Ink jet recording device

Abstract

To solve such a problem that, when a user performs recording on multiple recording media, if cap suction is executed after recording on the recording medium is finished and before recording on the next recording medium is started, recording on the next recording medium cannot be started until cap suction is finished.SOLUTION: An ink jet recording device that performs recording by discharging ink to a recording medium includes: a recording head that discharges ink; a cap that receives the ink discharged from the recording head; a pump that discharges the ink accumulated inside the cap; and control means that performs control of shifting the ink jet recording device to the sleep state after executing cap suction that uses the pump to suction the ink accumulated inside the cap when recording on the recording medium is not performed for a prescribed period of time.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a method for forming an image on a recording medium by ejecting ink from nozzles formed in a recording head. The present invention relates to an inkjet recording apparatus. [Background technology]

[0002] Inkjet recording devices that eject ink to form an image on a recording medium such as recording paper are known as a type of output device for computers and workstations. This inkjet recording device includes a recording head having nozzles that eject ink, a carriage that carries the recording head and moves back and forth in a predetermined direction, and a recording medium transport device that transports the recording medium. In an inkjet recording device, since recording is performed by ejecting ink from the recording head, it is necessary to maintain the recording head in a state in which it is always capable of ejecting ink. Operations for maintaining the ejection performance of the recording head include nozzle suction and preliminary ejection.

[0003] Nozzle suction is a method of expelling and removing air bubbles and foreign matter that have become trapped inside the nozzles by suctioning from the outside. Inkjet recording devices are equipped with a cap that covers the nozzles of the recording head. A pump for generating negative pressure is connected to the cap. With the nozzles covered with the cap, the pump is driven to apply negative pressure to the nozzles, thereby sucking ink out of the nozzles.

[0004] Preliminary ejection prevents the ink inside the nozzle from drying out by ejecting it. Preliminary ejection is also called preliminary discharge. When performing preliminary ejection, ink is ejected from the nozzle toward the cap. The ink ejected from the nozzle is stored inside the cap. An absorber made of a porous material is installed inside the cap, which absorbs and holds the ink ejected into the cap.

[0005] Some inkjet recording devices record on mail, including envelopes. Some inkjet recording devices for recording on mail require the user to insert recording media one by one into the recording device and record while holding the recording media. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2002-52744 A Summary of the Invention [Problem to be solved by the invention]

[0007] In the prior art document, when the amount of ink accumulated in the cap due to preliminary ejection reaches a predetermined amount, cap suction is performed to remove the ink from inside the cap. Cap suction is a process in which the ink accumulated inside the cap is discharged to the outside by driving the pump with the cap not covering the nozzles.

[0008] In a conventional recording device, when a user records on multiple recording media with a certain amount of ink stored in the cap, cap suction may be performed after recording on one recording medium is completed and before recording on the next recording medium is started. In a recording device in which the motor that drives the pump also serves as a drive source for other recording operations, the recording operation cannot be performed in parallel with nozzle suction. Therefore, if cap suction is performed after recording on a recording medium is completed and before recording on the next recording medium is started, there is a problem that recording on the next recording medium cannot be started until cap suction is completed. [Means for solving the problem]

[0009] In order to solve the above problems, the inkjet recording device of the present invention is characterized by having a recording head that ejects ink, a cap that receives the ink ejected from the recording head, a pump that discharges ink stored inside the cap, and a control means that, when recording on a recording medium is not performed for a predetermined period of time, performs cap suction to suck up the ink stored inside the cap using the pump, and then controls the inkjet recording device to transition to a sleep state. Effect of the Invention

[0010] According to the present invention, it is possible to provide an inkjet recording apparatus capable of preventing cap suction from being executed after recording on a recording medium is completed and before recording on the next recording medium is started. [Brief description of the drawings]

[0011] [Figure 1] 1 is a perspective view showing a configuration of an image recording apparatus according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a block diagram showing a schematic configuration of a control system in the present embodiment. [Diagram 3] FIG. 2 is a perspective view showing a configuration of a paper feed section inside a recording head. [Figure 4] 5 is a schematic diagram showing the positional relationship between the print head and the cap during preliminary ejection. FIG. [Diagram 5] FIG. 11 is a flow diagram showing a conventional cap suction process after preliminary ejection. [Figure 6] FIG. 11 is a flowchart showing a cap suction process at the time of transition to a sleep mode in the embodiment. [Figure 7] FIG. 11 is a flowchart showing a cap suction process at the time of transition to sleep in the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of an inkjet recording apparatus according to the present invention will be described with reference to the drawings. In an inkjet recording apparatus, since recording is performed by ejecting ink from a recording head onto a recording medium, it is necessary to maintain the recording head in a state in which it is always capable of ejecting ink. The operation for maintaining the ejection performance of the recording head will be described below.

[0013] "Capping" Capping is the act of covering the face on which the nozzles are provided with a cap to prevent the moisture in the ink inside the nozzles from evaporating when printing is not in progress. An absorbent is provided inside the cap, and by capping the face while the absorbent contains ink, it is possible to prevent the ink inside the nozzles from drying out.

[0014] "Pre-ejection" Ink in the nozzles of the print head may become unstable over time as moisture evaporates. In order to enable stable ink ejection, preliminary ejection is an operation in which ink is ejected at a predetermined timing other than onto the print medium and ink with evaporated moisture is discharged from the nozzles. The preliminary ejection ink is discharged into the cap.

[0015] "Nozzle suction" When air bubbles get mixed in the ink inside the nozzle, the ink ejection performance decreases. Also, if the water in the ink inside the nozzle evaporates, there are cases where the ejection performance cannot be improved by preliminary ejection alone. To deal with this, nozzle suction is an operation in which negative pressure is applied to the inside of the cap while the nozzle is covered with a cap, and the ink inside the nozzle is sucked and removed. The negative pressure is applied to the inside of the cap by a suction pump connected to the cap.

[0016] "Cap suction" This is suction performed to remove ink that has accumulated inside the cap. By performing suction with a pump while the cap is separated from the recording head, the ink that has accumulated inside the cap is discharged to the outside.

[0017] "Wipping" If foreign matter such as paper powder or dust adheres to the area around the nozzle, ink may not be ejected properly. In order to remove this, wiping is the action of wiping the area around the nozzle with a flexible blade such as rubber. The member that performs the wiping is called a wiper. <First embodiment>

[0018] FIG. 1 is a perspective view showing the configuration of recording device 100. Recording device 100 is an inkjet recording device that records on mail items, including envelopes, as recording media. A user inserts recording media one by one into recording device 100, and records while holding the recording media. When recording device 100 has finished recording on the recording media, the user removes the recorded recording media from recording device 100.

[0019] The recording device 100 is connected to a host device (not shown) for sending image information (including recording data and commands) to the recording device 100. A user can set a recording medium in the recording device 100 by inserting the recording medium in the direction of arrow A. The recording device 100 is equipped with a recording medium detection means for detecting the presence or absence of a recording medium set. After the recording device 100 detects the recording medium, the lifter 11 rises, and the recording medium is fixed in place by being sandwiched between the lifter 11 and the plate member 19. The recording device 100 then proceeds to a recording operation.

[0020] The recording device 100 includes a carriage motor (not shown) for moving the carriage unit 13, which holds the recording head 50, to the recording area. The driving force of a DC motor used in the carriage motor can cause the carriage unit 13 to scan back and forth in the direction indicated by the arrow B via a belt 18.

[0021] A transmissive sensor (not shown) is provided on the carriage unit 13. The transmissive sensor reads the linear scale 15 to control the scanning speed of the carriage unit 13 and determine the ejection timing of the print head. In this embodiment, the linear scale is used to control the DC motor and the print head, but a stepping motor may also be used.

[0022] Also provided is a recovery unit 14 for cleaning and capping the recording head 50. The recovery unit 14 includes a cap 51 and a pump (not shown). When a discharge defect such as non-discharge or distortion occurs in the recording head, the recovery unit 14 can perform an operation for maintaining the discharge performance of the recording head as necessary.

[0023] Each operation of the device (carriage unit scanning, lifter operation, recording head drive, maintenance operation, etc.) is controlled by a control unit 16 provided on the rear surface of the main body. The recording head is connected to the control unit 16 via a carriage board (not shown) provided in the carriage unit 13 and a flexible cable 17.

[0024] The schematic configuration of the control system will be described with reference to Fig. 2. Image data, recording commands, etc. sent from the host device 101 are sent to the CPU 25 via the interface controller 24. The CPU 25 comprehensively controls the entire recording device 100, including the recording operation based on the image data, detection of the recording medium by the recording medium detection means 20, and maintenance operation of the recording head. When the CPLD 26 analyzes the command sent from the host PC 23, it develops the image data of the image data into a bitmap in the image memory 27 and draws it.

[0025] As an operational process before recording, the CPLD 26 drives the lift motor 30 based on the detection result of the recording medium detection means 20 via the output port 28 and the motor drive unit 29. The lift motor 30 is controlled based on the detection result of the lift cam sensor 43, and the detailed operation of the lift motor 30 will be described later. Next, the carriage motor 22 is driven based on the detection result of the linear scale detection unit 21. Then, the recording head 12 is separated from the recovery unit 14, and reciprocating scanning of the carriage unit 13 is started.

[0026] When the carriage unit 13 reaches the recording area position on the recording medium, the CPU 25 sequentially reads the recording data from the image memory 27 and outputs the recording data to the recording head 12 via the recording head control circuit 35. The recording head control circuit 35 controls the timing of applying a drive pulse to a heating element provided inside the nozzle of the recording head 12. The application of the drive pulse forms air bubbles on the surface of the heating element, causing ink droplets to be ejected from the ejection nozzle.

[0027] After printing on the forward path, the scanning of the carriage unit 13 is stopped at a predetermined position, and then the scanning direction is reversed to start scanning on the return path. As in the forward path, when the carriage unit 13 reaches the printing area position on the printing medium, printing on the return path is started by ejecting ink droplets from the ejection nozzles.

[0028] The CPU 25 executes a control program stored in a program ROM 31. The program ROM 31 stores the control program and various tables for implementing the operation of this embodiment. A work RAM 32 is used as a working memory for the CPU 25. When a recovery operation is selected by the host device 101, the CPU 25 drives a pump via an output port 28 and a motor drive unit 29 to control the suction of ink, etc.

[0029] 3 is a perspective view showing the configuration of the lifter unit. When a user inserts a recording medium S into the main body, one corner of the recording medium S is guided by a sub-lifter 44 to the position of the recording medium detection flag 40. When the recording medium S pushes the recording medium detection flag 40, the recording medium detection means 20 detects that the recording medium S has been set.

[0030] After detecting the recording medium S, the lifter cam 42 is rotated to a predetermined position by the lift motor 30. The movement of the lifter cam 42 is transmitted to the lifter 11 via the lifter arm 41, thereby raising and lowering the lifter 11. The position information of the lift cam 42 is detected by a lift cam sensor 43. Furthermore, the lift cam 42 is controlled to be at a predetermined position based on the detection result of the lift cam sensor 43 during the initialization operation performed when the printer device 100 is started up. The driving force from the lift motor 30 to the lifter cam 42 is transmitted by a one-way clutch only when the lift motor 30 rotates forward.

[0031] 4 is a schematic diagram showing the positional relationship between the recording head 50 and the cap 51 during preliminary ejection. The recording device 100 performs preliminary ejection from the head 50 onto the cap 51 at a predetermined timing to enable stable ejection. The preliminary ejection is performed immediately before recording on the recording medium S or immediately after wiping. When a predetermined number of shots of preliminary ejection are performed on the cap 51, the ink accumulated in the cap 51 is sucked and collected by a pump via a tube 52 connected to the bottom surface of the cap 51. The pump is driven by the lift motor 30. The driving force from the lift motor 30 to the pump is transmitted by a one-way clutch only when the lift motor 30 rotates in reverse.

[0032] Figure 5 is a flow diagram showing a conventional cap suction process after preliminary ejection. In the process in Figure 5, when a recording medium is detected, the cap is separated before recording, and then pre-print preliminary ejection (S01) is performed before recording starts (S02). After recording is completed, a determination is made as to whether the count value, which is the cumulative number of preliminary ejections onto the cap, is equal to or greater than a specified value (S03), and if the count value is equal to or greater than the specified value, cap suction (S04) is performed. After cap suction is performed, the count value is reset to zero (S05) and capping is performed (S06) to end the process. On the other hand, if it is determined (S03) that the ink in the cap is less than the specified value, capping (S06) is performed to end the process.

[0033] This cap suction operation discharges the ink inside the cap, making it possible to avoid problems such as ink overflowing from the cap and ink accumulated inside the cap adhering to the nozzles of the recording head 50. In the recording device 100 of this embodiment, the preliminary ejection before recording is 150 shots per nozzle, and the default value of S03 is 3000 shots per nozzle, so that cap suction is performed every 20 sheets recorded.

[0034] For example, if the recording device 100 goes into sleep mode with the count value at 2850 shots, the recording device 100 subsequently detects a recording medium inserted by the user and returns from sleep mode, and when pre-printing preliminary ejection is performed in S01, the count value becomes 3000. Then, S03 returns Yes, and cap suction is performed after recording on the first sheet is completed. If the user wishes to record multiple sheets, recording on the second sheet cannot start until cap suction is completed.

[0035] FIG. 6 is a flow diagram showing the cap suction process at the time of sleep transition according to this embodiment. In the process of FIG. 6, when the recording device 100 receives a sleep command, it executes cap suction (S11). The sleep command can be sent from the host device 101 by the user, or the host device 101 may set the time until sleep transition in advance and transmit a command to the recording device 100 to put the recording device 100 into the sleep state according to the elapsed time since the user last used the device. Alternatively, the recording device 100 may set the time until the transition to the sleep state and transition the recording device 100 to the sleep state according to the elapsed time since the user last used the recording device 100. When transitioning to the sleep state, after cap suction (S11), the count value is reset (S12), and then the recording device 100 transitions to the sleep state and ends.

[0036] In the sleep state, some functions of the CPU 25 are stopped and the excitation of the carriage motor 22 and the lift motor 30 is cut off to reduce the standby power consumption of the recording device 100. The sleep state is released when a command is sent from the host device 101 to the recording device 100, when the recording medium detection means 20 detects that a recording medium S has been set, or when the user operates a button on the recording device 100.

[0037] Because the process shown in the flow diagram of FIG. 6 causes the ink in the cap to be discharged by the pump and the count value to be reset, after the recording device 100 returns from sleep, cap suction will not be performed before recording on the recording medium until the count value again reaches the specified value, i.e., until 20 sheets have been recorded.

[0038] The recording device 100 starts recording when the user manually inserts the recording medium, and removes the recording medium after recording is completed. This type of recording device is often used to record a relatively small number of sheets at a time. Therefore, according to this embodiment, it is possible to prevent the cap suction from being performed before recording starts on the recording medium. <Second embodiment>

[0039] In the first embodiment, cap suction is always performed when transitioning to the sleep state, but by not performing cap suction depending on the conditions, the impact on the life of the lift motor 30 can be reduced. In the process according to the flow diagram of FIG. 7, when a sleep command is received, it is determined (S21) whether the number of preliminary discharges to the cap is equal to or greater than a sleep specified value. The sleep specified value in S21 is different from the cap suction specified value in the determination (S03) described in the process of FIG. 7, and a value smaller than the cap suction specified value in S03 is used. If the number is equal to or greater than the sleep specified value in S21, cap suction (S22) is performed, and then the count value is reset (S23), and the process transitions to sleep (S24) and ends. If the number is less than the specified value in S21, the process transitions to sleep (S24) and ends.

[0040] The cap suction specified value for S03 is 3000 shots per nozzle, whereas the sleep specified value for S21 in this embodiment is 1500 shots / nozzle. Since the pre-print preliminary ejection is 150 shots / nozzle, cap suction (S04) is performed every 20 sheets of printing. When transitioning to sleep, cap suction is set to be performed if 10 or more sheets have been printed since the count value was reset.

[0041] The sleep specified value may be recorded in advance in a storage area of ​​the CPU 25 of the recording device 100, or may be set by the user within a range smaller than the cap suction specified value.

[0042] As described in the first embodiment, the recording device 100 is often used to record a relatively small number of sheets. Therefore, by setting the sleep default value according to the user's usage, it is possible to reduce the frequency with which cap suction is performed and to reduce the impact on the life of the lift motor 30. [Explanation of symbols]

[0043] 100 Recording device 101 Host device 11 Lifter 13 Carriage unit 14 Healing Unit 15 Linear Scale 16 Control section 17 Flexible Cable 18 Belt 19 Plate member 20 Recording medium detection means 21 Linear scale detector 22 Carriage motor 24 Interface Controller 25 CPU 26 CPLD 27 Image Memory 28 Output Ports 29 Motor control unit 30 Lift motor 31 Program ROM 32 Work RAM 33 Pump motor 35 Recording head control device 40 Recording medium detection flag 41 Lifter Arm 42 Lift Cam 43 Lift cam sensor 44 Sub-lifter 50 Recording head 51 Cap 52 Pump

Claims

1. An inkjet recording apparatus that performs recording by ejecting ink onto a recording medium, A recording head that ejects ink; a cap for receiving ink ejected from the recording head; A pump that discharges ink stored inside the cap; a control means for controlling the inkjet recording device to transition to a sleep state after performing cap suction by using the pump to suck ink stored inside the cap when recording on a recording medium is not performed for a predetermined time; An ink jet recording apparatus comprising:

2. a counting unit that counts the number of ink droplets ejected from the recording head to the cap; the control means, when no recording is performed on the recording medium for a predetermined time, executes the cap suction based on the count result of the count means and then transitions the inkjet recording apparatus to a sleep state.

2. The inkjet recording apparatus according to claim 1,

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