Printing apparatus and printing method

Abstract

To solve the problem that it is necessary to perform printing after waiting until the temperature of the transporting belt becomes stable and the change in PG becomes stable, resulting in downtime.SOLUTION: A printing apparatus comprises: a conveying unit that has a conveying belt having an adhesive layer formed thereon and conveys a medium while supporting the medium on the adhesive layer; a recording unit that performs recording on the medium supported on the conveying unit, by discharging ink to the medium; a heating unit that heats the conveying unit; and a control unit that controls the conveying unit and the recording unit. The control unit obtains temperature information of the transporting belt, and on the basis of the obtained temperature information of the transporting belt, corrects at least one of a timing and ejection speed at which the recording unit ejects the ink, Printing can be started without waiting for a PG change caused by thermal expansion of the transporting belt due to heating to become stable by correcting the timing at which the recording unit ejects the ink, on the basis of the temperature information of the transporting belt.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a printing apparatus and a printing method, and particularly to a printing apparatus and a printing method for supporting and conveying a medium with an adhesive layer.

Background Art

[0002] In dip-dye printing for printing on fabric, there is known an image forming apparatus having a conveyor belt with an adhesive applied to the surface of the conveyor belt, and temporarily adhering and conveying the fabric with the conveyor belt. Further, in the image forming apparatus disclosed in Patent Document 1, when improving the adhesiveness of the adhesive by heating the conveyor belt in a heating unit, the temperature of the conveyor belt is controlled by changing the position of the heating unit according to the driving state of the conveyor belt.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a conventional image forming apparatus, when starting printing, heating of the conveyor belt is started by a heating unit. When the temperature of the conveyor belt rises, the conveyor belt thermally expands and the gap (hereinafter referred to as PG) with the print head changes. For this reason, printing has to be waited until the temperature of the conveyor belt stabilizes and the change in PG stabilizes, resulting in downtime.

Means for Solving the Problems

[0005] The present invention has a conveyance belt with an adhesive layer formed on its surface, and includes a conveyance unit that supports and conveys a medium with the adhesive layer, a recording unit that performs recording by discharging ink onto the medium supported by the conveyance unit, a heating unit that heats the conveyance unit, and a control unit that controls the conveyance unit and the recording unit. The control unit is configured to acquire temperature information of the conveyance belt and correct at least one of the timing or discharge speed at which the recording unit discharges ink based on the acquired temperature information.

Brief Description of the Drawings

[0006]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Modes for Carrying Out the Invention

[0007] Hereinafter, embodiments of the present invention will be described based on the drawings. FIG. 1 shows a schematic block diagram of a printing apparatus according to an embodiment of the present invention. In the figure, this printing apparatus 10 includes a conveying unit 20 having a conveying belt 21. The conveying belt 21 of the conveying unit 20 has an adhesive layer on its surface, and supports and conveys a cloth fabric, which is the medium, with this adhesive layer. The adhesive layer uses a heat - type glue adhesive. The conveying belt 21 is stretched between a pair of rollers 22a and 22b, and one of the rollers 22a is driven by a conveying motor 23. A heating unit 30 is installed facing the surface of the roller 22a. The heating unit 30 radiates radiant heat to the roller 22a and heats the surface of the conveying belt 21 that is stretched between the rollers 22a and 22b and is sequentially driven. Note that the heating unit 30 is separately controlled so that the conveying belt 21 reaches an appropriate temperature.

[0008] The recording unit 40 performs recording by discharging ink onto a cloth fabric, which is the medium supported by the conveying belt 21 of the conveying unit 20. The recording unit 40 includes a printing head 41 and a carriage 42 that supports the printing head 41 and reciprocates in a direction orthogonal to the driving direction of the conveying belt 21, and includes a carriage motor 42a that reciprocates the carriage 42.

[0009] In this way, the recording unit 40 performs recording by moving the printing head 41 in a direction intersecting the conveying direction of the medium, specifically, in a direction orthogonal thereto. Further, the recording unit 40 performs recording by reciprocating the printing head 41 in a direction intersecting the conveying direction of the medium.

[0010] The control unit 50 controls the conveying unit 20 and the recording unit 40. More specifically, the control unit 50 controls the conveying motor 23 of the conveying unit 20 to drive the cloth fabric, which is the medium, in a predetermined direction, and controls the carriage motor 42a for each printing pass to reciprocate the printing head 41 in a direction orthogonal to the conveying direction of the cloth fabric, and discharges ink droplets from the printing head 41 at a predetermined timing based on the speed of the PG and the carriage 42 and a predetermined ink droplet speed. The ink droplets reach the cloth fabric, which is the medium, through a predetermined path and form a predetermined pattern.

[0011] Further, the control unit 50 includes a temperature detection unit 51 for detecting the temperature of the conveyor belt 21 and a timer 52 capable of measuring a predetermined elapsed time. Note that it is not necessary to provide both the temperature detection unit 51 and the timer 52, and only one of them may be provided.

[0012] FIG. 2 schematically shows the ejection path of ink droplets. A method of repeatedly moving the print head 41 in a direction orthogonal to the conveyance direction of the medium for each print pass and then conveying the medium by a predetermined distance to perform printing is called a serial method. In the serial method, it is possible to increase the printing speed by reciprocating the print head 41, and it is called a bidirectional printing or BiD (bidirectional) method. On the other hand, a method of printing only when the print head 41 is driven in one direction is called a unidirectional printing or UniD (unidirectional) method.

[0013] FIG. 2 also shows the conveyor belt 21. Since the conveyor belt 21 is heated by the heating unit 30, the thickness t2 during heating after a predetermined time has elapsed is larger than the thickness t1 during cooling before printing. When the thickness of the conveyor belt 21 changes, the distance PG from the surface of the fabric, which is the medium supported on the surface of the conveyor belt 21, to the print head 41 changes. Specifically, it is PG1 during cooling and PG2 during heating.

[0014] Since the print head 41 is driven at a predetermined speed by the carriage 42, the ink droplets ejected from the print head 41 move obliquely as shown in FIG. 2 and reach the surface of the fabric. When PG changes, the landing position also changes. If PG becomes smaller, the image formation position shifts forward compared to when PG is large. In the case of unidirectional printing, even if PG changes and the landing position shifts, the image formation position only shifts in a predetermined direction, and the formed image does not change. In other words, when PG is large during cooling, it shifts toward the traveling direction side.

[0015] On the other hand, in the case of double-sided printing, based on the moving direction of the carriage 42, as the PG decreases, it shifts forward. Therefore, the image formation position in the forward path and the image formation position in the return path are different, and the images that are intended to be formed by printing in the forward and return paths cannot be formed correctly. To prevent such a situation, the conveyance belt 21 was sufficiently heated to reach the thickness t2 during heating, and the printer waited until the distance between the print head 41 and the medium became PG2.

[0016] Figure 3 is a flowchart of the program to be executed, and Figure 4 shows the relationship between the temperature and the thickness of the conveyance belt in a graph. First, the thickness of the conveyance belt and the temperature are almost proportional, and when the temperature information is obtained, the thickness can be calculated by multiplying by a predetermined coefficient.

[0017] As a user operation, when the power of the printing apparatus 10 is turned on in step S100, the control unit 50 executes the power-on process in the printing apparatus 10 in step S105. This is an initial startup process, which clears the memory and registers and waits for the next operation by the user. After this, the user can execute a printing process from other devices connected to the network or the like. Also, a printing medium such as a cloth fabric is set on the conveyance belt 21 of the conveyance unit 20 to perform preliminary preparations for printing.

[0018] When the user executes a printing operation from another device in step S200, the device transmits print data to the printing apparatus 10. In the printing apparatus 10, the printing operation is started in step S205. First, in S210, the heating unit 30 starts heating. This is called heater warm-up. Conventionally, after this, it was necessary to wait for a predetermined time until the conveyance belt 21 was sufficiently warmed up.

[0019] However, after the start of the printing operation, the control unit 50 repeats the following process for only the printing pass without waiting in step S215. That is, the print head 41 performs printing only for the printing pass and completes the printing.

[0020] In each printing pass, first, in step S220, the temperature of the conveyance belt 21 is acquired. Specifically, the control unit 50 acquires the current temperature information of the conveyance belt 21 detected by the temperature detection unit 51. In step S225, the control unit 50 determines whether the acquired temperature of the conveyance belt 21 has reached a predetermined temperature. If not, in step S230, the belt displacement amount (or PG) due to thermal expansion is calculated. As shown in FIG. 4, since a proportional relationship holds between the temperature and the conveyance belt 21, the thickness tn corresponding to the temperature Cn detected by the temperature detection unit 51 can be calculated. After that, in step S235, the control unit 50 calculates the landing position deviation correction amount (discharge timing) from the PG, CR speed, and ink droplet speed. Note that in order to eliminate the landing position deviation, in addition to the discharge timing, it is also possible to correct the discharge speed as described later. That is, at least one of the discharge timing or the discharge speed of the ink may be corrected.

[0021] Prior to this, the control unit 50 controls the carriage motor 42a to start driving the print head 41 in the forward or return path. Since the thickness of the conveyance belt 21 increases by a predetermined amount, the PG decreases. At that time, the control unit 50 has grasped the CR speed it controls, and furthermore, the ink droplet speed should be a predetermined speed in printing with the normal print head 41.

[0022] For example, if an ink droplet is discharged at the original discharge timing, due to the thickness of the conveyance belt 21 increasing by a predetermined amount, it reaches the cloth fabric at a position a predetermined distance ahead corresponding to the increased thickness. Conversely, before the thickness increases, it is shifted by a predetermined distance in the advancing direction. Therefore, if the ink droplet is discharged at the timing of the position a predetermined distance ahead, the ink droplet should land at the original image formation position. The timing calculated in this way by inverse calculation becomes the landing position deviation correction amount.

[0023] In step S240, the control unit 50 drives the conveyance motor 23 for recording by the recording unit 40 (belt conveyance), and in step S245, the recording unit 40 performs a CR operation to eject ink. At this time, the landing position deviation correction amount is taken into account. Also, the CR operation refers to the carriage operation, and while being synchronized with the driving operation of the carriage motor 42a by the control unit 50 and the driving of the conveyance motor 23, it represents an operation of ejecting ink droplets from the moving print head 41 at a predetermined ejection timing to perform printing.

[0024] Depending on whether each printing pass is the forward path or the return path, an appropriate correction amount for the ejection timing is calculated, and by taking this into account and ejecting the ink droplets, even if printing is started when the conveyance belt 21 is not sufficiently warmed up, a desired image can be obtained for the formed image.

[0025] In this way, since printing can be performed without waiting for the change in the PG (gap) between the conveyance belt 21 and the print head 41 to stabilize due to the heating by the heating unit 30, the downtime can be reduced.

[0026] In the above, step S220 corresponds to a step of acquiring the temperature information of the conveyance belt, and step S230 corresponds to a step of correcting the timing of ejecting the ink based on the acquired temperature information.

[0027] Also, the control unit 50 repeatedly executes the correction of at least one of the timing of ejecting the ink or the ejection speed for each printing pass of the print head 41.

[0028] Incidentally, in step S225, the control unit 50 determines whether the temperature of the conveyor belt 21 obtained has reached a predetermined temperature. If it has reached, in step S240, the conveyor motor 23 is driven, and in step S245, the CR operation is performed to eject the ink. At this time, since step S235 is not executed, the landing position deviation correction amount is not taken into account. The fact that the temperature has reached the predetermined temperature means that the thickness of the conveyor belt 21 has become the thickness assumed in advance, so correction of the landing position is not necessary. Also, since there is no need to calculate the correction amount, the amount of arithmetic processing can be reduced.

[0029] In this way, the control unit 50 repeats the correction of at least one of the ink ejection timing or the ejection speed until the temperature of the conveyance unit 20 reaches a predetermined temperature. When all the print passes are repeated, in step S250, the printing is completed, and in step S255, the user checks the print result.

[0030] FIG. 5 is a flowchart of the program to be executed according to the modification example, and FIG. 6 shows the time change of the temperature in a graph. FIG. 6 shows that the temperature of the conveyor belt 21 changes from C0 to C1 until the time M1 after the heater warms up, and then the temperature becomes substantially constant at C1. In the above-described embodiment, the temperature of the conveyor belt 21 was detected by the temperature detection unit 51, and the thickness of the conveyor belt 21 was calculated from the temperature. However, as shown in FIG. 6, there is a predetermined correlation between the time after the power of the printing apparatus 10 is turned on and the temperature of the conveyor belt 21. Therefore, based on this graph, the temperature can be indirectly estimated from the time. In this embodiment, a timer 52 is provided, and it is possible to measure a predetermined elapsed time.

[0031] The flowchart shown in FIG. 5 and the flowchart shown in FIG. 3 perform substantially the same processing for the steps that match except for the thousands place, so detailed description is omitted. What differ greatly are step S1220 and step S1225. In step S1220, the control unit 50 acquires the elapsed time by the timer 52, and calculates and acquires the temperature of the conveyor belt 21 based on the graph shown in FIG. 6.

[0032] When the user turns on the power of the printing apparatus 10 in step S1100, the control unit 50 executes the power-on process in the printing apparatus 10 in step S1105. When the user transmits print data from another device to the printing apparatus 10 in step S1200, the printing apparatus 10 starts the printing operation in step S1205 and starts the heater warm-up of the heating unit 30 in S1210. The timer 52 measures the elapsed time from this heater warm-up.

[0033] After the start of the printing operation, without waiting, the control unit 50 repeats the following process for only the printing path in step S1215. In each of the printing paths, the temperature of the conveyor belt 21 is acquired in step S1220. That is, the control unit 50 acquires the elapsed time by the timer 52, and calculates and acquires the temperature of the conveyor belt 21 based on the graph shown in FIG. 6.

[0034] Next, in step S1225, the control unit 50 determines whether a predetermined time has elapsed since the power was turned on. If not reached, in step S1230, the belt displacement amount (or PG) due to thermal expansion is calculated from the calculated temperature of the conveyor belt 21, and in step S1235, the landing position deviation correction amount (discharge timing) is calculated from the PG, CR speed, and ink droplet speed. The calculation of this correction amount can not only acquire the current temperature information of the conveyor belt 21 detected by the temperature detection unit 51 in step S220, but also calculate and acquire the temperature of the conveyor belt 21 from the elapsed time from the heater warm-up in step S1220.

[0035] In this way, the control unit 50 estimates the temperature of the conveyor belt based on a predetermined elapsed time and uses it as the temperature information. In this embodiment, the elapsed time is the elapsed time since the start of printing, specifically, the start time since the heater warmed up. There are various methods for obtaining the elapsed time. For example, printing start information can be obtained, the printing start time can be obtained, and then the elapsed time until the current time can be obtained. Alternatively, a timer 52 that always measures the time may be provided.

[0036] After that, in step S1240, the control unit 50 drives the conveyance motor 23 for recording by the recording unit 40 (belt conveyance), and in step S1245, the recording unit 40 performs a CR operation to eject ink. In the CR operation, ink droplets are ejected taking into account the correction amount for appropriate ejection timing. Therefore, even if printing is started when the conveyor belt 21 is not sufficiently warmed up, the desired image can be obtained.

[0037] In step S1225, when it is determined that a predetermined time has elapsed since the power was turned on, in step S1240, the conveyance motor 23 is driven, and in step S1245, a CR operation is performed to eject ink. At this time, since step S1235 has not been executed, the landing position deviation correction amount is not taken into account. However, the fact that a predetermined time has elapsed means that the conveyor belt 21 has reached a predetermined temperature and the expected thickness, so correction of the landing position is not necessary. And since there is no need to calculate the correction amount, the amount of arithmetic processing can be reduced.

[0038] In this way, the control unit 50 repeatedly corrects at least one of the ink ejection timing or the ejection speed until the elapsed time reaches a predetermined time. In this embodiment, step S1220 corresponds to the step of obtaining the temperature information of the adhesive layer, and step S1230 corresponds to the step of correcting the ink ejection timing based on the obtained temperature information.

[0039] FIG. 7 is a flowchart of a program to be executed according to a modified example. In this embodiment, in order to eliminate the landing position deviation, the ejection speed is corrected. The flowchart shown in FIG. 7 and the flowcharts shown in FIGS. 3 and 5 perform substantially the same processing for the steps that match except for the thousands place, so detailed description thereof will be omitted. What is significantly different is step S2235 and step S2245. In step S2235, the control unit 50 calculates the landing position deviation correction amount (speed value) from the PG, CR speed and the ink droplet speed, and in step S2245, the CR operation (taking into account the landing position deviation correction amount) is performed to eject the ink.

[0040] In the above-described embodiment, the correction amount is taken into account in the ejection timing. Specifically, since the landing position deviates in the traveling direction while the thickness of the conveyor belt is thin, the timing at which the ink droplets are ejected at a position a predetermined distance ahead is the landing position deviation correction amount. Similarly, even if the ejection is performed at the same timing while the thickness of the conveyor belt is thin, if the ejection speed is slow, the ink can land at the same position. Thus, the correction amount for changing the ejection speed so that the landing position does not deviate becomes the landing position deviation correction amount. The control unit 50 corrects the landing position deviation before the conveyor belt warms up in steps S2235 and S2245.

[0041] Needless to say, the present invention is not limited to the above embodiments. As is obvious to those skilled in the art, · Appropriately changing the combination of mutually replaceable members, configurations, etc. disclosed in the above embodiments and applying them · Although not disclosed in the above embodiments, appropriately replacing members and configurations, etc. that are known technologies and are mutually replaceable with the members and configurations, etc. disclosed in the above embodiments, and also changing their combinations and applying them · Although not disclosed in the above embodiments, appropriately replacing members and configurations, etc. that can be assumed by those skilled in the art as substitutes for the members and configurations, etc. disclosed in the above embodiments based on known technologies, etc., and also changing their combinations and applying them are disclosed as one embodiment of the present invention.

Explanation of Symbols

[0042] 10…Printing device, 20…Conveyor section, 22a, 22b…Rollers, 23…Conveyor motor, 30…Heating section, 40…Recording section, 41…Printing head, 42…Carriage, 42a…Carriage motor, 50…Control section, 51…Temperature detection section, 52…Timer.

Claims

1. A printing apparatus comprising a conveyance belt having an adhesive layer formed on its surface, a conveyance unit that supports and conveys a medium with the adhesive layer, a recording unit that performs recording by discharging ink onto the medium supported by the conveyance unit, a heating unit that heats the conveyance unit, and a control unit that controls the conveyance unit and the recording unit, wherein the control unit acquires temperature information of the conveyance belt and corrects at least one of the timing or discharge speed at which the recording unit discharges ink based on the acquired temperature information. The recording unit performs recording by moving a print head in a direction intersecting the conveyance direction of the medium. The recording unit performs recording by reciprocating the print head in a direction intersecting the conveyance direction of the medium. The printing apparatus further includes a temperature detection unit that detects the temperature of the conveyance unit, and the control unit acquires the temperature information of the conveyance belt from the temperature detection unit. The control unit repeatedly corrects at least one of the timing or discharge speed at which ink is discharged for each print pass of the print head. The control unit repeatedly corrects at least one of the timing or discharge speed at which ink is discharged until the temperature of the conveyance unit reaches a predetermined temperature.

2. The printing apparatus according to claim 1, wherein the recording unit performs recording by moving a print head in a direction intersecting the conveyance direction of the medium.

3. The printing apparatus according to claim 2, wherein the recording unit performs recording by reciprocating the print head in a direction intersecting the conveyance direction of the medium.

4. The printing apparatus according to claim 1, further comprising a temperature detection unit that detects the temperature of the conveyance unit, wherein the control unit acquires the temperature information of the conveyance belt from the temperature detection unit.

5. The printing apparatus according to claim 2, wherein the control unit repeatedly corrects at least one of the timing or discharge speed at which ink is discharged for each print pass of the print head.

6. The printing apparatus according to claim 1, wherein the control unit repeatedly corrects at least one of the timing or discharge speed at which ink is discharged until the temperature of the conveyance unit reaches a predetermined temperature.

7. The printing apparatus according to claim 1, wherein the control unit acquires print start information including a print start time, and estimates the temperature of the conveyance belt based on the elapsed time from the print start time to obtain the temperature information.

8. The printing apparatus according to claim 1, wherein the control unit repeatedly corrects at least one of the timing or discharge speed at which ink is discharged until the elapsed time reaches a predetermined time.

9. A printing method in which a conveyance belt having an adhesive layer formed on its surface supports and conveys a medium with the adhesive layer, and performs recording by discharging ink onto the supported medium, and heats the adhesive layer, the method comprising: a step of acquiring temperature information of the conveyance belt; a step of acquiring temperature information of the conveyance belt; A printing method characterized by performing a step of correcting at least one of the timing or the discharge speed of discharging the ink based on the acquired temperature information.

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