JP2023162611A - Liquid discharge device, control method for the same and program - Google Patents

Abstract

An object of the present invention is to suppress contact of a sheet-like medium with a nozzle surface, as well as suppress deterioration in recording quality and recording speed.
SOLUTION: After receiving a recording command (S1: YES), a CPU of a printer determines a floating amount X in an edge region of a sheet (S2). Thereafter, the CPU determines whether the floating amount X is equal to or greater than a predetermined amount Xt (S3). If the CPU 101 determines that the floating amount If so (S3: NO), the edge control is not performed for the edge area of the paper, but the same control as for the center area of the paper is performed.
[Selection diagram] Figure 11

Description

The present invention relates to a liquid ejection device that ejects liquid onto a sheet-like medium, a control method thereof, and a program.

Patent Document 1 states that if the recording paper (sheet-like medium) is not pressed by the upstream presser (upstream presser member), the upstream end of the recording paper will lift up, causing the recording paper to touch the ink ejection surface (nozzle). It has been shown that there is a risk of contact with the surface. In order to suppress this problem, Patent Document 1 discloses that, as the last unit printing process, the second unit printing process (conveying the recording paper a distance smaller than the conveyance amount of the recording paper P in the first conveyance process by the nozzle shift amount) It is shown that the skip conveyance process (large conveyance) is executed after that (small conveyance).

Japanese Patent Application Publication No. 2017-177775

The edge control including small conveyance and large conveyance as described above is effective in suppressing the contact of the sheet media with the nozzle surface, but compared to control that keeps the conveyance amount constant, it causes conveyance variations. The number of times of transportation is easy to increase. Recording quality may deteriorate due to variations in conveyance, and recording speed may decrease due to an increase in the number of conveyances. Therefore, if edge control is performed even when there is a low possibility that the sheet-like medium will come into contact with the nozzle surface, problems may arise such as deterioration of recording quality and recording speed.

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid ejecting device, a control method thereof, and a program therefor, which can suppress contact of a sheet-like medium with a nozzle surface, and suppress deterioration of recording quality and recording speed. .

According to a first aspect of the present invention, there is provided a transport mechanism that transports a sheet-like medium in a transport direction, and a nozzle surface in which a nozzle is formed, and the liquid is applied from the nozzle to the sheet-like medium transported by the transport mechanism. The conveyance mechanism includes a discharge section that discharges the discharge, and a control section, and the conveyance mechanism is disposed upstream of the discharge section in the conveyance direction and presses the sheet-like medium so that the sheet-like medium approaches the nozzle surface. an upstream pressing member that restricts the movement of the sheet-like medium, and a downstream pressing member that is disposed on the downstream side of the discharge section in the conveying direction and presses the sheet-like medium to prevent the sheet-like medium from approaching the nozzle surface. , the control unit executes a determination process for determining a floating amount of an end region in the conveyance direction of the sheet-like medium, and a determining process for determining whether the floating amount is a predetermined amount or more, If it is determined in the determination process that the amount of floating is equal to or greater than the predetermined amount, and only one of the upstream pressing member and the downstream pressing member is pressing the sheet-like medium, the conveying mechanism is end control for causing large conveyance to be performed after conveyance and discharging liquid from the discharge unit during the plurality of short conveyances, wherein the short conveyance causes the conveyance mechanism to convey the sheet-like medium by a small conveyance amount; The large conveyance is to cause the conveyance mechanism to convey the sheet-like medium by a large conveyance amount that is larger than the small conveyance amount. If it is determined that the above is not the case, when only one of the upstream pressing member and the downstream pressing member is pressing the sheet-like medium, or when both the upstream pressing member and the downstream pressing member are holding the sheet-like medium There is provided a liquid ejecting apparatus characterized in that the same control as described above is executed on the transport mechanism and the ejecting section.

According to a second aspect of the present invention, there is provided a transport mechanism that transports a sheet-like medium in a transport direction, and a nozzle surface in which a nozzle is formed, and the liquid is applied from the nozzle to the sheet-like medium transported by the transport mechanism. In the liquid ejecting apparatus, the transport mechanism is disposed upstream of the ejecting part in the transport direction, and presses the sheet-like medium so that the sheet-like medium approaches the nozzle surface. an upstream pressing member that restricts the movement of the sheet-like medium, and a downstream pressing member that is disposed on the downstream side of the discharge section in the conveying direction and presses the sheet-like medium to prevent the sheet-like medium from approaching the nozzle surface. A control method for controlling a liquid ejecting device including: a determination process for determining a floating amount of an end region in the conveying direction of a sheet-like medium; and a judgment for determining whether the floating amount is a predetermined amount or more. and when it is determined in the determination process that the amount of floating is equal to or greater than the predetermined amount, when only one of the upstream pressing member and the downstream pressing member is pressing the sheet-like medium, the An end control that causes a conveyance mechanism to perform a large conveyance after a plurality of small conveyances, and causes the discharge unit to eject a liquid between the plurality of short conveyances, the small conveyance causing the conveyance mechanism to perform a sheet-shaped conveyance. in the determination process; When it is determined that the amount of floating is not equal to or greater than the predetermined amount, when only one of the upstream pressing member and the downstream pressing member is pressing the sheet-like medium, both the upstream pressing member and the downstream pressing member press the sheet. A control method is provided, characterized in that the same control as when pressing the medium is performed on the transport mechanism and the discharge section.

According to a third aspect of the present invention, there is provided a transport mechanism that transports a sheet-like medium in a transport direction, and a nozzle surface in which a nozzle is formed, and the liquid is supplied from the nozzle to the sheet-like medium transported by the transport mechanism. In the liquid ejecting apparatus, the transport mechanism is disposed upstream of the ejecting part in the transport direction, and presses the sheet-like medium so that the sheet-like medium approaches the nozzle surface. an upstream pressing member that restricts the movement of the sheet-like medium, and a downstream pressing member that is disposed on the downstream side of the discharge section in the conveying direction and presses the sheet-like medium to prevent the sheet-like medium from approaching the nozzle surface. A liquid ejecting device including the liquid ejecting device functions as a determining means for determining the floating amount of the end region in the conveyance direction of the sheet-like medium, and a determining means for determining whether the floating amount is a predetermined amount or more, When the determining means determines that the amount of floating is equal to or greater than the predetermined amount, when only one of the upstream pressing member and the downstream pressing member is pressing the sheet-like medium, the conveying mechanism is end control for causing large conveyance to be performed after conveyance and discharging liquid from the discharge unit during the plurality of short conveyances, wherein the short conveyance causes the conveyance mechanism to convey the sheet-like medium by a small conveyance amount; The large conveyance is to cause the conveyance mechanism to convey the sheet-like medium by a large conveyance amount that is larger than the small conveyance amount. If it is determined that the above is not the case, when only one of the upstream pressing member and the downstream pressing member is pressing the sheet-like medium, or when both the upstream pressing member and the downstream pressing member are holding the sheet-like medium There is provided a program characterized in that the same control as described above is executed on the transport mechanism and the discharge section.

According to the present invention, when it is determined that the amount of floating is equal to or greater than a predetermined amount, contact of the sheet-like medium with the nozzle surface can be suppressed by executing edge control. On the other hand, if it is determined that the amount of floating is not equal to or greater than the predetermined amount, edge control is not performed, thereby suppressing a decrease in recording quality or recording speed.

FIG. 1 is a schematic side view showing the internal structure of the printer according to the first embodiment of the present invention, and is a schematic side view showing a state in which a roll body is accommodated. FIG. 2 is a schematic side view showing a state in which cut sheets are accommodated in the printer of FIG. 1; FIG. 3 is a partial cross-sectional view of the head. 2 is an enlarged view of region IV shown in FIG. 1. FIG. 5 is a plan view of the periphery of the head shown in FIG. 4. FIG. (a) is a sectional view taken along the line VIA-VIA in FIG. 5. (b) is a side view seen from the direction of arrow VIB in FIG. 5. FIG. 2 is a block diagram showing the electrical configuration of the printer in FIG. 1. FIG. FIG. 5 is a diagram corresponding to FIG. 4 for explaining central control. 5 is a diagram corresponding to FIG. 4 for explaining edge control for the leading edge of a sheet. FIG. 5 is a diagram corresponding to FIG. 4 for explaining edge control for the trailing edge of a sheet. FIG. FIG. 2 is a flow diagram showing control details regarding recording in the printer of FIG. 1. FIG. 7 is a graph showing the relationship between the paper leading edge position and the floating amount. FIG. 7 is a flow diagram showing control details regarding recording in a printer according to a second embodiment of the present invention.

<First embodiment>
As shown in FIGS. 1 and 2, a printer 1 (liquid ejection device) according to a first embodiment of the present invention includes a housing 1a, and paper feed trays 10 and 20 that are detachable from the housing 1a. It is equipped with a paper discharge tray 6. The paper feed tray 10 corresponds to the "first accommodating section" and "accommodating section" of the present invention, and the paper feed tray 20 corresponds to the "second accommodating section" of the present invention.

The paper feed trays 10 and 20 have a box shape that opens upward, and are movable in the front and rear directions with respect to the housing 1a. The paper feed trays 10 and 20 are pulled out from the housing 1a by being moved forward with respect to the housing 1a, and are attached to the housing 1a by being moved backward with respect to the housing 1a. The paper feed trays 10 and 20 can take an attached position where they are attached to the housing 1a (see FIGS. 1 and 2), and a pulled out position (not shown) in front of the attached position. When the paper feed trays 10 and 20 are in the mounting position, the paper feed tray 20 overlaps the paper feed tray 10 in the vertical direction and is arranged above the paper feed tray 10.

The paper discharge tray 6 is constituted by the upper front side wall of the housing 1a. By rotating around an axis 6a along the left-right direction, the paper ejection tray 6 can be moved between an open position (not shown) in which the opening 1x of the housing 1a is opened and a closed position (FIGS. 1 and 2) in which the opening 1x is closed. ).

The printer 1 further includes a transport mechanism 3, a cutting mechanism 4, a head 5, and a control device 100. Elements of the transport mechanism 3 other than rollers 14a and 14b, which will be described later, the cutting mechanism 4, the head 5, and the control device 100 are supported by the housing 1a.

The conveyance mechanism 3 is configured to selectively convey paper P from the paper feed trays 10 and 20, and includes rollers 14a and 14b, rollers 32 and 35, arms 33 and 36, and roller pairs 37a and 37b. 38, 39, a platen 9, a corrugated plate 31, a roller 34, and a conveyance motor 30 (see FIG. 7) for driving each of the rollers.

Paper P is a general term for roll paper Pr (see FIG. 1) and cut paper Pc (see FIG. 2), and corresponds to the "sheet-like medium" of the present invention. The cut paper Pc has a shorter length in the transport direction (the direction in which the paper P is transported by the transport mechanism 3) than the roll paper Pr.

In the conveyance mechanism 3, the rollers 14a, 14b, the roller 35 and the arm 36, the roller pairs 37a, 37b, 38, 39, the roller 34, and the platen 9 pass from the paper feed tray 10 below the head 5. A transport path T1 is configured along which the roll paper Pr is transported to the paper discharge tray 6 (see FIG. 1). In the conveyance mechanism 3, the roller 32, the arm 33, the roller pairs 37a, 38, 39, the roller 34, and the platen 9 transport cut sheets from the paper feed tray 20 to the paper output tray 6 through the lower part of the head 5. A transport path T2 along which Pc is transported is configured (see FIG. 2). In the transport paths T1 and T2, the portion from the roller pair 37a to the paper discharge tray 6 is common.

The paper feed tray 10 can accommodate a roll body R, as shown in FIG. The roll body R is a long roll paper Pr wound around the outer peripheral surface of a cylindrical core member Rc. The roll body R is accommodated in the paper feed tray 10 with its rotation axis Rx (the central axis of the core member Rc) extending along the left-right direction.

Rollers 14a and 14b are arranged at the bottom of the paper feed tray 10. The rollers 14a and 14b are rotatable about an axis along the left-right direction. When the roll body R is housed in the paper feed tray 10, the outer circumferential surface of its lower portion is supported by rollers 14a and 14b.

When setting the roll body R, the roll body R is manually rotated in the counterclockwise direction in FIG. 1, and the roll paper Pr is unwound from the roll body R. Then, the leading end (downstream end in the conveyance direction) of the roll paper Pr is held between the roller 35 and the bottom wall 11 of the paper feed tray 10. In this state, when the conveyance motor 30 (see FIG. 7) is driven under the control of the control device 100, the rollers 14a, 14b, and 35 rotate, and the roll paper Pr is fed backward. The roll paper Pr fed by the roller 35 from the paper feed tray 10 comes into contact with the rear side wall 12 of the paper feed tray 10, moves along the side wall 12, and is guided to the cutting mechanism 4.

The roller 35 is supported by one end of the arm 36. The other end of the arm 36 is supported by the housing 1a via a shaft 36a extending in the left-right direction. The arm 36 is rotatable about a shaft 36a. The arm 36 is biased by a biasing member (not shown) so that the roller 35 approaches the bottom wall 11.

The cutting mechanism 4 includes a cutter 4a and a cutting motor 40 (see FIG. 7). The cutter 4a is arranged above the rear side wall 12 of the paper feed tray 10 and below the roller pair 37b. The cutter 4a includes, for example, a disk-shaped rotating blade and a driven blade. Alternatively, the cutter 4a may include a rotating blade and a fixed blade. When the cutting motor 40 is driven under the control of the control device 100, the rotary blade reciprocates in the left-right direction while rotating. The roll paper Pr is cut in the left-right direction by the cutter 4a.

As shown in FIG. 2, the paper feed tray 20 can accommodate a plurality of cut sheets Pc stacked vertically. The cut paper Pc is supported on the upper surface of the bottom wall 21 of the paper feed tray 20.

When the paper feed tray 20 is attached to the housing 1a and no cut paper Pc is stored in the paper feed tray 20, the roller 32 contacts the bottom wall 21 (see FIG. 1). When the paper feed tray 20 is attached to the housing 1a and cut paper Pc is accommodated in the paper feed tray 20, the roller 32 comes into contact with the uppermost layer of cut paper Pc (see FIG. 2). In this state, when the conveyance motor 30 (see FIG. 7) is driven under the control of the control device 100, the roller 32 rotates and the cut paper Pc is fed backward.

The roller 32 is supported by one end of the arm 33. The other end of the arm 33 is supported by the housing 1a via a shaft 33a extending in the left-right direction. The arm 33 is rotatable about a shaft 33a (see FIGS. 1 and 2). The arm 33 is biased by a biasing member (not shown) so that the roller 32 approaches the bottom wall 21 .

The head 5 (which corresponds to the "discharge section" of the present invention) includes a flow path unit 51 and an actuator unit 52, as shown in FIG. Inside the flow path unit 51, a common flow path 51x communicating with an ink tank (not shown) and a plurality of individual flow paths 51y branched from the common flow path 51x are formed. Each individual flow path 51y includes a pressure chamber 51c and a nozzle 51n. The nozzle 51n is located at the tip of the individual flow path 51y and opens at the bottom surface of the flow path unit 51. The lower surface of the channel unit is a nozzle surface 5a on which a plurality of nozzles 51n are formed. The pressure chamber 51c is open on the upper surface of the flow path unit 51. The actuator unit 52 includes a diaphragm 521 arranged on the upper surface of the flow path unit 51 so as to cover the plurality of pressure chambers 51c, a piezoelectric layer 522 arranged on the upper surface of the diaphragm 521, and a plurality of diaphragms on the upper surface of the piezoelectric layer 522. and a plurality of individual electrodes 523 arranged to face each of the pressure chambers 51c. The portion of the diaphragm 521 and piezoelectric layer 522 sandwiched between each individual electrode 523 and each pressure chamber 51c functions as an individual unimorph type actuator for each pressure chamber 51c, and each individual electrode by the driver IC 50 (see FIG. 3) functions as an individual unimorph actuator for each pressure chamber 51c. It can be deformed independently according to the application of voltage to 523. By deforming the actuator so as to be convex toward the pressure chamber 51c, the volume of the pressure chamber 51c is reduced, pressure is applied to the ink within the pressure chamber 51c, and the ink is ejected from the nozzle 51n.

The head 5 is held by a carriage 5c, as shown in FIGS. 4 and 5. The carriage 5c is movable in the left-right direction by a scanning mechanism 8 (see FIG. 5) while holding the head 5. The left-right direction is a direction perpendicular to the conveyance direction around the head 5 and parallel to the nozzle surface 5a, and corresponds to the "scanning direction" of the present invention.

As shown in FIG. 5, the scanning mechanism 8 includes two guide rails 81 and 82 that support the carriage 5c, an endless belt 83 connected to the carriage 5c, and a scanning motor 80. The endless belt 83 is connected to the scanning motor 25. When the scanning motor 25 is driven under the control of the control device 100, the endless belt 83 runs, and the carriage 5c and head 5 move in the scanning direction along the guide rails 81, 82.

As shown in FIG. 4, the platen 9 is disposed below the head 5 and the carriage 5c and parallel to the nozzle surface 5a, and has a surface that supports the paper P. Six ribs 9a (see FIG. 5) each extending in the transport direction are formed in the upstream region of the surface in the transport direction. The six ribs 9a are arranged at equal intervals in the scanning direction, as shown in FIG.

A pair of rollers 38 and 39 are arranged to sandwich the platen 9 in the conveying direction. As shown in FIG. 4, the roller pair 38 is arranged on the upstream side of the head 5 in the conveying direction, and includes an upper roller 38a and a lower roller 38b. The roller pair 39 is arranged on the downstream side of the head 5 in the conveyance direction, and includes an upper roller 39a and a lower roller 38b.

The base of the corrugated plate 31 is arranged above the upper roller 38a of the roller pair 38. The tip (downstream end in the conveying direction) of the corrugated plate 31 faces the surface of the platen 9 with a slight distance therebetween. As shown in FIG. 5, seven corrugated plates 31 are provided at equal intervals in the scanning direction. The six ribs 9a are arranged between adjacent corrugated plates 31 in the scanning direction.

As shown in FIG. 5, the roller pairs 39 include six sets each consisting of an upper roller 39a and a lower roller 39b. The six sets are arranged at equal intervals in the scanning direction. Each of the six sets has the same position in the scanning direction as the six ribs 9a.

As shown in FIG. 4, a roller 34 is arranged downstream of the roller pair 39 in the conveyance direction. As shown in FIG. 5, seven rollers 34 are provided at equal intervals in the scanning direction. The six roller pairs 39 are arranged between adjacent rollers 34 in the scanning direction. The seven rollers 34 are aligned in position with the seven corrugated plates 31 in the scanning direction, respectively.

The rollers 38a, 38b, and 39b are rubber rollers with no protrusions formed on their outer circumferential surfaces, whereas the rollers 34, 39a are spur rollers with a plurality of protrusions formed on their outer circumferential surfaces. This makes it difficult for ink that has landed on the surface of the paper P to adhere to the rollers 34, 39a.

As shown in FIG. 6(a), the upper end of each rib 9a is located above the tip of each corrugated plate 31. In this positional relationship, the upper ends of the six ribs 9a support the paper P from below, and the tips of the seven corrugated plates 31 press the paper P from above, thereby creating waves in the paper P along the scanning direction. A shape is given.

As shown in FIG. 6(b), the contact point between the upper roller 39a and the lower roller 39b is located above the lower end of the roller 34. In this positional relationship, the six lower rollers 39b support the paper P from below, and the seven rollers 34 press the paper P from above, giving the paper P a wave shape along the scanning direction. Ru.

As shown in FIGS. 6A and 6B, the paper P is given a wave shape along the scanning direction, giving stiffness to the paper P and achieving good conveyance.

Here, the corrugated plate 31 corresponds to the "upstream pressing member" of the present invention, and the upper roller 39a corresponds to the "downstream pressing member" of the present invention. As shown in FIG. 4, the corrugated plate 31 is arranged on the upstream side of the head 5 in the conveyance direction, and presses the paper P to prevent the paper P from approaching the nozzle surface 5a. The upper roller 39a is disposed on the downstream side of the head 5 in the conveyance direction, and presses the paper P to prevent the paper P from approaching the nozzle surface 5a.

As shown in FIG. 7, the control device 100 includes a CPU (Central Processing Unit) 101, a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, and an ASIC (Application Specific Integrated Circuit) that includes various control circuits. 104. The control device 100 is communicably connected to an external device (not shown) such as a PC (Personal Computer). The CPU 101 and the ASIC 104 correspond to the "control unit" of the present invention.

The ROM 102 stores programs and data for the CPU 101 to control various operations. The RAM 103 temporarily stores data used when the CPU 101 executes the above program. The CPU 101 issues instructions to the ASIC 104 in accordance with programs and data stored in the ROM 102 and RAM 103 based on recording instructions received from an external device.

The ASIC 104 is connected to a transport motor 30, a driver IC 50, a scanning motor 80, and a cutting motor 40. The ASIC 104 controls the conveyance motor 30, the driver IC 50, and the scanning motor 80 (and the cutting motor 40 when recording on roll paper Pr) according to commands from the CPU 101, and performs a recording process to record an image on the paper P. Execute.

In the recording process, the ASIC 104 alternately performs a transport operation in which the transport mechanism 3 transports the paper P in the transport direction, and an ejection operation in which the scanning mechanism 8 moves the head 5 in the scanning direction and ejects ink from the nozzles 51n. Let it happen. That is, during recording, the paper P is conveyed intermittently. The discharge operation is performed during a conveyance stop between one conveyance operation and the next conveyance operation. By repeating the conveyance operation and the ejection operation alternately, ink dots are formed on the surface of the paper P, and an image is recorded.

One ejection operation is performed depending on the recording resolution, printing speed, etc., ``(i) when the head 5 ejects ink while moving forward or backward in the scanning direction'' and ``(ii) when the head 5 ejects ink while moving forward or backward in the scanning direction.'' There is a case where one or more reciprocating movements are made in the direction and ink is ejected in each of the forward and backward movements.

Here, conveyance control in recording processing will be explained with reference to FIGS. 8 to 10.

As shown in FIG. 8, when both the corrugated plate 31 and the upper roller 39a are holding down the paper P, the ASIC 104 executes "central control" that causes the transport mechanism 3 to transport the paper P by a constant reference transport amount D0. do.

As shown in FIGS. 9 and 10, when only one of the corrugated plate 31 and the upper roller 39a is holding down the paper P, the ASIC 104 determines that the floating amount X of the paper P is equal to or greater than a predetermined amount If it is determined, "end control" is executed to cause the conveyance mechanism 3 to perform large conveyance after a plurality of small conveyances, and to perform a discharge operation between a plurality of short conveyances.

FIG. 9 shows edge control for the leading edge (downstream end in the conveyance direction) region of the paper. In FIG. 9, the paper P indicated by the broken line is held down by the corrugated plate 31 and not held down by the upper roller 39a.

FIG. 10 shows edge control for the rear end (upstream end in the conveyance direction) region of the paper. In FIG. 10, the paper P indicated by the broken line is held down by the upper roller 39a and is not held down by the corrugated plate 31.

9 and 10 illustrate "(ii) the case where the head 5 makes one or more reciprocating movements in the scanning direction and ejects ink in each of the forward and backward movements" in one ejection operation. There is. In this example, a large transport is performed after a plurality of small transports, and a plurality of small transports are performed after a large transport.

The small conveyance is to cause the conveyance mechanism 3 to convey the paper P by small conveyance amounts D1a, D1b, D1a', D1b' (an amount smaller than the reference conveyance amount D0). The large conveyance is to cause the conveyance mechanism 3 to convey the paper P by large conveyance amounts D2a, D2a' (larger than the small conveyance amounts D1a, D1b, D1a', D1b', and larger than the reference conveyance amount D0). The large transport amount D2a, D2a' is the length of the nozzle area in the transport direction (from the most upstream nozzle 51n in the transport direction to the most downstream nozzle 51n among the plurality of nozzles 51n formed in the head 5). (distance in the transport direction).

The small transport amounts D1a, D1b, D1a', and D1b' are not limited to being the same, but may be different from each other. The large conveyance amounts D2a and D2a' are not limited to being the same, but may be different from each other. Further, in the plurality of small conveyances that are performed continuously, the conveyance amount is constant in FIGS. 9 and 10, but the conveyance amount is not limited to being constant.

The floating amount X is the floating amount (distance from the surface of the platen 9 to the highest point of the paper P) of the end region (including the leading edge region and the trailing edge region; in FIG. 9, the leading edge region of the paper P) in the conveyance direction of the paper P. ). The end region is a region including the end (leading edge or trailing end) of the paper P, and the length of the end region in the conveying direction is, for example, the length in the conveying direction from the tip of the corrugated plate 31 to the upper roller 39a. It is the value obtained by adding the length of the nozzle area in the transport direction. In FIGS. 9 and 10, the leading edge region and the trailing edge region of the paper P are curved so as to be upwardly convex, but they may also be downwardly convex.

Next, with reference to FIG. 11, details of control related to recording will be explained.

First, the CPU 101 determines whether a recording command has been received from an external device (S1).

If it is determined that a recording command has not been received from the external device (S1: NO), the CPU 101 repeats the process of S1.

If it is determined that a recording command has been received from the external device (S1: YES), the CPU 101 determines the floating amount X of each of the leading edge region and trailing edge region of the paper P (S2: determination process).

Here, the floating amount X changes depending on the position of the leading edge or trailing edge of the paper P in the conveyance direction. For example, as shown in FIG. 12, if the amount of floating when the leading edge of the paper P is at the same position in the conveying direction as the leading edge of the corrugated plate 31 (see FIG. 9) is the initial value X0, the leading edge of the paper P is moved from that position. The amount of floating gradually increases as it moves downstream in the conveyance direction. The floating amount X reaches its maximum value when the leading edge of the paper P is at the same position as the roller 39a in the conveying direction. Thereafter, as the leading edge of the paper P moves downstream of the roller 39a in the transport direction, the floating amount gradually decreases, and becomes constant when the leading edge of the paper P passes a predetermined position downstream of the roller 39a in the transport direction. becomes.

Further, the floating amount X changes based on parameters such as the amount of ink ejected to the edge region (leading edge region or trailing edge region) of the paper P, the type of paper P, the type of ink, and the like. For example, as shown in FIG. 12, the greater the discharge amount, the greater the floating amount X. In the example of FIG. 12, when the ejection amount is small, the floating amount X is smaller than the predetermined amount Xt regardless of the position of the leading edge of the paper P, but when the ejection amount is medium or large, the floating amount becomes larger than the predetermined amount Xt when The predetermined amount Xt is, for example, the distance between the surface of the platen 9 and the nozzle surface 5a (see FIG. 9).

To derive the ejection amount, the image data included in the recording command is converted into density data for each color of RGB, and the density data is converted into ejection data (data indicating the ejection amount in each ejection period for each nozzle 51n).

The ROM 103 stores a function (a function indicating the relationship between the position of the leading edge or trailing edge of the sheet P in the conveyance direction and the floating amount X) and a table as shown in FIG. 12 corresponding to each of the above-mentioned parameters. The functions and tables are based on experiments conducted in advance.

In S2, the CPU 101 determines the maximum value of the floating amount X in each of the leading edge region and trailing edge region (edge region) of the paper P based on the above-mentioned functions and tables stored in the ROM 103.

Note that the printer 1 has a paper feed tray 10 that accommodates roll paper Pr and a paper feed tray 20 that accommodates cut paper Pc, and in S2, when the transport mechanism 3 transports the roll paper Pr from the paper feed tray 10, , the floating amount X is corrected to be larger than when the cut paper Pc is transported by the transport mechanism 3 from the paper feed tray 20. Specifically, in the case of roll paper transport, the initial value X0 of the function shown in FIG. 12 is made larger than in the case of cut paper transport.

After S2, the CPU 101 determines whether the floating amount X is greater than or equal to a predetermined amount Xt (S3: determination process). In S2, the maximum value of the floating amount X of each of the leading edge region and trailing edge region of the paper P is determined. In S3, it is determined whether each of the maximum floating amounts X of the leading edge region and trailing edge region of the paper P is equal to or greater than a predetermined amount Xt.

If it is determined that at least one of the maximum floating amounts X of the leading edge region and trailing edge region of the paper P is equal to or greater than the predetermined amount Xt (S3: YES), the CPU 101 controls the transport motor 30, driver IC 50, and scanning motor through the ASIC 104. 80 (and the cutting motor 40 when recording on roll paper Pr) to execute the recording process. At this time, edge control (see FIGS. 9 and 10) is performed for the area in which the floating amount X is determined to be equal to or greater than the predetermined amount Xt among the leading edge area and trailing edge area of the paper P (S4).

In S4, the ASIC 104 advances the timing to start edge control and increases the large conveyance amounts D2a and D2a' (see FIGS. 9 and 10) as the floating amount X determined in S2 increases. In order to increase the large transport amounts D2a and D2a', the ASIC 104, for example, advances the timing of starting small transport before large transport, delays the timing of starting small transport after large transport, or The conveyance amount of multiple small conveyances may be reduced without changing the timing of starting the small conveyance before the large conveyance.

The start timing of the large transport and the values of the large transport amounts D2a and D2a' are determined based on the function shown in FIG. For example, in FIG. 12, when the discharge amount is large, the floating amount X gradually increases from the initial value X0, and large conveyance is started at the timing when it reaches a value slightly smaller than the predetermined amount Xt. Then, the large conveyance is completed at the timing when the floating amount X gradually decreases from the maximum value and reaches a value slightly smaller than the predetermined amount Xt.

The number of small conveyances and the values of the small conveyance amounts D1a, D1b, D1a', and D1b' are determined according to the recording resolution and recording speed.

Further, in S4, the ASIC 104 causes the scanning mechanism 8 (see FIG. 5) to position the head 5 outside the transport area (the position of the head 5 shown in FIG. 5) after the short transport and before the large transport. Then, the ASIC 104 causes the transport mechanism 3 to perform large transport with the head 5 disposed outside the transport area. The conveyance area is an area where the paper P is conveyed by the conveyance mechanism 3 (the area indicated by a dashed line in FIG. 5).

If it is determined that both the maximum floating amount X of the leading edge region and trailing edge region of the paper P are not equal to or greater than the predetermined amount Xt (S3: NO), the CPU 101 controls the transport motor 30, driver IC 50, and scanning motor 80 ( Furthermore, when recording on the roll paper Pr, the cutting motor 40) is controlled to execute the recording process. At this time, the ASIC 104 does not perform edge control (see FIGS. 9 and 10) but performs central control (see FIG. 8) for the leading edge and trailing edge areas of the paper P (S5). That is, when only one of the corrugated plate 31 and the upper roller 39a is holding down the paper P, the ASIC 104 performs the same control on the transport motor 30 and the same as when both the corrugated plate 31 and the upper roller 39a are holding down the paper P. This is executed for the driver IC 50.

After S4 or S5, the CPU 101 ends the routine.

As described above, according to the present embodiment, when it is determined that the floating amount Therefore, contact of the paper P with the nozzle surface 5a can be suppressed. On the other hand, if it is determined that the floating amount X is not equal to or greater than the predetermined amount Xt (S3: NO), by not performing edge control, it is possible to suppress a decrease in recording quality and a decrease in recording speed.

In S2 (determination process), the CPU 101 determines that the greater the amount of ink (ejection amount) ejected from the nozzle 51n onto the paper P, the greater the floating amount X (see FIG. 12). In this case, the floating amount X can be effectively determined based on the phenomenon that the paper P curls due to the adhesion of ink.

In S2 (determination process), the CPU 101 determines that the greater the ejection amount to the edge region of the paper P rather than the entire paper P, the greater the floating amount X. In this case, the floating amount X can be determined more accurately.

When performing edge control, the ASIC 104 increases the large transport amounts D2a and D2a' (see FIGS. 9 and 10) as the floating amount X increases. In this case, contact of the paper P with the nozzle surface 5a can be more reliably suppressed.

When executing edge control, the ASIC 104 advances the timing of starting edge control as the floating amount X increases. In this case, contact of the paper P with the nozzle surface 5a can be more reliably suppressed.

The ASIC 104 causes the scanning mechanism 8 (see FIG. 5) to position the head 5 outside the conveyance area (the position of the head 5 shown in FIG. 5) after the small conveyance and before the large conveyance in end control, so that the head 5 The transport mechanism 3 is caused to carry out large-scale transport while being placed outside the transport area. In this case, contact of the paper P with the nozzle surface 5a can be more reliably suppressed.

When both the corrugated plate 31 and the upper roller 39a are holding down the paper P, the ASIC 104 executes central control (see FIG. 8) to keep the conveyance amount D0 constant. This provides stable recording quality.

In S2, the CPU 101 determines that when the transport mechanism 3 transports the roll paper Pr from the paper feed tray 10, the floating amount to correct. Roll paper Pr tends to curl more easily than cut paper Pc, and the floating amount X tends to increase. Therefore, when the roll paper Pr is transported, by correcting the floating amount X in the direction of increasing it, it is possible to easily perform edge control and reliably suppress contact of the paper P with the nozzle surface 5a. .

<Second embodiment>
The printer (liquid ejecting device) according to the second embodiment of the present invention differs from the first embodiment in control details.

In the first embodiment (see FIG. 11), in S2, the CPU 101 determines whether the transport mechanism 3 transports the roll paper Pr from the paper feed tray 10 or the transport mechanism 3 transports the cut paper Pc from the paper feed tray 20. The amount of floating X is corrected in a direction that becomes larger than that of .

In contrast, in the second embodiment (see FIG. 13), instead of performing the above correction in S2, the CPU 101 transfers the roll paper Pr from the paper feed tray 10 to the transport mechanism 3 after receiving the recording command and before S2. It is determined whether or not to be transported (S20). If it is determined that the transport mechanism 3 is to transport the roll paper Pr from the paper feed tray 10 (S20: YES), the CPU 101 advances the process to S4 and executes the recording process with edge control via the ASIC 104. On the other hand, if it is determined that the transport mechanism 3 is not to transport the roll paper Pr from the paper feed tray 10 (that is, to transport the cut paper Pc from the paper feed tray 20) (S20: NO), the CPU 101 shifts the process to S2. Then, as in the first embodiment, it is selected whether or not to perform end control in accordance with the floating amount X.

This embodiment has been developed by focusing on the fact that roll paper Pr is more likely to curl and have a larger floating amount X than cut paper Pc, and when roll paper Pr is transported (S20: YES) By executing edge control (S4), contact of the paper P with the nozzle surface 5a can be reliably suppressed.

<Modified example>
Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made within the scope of the claims.

Although the upstream pressing member is the corrugated plate 31 in the above-described embodiment, it is not limited thereto, and may be a roller.

Although the downstream pressing member is the roller 39a in the above-described embodiment, it is not limited thereto, and may be a plate.

In the above embodiment, the floating amount is determined based on the ejection amount, paper type, etc., but it may also be the ejection amount itself (the ejection amount is determined in the determination process, and the ejection amount is determined by a predetermined amount in the judgment process). You may judge whether the above is true or not.

Placing the discharge section outside the transport area by the scanning mechanism after the small transport and before the large transport is performed when the floating amount is relatively large, and does not need to be performed when the floating amount is relatively small.

In order to reduce the amount of floating, the time interval between one conveyance operation and the next conveyance operation may be made longer than a predetermined time.

As the control when both the upstream pressing member and the downstream pressing member are holding down the sheet-like medium, central control (control for conveying the sheet-like medium at a constant reference conveyance amount) was exemplified in the above-mentioned embodiments. but not limited to. For example, when both the upstream pressing member and the downstream pressing member hold down the sheet-like medium, the conveyance amount of each conveyance operation may not be constant.

In FIGS. 9 and 10, in one ejection operation, "(ii) When the head 5 makes one or more reciprocating movements in the scanning direction and ejects ink in each of the forward and backward movements," Although an example has been shown in which a large conveyance is performed after a small conveyance, and a plurality of small conveyances are performed after a large conveyance, the present invention is not limited to this. For example, depending on the recording resolution and recording speed, in one ejection operation, "(i) When the head 5 ejects ink while moving forward or backward in the scanning direction," it may be necessary to eject ink multiple times after a large conveyance. There is no need for small conveyance.

The ejection unit is not limited to a serial type in which liquid is ejected from a nozzle while moving in the left-right direction, but may be a line type in which liquid is ejected from a nozzle in a fixed position. That is, the liquid ejecting device of the present invention is not limited to having a scanning mechanism.

The liquid ejected from the nozzle is not limited to ink, and may be any liquid (for example, a treatment liquid that aggregates or precipitates components in the ink, a liquid in which metal particles are dispersed in a solvent, etc.).

The sheet-like medium is not limited to paper, but may also be cloth or plastic film. That is, the sheet-like medium may be made of any material as long as it is sheet-like.

The present invention is not limited to printers, but can also be applied to facsimiles, copy machines, multifunction devices, and the like.

The program according to the present invention can be recorded and distributed on a removable recording medium such as a flexible disk or a fixed recording medium such as a hard disk, or can be distributed via a communication line.

1 Printer (liquid ejection device)
3 Transport mechanism 5 Head (discharge section)
5a Nozzle surface 8 Scanning mechanism 10 Paper feed tray (first storage section; storage section)
20 Paper feed tray (second storage section)
31 Corrugate plate (upstream holding member)
39a Upper roller (downstream pressing member)
51n nozzle 100 control device 101 CPU (control unit)
104 ASIC (control unit)
P Paper (sheet-like media)
R roll body

Claims (11)

a conveyance mechanism that conveys the sheet-like medium in the conveyance direction;
a discharge unit having a nozzle surface on which a nozzle is formed, and configured to discharge liquid from the nozzle onto a sheet-like medium conveyed by the conveyance mechanism;
comprising a control unit;
The transport mechanism is
an upstream pressing member that is disposed on the upstream side in the conveying direction with respect to the discharge section and presses the sheet-like medium to prevent the sheet-like medium from approaching the nozzle surface;
a downstream pressing member disposed on the downstream side in the conveying direction with respect to the discharge section and pressing down on the sheet-like medium to prevent the sheet-like medium from approaching the nozzle surface;
The control unit includes:
a determination process for determining a floating amount of an end region of the sheet-like medium in the conveyance direction;
executing a determination process of determining whether the floating amount is equal to or greater than a predetermined amount;
If it is determined in the determination process that the amount of floating is equal to or greater than the predetermined amount, and only one of the upstream pressing member and the downstream pressing member is pressing the sheet-like medium, the conveying mechanism is end control for causing large conveyance to be performed after conveyance and discharging liquid from the discharge unit during the plurality of short conveyances, wherein the short conveyance causes the conveyance mechanism to convey the sheet-like medium by a small conveyance amount; executing edge control, wherein the large conveyance is to cause the conveyance mechanism to convey the sheet-like medium by a large conveyance amount that is larger than the small conveyance amount;
If it is determined in the determination process that the floating amount is not equal to or greater than the predetermined amount, and only one of the upstream pressing member and the downstream pressing member is pressing the sheet-like medium, the upstream pressing member and the downstream pressing member A liquid ejecting apparatus characterized in that the same control is performed on the transport mechanism and the ejecting section as when both are holding down a sheet-like medium. The liquid ejecting device according to claim 1, wherein the control unit determines in the determination process that the larger the amount of liquid ejected from the nozzle onto the sheet-like medium, the larger the floating amount. 3. The control unit determines, in the determination process, that the greater the amount of liquid discharged from the nozzle to the end region of the sheet-like medium, the greater the floating amount. liquid dispensing device. The liquid ejecting device according to any one of claims 1 to 3, wherein the control unit increases the large transport amount as the floating amount increases when executing the end control. . The controller according to any one of claims 1 to 3, when executing the end control, the larger the floating amount is, the earlier the timing of starting the end control is. Liquid discharge device. further comprising a scanning mechanism that moves the discharge section in a scanning direction perpendicular to the conveyance direction and parallel to the nozzle surface,
The control unit causes the scanning mechanism to dispose the ejection unit outside a sheet-like medium conveyance area by the conveyance mechanism after the small conveyance and before the large conveyance in the end control, and causes the ejection unit to The liquid ejecting device according to any one of claims 1 to 3, wherein the transport mechanism is configured to perform the large transport while being disposed outside the transport area. The control unit executes central control to cause the transport mechanism to transport the sheet-like medium at a constant reference transport amount when both the upstream pressing member and the downstream pressing member are pressing the sheet-like medium,
The liquid ejecting device according to claim 1, wherein the reference transport amount is larger than the small transport amount and smaller than the large transport amount. a first accommodating portion capable of accommodating a roll body in which a sheet-like medium is wound into a roll;
further comprising a second storage section capable of storing a plurality of sheet media in a stacked state;
The control unit is configured to control a direction in which the amount of floating increases when the transport mechanism transports the sheet-like medium from the first storage unit, compared to when the transport mechanism transports the sheet-form medium from the second storage unit. 4. The liquid ejecting device according to claim 1, wherein the liquid ejecting device corrects the amount of liquid. Further comprising a storage section capable of storing a roll body in which the sheet-like medium is wound into a roll shape,
The liquid ejecting device according to any one of claims 1 to 3, wherein the control unit executes the end control when causing the transport mechanism to transport the sheet-like medium from the storage unit. A liquid comprising: a conveyance mechanism that conveys a sheet-like medium in a conveyance direction; and a discharge section that has a nozzle surface in which a nozzle is formed and discharges liquid from the nozzle onto the sheet-like medium conveyed by the conveyance mechanism. In the discharge device, the conveyance mechanism includes an upstream pressing member that is disposed upstream of the discharge section in the conveyance direction and presses the sheet-like medium to prevent the sheet-like medium from approaching the nozzle surface; A control method for controlling a liquid ejection device, comprising: a downstream pressing member disposed on the downstream side in the conveying direction with respect to the ejection portion, and suppressing the sheet-like medium to prevent the sheet-like medium from approaching the nozzle surface. There it is,
a determination process for determining a floating amount of an end region of the sheet-like medium in the conveyance direction;
executing a determination process of determining whether the floating amount is equal to or greater than a predetermined amount;
If it is determined in the determination process that the amount of floating is equal to or greater than the predetermined amount, and only one of the upstream pressing member and the downstream pressing member is pressing the sheet-like medium, the conveying mechanism is end control for causing large conveyance to be performed after conveyance and discharging liquid from the discharge unit during the plurality of short conveyances, wherein the short conveyance causes the conveyance mechanism to convey the sheet-like medium by a small conveyance amount; executing edge control, wherein the large conveyance is to cause the conveyance mechanism to convey the sheet-like medium by a large conveyance amount that is larger than the small conveyance amount;
If it is determined in the determination process that the floating amount is not equal to or greater than the predetermined amount, and only one of the upstream pressing member and the downstream pressing member is pressing the sheet-like medium, the upstream pressing member and the downstream pressing member A control method characterized in that the same control is performed on the transport mechanism and the discharge unit as when both are pressing the sheet-like medium. A liquid comprising: a conveyance mechanism that conveys a sheet-like medium in a conveyance direction; and a discharge section that has a nozzle surface in which a nozzle is formed and discharges liquid from the nozzle onto the sheet-like medium conveyed by the conveyance mechanism. In the discharge device, the conveyance mechanism includes an upstream pressing member that is disposed upstream of the discharge section in the conveyance direction and presses the sheet-like medium to prevent the sheet-like medium from approaching the nozzle surface; A liquid ejection device including a downstream pressing member disposed on the downstream side in the conveying direction with respect to the ejection portion and holding down the sheet-like medium to prevent the sheet-like medium from approaching the nozzle surface;
determining means for determining the floating amount of the end region in the conveyance direction of the sheet-like medium, and
functioning as a determining means for determining whether the floating amount is equal to or greater than a predetermined amount;
When the determining means determines that the amount of floating is equal to or greater than the predetermined amount, when only one of the upstream pressing member and the downstream pressing member is pressing the sheet-like medium, the conveying mechanism is end control for causing large conveyance to be performed after conveyance and discharging liquid from the discharge unit during the plurality of short conveyances, wherein the short conveyance causes the conveyance mechanism to convey the sheet-like medium by a small conveyance amount; that is, the large conveyance causes the conveyance mechanism to carry out an end control in which the sheet-like medium is conveyed by a large conveyance amount that is larger than the small conveyance amount;
If the determining means determines that the floating amount is not equal to or greater than the predetermined amount, and only one of the upstream pressing member and the downstream pressing member is pressing the sheet-like medium, the upstream pressing member and the downstream pressing member A program for causing the transport mechanism and the ejecting unit to perform the same control as when both are pressing a sheet-like medium.

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