Liquid dispensing device

Abstract

To prevent a user from suffering from a feeling of unpleasant noise as much as possible when determining whether liquid is normally discharged from a nozzle.SOLUTION: Discharge determination processing for determining whether ink is normally discharged from a nozzle is executed on the basis of a discharge determination signal to be output when an ink jet head is caused to perform inspection drive. When a first condition is satisfied (S101:YES), first discharge determination processing for causing the ink jet head to perform the inspection drive after performing a preparatory operation is executed as the discharge determination processing (S102). When the first condition is not satisfied (a second condition is satisfied) (S101:NO), second discharge determination processing for causing the ink jet head to perform inspection drive without performing the preparatory operation is executed as the discharge determination processing (S103). The preparatory operation includes carriage drive for driving a carriage motor and positioning a carriage at a maintenance position.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection device that ejects liquid from a nozzle. [Background technology]

[0002] As an example of a liquid ejection device that ejects liquid from nozzles, Patent Document 1 describes an inkjet printer that performs recording by ejecting ink from nozzles. The inkjet printer described in Patent Document 1 has a test area including an electrode member provided in a capping member that covers the nozzles. Then, with a potential difference generated between the print head and the test area, the print head is caused to eject ink from the nozzles toward the test area, and based on the change in voltage in the test area, it is inspected whether ink has been ejected properly from the nozzles. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-136858 Summary of the Invention [Problem to be solved by the invention]

[0004] Some inkjet printers have a carriage position detection mechanism such as an encoder and encoder sensor. This carriage position detection mechanism determines the exact current position of the carriage by integrating encoder pulses from a specific position. However, once the encoder sensor is turned off, the encoder pulses obtained when the sensor is off cannot be acquired, reducing the reliability of the current carriage position. Therefore, in inkjet printers such as those described in Patent Document 1, when the print head is caused to eject ink from the nozzles toward an inspection area to check whether the ink is ejected properly from the nozzles, the print head is moved to a position where the nozzles face the inspection area every time.

[0005] However, when the user is not using the inkjet printer, if the print head is moved to a position where the nozzles face the inspection area, the user may find the carriage driving noise unpleasant.

[0006] An object of the present invention is to provide a liquid ejection device that can minimize the occurrence of unpleasant noise felt by the user when determining whether or not liquid has been ejected normally from the nozzles. [Means for solving the problem]

[0007] The liquid ejection device of the present invention comprises a liquid ejection head having nozzles for ejecting liquid, a carriage on which the liquid ejection head is mounted, a carriage movement mechanism for moving the carriage, a carriage motor which is a drive source for the carriage movement mechanism, and an ejection determination signal output unit which, when a test drive for ejecting liquid from the nozzles in the liquid ejection head is performed while the carriage is positioned at a predetermined position, outputs an ejection determination signal according to whether or not liquid has been ejected normally from the nozzles by the test drive. A memory unit; and a control unit, wherein the control unit causes the liquid ejection head to perform the test drive, and executes a discharge determination process that determines whether liquid has been normally ejected from the nozzles based on the discharge determination signal output from the discharge determination signal output unit when the test drive has been performed, and when a first condition is satisfied when the discharge determination process is performed, executes a first discharge determination process as the discharge determination process, which drives the carriage motor to cause the carriage movement mechanism to perform carriage drive to position the carriage at the predetermined position, and then causes the liquid ejection head to perform the test drive, and when a second condition different from the first condition is satisfied, executes a second discharge determination process as the discharge determination process, which causes the liquid ejection head to perform the test drive without causing the carriage movement mechanism to perform the carriage drive. The storage unit stores automatic processing information related to automatically executing the discharge determination process, and the second condition is a condition that the control unit automatically executes the discharge determination process based on the automatic processing information. . a carriage moving mechanism for moving the carriage; a carriage motor as a drive source of the carriage moving mechanism; a discharge determination signal output unit for outputting a discharge determination signal in accordance with whether or not liquid has been normally discharged from the nozzles by test drive when test drive for discharging liquid from the nozzles is performed in the liquid discharge head with the carriage positioned at a predetermined position; a storage unit; and a control unit, wherein the control unit causes the liquid discharge head to perform the test drive, and executes a discharge determination process for determining whether or not liquid has been normally discharged from the nozzles based on the discharge determination signal output from the discharge determination signal output unit when the test drive is performed, and when a first condition is met when the discharge determination process is executed, drives the carriage motor to A first ejection determination process is executed as the ejection determination process, in which the carriage movement mechanism performs carriage drive to position the carriage at the predetermined position, and then the liquid ejection head performs the inspection drive.When a second condition different from the first condition is satisfied, a second ejection determination process is executed as the ejection determination process, in which the carriage movement mechanism does not perform the carriage drive, but the liquid ejection head performs the inspection drive.Carriage position information indicating whether the carriage is located at the predetermined position is stored in the memory unit immediately before the liquid ejection device switches to a sleep state or a power-off state.The second condition is a condition in which the ejection determination process is executed after the liquid ejection device is restored from a sleep state or switched from a power-off state to a power-on state, and the carriage position information indicates that the carriage is located at the predetermined position. a carriage moving mechanism for moving the carriage; a carriage motor that is a drive source for the carriage moving mechanism; a discharge determination signal output unit that, when a test drive for discharging liquid from the nozzles is performed in the liquid discharge head with the carriage positioned at a predetermined position, outputs a discharge determination signal in accordance with whether or not liquid has been normally discharged from the nozzles by the test drive; and a control unit, wherein the control unit causes the liquid discharge head to perform the test drive, and performs a discharge determination process that determines whether or not liquid has been normally discharged from the nozzles based on the discharge determination signal output from the discharge determination signal output unit when the test drive is performed. When executing the ejection determination process, if a first condition is satisfied, a first ejection determination process is executed as the ejection determination process, in which the carriage motor is driven to cause the carriage movement mechanism to perform carriage drive to position the carriage at the predetermined position, and then the liquid ejection head is caused to perform the inspection drive, and when a second condition different from the first condition is satisfied, a second ejection determination process is executed as the ejection determination process, in which the carriage movement mechanism is not caused to perform the carriage drive, but the liquid ejection head is caused to perform the inspection drive, the first condition being a condition that the ejection determination process is executed at a time that is included in a predetermined time period that is part of a day, and the second condition being a condition that the ejection determination process is executed at a time that is not included in the predetermined time period. a carriage moving mechanism for moving the carriage; a carriage motor that is a drive source of the carriage moving mechanism; a discharge determination signal output unit that, when a test drive for discharging liquid from the nozzles is performed in the liquid discharge head with the carriage positioned at a predetermined position, outputs a discharge determination signal in accordance with whether liquid has been normally discharged from the nozzles by the test drive; and a control unit; wherein the control unit causes the liquid discharge head to perform the test drive, and executes a discharge determination process that determines whether liquid has been normally discharged from the nozzles based on the discharge determination signal output from the discharge determination signal output unit when the test drive is performed, and when a first condition is satisfied when the discharge determination process is executed, the control unit moves the carriage to a predetermined position; A first ejection determination process is executed as the ejection determination process, in which a motor is driven to cause the carriage movement mechanism to perform carriage drive to position the carriage at the predetermined position, and then the liquid ejection head is caused to perform the test drive.When a second condition different from the first condition is satisfied, a second ejection determination process is executed as the ejection determination process, in which the carriage movement mechanism is not caused to perform the carriage drive, but the liquid ejection head is caused to perform the test drive.In the ejection determination process, the test drive is executed for each of the multiple nozzles in turn, and it is determined whether liquid was ejected normally from the nozzle based on the ejection determination signal output from the ejection determination signal output unit when the test drive is executed for each nozzle.If it is determined in the second ejection determination process that liquid was not ejected normally consecutively from a predetermined number of the nozzles, the second ejection determination process is discontinued. a control unit; and a control section. The liquid ejection device of the present invention includes a liquid ejection head having nozzles that eject liquid, a carriage on which the liquid ejection head is mounted, a carriage movement mechanism that moves the carriage, a carriage motor that is a drive source of the carriage movement mechanism, a discharge determination signal output unit that, when a test drive is performed to eject liquid from the nozzles in the liquid ejection head with the carriage positioned at a predetermined position, outputs a discharge determination signal in accordance with whether or not liquid has been normally ejected from the nozzles by the test drive, a cap that covers the nozzles, a cap movement mechanism that moves the cap between a cap position for covering the nozzles and an uncap position spaced apart from the liquid ejection head, a cap motor that is a drive source of the cap movement mechanism, and a control section. The discharge determination signal output unit includes an electrode arranged in the cap, and a voltage supply unit that generates a potential difference between the liquid ejection head and the electrode, and the predetermined position is a position of the carriage where the nozzles face the cap, and when the carriage is positioned at the predetermined position and the cap and outputs, as the ejection determination signal, a signal corresponding to an electrical change when the liquid ejection head is driven for inspection with the cap positioned at the cap position and a potential difference generated between the liquid ejection head and the electrode by the voltage supply unit; the control unit causes the liquid ejection head to perform the inspection drive, and executes an ejection determination process for determining whether or not liquid has been normally ejected from the nozzle based on the ejection determination signal output from the ejection determination signal output unit when the inspection drive is performed; when executing the ejection determination process, if a first condition is satisfied, the control unit executes a first ejection determination process as the ejection determination process, which drives the carriage motor to cause the carriage movement mechanism to perform carriage drive to position the carriage at the predetermined position, and then causes the liquid ejection head to perform the inspection drive; and when a second condition different from the first condition is satisfied, the control unit executes a second ejection determination process as the ejection determination process, which causes the liquid ejection head to perform the inspection drive without causing the carriage movement mechanism to perform the carriage drive;The cap motor is driven to cause the cap moving mechanism to perform cap driving for positioning the cap at the cap position, and the carriage moving mechanism is caused to perform the carriage driving, and then the liquid ejection head is caused to perform the inspection driving, and in the second ejection determination process, the cap moving mechanism is not caused to perform the cap driving, and the carriage moving mechanism is not caused to perform the carriage driving, and the liquid ejection head is caused to perform the inspection driving. [Effects of the Invention]

[0008] When the ejection determination process is executed, if the first condition is satisfied, a first ejection determination process is executed as the ejection determination process, in which carriage driving is performed and then inspection driving is performed, and if the second condition is satisfied, a second ejection determination process is executed as the ejection determination process, in which inspection driving is performed without carriage driving.

[0009] In the first ejection determination process, the carriage is driven to position the carriage at a predetermined position, which generates carriage motor drive noise, but it is possible to reliably determine whether liquid is ejected normally from the nozzles. On the other hand, in the second ejection determination process, the carriage is not driven but instead driven for testing, so no carriage motor drive noise is generated.

[0010] The second condition is set to a condition that makes the carriage motor drive sound unpleasant to the user, and by executing the second ejection determination process when the second condition is met, it is possible to prevent the carriage motor drive sound from being generated in situations that make the user feel uncomfortable.On the other hand, by executing the first ejection determination process when a first condition different from the second condition is met, it is possible to reliably determine whether or not liquid is ejected normally from the nozzles.

[0011] Furthermore, since the situation in which the carriage is not positioned in the specified position in the liquid ejection device immediately before the ejection determination process is executed does not occur very often, even when the carriage is not driven but a test drive is performed, a situation in which it is not possible to determine whether liquid has been ejected normally from the nozzle does not occur very often. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic configuration diagram of a printer according to a first embodiment. [Figure 2] 3A and 3B are diagrams for explaining electrodes arranged in a cap and the connection relationship between the electrodes and a high-voltage power supply circuit and a signal processing circuit. [Figure 3] FIG. 1(a) is a diagram showing the signal output from the signal processing circuit when ink is ejected from the nozzle during test drive, and FIG. 1(b) is a diagram showing the signal output from the signal processing circuit when ink is not ejected from the nozzle during test drive. [Figure 4] FIG. 2 is a block diagram showing the electrical configuration of the printer. [Figure 5] 10A is a flowchart showing the flow of a process for determining whether ink has been ejected normally from a nozzle, and FIG. 10B is a diagram for explaining a first condition. [Figure 6] 10 is a flowchart showing the flow of a process for determining whether ink has been normally ejected from the nozzles in the second embodiment. [Figure 7] 10A is a flowchart showing the flow of processing performed when returning from a sleep state and when the power is turned on in the second embodiment, and FIG. 10B is a diagram for explaining the second condition. [Figure 8] 10 is a flowchart showing the flow of processing for determining whether ink has been normally ejected from the nozzles in an example in which the second ejection determination process is stopped if the nozzles are not covered with caps. [Figure 9] FIG. 10 is a diagram for explaining a first condition in an example in which the second discharge determination process is stopped when the nozzle is not covered with a cap. DETAILED DESCRIPTION OF THE INVENTION

[0013] [First embodiment] A first preferred embodiment of the present invention will now be described.

[0014] <Overall printer configuration> As shown in FIG. 1, the printer 1 (the "liquid ejection device" of the present invention) according to the first embodiment includes a carriage 2, a subtank 3, an inkjet head 4 (the "liquid ejection head" of the present invention), a platen 5, conveying rollers 6 and 7, a maintenance unit 8, an outlet 9, etc.

[0015] The carriage 2 is supported by two guide rails 11 and 12 extending in the scanning direction. In the following description, the right and left sides of the scanning direction are defined as shown in FIG. 1. The carriage 2 is connected to a carriage movement mechanism 13. The carriage movement mechanism 13 has a drive pulley 21, a driven pulley 22, and a belt 23.

[0016] The drive pulley 21 is disposed at the right end of the guide rail 12. The drive pulley 21 is connected to a carriage motor 86, which is a drive source of the carriage movement mechanism 13. The driven pulley 22 is disposed at the left end of the guide rail 12. The belt 23 is an endless belt, and is wound around the drive pulley 21 and the driven pulley 22. The portion of the belt 23 between the drive pulley 21 and the driven pulley 22 in the scanning direction is fixed to the carriage 2. In the carriage movement mechanism 13, when the carriage motor 86 is driven, the drive pulley 21 rotates, causing the belt 23 to travel in the scanning direction and the driven pulley 22 to rotate in response. As the belt 23 travels in the scanning direction, the carriage 2 fixed to the belt 23 moves along the guide rails 11 and 12 in the scanning direction.

[0017] The printer 1 also includes a linear encoder 14 for acquiring information on the position of the carriage 2 in the scanning direction and the movement speed of the carriage 2. The linear encoder 14 includes an encoder belt 31 and an encoder sensor 32.

[0018] The encoder belt 31 is disposed on the guide rail 12 and extends in the scanning direction over substantially the entire length of the guide rail 12. The encoder belt 31 has a plurality of slits (not shown) aligned in the scanning direction.

[0019] The encoder sensor 32 is provided on the carriage 2. The encoder sensor 32 has a light-emitting element 36 and a light-receiving element 37. The light-emitting element 36 is located upstream of the encoder belt 31 in the transport direction perpendicular to the scanning direction. The light-receiving element 37 is located downstream of the encoder belt 31 in the transport direction. The light-emitting element 36 and the light-receiving element 37 face each other in the transport direction, and the encoder belt 31 is disposed between the light-emitting element 36 and the light-receiving element 37.

[0020] The light-emitting element 36 emits light toward the light-receiving element 37. When the light-emitting element 36 and the light-receiving element 37 face the slits of the encoder belt 31, the light emitted from the light-emitting element 36 passes through the slits and is received by the light-receiving element 37. When the light-emitting element 36 and the light-receiving element 37 face a part of the encoder belt 31 other than the slits, the light emitted from the light-emitting element 36 is blocked by the encoder belt 31, and the light is not received by the light-receiving element 37.

[0021] As the carriage 2 moves in the scanning direction, it alternates between a state in which the light receiving element 37 receives the light emitted from the light emitting element 36 and a state in which the light receiving element 37 does not receive the light emitted from the light emitting element 36. This makes it possible to obtain information about the position of the carriage 2 in the scanning direction based on the number of times the above two states are switched (the number of slits passed) when the carriage 2 is moved in the scanning direction, for example, from a maintenance position described below. Furthermore, it is possible to obtain information about the moving speed of the carriage 2 based on the time interval between the above two states.

[0022] The positional relationship between the light-emitting element 36 and the light-receiving element 37 in the encoder sensor 32 may be reversed from that described above. In addition, in the first embodiment, the encoder sensor is a so-called transmissive type in which the encoder belt 31 is disposed between the light-emitting element 36 and the light-receiving element 37 in the conveying direction, but this is not limited to this. The encoder sensor may be a so-called reflective type in which the light-emitting element and the light-receiving element are located on the same side of the encoder belt in the conveying direction. In this case, when the carriage 2 is moved in the scanning direction, the state alternates between one in which the light-receiving element receives light that is emitted from the light-emitting element and reflected by the encoder belt, and another in which the light-emitting element transmits through the encoder belt and does not receive the light.

[0023] The subtank 3 is mounted on the carriage 2. The subtank 3 is connected to four ink cartridges (not shown) via tubes (not shown). The four ink cartridges store black, yellow, cyan, and magenta ink ("liquid" according to the present invention), respectively, and the four ink cartridges supply the above four colors of ink to the subtank 3.

[0024] The inkjet head 4 is mounted on the carriage 2 and connected to the lower end of the subtank 3. The inkjet head 4 is supplied with the four colors of ink from the subtank 3. The inkjet head 4 ejects ink from a plurality of nozzles 10 formed on its lower surface, a nozzle face 4a. More specifically, the plurality of nozzles 10 are arranged in the transport direction to form nozzle rows 19, and on the nozzle face 4a, four nozzle rows 19 are lined up in the scanning direction. Black, yellow, cyan, and magenta inks are ejected from the plurality of nozzles 10 in that order, starting from the nozzles constituting the nozzle row 19 on the right side in the scanning direction.

[0025] The platen 5 is disposed below the inkjet head 4 and faces the multiple nozzles 10. The platen 5 extends over the entire length of the recording paper P in the scanning direction and supports the recording paper P from below. The transport roller 6 is disposed upstream of the inkjet head 4 and platen 5 in the transport direction. The transport roller 7 is disposed downstream of the inkjet head 4 and platen 5 in the transport direction. The transport rollers 6 and 7 are connected to a transport motor 87 (see FIG. 4) via gears and the like (not shown). When the transport motor 87 is driven, the transport rollers 6 and 7 rotate and the recording paper P is transported in the transport direction.

[0026] The maintenance unit 8 includes a cap 71, a suction pump 72, and a waste liquid tank 73. The cap 71 is disposed to the right of the platen 5 in the scanning direction. When the carriage 2 is positioned at a maintenance position (the "predetermined position" of the present invention) to the right of the platen 5 in the scanning direction, the multiple nozzles 10 face the cap 71.

[0027] The cap 71 is also connected to a cap lifting mechanism 74 (the "cap moving mechanism" of the present invention). The cap lifting mechanism 74 is connected to a cap motor 88 (see FIG. 4). When the cap motor 88 is driven, the cap lifting mechanism 74 raises and lowers the cap 71 between a cap position for covering the nozzles 10 and an uncap position that is lower than the cap position and away from the inkjet head 4. When the carriage 2 is positioned at the maintenance position so that the plurality of nozzles 10 and the cap 71 face each other, the cap lifting mechanism 74 raises the cap 71 to the cap position. This brings the upper end of the cap 71 into close contact with the nozzle surface 4a, covering the plurality of nozzles 10. When the cap 71 is positioned at the uncap position, the plurality of nozzles 10 are not covered by the cap 71. Note that the cap 71 does not necessarily have to cover the plurality of nozzles 10 by coming into close contact with the nozzle surface 4a. The cap 71 may cover the nozzles 10 by being attached to a frame (not shown) or the like that is arranged around the nozzle surface 4 a of the inkjet head 4 , for example.

[0028] The suction pump 72 is a tube pump or the like, and is connected to the cap 71 and the waste liquid tank 73. In the maintenance unit 8, when the suction pump 72 is driven with the cap 71 in place, it is possible to perform a so-called suction purge, which discharges ink from the inkjet head 4 through the multiple nozzles 10. The ink discharged by the suction purge is stored in the waste liquid tank 73.

[0029] For convenience, the cap 71 has been described as covering all of the nozzles 10 together, and ink in the inkjet head 4 is discharged from all of the nozzles 10 during suction purging. However, this is not limiting. For example, the cap 71 may have separate portions covering the nozzles 10 constituting the rightmost nozzle row 19 that ejects black ink and the nozzles 10 constituting the three leftmost nozzle rows 19 that eject color inks (yellow, cyan, and magenta ink), so that either the black ink or the color ink in the inkjet head 4 can be selectively discharged during suction purging. Alternatively, for example, a cap 71 may be provided for each nozzle row 19, and ink may be discharged from the nozzles 10 for each nozzle row 19 individually during suction purging.

[0030] As shown in FIG. 2, an electrode 76 having a rectangular planar shape is disposed within the cap 71. The electrode 76 is connected to a high-voltage power supply circuit 77 (referred to as a "voltage supply unit" in the present invention) via a resistor 79. The high-voltage power supply circuit 77 applies a predetermined voltage (e.g., approximately 600 V) to the electrode 76 when performing the test drive described below. Meanwhile, the inkjet head 4 is maintained at ground potential. This generates a predetermined potential difference between the inkjet head 4 and the electrode 76. A signal processing circuit 78 is connected to the electrode 76. The signal processing circuit 78 includes a differentiation circuit and outputs an ejection determination signal corresponding to the voltage of the electrode 76. However, the signal output from the signal processing circuit 78 may be a current signal. In the first embodiment, the electrode 76, the high-voltage power supply circuit 77, the signal processing circuit 78, and the resistor 79 together correspond to the "ejection determination signal output unit" in the present invention.

[0031] In the first embodiment, a predetermined voltage is applied to the electrode 76, the inkjet head 4 is held at ground potential, and the signal processing circuit 78 outputs a signal corresponding to the voltage of the electrode 76. However, the present invention is not limited to this. Alternatively, the electrode 76 may be held at ground potential and a predetermined voltage may be applied to the inkjet head 4, thereby generating a potential difference between the electrode 76 and the inkjet head 4, and the signal processing circuit 78 may be connected to the inkjet head 4 and output an ejection determination signal corresponding to the voltage of the inkjet head 4.

[0032] In the above-described cap state, when a voltage is applied to the electrode 76 by the high-voltage power supply circuit 77 and the inspection driving described below is not performed, the voltage of the signal output from the signal processing circuit 78 becomes the voltage V0 shown in Figures 3(a) and (b).

[0033] Furthermore, in the first embodiment, after the capping is performed, a test drive can be performed in which the inkjet head 4 is driven to eject ink from the nozzles 10 toward the electrodes 76 while a voltage is applied to the electrodes 76 by the high-voltage power supply circuit 77.

[0034] When ink is ejected from the nozzle 10 by the test drive, the ink ejected from the nozzle 10 is charged. As a result, the charged ink approaches the electrode 76, and the potential of the electrode 76 changes until the ink lands on the electrode 76. Then, after the charged ink lands on the electrode 76, the potential of the electrode 76 attenuates and returns to the potential before the ink was ejected.

[0035] 3(a), the signal output from the signal processing circuit 78 rises from voltage V0 to voltage V1, which is greater than voltage V0, then drops to voltage V2, which is less than voltage V0, and then repeats rising and falling while attenuating before returning to voltage V0. As a result, the signal output from the signal processing circuit 78 becomes a signal whose maximum value is voltage V1 and whose minimum value is voltage V2.

[0036] On the other hand, if ink is not ejected from the nozzle 10 by the test drive, the signal output from the signal processing circuit 78 will hardly change from the voltage V0, as shown in FIG. 3(b).

[0037] In this way, in the first embodiment, the signal output from the signal processing circuit 78 differs depending on whether or not ink has been ejected from the nozzle 10 by the test drive. In the first embodiment, this fact is used to determine whether or not ink has been ejected normally from the nozzle 10.

[0038] For example, if the difference between the maximum and minimum values ​​of the signal output from the signal processing circuit 78 is equal to or greater than a threshold value, it is determined that ink has been ejected normally from the nozzle 10. If the difference between the maximum and minimum values ​​is less than the threshold value, it is determined that ink has not been ejected normally from the nozzle 10. In this case, the maximum value is the maximum value in a portion of a predetermined determination period starting from the timing at which the test drive is performed, the portion of the determination period including the timing at which the value of the signal output from the signal processing circuit 78 is estimated to be maximum when ink is ejected from the nozzle 10 by the test drive. Alternatively, the maximum value may be the maximum value in the entire determination period. Furthermore, the minimum value is the minimum value in a portion of the determination period including the timing at which the value of the signal output from the signal processing circuit 78 is estimated to be minimum when ink is ejected from the nozzle 10 by the test drive. Alternatively, the minimum value may be the minimum value in the entire determination period.

[0039] Furthermore, in the first embodiment, whether ink has been ejected normally from the nozzle 10 is determined based on whether the difference between the maximum and minimum values ​​of the signal output from the signal processing circuit 78 is equal to or greater than a threshold value, but this is not limiting. For example, whether ink has been ejected normally from the nozzle 10 may be determined based on other criteria, such as whether the maximum value is equal to or greater than a threshold value, or whether the minimum value is equal to or less than a threshold value, etc.

[0040] The outlet 9 can be connected to an AC power supply (not shown). When the outlet 9 is plugged in and connected to the AC power supply, power is supplied to the printer 1. When the outlet 9 is unplugged, power is not supplied to the printer 1.

[0041] <Printer electrical configuration> Next, the electrical configuration of the printer 1 will be described. As shown in Figure 4, the printer 1 is equipped with a control unit 80. The control unit 80 is made up of a CPU (Central Processing Unit) 81, a ROM (Read Only Memory) 82, a RAM (Random Access Memory) 83, a flash memory 84 (the "storage unit" of the present invention), an ASIC (Application Specific Integrated Circuit) 85, and the like. The control unit 80 controls the operation of a carriage motor 86, an inkjet head 4, a conveying motor 87, a cap motor 88, a suction pump 72, a high-voltage power supply circuit 77, and the like. The control unit 80 also receives signals from the encoder sensor 32 and the signal processing circuit 78.

[0042] In addition to the components described above, the printer 1 also includes a display unit 69, an operation unit 68 (a "signal receiving unit" according to the present invention), and a clock unit 67. The display unit 69 is, for example, a liquid crystal display provided on the housing of the printer 1. The control unit 80 controls the display unit 69 to display necessary information on the display unit 69. The operation unit 68 is, for example, buttons provided on the housing of the printer 1 or a touch panel provided on the display unit 69. The operation unit 68 receives signals based on user operations and transmits the received signals to the control unit 80. The clock unit 67 transmits a signal indicating the current time to the control unit 80.

[0043] The control unit 80 may be configured such that only the CPU 81 performs various processes, or such that only the ASIC 85 performs various processes, or such that the CPU 81 and the ASIC 85 work together to perform various processes. The control unit 80 may be configured such that one CPU 81 performs processes independently, or such that multiple CPUs 81 share the processes. The control unit 80 may be configured such that one ASIC 85 performs processes independently, or such that multiple ASICs 85 share the processes.

[0044] <Processing during recording> Next, a description will be given of the processing of the control unit 80 when recording on recording paper P in the printer 1. In the first embodiment, for example, when a user performs an operation on the operation unit 68 to instruct recording on recording paper P, a recording command instructing recording is sent from the operation unit 68 to the control unit 80, and the control unit 80 receives this recording command.

[0045] Then, upon receiving a recording command, the control unit 80 controls the conveyance motor 87 and a paper feeder (not shown) to supply the recording paper P. Next, the control unit 80 drives the carriage motor 86 to cause the carriage movement mechanism 13 to move the carriage 2 in the scanning direction, while repeatedly causing the inkjet head 4 to eject ink from the multiple nozzles 10 toward the recording paper P, and drives the conveyance motor 87 to cause the conveyance rollers 6 and 7 to convey the recording paper P a predetermined distance in the conveyance direction, thereby performing recording on the recording paper P. After recording on the recording paper P is completed, the control unit 80 drives the conveyance motor 87 to cause the conveyance rollers 6 and 7 to eject the recording paper P on which recording has been completed.

[0046] <Processing when determining discharge> Next, a description will be given of the processing of the control unit 80 when determining whether or not ink has been normally ejected from the nozzle 10. In the first embodiment, the ejection determination processing for determining whether or not ink has been normally ejected from the nozzle 10 is executed by performing processing according to the flow of Fig. 5(a).

[0047] The flow in Fig. 5(a) starts when a user operates the operation unit 68 to instruct a test to determine whether ink is being ejected normally from the nozzles 10, and the control unit 80 receives a signal corresponding to that operation from the operation unit 68. Alternatively, the control unit 80 automatically starts the processing of the flow in Fig. 5(a) based on automatic processing information stored in the flash memory 84 that relates to automatically executing the ejection determination process.

[0048] For example, the printer 1 is configured to store information specifying the time at which the discharge determination process is to be automatically executed as automatic processing information in the flash memory 84 based on the user's operation of the operation unit 68. When the information specifying this time is stored in the flash memory 84, the control unit 80 automatically performs processing according to the flow of Fig. 5(a) when it receives a signal indicating that the time has arrived from the clock unit 67. However, the automatic processing information is not limited to information specifying the time at which the discharge determination process is to be automatically executed, and may be other information.

[0049] 5(a) in more detail, the control unit 80 determines whether a first condition, which will be described next, is satisfied (S101). If the first condition is satisfied (S101: YES), the control unit 80 executes a first ejection determination process as the ejection determination process (S102). If the first condition is not satisfied (S101: NO), the control unit 80 executes a second ejection determination process as the ejection determination process (S103).

[0050] <First condition> Here, the first condition will be explained. FIG. 5(b) shows a list of the first conditions. Information on these first conditions is stored in the flash memory 84. In the first embodiment, conditions A1 to A3 are set as the first conditions. Condition A1 is a condition that "the discharge determination process is executed first after power is supplied to the printer 1." Condition A2 is a condition that "the discharge determination process is executed immediately before recording based on a recording command from the user, immediately after the recording, or during the recording." Condition A3 is a condition that "the discharge determination process is executed at a time included in a predetermined time period." Then, when any of conditions A1 to A3 is satisfied, the control unit 80 determines in S101 that the first condition is satisfied.

[0051] Regarding condition A1, "after power is supplied to the printer 1" means, for example, "after the outlet 9 is plugged in and connected to an AC power source."

[0052] Regarding condition A2, for example, if information specifying the time to automatically execute the discharge determination process is stored in flash memory 84 as automatic processing information, and if the discharge determination process is not executed automatically at the specified time for some reason, such as the power outlet 9 being unplugged and no power being supplied to the printer 1, the discharge determination process is executed by performing processing according to the flow in Fig. 5(a) immediately before the first subsequent recording on the recording paper P. Also, for example, if the discharge determination process is not executed at the specified time and the first subsequent recording on the recording paper P is in high-speed mode, the discharge determination process is not executed immediately before the recording, but is executed by performing processing according to the flow in Fig. 5(a) immediately after the recording.

[0053] Also, for example, when a paper jam occurs during recording on recording paper P and the jammed recording paper P is then removed by the user, the discharge determination process is executed by performing processing according to the flow of Figure 5(a) before resuming recording on the recording paper P.

[0054] Regarding condition A3, the predetermined time period is a time period during which the user is unlikely to feel uncomfortable even if the driving noise of the carriage motor 86 and the cap motor 88 is generated, such as during the day.

[0055] In the first embodiment, the condition that the first condition is not satisfied corresponds to the "second condition" of the present invention. That is, when the second condition is satisfied, the control unit 80 executes the second discharge determination process as the discharge determination process.

[0056] <First Discharge Judgment Process> In the first discharge determination process of S102, the control unit 80 performs a preparatory operation to achieve the capped state (positioning the carriage 2 at the maintenance position and positioning the cap 71 at the capped position) (S201). The preparatory operation includes carriage drive (S201a) performed by the carriage moving mechanism 13 by driving the carriage motor 86, and cap drive (S201b) performed by the cap lifting mechanism 74 by driving the cap motor 88.

[0057] For example, the control unit 80 drives the cap lifting mechanism 74 by rotating the cap motor 88 a predetermined amount in the same direction as when the cap lifting mechanism 74 lifts the cap 71. As a result, if the cap 71 is located at the cap position, the cap 71 does not move and remains at the cap position. On the other hand, if the cap 71 is located below the cap position, the cap 71 is lifted to the cap position.

[0058] Next, the control unit 80 drives the carriage movement mechanism 13 by rotating the carriage motor 86 a predetermined amount. At this time, if the carriage 2 is located at the maintenance position, the cap 71 is in close contact with the nozzle surface 4a, and the movement of the carriage 2 in the scanning direction is restricted by a carriage rocker (not shown) that is integral with the cap 71, so the carriage 2 does not move and the signal output from the encoder sensor 32 does not change. On the other hand, if the carriage 2 is located at a position other than the maintenance position, the carriage 2 moves in the scanning direction, and the signal output from the encoder sensor 32 changes. As a result, it is possible to confirm that the carriage 2 is in the capped state based on the fact that the output from the encoder sensor 32 does not change.

[0059] On the other hand, when the carriage 2 moves and the signal output from the encoder sensor 32 changes, the control unit 80 further drives the cap motor 88 to cause the cap lifting mechanism 74 to lower the cap 71 to the uncapped position, and then drives the carriage motor 86 to cause the carriage moving mechanism 13 to move the carriage 2 to the maintenance position. Thereafter, the cap motor 88 is driven to cause the cap lifting mechanism 74 to lift the cap 71 to the capped position.

[0060] After such preparatory operations are performed, the carriage is in the capped state. That is, the carriage driving in the preparatory operations is for positioning the carriage 2 at the maintenance position. Also, the cap driving in the preparatory operations is for positioning the cap 71 at the cap position.

[0061] Next, the control unit 80 sets one of the plurality of nozzles 10 of the inkjet head 4 as a target nozzle for determining whether ink has been ejected normally (S202). Next, the control unit 80 causes the inkjet head 4 to perform a test drive to eject ink from the target nozzle (S203). Then, when the test drive is performed, the control unit 80 determines whether ink has been ejected normally from the target nozzle based on the ejection determination signal output from the signal processing circuit 78, and stores information on the determination result in the flash memory 84 (S204).

[0062] Next, if the control unit 80 determines whether or not ink has been ejected normally for any of the nozzles 10 in the inkjet head 4 (S205: NO), it changes the target nozzle to another nozzle 10 for which it has not been determined whether or not ink has been ejected normally (S206) and returns to S203. If it has been determined whether or not ink has been ejected normally for all of the nozzles 10 in the inkjet head 4 (S205: YES), the process ends.

[0063] <Second Discharge Judgment Process> In the second discharge determination process of S103, the control unit 80 executes the processes of S301 to S305, which are the same as S202 to S206 in the first discharge determination process. That is, in the second discharge process, the control unit 80 does not execute the preparatory operations (carriage drive and cap drive), but executes operations such as test drive to determine whether ink has been normally discharged from the nozzles 10.

[0064] <Effects> In the first embodiment, when the ejection determination process is executed, if the first condition is met, a first ejection determination process is executed as the ejection determination process, in which a preparatory operation including carriage drive to position the carriage 2 at the maintenance position is performed, and then an inspection drive is performed. Also, in the first embodiment, when the ejection determination process is executed, if the first condition is not met, a second ejection determination process is executed as the ejection determination process, in which an inspection drive is performed without performing a preparatory operation, assuming that the second condition is met.

[0065] In the first discharge determination process, the carriage motor 86 generates driving noise due to carriage drive, but the carriage 2 can be driven for inspection with the carriage 2 securely positioned at the maintenance position. On the other hand, in the second discharge determination process, the carriage motor 86 does not generate driving noise due to carriage drive because the carriage is driven for inspection without performing preparatory operations.

[0066] Then, if the first condition is set so that the first condition is not met (the second condition is met) in a situation where the user is likely to find the driving sound of the carriage motor 86 unpleasant, then when the first condition is met, the first ejection determination process is executed, thereby making it possible to reliably determine whether or not ink has been ejected normally from the nozzles 10. Furthermore, when the first condition is not met (the second condition is met), the second ejection determination process is executed, thereby making it possible to prevent the driving sound of the carriage motor 86 from being generated in a situation where the user is likely to find the driving sound unpleasant.

[0067] Here, in the second ejection determination process, the test drive is performed without confirming whether the carriage 2 is positioned at the maintenance position. However, because the situation in which the carriage 2 is not positioned at the maintenance position in the printer 1 immediately before the ejection determination process is performed does not occur very often, even when the test drive is performed without performing the preparatory operation, a situation in which it cannot be determined whether ink has been ejected normally from the nozzles 10 does not occur very often.

[0068] Furthermore, in the second ejection determination process, if the test drive is performed while the carriage 2 is positioned at the maintenance position, the ink ejected from the nozzles 10 by the test drive will adhere to the platen 5, etc. However, since the amount of ink ejected from the nozzles 10 by the test drive is not that large, no major problem will occur.

[0069] Furthermore, when the ejection determination process is executed for the first time after power is supplied to the printer 1, there is a higher possibility that the carriage 2 will not be positioned in the maintenance position compared to when the ejection determination process is executed thereafter.

[0070] Therefore, in the first embodiment, the condition A1 is set as the first condition, which is to execute the ejection determination process first after power is supplied to the printer 1. As a result, when the ejection determination process is executed in a situation where it is highly likely that the carriage 2 is not positioned at the maintenance position, by executing the first ejection determination process, it is possible to reliably determine whether ink has been ejected normally from the nozzles 10.

[0071] Furthermore, when recording on recording paper P, the driving sound of carriage motor 86 is generated during a recording pass, but when recording on recording paper P is performed based on a recording command from the user, the user normally tolerates the driving sound of carriage motor 86 generated during recording. Therefore, even if the driving sound of carriage motor 86 generated by carriage drive is generated immediately before, immediately after, and during the recording, the user is unlikely to find it unpleasant.

[0072] Therefore, in the first embodiment, condition A2, which requires that the ejection determination process be executed immediately before, immediately after, or during recording based on a recording command from the user, is set as the first condition. As a result, when the ejection determination process is executed in a situation where the user is unlikely to find the driving sound of the carriage motor 86 unpleasant, it is possible to reliably determine whether ink has been ejected normally from the nozzles 10 by executing the first ejection determination process.

[0073] Furthermore, whether or not a user finds the driving sound of the carriage motor 86 unpleasant varies depending on the time of day. For example, a user is less likely to find the driving sound of the carriage motor 86 unpleasant during the day, but is more likely to find it unpleasant at night.

[0074] Therefore, in the first embodiment, the condition A3 that the discharge determination process is executed at a time included in a predetermined time period that is part of a day is set as the first condition. In this case, if the time at which the discharge determination process is executed is a time that is not included in the predetermined time period of a day, the first condition is not met. In other words, in the first embodiment, the condition that the discharge determination process is executed at a time that is not included in the predetermined time period of a day is set as the second condition.

[0075] As a result, when the ejection determination process is executed during a time period when the user is unlikely to find the driving sound of the carriage motor 86 unpleasant, the first ejection determination process can be executed to reliably determine whether or not ink has been ejected normally from the nozzles 10. Furthermore, when the ejection determination process is executed during a time period when the user is likely to find the driving sound of the carriage motor 86 unpleasant, the second ejection determination process can be executed to prevent the driving sound of the carriage motor 86 from being generated.

[0076] Furthermore, in the first embodiment, in the first ejection determination process, the test drive is performed after performing preparatory operations including cap drive to position the cap 71 at the cap position and carriage drive to position the carriage 2 at the maintenance position, so that the test drive can be performed in the capped state (the cap 71 is at the cap position and the carriage 2 is at the maintenance position) although drive sounds of the cap motor 88 and the carriage motor 86 are generated. As a result, it can be more accurately determined whether ink has been ejected normally from the nozzles 10.

[0077] On the other hand, in the second ejection determination process, by performing the test drive without performing the preparatory operations (cap drive and carriage drive), the driving noise of the cap motor 88 and the carriage motor 86 is not generated, making it less likely to be unpleasant for the user. Here, in the second ejection determination process, the test drive is performed without confirming whether the printer 1 is in the capped state. However, since a situation in which the printer 1 is not in the capped state immediately before the ejection determination process is executed does not occur very often, even when the test drive is performed without performing the preparatory operations, a situation in which it is not possible to determine whether ink has been ejected normally from the nozzles 10 does not occur very often.

[0078] [Second embodiment] Next, a second preferred embodiment of the present invention will be described. The second embodiment also relates to a printer 1 similar to that of the first embodiment. However, unlike the first embodiment, in the second embodiment, the control unit 80 executes the discharge determination process by performing processing according to the flow of FIG.

[0079] To explain the flow of FIG. 6 in more detail, the control unit 80 determines whether a second condition, which will be described later, is satisfied (S401).

[0080] If the second condition is satisfied (S401: YES), the control unit 80 executes the second discharge determination process as the discharge determination process (S402). If the second condition is not satisfied (S401: NO), the control unit 80 executes the first discharge determination process as the discharge determination process (S403).

[0081] In the second discharge determination process of S402, the control unit 80 executes the processes of S301 to S305, similar to the second discharge determination process of S103 in the first embodiment. In the first discharge determination process of S403, the control unit 80 executes the processes of S201 to S206, similar to the first discharge determination process of S102 in the first embodiment.

[0082] In addition, in the second embodiment, when the printer 1 returns from a sleep state, and when the printer 1 switches from a power-off state to a power-on state, the control unit 80 performs processing in accordance with the flow of Figure 7(a).

[0083] Here, the power-off state refers to a state in which the supply of power to almost all parts of the printer 1 is stopped, except for the clock unit 67, etc. On the other hand, the sleep state refers to a state in which the supply of power to some motors, etc. of the printer 1 is stopped. The sleep state consumes more power than the power-off state. On the other hand, the time required to return to a state in which recording on the recording paper P is possible after returning from the sleep state is shorter than the time required to return to a state in which recording on the recording paper P is possible after switching from the power-off state to the power-on state.

[0084] 7(a) in more detail, the control unit 80 waits until it receives either a sleep signal that instructs the printer 1 to go into sleep mode or a power-off signal that instructs the printer 1 to be powered off (S501: NO, S502: NO). The sleep signal and the power-off signal are sent from the operation unit 68 to the control unit 80 based on, for example, an operation of the operation unit 68 by the user.

[0085] When the sleep signal is received (S501: YES), the control unit 80 stores confirmation information ("carriage position information" of the present invention) in the flash memory 84 (S503). The confirmation information is information indicating whether or not the state is capped, that is, whether or not the carriage 2 is located at the maintenance position and the cap 71 is located at the cap position.

[0086] In S503, the control unit 80 stores confirmation information in the flash memory 84 based on the state of the printer 1 when the sleep signal was received. For example, if the control unit 80 receives the sleep signal when the printer 1 is definitely in the capped state, such as when the printer 1 is in a standby state where it is not recording on recording paper P, the control unit 80 stores confirmation information indicating that the printer 1 is in the capped state in the flash memory 84. Furthermore, if the sleep signal is received in a state other than the above, the control unit 80 stores confirmation information in the flash memory 84 indicating that it is unclear whether the printer 1 is in the capped state.

[0087] After storing the confirmation signal in the flash memory 84 in S503, the control unit 80 executes sleep processing (S504) and ends the processing. In the sleep processing in S504, the control unit 80 stops the supply of power to some of the motors and the like of the printer 1.

[0088] When the power-off signal is received (S502: YES), the control unit 80 stores confirmation information in the flash memory 84 (S505). In S505, the control unit 80 stores the confirmation information in the flash memory 84 based on the state of the printer 1 when the power-off signal was received. For example, if the control unit 80 receives the power-off signal when the printer 1 is definitely in the capped state, such as when the printer 1 is in a standby state where it is not recording on recording paper P, the control unit 80 stores a confirmation signal indicating that the printer 1 is in the capped state in the flash memory 84. Furthermore, if the control unit 80 receives the power-off signal in a state other than the above, the control unit 80 stores confirmation information in the flash memory 84 indicating that it is unclear whether the printer 1 is in the capped state.

[0089] After storing the confirmation signal in the flash memory 84 in S505, the control unit 80 executes a power-off process (S506) and ends the process. In the power-off process of S506, the control unit 80 stops the supply of power to parts of the printer 1 other than the clock unit 67, etc.

[0090] <Second condition> Next, the second condition will be described. FIG. 7B shows a list of the second conditions. Information on these second conditions is stored in the flash memory 84. In the second embodiment, conditions B1 to B3 are set as the second conditions. Condition B1 is a condition that "the printer 1 is automatically restored from a sleep state or switched from a power-off state to a power-on state, and then the discharge determination process is executed, and the confirmation information stored in the flash memory 84 indicates that the printer 1 is in a capped state (the carriage 2 is located at the maintenance position)." Condition B2 is a condition that "the discharge determination process is executed automatically at a specified time." Condition B3 is a condition that "the discharge determination process is executed at a time of day that is not included in a predetermined time period." Then, if any of conditions B1 to B3 is satisfied, the control unit 80 determines in S401 that the second condition is satisfied.

[0091] In the second embodiment, the condition that the second condition is not satisfied corresponds to the "first condition" of the present invention. That is, when the first condition is satisfied, the control unit 80 executes the first discharge determination process as the discharge determination process.

[0092] <Effects> In the second embodiment, when the discharge determination process is executed, if the second condition is satisfied, a second discharge determination process is executed in which test driving is performed without performing preparatory operations. Also, in the second embodiment, when the discharge determination process is executed, if the second condition is not satisfied, a first discharge determination process is executed in which test driving is performed after performing preparatory operations, assuming that the first condition is satisfied.

[0093] As a result, if the second condition is set so that it is met in a situation where the user is likely to find the driving sound of the carriage motor 86 unpleasant, then when the first condition is met (the second condition is not met), the first ejection determination process is executed, thereby making it possible to reliably determine whether or not ink has been ejected normally from the nozzles 10. Furthermore, when the second condition is met, the second ejection determination process is executed, thereby making it possible to prevent the driving sound of the carriage motor 86 from being generated in a situation where the user is likely to find the driving sound unpleasant.

[0094] Furthermore, if the carriage motor 86 is driven to drive the carriage when the control unit 80 automatically performs the ejection determination process, rather than as a process associated with an operation performed based on the user operating the operation unit 68, the user will hear the driving sound of the carriage motor 86 at an unexpected time, which is likely to be unpleasant.

[0095] For example, when the printer 1 is in a sleep state or when the printer 1 is powered off, the user normally assumes that no noise will be generated by the printer 1. Therefore, if the automatically executed discharge determination process is executed after the printer 1 is restored from a sleep state or after the printer 1 is switched from a power-off state to a power-on state, and the carriage motor 86 is driven to drive the carriage, the user will hear the driving sound of the carriage motor 86 at an unexpected time, which is likely to be unpleasant.

[0096] On the other hand, if the printer 1 is in a capped state (the carriage 2 is in the maintenance position) when it switches to a sleep state or a power-off state, it is estimated that the nozzle 10 will remain covered by the cap 71 even when the printer 1 subsequently returns from the sleep state or switches from a power-off state to a power-on state.

[0097] Furthermore, if the discharge determination process is executed automatically at a specified time, there is no need to execute the discharge determination process immediately before recording on the recording paper P, and the time from when a recording command is received to when recording starts can be kept short. On the other hand, if the driving sound of the carriage motor 86 is generated when the discharge determination process is executed automatically at a specified time, the user may feel uncomfortable depending on the specified time, for example, if the specified time is late at night. Furthermore, even if it is not late at night, the user may not always remember the specified time for the printer 1. This may cause the user to feel uncomfortable.

[0098] For these reasons, in the second embodiment, confirmation information indicating whether the printer 1 is in the capped state (the carriage 2 is in the maintenance position) is stored in the storage unit immediately before the printer 1 switches to the sleep state or the power-off state. Then, the printer 1 is automatically restored from the sleep state or switched from the power-off state to the power-on state, and then the discharge determination process is executed, and condition B1, in which the confirmation information indicates that the printer 1 is in the capped state (the carriage 2 is in the maintenance position), is set as the second condition.

[0099] As a result, when the ejection determination process is performed in a situation where the user is likely to find the driving sound of the carriage motor 86 unpleasant, if it is estimated that the nozzles 10 are covered with the caps 71, the second ejection determination process is performed to prevent the driving sound of the carriage motor 86 from being generated. On the other hand, if it is not estimated that the nozzles 10 are covered with the caps 71, the first ejection determination process is performed to reliably determine whether ink has been ejected normally from the nozzles 10, although driving sound of the carriage motor 86 due to carriage drive and cap positioning will be generated. As a result, it is possible to minimize the driving sound of the carriage motor 86 in a situation where the user is likely to find the driving sound of the carriage motor 86 unpleasant.

[0100] Furthermore, condition B2, which requires that the discharge determination process be automatically executed at a specified time, is set as the second condition. This allows the second discharge determination process to be executed when the discharge determination process is automatically executed in a situation where the user is likely to find the driving noise of the carriage motor unpleasant, so that the driving noise of the carriage motor is not generated.

[0101] In the second embodiment, the condition B3 that the discharge determination process is executed at a time that is not included in the predetermined time period of the day is set as the second condition. In this case, if the time that the discharge determination process is executed is a time that is included in the predetermined time period of the day, the second condition is not satisfied. In other words, in the second embodiment, the condition that the time that the discharge determination process is executed is a time that is included in the predetermined time period of the day is set as the first condition.

[0102] As a result, when the ejection determination process is executed during a time period when the user is unlikely to find the driving sound of the carriage motor 86 unpleasant, the first ejection determination process can be executed to reliably determine whether or not ink has been ejected normally from the nozzles 10. Furthermore, when the ejection determination process is executed during a time period when the user is likely to find the driving sound of the carriage motor 86 unpleasant, the second ejection determination process can be executed to prevent the driving sound of the carriage motor 86 from being generated.

[0103] <Modification> Although the first and second preferred embodiments of the present invention have been described above, the present invention is not limited to the first and second embodiments, and various modifications are possible within the scope of the claims.

[0104] In the first embodiment, the conditions A1 to A3 shown in Fig. 5(b) are set as the first conditions, but this is not limiting. Only one or two of the conditions A1 to A3 may be set as the first conditions.

[0105] Alternatively, at least one of the conditions A1 to A3 and at least one other condition may be set as the first condition, or only the at least one other condition may be set as the first condition.

[0106] In the second embodiment, the conditions B1 to B3 shown in Fig. 6(b) are set as the second conditions, but this is not limiting. Only one or two of the conditions B1 to B3 may be set as the second conditions.

[0107] Alternatively, for example, instead of condition B1, the second condition may be set as follows, regardless of whether the ejection determination process is executed automatically: "the printer 1 is restored from a sleep state or switched from a power-off state to a power-on state to execute the ejection determination process, and the confirmation information stored in the flash memory 84 indicates that the printer is in a capped state."

[0108] Alternatively, for example, instead of condition B1, a condition that "the printer 1 is restored from a sleep state or switched from a power-off state to a power-on state and the discharge determination process is automatically executed" may be set as the second condition. In this case, the processes of S503 and S505 for storing the confirmation information in the flash memory 84 are not necessary.

[0109] Alternatively, for example, instead of conditions B2 and B3, a condition that "the discharge process is executed at a specified time, and the specified time is not included in a predetermined time period" may be set as the second condition.

[0110] Alternatively, for example, instead of conditions B1 and B2, a condition that the discharge determination process is automatically executed based on automatic process information may be set as the second condition.

[0111] Alternatively, at least one of the conditions described above and at least one other condition may be set as the second condition, or only the at least one other condition may be set as the second condition.

[0112] Furthermore, in the first and second embodiments, the second discharge determination process is executed only when the second condition is satisfied, regardless of whether the nozzle is actually in the capped state or not, but the present invention is not limited to this.

[0113] In one modified example, the control unit 80 executes the discharge determination process by performing processing according to the flow of Fig. 8. To explain in more detail, in this modified example, as in the first embodiment, if the first condition is satisfied (S601: YES), the control unit 80 executes the first discharge determination process (S602), and if the first condition is not satisfied (S601: NO), the control unit 80 determines that the second condition is satisfied and executes the second discharge determination process (S603).

[0114] In the first discharge determination process of S602, the control unit 80 executes the processes of S201 to S206, similar to the first discharge determination process of S102 in the first embodiment.

[0115] The second discharge determination process of S603 differs from the second discharge determination process of S103 in the first embodiment. To explain in more detail, in the second discharge determination process of S603, the control unit 80 first resets the value of a variable N to 0 (S701). The value of the variable N corresponds to the number of nozzles 10 that were determined not to have continuously discharged ink normally in the second discharge determination process.

[0116] Next, the control unit 80 executes the processes of S702 to S704, which are the same as S301 to S303 in the first embodiment. If it is determined that ink has been ejected normally from the nozzle 10 (S705: YES), the control unit 80 resets the value of the variable N to 0 (S706) and then executes the processes of S710 and S711, which are the same as S305 and S306 in the first embodiment. Then, after the target nozzle is changed in S711, the process returns to S703.

[0117] If it is determined that ink was not ejected normally from the nozzle 10 (S705: NO), the control unit 80 increments the value of the variable N by 1 (S707) and then determines whether the value of the variable N is equal to or greater than a predetermined value Na (S708). The predetermined value Na is, for example, approximately 30. If the value of the variable N is less than the predetermined value Na (S708: NO), the control unit 80 proceeds to S710.

[0118] If the value of the variable N is equal to or greater than the predetermined value Na (S708: YES), the control unit 80 stops the second discharge determination process (S709) and returns to S601. In S709, the control unit 80 performs an operation required to stop the second discharge determination process, such as stopping the application of voltage to the electrode 76 by the high-voltage power supply circuit 77.

[0119] 9, in this modification, in addition to the conditions A1 to A3 described in the first embodiment, a condition A4 is set as the first condition. Condition A4 is a condition that "the second discharge determination is stopped." Therefore, when the process returns from S709 to S601, the first condition is met (S601: YES), and the control unit 80 executes the first discharge determination process (S602).

[0120] When the test drive is performed in a state that is not capped (when the carriage 2 is not positioned at the maintenance position), the ejection determination signal output from the signal processing circuit 78 when the test drive is performed will be a signal indicating that ink was not ejected normally from the nozzles 10, regardless of whether ink was ejected normally from the nozzles 10. On the other hand, when the test drive is performed in a capped 71 state, it is unlikely that a large number of nozzles 10 (for example, about 30 nozzles) will be consecutively determined to have not ejected ink normally.

[0121] Therefore, in this modified example, when the second ejection determination process is executed and it is determined that ink has not been ejected normally from Na nozzles 10 (the "predetermined number" of the present invention) consecutively, it is determined that the nozzles are not in a capped state (the carriage 2 is not positioned at the maintenance position), and the second ejection determination process is stopped. This prevents ink from being wasted, and also reduces the impact of ink being ejected from the nozzles 10 due to inspection driving when the carriage 2 is positioned at a position other than the maintenance position.

[0122] Furthermore, in this modified example, the condition that the second ejection determination process has been stopped is set as the first condition. Therefore, after the second ejection determination process is stopped, the first ejection determination process is executed assuming that the first condition that the second ejection determination process has been stopped is met. This causes the carriage motor 86 to generate driving noise due to carriage and cap drive, but it is possible to reliably determine whether ink has been ejected normally from the nozzles 10.

[0123] In the above-described modified example, after the second discharge determination is stopped in S709, the process returns to S601, but this is not limiting. After the second discharge determination is stopped, the process may be ended immediately.

[0124] Furthermore, in the above modification, similarly to the second embodiment, if the second condition is satisfied, the second discharge determination process similar to S603 may be executed, and if the second condition is not satisfied, the first condition may be satisfied and the first discharge determination process similar to S602 may be executed. However, in this case, after the second discharge determination process is stopped in S709, the process may proceed directly to the first discharge determination process.

[0125] In the first embodiment, a first condition is set, and if the first condition is satisfied, a first discharge determination process is executed, and if the first condition is not satisfied, a second condition is assumed to be satisfied and a second discharge determination process is executed. Meanwhile, in the second embodiment, a second condition is set, and if the second condition is satisfied, a second discharge determination process is executed, and if the second condition is not satisfied, a first condition is assumed to be satisfied and a first discharge determination process is executed. However, this is not limited to this.

[0126] For example, a first condition and a second condition that cannot be satisfied simultaneously may be set, and a first ejection determination process may be executed when the first condition is satisfied, a second ejection determination process may be executed when the second condition is satisfied, and a different process may be executed when neither the first condition nor the second condition is satisfied.

[0127] In addition, in the first and second embodiments, the preparatory operation included carriage drive performed by the carriage moving mechanism 13 by driving the carriage motor 86, and cap drive performed by the cap lifting mechanism 74 by driving the cap motor 88, but is not limited to this.

[0128] For example, if the printer is equipped with a sensor capable of detecting whether the cap 71 is in the cap position, it can be determined whether the cap 71 is in the cap position based on a signal from this sensor. In this case, in the preparatory operation, when it is determined based on the signal from the sensor that the cap 71 is in the cap position, the carriage can be driven, and it can be determined whether the carriage 2 is in the maintenance position based on a signal from the encoder sensor 32. In this case, in the preparatory operation, the carriage motor 86 is driven, but the cap motor 88 is not driven. In other words, by driving the carriage without driving the cap, it can be confirmed whether the nozzles 10 are covered by the cap 71.

[0129] However, even in this case, if it is determined based on the signal from the sensor that the cap 71 is not positioned at the cap position, and if it is determined based on the carriage drive that the carriage 2 is not positioned at the maintenance position, it is necessary to perform carriage drive and cap drive as described in the first embodiment.

[0130] Alternatively, for example, the printer may not be equipped with a cap motor, and the cap lifting mechanism may raise the cap 71 in conjunction with the movement of the carriage 2 when the carriage 2 approaches the maintenance position, and lower the cap 71 in conjunction with the movement of the carriage 2 when the carriage 2 leaves the maintenance position.The preparatory operation then includes only carriage drive, which drives the carriage motor 86.

[0131] Furthermore, in the first and second embodiments, the user instructs the printer 1 to record on the recording paper P by operating the operation unit 68, but this is not limiting. For example, the user may instruct the printer 1 to record on the recording paper P by operating a PC connected to the printer. In this case, the printer receives the recording command from the PC at a connection unit with the PC. In other words, the connection unit of the printer with the PC corresponds to the "instruction signal receiving unit" of the present invention. The user may also operate the PC to instruct the PC to perform a test to determine whether ink is being ejected normally from the nozzles 10.

[0132] In addition, in the first and second embodiments, when the inkjet head 4 is driven for testing, it is determined whether or not ink is ejected normally from the nozzle 10 based on an ejection determination signal output from the signal processing circuit 78 in response to a change in voltage from the nozzle 10 to the electrode 76 arranged in the cap 71, but this is not limited to this.

[0133] For example, instead of electrode 76, an electrode may be provided that extends vertically and faces the space below nozzle 10 when carriage 2 is located at the maintenance position. Then, signal processing circuit 78 may output a signal (the "ejection determination signal" of the present invention) that corresponds to a change in voltage of the electrode when inspection driving is performed with carriage 2 located at the maintenance position. In this case, the combination of the vertically extending electrode, high-voltage power supply circuit 77, signal processing circuit 78, and resistor 79 corresponds to the "ejection determination signal output unit" of the present invention.

[0134] Alternatively, for example, an optical sensor (the "ejection determination signal output unit" of the present invention) may be provided that directly detects ink ejected from the nozzles 10 and outputs a signal (the "ejection determination signal" of the present invention) in accordance with the detection result when the carriage 2 is positioned at a predetermined position such as a maintenance position. Then, based on the signal output from this optical sensor, it may be determined whether ink has been ejected normally from the nozzles 10.

[0135] Alternatively, for example, as described in Japanese Patent No. 4929699, a voltage detection circuit (the "ejection determination signal output unit" of the present invention) that detects changes in voltage when ink is ejected from the nozzles may be connected to a plate on which the nozzles of the inkjet head are formed, and whether or not ink has been ejected normally from the nozzles may be determined based on the signal (the "ejection determination signal" of the present invention) output from the voltage detection circuit when an operation to eject ink from the nozzles is performed with the carriage moved to the inspection position.

[0136] Furthermore, in the first and second embodiments, the test drive is performed on all the nozzles 10 of the inkjet head 4 to determine whether ink is ejected normally from the nozzles 10, but this is not limited to this. For example, the test drive may be performed on only some of the nozzles 10 of the inkjet head 4, such as every other nozzle 10 in each nozzle row 19, to determine whether ink is ejected normally from the nozzles 10. Then, for the other nozzles 10, it may be estimated whether ink is ejected normally from the nozzles 10 based on the determination results for the some of the nozzles 10.

[0137] In the above example, the discharge determination signal output from the signal processing circuit 78 is a signal that indicates whether or not ink has been discharged from the nozzle 10. When the discharge determination signal indicates that ink has been discharged from the nozzle 10, it is determined that ink has been normally discharged from the nozzle 10. However, this is not limited to this. The discharge determination signal may be a signal that indicates a discharge mode other than whether or not ink has been discharged, such as the ink discharge direction or discharge speed. When the discharge determination signal indicates that ink has been discharged from the nozzle 10 in a predetermined discharge mode, it may be determined that ink has been normally discharged from the nozzle 10.

[0138] In the above, an example has been described in which the present invention is applied to a printer equipped with a so-called serial head that ejects ink from multiple nozzles while moving in the scanning direction together with the carriage, but the present invention is not limited to this. For example, the present invention can also be applied to a printer equipped with a so-called line head that extends across the entire length of the recording paper in the scanning direction.

[0139] Although the above description has been given of an example in which the present invention is applied to a printer that ejects ink from nozzles to record on recording paper P, the present invention is not limited to this. The present invention can also be applied to printers that record images on recording media other than recording paper, such as T-shirts, outdoor advertising sheets, cases for mobile devices such as smartphones, cardboard, and resin materials. The present invention can also be applied to liquid ejection devices that eject liquids other than ink, such as liquid resins and metals. [Explanation of symbols]

[0140] 1: Printer 2: Carriage 4: Inkjet head 13: Carriage movement mechanism 71: Cap 74: Cap lifting mechanism 76: Electrode 77: High voltage power supply circuit 78: Signal processing circuit 79: Resistance 80: Control unit 84: Flash memory 86: Carriage motor 88: Cap motor

Claims

1. a liquid ejection head having nozzles for ejecting liquid; a carriage on which the liquid ejection head is mounted; a carriage moving mechanism that moves the carriage; a carriage motor that is a drive source for the carriage movement mechanism; an ejection determination signal output unit that, when a test drive for ejecting liquid from the nozzles is performed in the liquid ejection head with the carriage positioned at a predetermined position, outputs an ejection determination signal in accordance with whether or not liquid has been normally ejected from the nozzles by the test drive; A memory unit; a control unit, The control unit causing the liquid ejection head to perform the test drive, and executing an ejection determination process to determine whether or not liquid has been ejected normally from the nozzles based on the ejection determination signal output from the ejection determination signal output unit when the test drive has been performed; When the discharge determination process is executed, If the first condition is satisfied, a first ejection determination process is executed as the ejection determination process, in which the carriage motor is driven to cause the carriage movement mechanism to perform carriage drive for positioning the carriage at the predetermined position, and then the liquid ejection head is driven for inspection; When a second condition different from the first condition is satisfied, a second ejection determination process is executed as the ejection determination process, in which the carriage moving mechanism is not caused to perform the carriage drive but the liquid ejection head is caused to perform the inspection drive; the storage unit stores automatic processing information related to automatically executing the discharge determination process; The liquid ejection device according to claim 1, wherein the second condition is a condition that the control unit automatically executes the ejection determination process based on the automatic process information.

2. The liquid ejection device described in claim 1, characterized in that the second condition is a condition in which the control unit automatically wakes up the liquid ejection device from a sleep state or switches the liquid ejection device from a power-off state to a power-on state based on the automatic processing information, and then executes the ejection determination process.

3. 3. The liquid ejection apparatus according to claim 1, wherein the automatic processing information is information that specifies a time when the ejection determination process is to be automatically executed.

4. a liquid ejection head having nozzles for ejecting liquid; a carriage on which the liquid ejection head is mounted; a carriage moving mechanism that moves the carriage; a carriage motor that is a drive source for the carriage movement mechanism; an ejection determination signal output unit that, when a test drive for ejecting liquid from the nozzles is performed in the liquid ejection head with the carriage positioned at a predetermined position, outputs an ejection determination signal in accordance with whether or not liquid has been normally ejected from the nozzles by the test drive; A memory unit; a control unit, The control unit causing the liquid ejection head to perform the test drive, and executing an ejection determination process to determine whether or not liquid has been ejected normally from the nozzles based on the ejection determination signal output from the ejection determination signal output unit when the test drive has been performed; When the discharge determination process is executed, If the first condition is satisfied, a first ejection determination process is executed as the ejection determination process, in which the carriage motor is driven to cause the carriage movement mechanism to perform carriage drive for positioning the carriage at the predetermined position, and then the liquid ejection head is driven for inspection; When a second condition different from the first condition is satisfied, a second ejection determination process is executed as the ejection determination process, in which the carriage moving mechanism is not caused to perform the carriage drive but the liquid ejection head is caused to perform the inspection drive; immediately before the liquid ejection device is switched to a sleep state or a power-off state, carriage position information indicating whether the carriage is located at the predetermined position is stored in the storage unit; The second condition is that the ejection determination process is executed after the liquid ejection device is restored from a sleep state or switched from a power-off state to a power-on state, and the carriage position information indicates that the carriage is located at the specified position.

5. a liquid ejection head having nozzles for ejecting liquid; a carriage on which the liquid ejection head is mounted; a carriage moving mechanism that moves the carriage; a carriage motor that is a drive source for the carriage movement mechanism; an ejection determination signal output unit that, when a test drive for ejecting liquid from the nozzles is performed in the liquid ejection head with the carriage positioned at a predetermined position, outputs an ejection determination signal in accordance with whether or not liquid has been normally ejected from the nozzles by the test drive; a control unit, The control unit causing the liquid ejection head to perform the test drive, and executing an ejection determination process to determine whether or not liquid has been ejected normally from the nozzles based on the ejection determination signal output from the ejection determination signal output unit when the test drive has been performed; When the discharge determination process is executed, If the first condition is satisfied, a first ejection determination process is executed as the ejection determination process, in which the carriage motor is driven to cause the carriage movement mechanism to perform carriage drive for positioning the carriage at the predetermined position, and then the liquid ejection head is driven for inspection; When a second condition different from the first condition is satisfied, a second ejection determination process is executed as the ejection determination process, in which the carriage moving mechanism is not caused to perform the carriage drive but the liquid ejection head is caused to perform the inspection drive; the first condition is a condition that the discharge determination process is executed at a time included in a predetermined time period that is a part of one day, The liquid ejection device according to claim 1, wherein the second condition is a condition that the ejection determination process is executed at a time of day that is not included in the predetermined time period.

6. a liquid ejection head having a plurality of nozzles for ejecting liquid; a carriage on which the liquid ejection head is mounted; a carriage moving mechanism that moves the carriage; a carriage motor that is a drive source for the carriage movement mechanism; an ejection determination signal output unit that, when a test drive for ejecting liquid from the nozzles is performed in the liquid ejection head with the carriage positioned at a predetermined position, outputs an ejection determination signal in accordance with whether or not liquid has been normally ejected from the nozzles by the test drive; a control unit, The control unit causing the liquid ejection head to perform the test drive, and executing an ejection determination process to determine whether or not liquid has been ejected normally from the nozzles based on the ejection determination signal output from the ejection determination signal output unit when the test drive has been performed; When the discharge determination process is executed, If the first condition is satisfied, a first ejection determination process is executed as the ejection determination process, in which the carriage motor is driven to cause the carriage movement mechanism to perform carriage drive for positioning the carriage at the predetermined position, and then the liquid ejection head is driven for inspection; When a second condition different from the first condition is satisfied, a second ejection determination process is executed as the ejection determination process, in which the carriage moving mechanism is not caused to perform the carriage drive but the liquid ejection head is caused to perform the inspection drive; in the ejection determination process, the test driving is performed for each of the plurality of nozzles in turn, and when the test driving is performed for each nozzle, it is determined whether or not liquid has been ejected normally from that nozzle based on the ejection determination signal output from the ejection determination signal output unit; The liquid ejection device is characterized in that, in the second ejection determination process, if it is determined that liquid has not been ejected normally consecutively from a predetermined number of the nozzles, the second ejection determination process is stopped.

7. the first condition is a condition that the second ejection determination process has been stopped, The control unit The liquid ejection apparatus according to claim 6 , wherein after the second ejection determination process is stopped, the first ejection determination process is executed assuming that the first condition that the second ejection determination process has been stopped is satisfied.

8. a liquid ejection head having nozzles for ejecting liquid; a carriage on which the liquid ejection head is mounted; a carriage moving mechanism that moves the carriage; a carriage motor that is a drive source for the carriage movement mechanism; an ejection determination signal output unit that, when a test drive for ejecting liquid from the nozzles is performed in the liquid ejection head with the carriage positioned at a predetermined position, outputs an ejection determination signal in accordance with whether or not liquid has been normally ejected from the nozzles by the test drive; a cap for covering the nozzle; a cap moving mechanism that moves the cap between a cap position for covering the nozzles and an uncap position away from the liquid ejection head; a cap motor that is a drive source of the cap moving mechanism; a control unit, The discharge determination signal output unit an electrode disposed within the cap; a voltage supply unit that generates a potential difference between the liquid ejection head and the electrode, the predetermined position is a position of the carriage where the nozzle faces the cap, a signal corresponding to an electrical change when the liquid ejection head is driven for testing, the signal corresponding to the electrical change being output as the ejection determination signal, with the carriage positioned at the predetermined position, the cap positioned at the cap position, and a potential difference being generated between the liquid ejection head and the electrode by the voltage supply unit; The control unit causing the liquid ejection head to perform the test drive, and executing an ejection determination process to determine whether or not liquid has been ejected normally from the nozzles based on the ejection determination signal output from the ejection determination signal output unit when the test drive has been performed; When the discharge determination process is executed, If the first condition is satisfied, a first ejection determination process is executed as the ejection determination process, in which the carriage motor is driven to cause the carriage movement mechanism to perform carriage drive for positioning the carriage at the predetermined position, and then the liquid ejection head is driven for inspection; When a second condition different from the first condition is satisfied, a second ejection determination process is executed as the ejection determination process, in which the carriage moving mechanism is not caused to perform the carriage drive but the liquid ejection head is caused to perform the inspection drive; In the first ejection determination process, the cap motor is driven to cause the cap movement mechanism to perform cap drive for positioning the cap at the cap position, and the carriage movement mechanism is caused to perform the carriage drive, and then the liquid ejection head is caused to perform the inspection drive; A liquid ejection device characterized in that, in the second ejection determination process, the cap moving mechanism is not caused to perform the cap drive, and the carriage moving mechanism is not caused to perform the carriage drive, and the liquid ejection head is caused to perform the inspection drive.

9. 9. The liquid ejection device according to claim 1, wherein the first condition is a condition that the ejection determination process is executed first after power is supplied to the liquid ejection device.

10. the control unit drives the carriage motor to cause the carriage movement mechanism to move the carriage, while causing the liquid ejection head to perform an ejection operation of ejecting liquid from the nozzles toward an ejection receiving medium; an instruction signal receiving unit that receives an ejection instruction signal from a user instructing the user to perform the ejection operation; A liquid ejection device described in any one of claims 1 to 3 and 6 to 8, characterized in that the first condition is a condition that the ejection judgment process is executed either immediately before the ejection operation performed based on the ejection instruction signal received by the instruction signal receiving unit, immediately after the ejection operation, or during the ejection operation.

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