029] For example, a host computer 214, which is an external device, generates print data using a printer driver 2141 in response to input of a print job including image data indicating an image to be printed and setting data for setting the print quality, etc. The MPU 201 receives the print data from the host computer 214 via an I / F (interface) unit 213. The MPU 201 reads and executes a desired program from a ROM 202, performs arithmetic processing based on the print data, and generates various signals for driving and controlling each element while temporarily storing the data in a RAM 203.

[0030] A carriage motor driver 208 drives the carriage motor 204 based on a signal from the MPU 201 to reciprocate the carriage 10, thereby causing the print head 5 to scan. A transport motor driver 209 drives the transport motor 205 based on a signal from the MPU 201, thereby rotating the transport rollers 2 and 6. A print head driver 207 drives the print head 5 based on a signal from the MPU 201, thereby performing printing. In this way, the MPU 201 repeats the intermittent transport and scan printing described above, performing printing on each sheet.

[0031] The temperature sensor 206 is capable of detecting the temperature of the power source including the motors 204 and 205 .

[0032] The operation and display unit 211 is typically a touch panel display. The operation and display unit 211 can receive operation inputs from the user and can also display necessary information based on signals from the MPU 201.

[0033] <About transport when recording on the back side> In double-sided printing, depending on the amount of ink used to record on the front side (the amount of ink ejected on the front side), the sheet may sag when recording on the back side. The sagging here refers to lifting from the platen 4, such as warping, curvature, or crease, caused by a relatively large amount of ink being ejected onto the sheet. This sagging can cause misalignment of the recording (misalignment of the ink landing position), as well as preventing the sheet from being properly transported between the downstream transport roller 6 and the spur 7a, which can even cause a paper jam. This can occur after the sheet has passed the upstream transport roller 2 but before it reaches the downstream transport roller 6, and can be particularly problematic as the sheet approaches the downstream transport roller 6.

[0034] Therefore, in this embodiment, when recording on the back side, the intermittent transport and scanning recording after the sheet has passed the upstream transport roller 2 and before it reaches the downstream transport roller 6 are at least partially different from the intermittent transport and scanning recording at other times.

[0035] 4 is a cross-sectional schematic diagram of an area including the print head 5, upstream transport roller 2, and downstream transport roller 6 in the printing device 50. The print head 5, which is scanned in the X direction during scan printing, includes a plurality of nozzles NZ arranged in the Y direction and capable of ejecting ink, and in one scan printing, an area corresponding to the arrangement length L1 of the nozzles NZ can be printed at once.

[0036] In this embodiment, the nozzles are divided into three groups from the upstream side to the downstream side: a first nozzle group GNZa, a second nozzle group GNZb, and a third nozzle group GNZc. In this case, the length L2 of each of the nozzle groups GNZa to GNZc is L2=L1 / 3 This can be expressed as:

[0037] In such a configuration, the transport amount for one intermittent transport (intermittent transport amount) can be changed depending on which of the nozzle groups GNZa to GNZc is driven, and in this embodiment, one scan printing is performed by selecting one of the following two printing modes. -Normal mode The intermittent transport amount is set to L1, and all of the nozzle groups GNZa to GNZc are driven. - Low speed mode The intermittent transport amount is set to L2 (=L1 / 3), and one of the nozzle groups GNZa to GNZc is driven. These details will be described later with reference to FIG. 8(a) and the like.

[0038] In this embodiment, 192 nozzles NZ are arranged in the Y direction at intervals of 600 dpi (dots per inch), and each of the nozzle groups GNZa to GNZc includes 64 nozzles NZ.

[0039] FIG. 5 is a schematic diagram illustrating the recording areas on the front and back sides of the sheet Sh. The upstream edge area when recording on the front side is referred to as the front side rear edge area (first edge area) fER. The front side rear edge area fER becomes the downstream edge area when recording on the back side, and therefore corresponds to the back side leading edge area. Depending on the amount of ink ejected in the front side rear edge area fER, when recording on the back side, the sheet Sh may bend slightly after passing through the upstream transport rollers 2 and before reaching the downstream transport rollers 6.

[0040] 6 is a flowchart showing an example of a print control method for enabling appropriate double-sided printing in such a case. This flowchart starts, for example, in response to receiving print data from the host computer 214. First, the print data received by the MPU 201 is analyzed, and a decision is made to start a print operation. The MPU 201 executes each process in this flowchart.

[0041] In step S10 (hereinafter simply referred to as "S10," and the same applies to other steps described later), sheet transport begins. Note that although there may be two or more sheets to be recorded on that are taken into the device body from the paper feed unit 51 by the paper feed roller 1, for ease of explanation, it is assumed below that a single sheet is taken into the device body.

[0042] In S12, recording on the front side of the taken-in sheet is started. This recording is started in the normal mode described above when the sheet is conveyed to a position (recording start position) where the recording head 5 can start recording after the sheet sensor 12 detects that the sheet has reached the upstream conveying rollers 2.

[0043] In S14, while continuing recording on the front side, the ink ejection amount in the front side rear end area fER is evaluated as the ink ejection amount DA. Note that since the ink ejection amount DA in S14 only needs to be determined by S18, S14 may be performed at another timing.

[0044] 7 is a schematic diagram showing an example of a method for evaluating the ink discharge amount DA in the front surface rear end region fER. The ink discharge amount DA can be evaluated by dividing the region fER into multiple grids and calculating the ink discharge amount for each grid. As an example, the region fER is divided into n rows of grids (n is an integer greater than or equal to 2), each aligned along the sheet transport direction. For example, for the first grid, the number of ink dots in each of several regions aligned in the transport direction is calculated, and the maximum value of these is calculated as the ink ejection amount DM1. Using a similar procedure, ink ejection amounts DM2 to DMn are calculated for the second to nth grids, respectively.

[0045] Based on the ink discharge amounts DM1 to DMn calculated in this way, the ink discharge amount in the front surface rear end area fER is evaluated as the ink discharge amount DA, which is calculated as the average value of the ink discharge amounts DM1 to DMn in this embodiment. DA=ΣDMk / n (k=1~n) is obtained.

[0046] Referring again to Figure 6, in response to the completion of recording on the front side in S15, in S16, the sheet whose front side has been recorded is transported to the inversion transport mechanism 53 by the reverse rotation of the transport roller 2 (and incidentally the transport roller 6), and is inverted (see Figure 2(b)).

[0047] In S17, the reversed sheet is conveyed again to the conveying roller 2 by the relay roller 13, and then conveyed to the recording start position of the recording head 5, and recording on the back side of the reversed sheet is started accordingly. Recording on the back side is started at the same conveying speed as recording on the front side, that is, in the normal mode.

[0048] In S18, it is determined whether the ink ejection amount DA obtained by the procedure described with reference to Fig. 7 is greater than the reference amount Dref. If the ink ejection amount DA is greater than the reference amount Dref, the process proceeds to S20; if not, the process proceeds to S28.

[0049] In S20, it is determined whether the leading edge of the sheet being recorded on the back side is located in the predetermined mode change area D1. If the leading edge of the sheet has reached and entered the mode change area D1, the process proceeds to S24; if not, the process proceeds to S22.

[0050] 4 again, the mode switching region D1 can be set in a range from the upstream side of the spur 7b to the downstream side so as to include at least the spur 7b. Also, since it is sufficient for the sheet to reach the conveyance roller 6 so as to pass at least between the conveyance roller 6 and the spur 7a, the mode switching region D1 can be set in a range from the upstream side of the spur 7b to the conveyance roller 6. From the viewpoint of the sheet, when viewed in the direction facing the platen 4 (Z direction), when recording on the back side, the front surface rear end region fER overlaps the entire spur 7b at the timing immediately before the sheet reaches the conveyance roller 6. In this embodiment, in which 192 nozzles NZ are arranged at intervals of 600 dpi, the mode switching region D1 can be set in the range from a position 5 mm upstream of the spur 7b to a position 3 mm downstream of the spur 7b.

[0051] Referring again to FIG. 6, in S22, recording in the normal mode, which will be described in detail later with reference to FIG. 8(a), continues, and the process returns to S20.

[0052] In S24, the recording mode is switched and recording is performed in the low-speed mode, which will be described in detail later with reference to FIG. 8(b).

[0053] In S26, it is determined whether the leading edge of the sheet being recorded on the back side has passed through the mode switching area D1. In this embodiment, as described above, the leading edge of the sheet is identified based on the detection results of the leading edge detection sensor 91 and the optical sensor. If the leading edge of the sheet has passed through the mode switching area D1, the process proceeds to S28. If not, the process returns to S26, and recording in the low-speed mode continues until the leading edge of the sheet has passed through the mode switching area D1.

[0054] In S28, the recording mode is switched and recording in the normal mode is performed again. That is, while the sheet is passing through the mode switching area D1, recording in the low-speed mode is performed, and during other periods, recording in the normal mode is performed.

[0055] In response to the completion of recording on the back side in S30, the sheet on both the front and back sides of which recording has been completed is discharged to the paper discharge unit 52, and this flowchart ends.

[0056] 8A is a schematic diagram showing how printing in normal mode continues. That is, in normal mode, intermittent conveyance with an intermittent conveyance amount of L1 and scan printing in which all of the nozzle groups GNZa to GNZc are driven are repeated. 8(b) is a schematic diagram showing partial printing in low-speed mode. In low-speed mode, intermittent conveyance with an intermittent conveyance amount of L2 (=L1 / 3) and scanning printing by driving one of the nozzle groups GNZa to GNZc are repeated. In low-speed mode, the sheet is more likely to move toward the gap between the conveyance roller 6 and the spur 7a because the conveyance amount per scan is small, and misalignment of the printing position is less likely to occur because the area of ​​one scanning print is small.

[0057] In this embodiment, the recording head 5 is a serial head that performs scanning recording alternately with intermittent sheet transport, and the sheet transport speed corresponds to the intermittent sheet transport amount. For example, the transport speed is an average speed obtained based on the transport amount and the time required when multiple intermittent transports are performed. In this example, the transport speed for the normal mode in FIG. 8(a) corresponds to the value obtained by dividing the transport amount L1 by the sum of the time required for transport by the transport amount L1 and the time required for the corresponding scanning and recording. Similarly, the transport speed for the low-speed mode in FIG. 8(b) corresponds to the value obtained by dividing the transport amount L2 by the sum of the time required for transport by the transport amount L2 and the time required for the corresponding scanning and recording. In this embodiment, the sheet is transported by trapezoidal drive, and the maximum transport speed (maximum value of the transport speed) is substantially the same in the normal mode and the low-speed mode, but this is not limiting. For example, the maximum speed in the normal mode may be higher than that in the low-speed mode.

[0058] In this embodiment, among the nozzle groups GNZa to GNZc, the most upstream nozzle group GNZa is driven in the low-speed mode. Immediately before the sheet reaches the downstream conveyance rollers 6, the sheet is more likely to be prevented from floating up on the upstream side than on the downstream side, so it is preferable to drive the nozzle group GNZa in the low-speed mode.

[0059] According to this embodiment, when the ink discharge amount DA in the rear end region fER of the front surface is relatively large and the front end region of the back surface is relatively prone to bending during recording on the back surface, the recording on the back surface is performed at least partially in the low-speed mode. Thereby, the conveyance amount per time and the area of one-time scanning recording can be reduced, the recording position deviation can be suppressed, the occurrence of jams can be prevented, and duplex printing can be appropriately realized.

[0060] <Small parentheses> According to this embodiment, when recording on the back surface of the sheet, the upstream conveyance roller 2 changes the conveyance speed according to the ink discharge amount DA in the rear end region fER of the front surface of the sheet until the sheet reaches the downstream conveyance roller 6. For example, when the ink discharge amount DA in the rear end region fER of the front surface is larger than the reference amount Dref, there is a possibility that the front end region of the back surface corresponding to the rear end region fER of the front surface is relatively prone to bending during recording on the back surface. In this embodiment, the recording on the back surface until such a sheet reaches the downstream conveyance roller 6 can be performed at least partially at a relatively low conveyance speed as the low-speed mode.

[0061] On the other hand, when the ink discharge amount DA in the rear end region fER of the front surface is smaller than the reference amount Dref and larger than another reference amount Dref’ (<Dref), it may be conveyed at a conveyance speed smaller than the normal mode and larger than the low-speed mode. For example, as the semi-low-speed mode, the intermittent conveyance amount can be set to L3 (= L1 × 2 / 3), and two of the nozzle groups GNZa to GNZc can also be driven.

[0062] In this embodiment, the mode of performing the recording on the back surface at least partially in the low-speed mode when the ink discharge amount DA in the rear end region fER of the front surface is relatively large is exemplified, but when the ink discharge amount DA is relatively small, the recording on the back surface may be performed in the normal mode. That is, the recording mode may be switched based on the ink discharge amount DA and the conveyance speed of the sheet may be changed.

[0063] In this embodiment, the recording head 5 is a serial head that performs scanning recording alternately with the intermittent conveyance of the sheet, so the sheet conveyance speed corresponds to the intermittent conveyance amount of the sheet. That is, when the ink ejection amount DA in the rear end area fER of the front surface is larger than the reference amount Dref, recording on the back surface is performed in low-speed mode, and the intermittent conveyance amount at that time can be set to a smaller value than that in normal mode.

[0064] In this embodiment, the recording head 5 is a serial head, but in another embodiment, the recording head 5 may be a line head extending across the entire width of the sheet. In this case, the sheet is transported at a substantially constant speed relative to the line head, rather than the intermittent transport described above, and the transport speed may be changed according to the ink ejection amount DA in the front surface rear end region fER. In this case, the ink ejection interval from the line head may be adjusted according to the changed transport speed.

[0065] The contents of the computational processing exemplified in this embodiment may be partially modified without departing from the spirit of the invention. For example, some of the steps described with reference to FIG. 6 may be partially replaced without departing from the spirit of the invention.

[0066] Second Embodiment 6, S12 (start of recording on the front side) and S17 (start of recording on the back side) are executed in response to the sheet being transported to the recording start position of the recording head 5, as described above. Recording by the recording head 5 generally starts a predetermined period of time after the sheet reaches the recording start position of the recording head 5. That is, in this embodiment, the MPU 201 in FIG. 3 suspends sheet transport and waits for a waiting time from the time the sheet reaches the recording start position of the recording head 5 to the time the recording head 5 actually starts recording.

[0067] The standby time can be set as a preparation period for the operation of the print head 5, but in the case of double-sided printing or when printing multiple times in succession, it can also be set as a period to cool down the power sources such as the motors 204 and 205 shown in Fig. 3, which may have become heated as a result. For example, if the temperature of the power source becomes higher than a reference value, the standby time can be set to be longer, and this can be determined based on the detection result of the temperature sensor 206.

[0068] 9 is a list showing the waiting time when recording on the front side and the waiting time when recording on the back side, which can be set according to the detection result of the temperature sensor 206. The waiting time can be set separately for recording on the front side and for recording on the back side.

[0069] In this embodiment, the waiting time is set to time T0 (e.g., 0.1 seconds) as an initial value for both recording on the front side and recording on the back side. If the temperature detected by the temperature sensor 206 is higher than the reference temperature when recording on the front side, the waiting time can be reset or changed to time T1 (e.g., 10 seconds). Also, if the temperature detected by the temperature sensor 206 is higher than the reference temperature when recording on the back side, the waiting time can be reset or changed to time T2 (e.g., 1 second). In other words, if the detected temperature has reached the reference temperature, the waiting time can be set longer than when it has not.

[0070] In another embodiment, the standby time may be set for each temperature detected by the temperature sensor 206, or may be set separately for three or more cases, for example.

[0071] The sheet sag described in the first embodiment may be eliminated by the waiting time. Therefore, as an example, if the waiting time is longer than the reference time, steps S18 and thereafter may be omitted (the mode may not be shifted to the low-speed mode). As another example, the reference amount Dref referred to in S18 may be changed or adjusted depending on the waiting time.

[0072] 10(a), 10(b), and 10(c) are timing charts showing the relative relationship between the changes in the sheet conveyance speed and the scanning speed of the print head 5 during the first scan at the start of printing, for waiting times T0, T1, and T2, respectively. The horizontal axis corresponds to the time axis, and the vertical axis represents the sheet conveyance speed (the conveyance speed of the conveyance rollers 2 and 6) and the scanning speed of the print head 5 (the movement speed of the carriage 10).

[0073] During one scanning recording, the scanning speed of the recording head 5 increases to approximately the maximum value before recording begins, and after the recording is completed, the scanning speed of the recording head 5 decreases to zero. Recording can be started after the transport speed reaches zero (i.e., after the sheet transport has stopped), and therefore the timing at which the recording head 5 starts accelerating can be adjusted according to the standby time.

[0074] For example, in the example of FIG. 10(a) (waiting time T0 (0.1 seconds in this example)), it is required that the scanning speed of the print head 5 reach approximately its maximum value within a relatively short time after the transport speed reaches zero. Therefore, the timing at which the print head 5 starts accelerating can occur before the timing at which the transport rollers 2 and 6 start decelerating. On the other hand, in the example of FIG. 10(b) (waiting time T1 (10 seconds in this example)), the timing at which the print head 5 starts accelerating can occur after the timing at which the transport rollers 2 and 6 stop.

[0075] <Program> The present invention may be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in a computer of the system or device read and execute the program. For example, the present invention may be realized by a circuit (e.g., an ASIC) that realizes one or more functions.

[0076] <Other> In the above description, the recording device 50 employs an inkjet recording method, but the recording method is not limited to the above. Furthermore, the recording device 50 may be a single-function printer having only a recording function, or a multi-function printer having multiple functions such as a recording function, a fax function, and a scanner function. Furthermore, the recording device 50 may be a manufacturing device for manufacturing color filters, electronic devices, optical devices, microstructures, etc., using a predetermined recording method.

[0077] Furthermore, the term "recording" as used in this specification should be interpreted broadly. Therefore, the form of "recording" does not matter whether the object formed on the recording medium is significant information such as characters or figures, or whether it is visible to humans or not.

[0078] Furthermore, the term "recording medium" should be interpreted broadly, just like the above-mentioned "recording." Therefore, the concept of "recording medium" can include not only commonly used paper, but also any material that can accept ink, such as cloth, plastic film, metal plate, glass, ceramics, resin, wood, leather, etc.

[0079] Furthermore, "ink" should be interpreted broadly, just like the above-mentioned "recording." Therefore, the concept of "ink" includes not only a liquid that forms an image, design, pattern, etc. by being applied to a recording medium, but also ancillary liquids that can be used for processing the recording medium, treating the ink (for example, solidifying or insolubilizing the coloring material in the ink applied to the recording medium), etc.

[0080] Furthermore, in the embodiments, individual elements are named based on their main functions, but the functions described in the embodiments may be sub-functions and are not strictly limited to these expressions. Furthermore, these expressions can be replaced with similar expressions. For the same purpose, the expression "unit" can be replaced with "tool," "component," "member," "structure," "assembly," etc. Alternatively, these terms may be omitted or added.

[0081] Furthermore, two or more elements exemplified as selectable in the embodiments are not strictly limited to the examples and may be arbitrarily combined, for example, each of the two or more exemplified elements may be selected additionally or alternatively. As an example, when two elements A and B can be arbitrarily combined, they may be expressed as "A and / or B" or "at least one of A and B" to indicate either A only, B only, or both A and B.

[0082] Summary of the embodiment Some features exemplified in the embodiments are as follows: [1] a first conveying means for conveying a recording medium; a recording means for ejecting ink onto a first surface of the recording medium conveyed by the first conveying means and onto a second surface opposite to the first surface, and a second conveying means for conveying the recording medium recorded by the recording means; a reversing conveying means for reversing the recording medium on which recording has been performed on the first side by the recording means, and conveying the recording medium to the first conveying means so that recording can be performed on the second side by the recording means, an end area on the upstream side in the transport direction when the recording means records on the first surface is defined as a first end area; When the recording means records on the second side of the recording medium recorded on the first side, the first transport means changes the transport speed of the recording medium according to the ink ejection amount in the first end area. A recording device characterized by: [2] The first conveying means changes the conveying speed of the recording medium according to the ink ejection amount in the first end area until the recording medium from the reverse conveying means reaches the second conveying means. The recording device according to [1]. [3] When the ink ejection amount in the first end area is larger than the reference amount, the first conveying means reduces the conveying speed of the recording medium recorded on the first side. The recording device according to [1] or [2], [4] The recording means is a serial head that performs scanning recording on the recording medium alternately with intermittent conveyance of the recording medium by at least one of the first and second conveyance means, and the conveyance speed of the recording medium corresponds to the amount of intermittent conveyance of the recording medium. The recording device according to [3]. [5] the first conveying means is disposed upstream of the recording means in the conveying direction, The second conveying means is disposed downstream of the recording means in the conveying direction. The recording device according to any one of [1] to [4], characterized in that: [6] a platen for supporting a recording medium to be recorded by the recording means; a spur disposed between the recording means and the second conveying means for restricting the recording medium toward the platen, When viewed in a direction facing the platen, the first end area is set so as to overlap the entirety of the spur at a timing immediately before the recording medium reaches the second conveying means when recording is performed on the second surface by the recording means. The recording device according to [5]. [7] further comprising a driving means for driving at least one of the first and second transport means, and a detecting means for detecting the temperature of the driving means; The first conveying means waits for a waiting time, interrupting the conveyance of the recording medium, from the time when the recording medium reaches a position where the recording means can start recording, until the time when the recording means actually starts recording, and the waiting time is set based on the detection result of the detecting means. The recording device according to any one of [1] to [6], characterized in that: [8] The waiting time is set to be longer when the temperature of the driving means detected by the detecting means has reached the reference temperature than when it has not. The recording device according to [7]. [9] The waiting time is set separately for the case of recording on the first side and the case of recording on the second side. The recording device according to [8],

[10] a first conveying means for conveying a recording medium; a recording means for ejecting ink onto a first surface of the recording medium conveyed by the first conveying means and onto a second surface opposite to the first surface, and a second conveying means for conveying the recording medium recorded by the recording means; a reversing conveying means for reversing the recording medium on which recording has been performed on the first side by the recording means, and conveying the recording medium to the first conveying means so that recording can be performed on the second side by the recording means, recording on the first surface of the recording medium by the recording means; a step of inverting the recording medium on which the recording has been performed on the first side by the inverting conveying means; recording on the second surface of the recording medium by the recording means, an end area on the upstream side in the transport direction when the recording means records on the first surface is defined as a first end area; In the step of recording on the second surface, the transport speed of the recording medium by the first transport means is changed in accordance with the amount of ink ejected from the first end area. A method for controlling a recording apparatus.

[11] A program for causing a computer to execute each step of the control method described in

[10] . This program can be stored in a computer-readable non-volatile storage medium.

[0083] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0084] 50: recording device, 5: recording head, 2: upstream transport roller, 6: downstream transport roller, 53: Reverse conveying mechanism, 13: Relay roller, fER: Surface rear end area.

Claims

1. a first conveying means for conveying a recording medium; a recording means for ejecting ink onto a first surface of the recording medium conveyed by the first conveying means and onto a second surface opposite to the first surface, and a second conveying means for conveying the recording medium recorded by the recording means; a reversing conveying means for reversing the recording medium on which recording has been performed on the first side by the recording means, and conveying the recording medium to the first conveying means so that recording can be performed on the second side by the recording means, an end area on the upstream side in the transport direction when the recording means records on the first surface is defined as a first end area; When the recording means records on the second surface of the recording medium recorded on the first surface, the first transport means changes the transport speed of the recording medium in accordance with the ink ejection amount in the first end area. A recording device characterized by:

2. The first conveying means changes the conveying speed of the recording medium according to the ink ejection amount in the first end area until the recording medium from the reverse conveying means reaches the second conveying means.

2. The recording apparatus according to claim 1.

3. When the ink ejection amount in the first end area is larger than the reference amount, the first transport means reduces the transport speed of the recording medium on which recording has been performed on the first side.

2. The recording apparatus according to claim 1.

4. The recording means is a serial head that performs scanning recording on the recording medium alternately with intermittent conveyance of the recording medium by at least one of the first and second conveyance means, and the conveyance speed of the recording medium corresponds to the amount of intermittent conveyance of the recording medium.

4. The recording apparatus according to claim 3.

5. the first conveying means is disposed upstream of the recording means in the conveying direction, The second conveying means is disposed downstream of the recording means in the conveying direction.

2. The recording apparatus according to claim 1.

6. a platen for supporting a recording medium to be recorded by the recording means; a spur disposed between the recording means and the second conveying means for restricting the recording medium toward the platen, When viewed in a direction facing the platen, the first end region is set so as to overlap the entirety of the spur at a timing immediately before the recording medium reaches the second conveying means when recording is performed on the second surface by the recording means.

6. The recording apparatus according to claim 5.

7. further comprising a driving means for driving at least one of the first and second transport means, and a detecting means for detecting the temperature of the driving means; The first conveying means waits for a waiting time, interrupting the conveyance of the recording medium, from the time when the recording medium reaches a position where the recording means can start recording, until the time when the recording means actually starts recording, and the waiting time is set based on the detection result of the detecting means.

2. The recording apparatus according to claim 1.

8. The waiting time is set to be longer when the temperature of the driving means detected by the detecting means has reached the reference temperature than when it has not.

8. The recording apparatus according to claim 7.

9. The waiting time is set separately for the case of recording on the first side and the case of recording on the second side.

9. The recording apparatus according to claim 8.

10. a first conveying means for conveying a recording medium; a recording means for ejecting ink onto a first surface of the recording medium conveyed by the first conveying means and onto a second surface opposite to the first surface, and a second conveying means for conveying the recording medium recorded by the recording means; a reversing conveying means for reversing the recording medium on which recording has been performed on the first side by the recording means, and conveying the recording medium to the first conveying means so that recording can be performed on the second side by the recording means, recording on the first surface of the recording medium by the recording means; a step of inverting the recording medium on which the recording has been performed on the first side by the inverting conveying means; recording on the second surface of the recording medium by the recording means, an end area on the upstream side in the transport direction when the recording means records on the first surface is defined as a first end area; In the step of recording on the second surface, the transport speed of the recording medium by the first transport means is changed in accordance with the amount of ink ejected from the first end area. A method for controlling a recording apparatus.

11. A program for causing a computer to execute each step of the control method according to claim 10.

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