Liquid dispensing device

Abstract

To improve accuracy in detecting amounts of liquid in a liquid storage part.SOLUTION: A liquid discharge device is provided with estimating means that estimates, as estimated used amounts, amounts of liquid that are discharged by a recording head, after the timing at which first sensing means, which senses whether amounts of liquid stored in a liquid storage part are equal to first amounts or more or less than the first amounts, senses that the amounts of liquid stored in the liquid storage part have changed from a state where the amounts of liquid are equal to the first amounts or more into a state where the amounts of liquid are less than the first amounts, until the timing at which second sensing means, which senses whether amounts of liquid stored in the liquid storage part are equal to second amounts less than the first amounts or more or less than the second amounts, senses that the amounts of liquid stored in the liquid storage part have changed from a state where the amounts of liquid are equal to the second amounts or more into a state where the amounts of liquid are less than the second amounts. The estimating means calculates a first correction value for correcting the estimated used amounts on the basis of a first difference that is the difference between the first amounts and the second amounts, the estimated used amounts and a second difference that is the difference between the first difference and the estimated used amounts, and thereafter corrects the estimated used amounts on the basis of the correction value.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection device. [Background technology]

[0002] Conventionally, among liquid ejection devices that perform recording by ejecting liquid from a liquid ejection head onto a recording medium, there is known a device that detects the amount of liquid in a liquid storage section that stores the liquid. Patent Document 1 describes a configuration in which the remaining ink level is calculated or corrected in response to a determination by a sensor 11 of the presence or absence of ink in an ink tank 5. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3577011 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in Patent Document 1, ink counters C1 and C2 are used to calculate and correct the remaining ink level, which acquire and accumulate the number of ink dots consumed by the print head for each scan. Because there can be variations in the amount of ink ejected from the print head, there is a possibility that an error will occur between the estimated remaining amount and the actual remaining amount of ink.

[0005] The present invention has been made in view of the above-mentioned problems, and has an object to improve the accuracy of detecting the amount of liquid in a liquid storage portion. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the present invention provides a liquid ejection head that ejects liquid, a liquid storage section that stores liquid to be supplied to the liquid ejection head, a first detection means that detects whether the amount of liquid stored in the liquid storage section is equal to or greater than a first amount, and a second detection means that detects whether the amount of liquid stored in the liquid storage section is equal to or greater than a second amount that is less than the first amount, and from the time when the first detection means detects that the amount of liquid stored in the liquid storage section has changed from a state where it is equal to or greater than the first amount to a state where it is less than the first amount, the second detection means before During the time it is detected that the amount of liquid stored in the liquid storage section has changed from a state in which the amount is equal to or greater than the second amount to a state in which the amount is less than the second amount, liquid discharge Head On the recording medium Discharged a first amount of liquid and a second amount of liquid discharged from the liquid discharge head in order to recover the discharge performance of the liquid discharge head; and an estimation means for estimating a first difference that is a difference between the first amount and the second amount, a print correction value for correcting the first liquid amount based on the first difference and the second liquid amount; and a recovery correction value for correcting the second liquid amount based on the first difference and the second liquid amount. It is characterized by: [Effects of the Invention]

[0007] According to the present invention, it is possible to improve the accuracy of detecting the amount of liquid in the liquid storage portion. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a block diagram showing the hardware configuration of the recording apparatus. [Figure 2] FIG. [Figure 3] 2A and 2B are schematic diagrams showing the ink bottle and the state of the recording device when ink is being filled. [Figure 4] FIG. 2 is a diagram showing a schematic configuration of a print head and an ink tank unit of the printing apparatus. [Figure 5] FIG. 2 is a detailed view of the internal configuration of the ink tank unit. [Figure 6] 10 is a detailed view of the ink amount display relating to the ink tank section displayed on the display section. [Figure 7] FIG. 4 is a diagram showing non-volatile information related to the ink tank unit stored in the recording device. [Figure 8] 10 is a flowchart of a process executed when ink is used in the recording device. [Figure 9] 10 is a flowchart of a process for storing ink dot counts in non-volatile information. [Figure 10] 10 is a flowchart of a process for correcting estimated ink usage. [Figure 11] 10 is a flowchart of a process executed when the ink detection sensor 409 detects that there is no ink. [Figure 12] 10 is a flowchart of a process executed when the ink detection sensor 410 detects that there is no ink. [Figure 13] 10 is a flowchart of a process for creating an estimated ink usage amount correction value (overall). [Figure 14] 10 is a flowchart of a series of processes for creating an estimated ink usage amount correction value (printing) and an estimated ink usage amount correction value (recovery). [Figure 15] 10 is a flowchart of a process for clearing non-volatile information. DETAILED DESCRIPTION OF THE INVENTION

[0009] An example of an embodiment of a recording device and a liquid storage tank will be described in detail below with reference to the accompanying drawings. Note that the following embodiment does not limit the present invention, and not all of the combinations of features described in the embodiment are necessarily essential to the solution of the present invention. Furthermore, the positions, shapes, and the like of the components described in the embodiment are merely examples, and are not intended to limit the scope of the present invention to those alone.

[0010] (First embodiment) FIG. 1 is a block diagram showing an example of the hardware configuration of an inkjet recording apparatus 100 (hereinafter referred to as recording apparatus 100) as a liquid ejection apparatus. The recording apparatus 100 has a CPU 101, a ROM 102, a RAM 103, and an EEPROM 104. The CPU 101 is a central processing unit for controlling each section within the recording apparatus 100. The ROM 102 stores various program codes. The RAM 103 temporarily stores image data and the like when each service is executed, and buffers the data. The EEPROM 104 stores non-volatile information. The non-volatile information includes shipping destination information for the recording apparatus 100, the language setting to be displayed on the display unit 106, and the like. In the present invention, the ink tank information shown in FIG. 7 is particularly stored. Details will be described later using FIG. 7.

[0011] The recording device 100 has a communication unit 105. The communication unit 105 connects to an external device such as a host PC via a USB or a network. That is, the communication unit 105 connects to a USB or a network and communicates with the external device. The RAM 103 also stores image data and the like received by the communication unit 105.

[0012] The display unit 106 is configured, for example, by a liquid crystal display or the like, and is capable of displaying characters, figures, indicators, etc. The display unit 106 is not limited to a liquid crystal display, and can also be configured using an LED or other display. Information displayed on the display unit 106 includes, for example, setting information for the recording device 100 and information about the ink contained in the ink tank unit 110. Information about the ink includes, for example, information about the remaining amount of ink contained in the ink tank and color information. Driving of the display unit 106 is controlled by the CPU 101.

[0013] The operation unit 107 is made up of switches, hard keys, etc., which allow the user to perform various input operations. It is also possible for the display unit 106 to function as the operation unit 107 as well, such as a touch panel.

[0014] The recording device 100 has a scanner unit 108, a recording unit 109, and an ink tank unit 110. The ink tank unit 110 is a liquid storage unit that stores ink to be supplied to a recording head 401 (see FIG. 4) included in the recording unit 109. An ink tank unit 110 is provided for each color, and each ink tank unit is connected to the recording head via a supply tube 411 (see FIG. 4). The ink supplied through the supply tube 411 is ejected from the recording head onto a recording medium. The recording unit 109 has a carriage 402 (see FIG. 4) that carries the recording head and moves. When recording on a recording medium, the carriage 402 moves the recording head 401, ejecting ink to form an image on the recording medium. Recording on the recording medium by the recording unit 109 is performed based on image data received by the communication unit 105, image data read by the scanner unit 108, or the like.

[0015] The scanner unit 108 optically reads an original placed on the platen 201 (see FIG. 2) and converts it into electronic data, which is then converted into image data in a specified file format. The converted image data is sent to an external device via the communication unit 105 or stored in a storage area such as a HDD. The recording device 100 also has a copy function in which the scanner unit 108 reads an original placed on the platen 201, generates image data, and transfers the generated image data to the recording unit 109, which then records an image on a recording medium based on the image data.

[0016] The above-mentioned units are connected to one another via a bus 111, and are capable of transmitting and receiving data to and from one another. Note that the recording device 100 does not necessarily have to be equipped with a scanner unit.

[0017] Fig. 2 is a perspective view that schematically illustrates the recording device 100, and Fig. 3 is a schematic diagram showing the state of the recording device 100 when ink is being filled and the ink bottles. The recording device 100 in this embodiment has a box-shaped housing 111, and a recording unit 109 and an ink tank unit 110 are disposed inside the housing 111. A display unit 106 and an operation unit 107 are provided on the front of the recording device 100, and a document table 201 is provided on the top of the recording device 100.

[0018] In the recording apparatus 100 of this embodiment, the user can replenish the ink by injecting ink into the ink tank unit 110. The ink tank unit 110 has an ink inlet 302, which is closed by a cap 304 except when ink is being injected into the ink tank unit 110. When an ink tank cover 301 provided on the housing 111 is closed (the state shown in FIG. 2), the ink inlet 302 and cap 304 are covered by the ink tank cover 301.

[0019] When refilling ink, the user opens the ink tank cover 301, exposing the ink tank unit 110 and accessing the cap 304 and the ink inlet 302. The user removes the cap 304 of the ink tank unit 110 to be refilled from the ink inlet 302 to open the ink inlet 302, connects the inlet 305 of the ink bottle 303 to the ink inlet 302, and injects ink into the ink tank unit 110.

[0020] The recording device 100 is configured to be capable of ejecting a plurality of different color inks and recording color images on a recording medium. In this embodiment, the recording device 100 has ink tank units 110 110C, 110M, 110Y, and 110Bk, which respectively store four colors of ink: cyan (C), magenta (M), yellow (Y), and black (Bk).

[0021] Ink bottles 303 for injecting ink into the ink tank unit 110 to replenish the ink are also provided for each color. Ink bottles 303C, 303M, 303Y, and 303Bk, which contain cyan (C), magenta (M), yellow (Y), and black (Bk), respectively, are each equipped with an injector 305. In this embodiment, the ink tank units 110C, 110M, 110Y, and 110Bk are all identical in configuration, and the ink bottles 303C, 303M, 303Y, and 303Bk are also all identical in configuration. Below, the configuration of one representative ink tank unit 110 will be described.

[0022] 4 is a diagram showing the schematic configuration of the print head and ink tank section. The print head 401 is mounted on a carriage 402, which is supported by a guide shaft 403 and a belt 405. When driven by a carriage motor 404, the belt 405 rotates, and the carriage 402, which is connected to it, moves left and right in the figure.

[0023] The underside of the print head 401 is an ejection surface where ejection ports for ejecting ink are formed, and when the printing apparatus 100 is not printing, a cap unit 406 comes into close contact with the ejection surface to prevent the ejection ports from drying out. The cap unit 406 also has a recovery function as a recovery means for maintaining and recovering the ejection performance of the print head 401 by discharging ink from the ejection ports of the print head 401 and by driving a suction pump 415 to suck ink. To maintain its ejection performance, the print head 401 periodically performs preliminary ejection by ejecting ink into the cap unit 406. Waste ink discharged into the cap unit 406 is discharged via a discharge tube 413 to a waste ink absorber 414, where the waste ink is retained.

[0024] Ink 408 is contained in the ink tank section 110, and ink detection sensors 409 and 410 are provided. Each of the ink detection sensors 409 and 410 is composed of a pair of electrodes, and obtains a voltage or the like which is the potential difference between when a voltage is applied to the electrodes and when the application ends, and compares this electrical information with a threshold value which serves as a reference value to determine whether or not there is any ink remaining in the ink tank 407.

[0025] The ink tank unit 110 and the print head 401 are connected by a supply tube 411. A choke valve 412 is provided midway through the supply tube 411, and when ink 408 is supplied to the print head 401, a cap unit 406 is brought into close contact with the ejection port surface of the print head 401, and suction is performed by a suction pump 415 with the choke valve 412 closed. This allows suction to be performed with an increased internal pressure in the supply tube 411, making it possible to perform powerful suction to remove unwanted bubbles and foreign matter from the supply tube 411.

[0026] Figure 5 is a detailed diagram of the internal configuration of the ink tank unit 110. In this embodiment, the ink detection sensors 409, 410 are provided with their lower ends positioned at different locations so that the ink detection sensors 409, 410 can detect different amounts of ink. Remaining ink amount 501 is the lower limit of the amount of ink that can be detected by the upper ink detection sensor 409, and remaining ink amount 502 is the lower limit of the amount of ink that can be detected by the lower ink detection sensor 410. Ink amount 503 is the difference between remaining ink amount 501 and remaining ink amount 502. Ink amount 503 is determined by the physical installation positions of the ink detection sensors 409, 410.

[0027] 6 shows details of the ink amount display for the ink tank unit 110 displayed on the display unit 106. As shown in FIG. 6(a), the display unit 106 displays ink amounts 601 to 604 for all colors of cyan (C), magenta (M), yellow (Y), and black (Bk).

[0028] The relationship between the ink amount display and detection by the ink detection sensors 409, 410 will be explained. When ink is detected by the ink detection sensor 409, it is displayed as remaining ink amount display 605 as shown in FIG. 6(b-1). When ink detection sensor 409 no longer detects ink, it is displayed as remaining ink amount 606 as shown in FIG. 6(b-2). While ink detection sensor 409 detects that there is no ink and ink detection sensor 410 detects that there is ink, it displays remaining ink amount 607, which is estimated based on the amount of ink ejected from the print head 401, as shown in FIG. 6(b-3). Furthermore, when ink detection sensor 410 detects that there is no ink, it displays remaining ink amount 608 as shown in FIG. 6(b-4).

[0029] When the ink detection sensor 410 detects that there is no ink, the remaining ink amount 609 is displayed as shown in Fig. 6(b-5) based on the amount of ink ejected from the recording head 401. Furthermore, when it is estimated that there is no ink left in the ink tank unit 110, the remaining ink amount 610 is displayed as shown in Fig. 6(b-6).

[0030] 7 shows non-volatile information related to the ink tank unit 110 stored in the recording device 100. The non-volatile information related to the ink tank unit 110 is stored in the EEPROM 104. Ink tank information 1 701 holds information related to the remaining amount of ink for each ink tank. Ink tank information exists for each ink tank, from ink tank information 1 701 to ink tank information 2 712, and ink tank information 3 713.

[0031] Each ink tank information includes an ink amount estimated value 702, a dot count tally flag 703, an inter-sensor dot count (total) 704, an inter-sensor dot count (printing) 705, an inter-sensor dot count (recovery) 706, an estimated ink usage correction value (total) 707, an estimated ink usage correction value (printing) 708, an estimated ink usage correction value (recovery) 709, a previous inter-sensor dot count (printing) 710, and a previous inter-sensor dot count (recovery) 711.

[0032] The ink amount estimate 702 holds information relating to the estimated value of the amount of ink present in the ink tank unit 110. The method for estimating the remaining ink amount will be described later with reference to FIG. 8. The dot count tally flag 703 holds information on whether to measure the number of ink droplets ejected from the print head 401 (dot count). The dot count tally process will be described later in detail with reference to FIG. 9.

[0033] Inter-sensor dot count (total) 704, inter-sensor dot count (printing) 705, and inter-sensor dot count (recovery) 706 store information about the dot count values ​​from the print head 401 for each application for which the print head 401 ejected ink. In this embodiment, the information is stored in three categories: the dot count used in the print process (recording), the dot count used in the recovery process, and the total dot count used in both the print process and the recovery process. Details of the inter-sensor dot count aggregation process will be described later with reference to FIG. 9.

[0034] Estimated ink usage amount correction value (total) 707, estimated ink usage amount correction value (printing) 708, and estimated ink usage amount correction value (recovery) 709 hold information about the correction values ​​used when estimating ink usage. In this embodiment, they hold estimated ink usage amount correction values ​​for three items: the amount of ink used in the printing process, the amount of ink used in the recovery process, and the total amount of ink used in both the printing process and the recovery process. Details of the method for creating the estimated ink usage amount correction process and the estimated ink usage correction method will be described later with reference to Figures 10, 13, and 14.

[0035] Fig. 8 is a flowchart of a series of processes executed when ink is used in the recording device 100. The processes in Fig. 8 are executed by the CPU 101 when a process using various inks is completed, such as when a printing process or a recovery process is completed, and the CPU 101 reads out a program stored in the ROM 102 into the RAM 103 and executes the program.

[0036] In S801, the dot count value of the ink for which an ejection command has been issued to the print head 401 during processing that uses ink is measured. In S802, a dot count tally flag is obtained from non-volatile information, and it is determined whether or not dot count tallying is necessary. If it is determined that tallying is necessary (Yes in S802), the process proceeds to S803, and if it is determined that tallying is not necessary (No in S802), the process proceeds to S804. Details of switching the tally flag will be described later with reference to FIGS. 11 and 12.

[0037] In S803, the ink dot count value measured in S801 is saved as non-volatile information. Details of the dot count saving process will be described later with reference to FIG. 9. In S804, an estimated amount of ink used in the process using ink is calculated based on the ink dot count value measured in S801 and the mass per dot of ink. In S805, a correction process is performed for the estimated ink usage calculated in S804. Details of the estimated ink usage correction process will be described later with reference to FIG. 10. In S806, the estimated ink amount value 702 is updated by subtracting the estimated ink usage corrected in S805 from the estimated ink amount value 702 saved in the non-volatile information. In addition, the remaining ink amount display displayed on the display unit 106 of the recording device is updated based on the updated estimated ink amount value 702.

[0038] 9 is a flowchart of a series of processes for saving ink dot counts in non-volatile information. This process is performed by the CPU 101 reading a program stored in the ROM 102 into the RAM 103 and executing it when it is determined that dot counting is necessary when ink is used in the recording device 100 (Yes in S802 in FIG. 8).

[0039] In S901, the sensor-to-sensor dot count (total) 704 obtained from the non-volatile information is updated by adding the dot count value measured in the dot count measurement process to the sensor-to-sensor dot count (total) 704. In S902, the purpose for which ink is to be used is determined. If the purpose for which ink is to be used is printing processing (print in S902), the process proceeds to S903, and if the purpose for which ink is to be used is recovery processing (recovery in S902), the process proceeds to S904.

[0040] In S903, the dot count value measured in the dot count measurement process is added to the sensor-to-sensor dot count (print) 705 obtained from the non-volatile information, thereby updating the sensor-to-sensor dot count (print) 705. In S904, the dot count value measured in the dot count measurement process is added to the sensor-to-sensor dot count (recovery) 706 obtained from the non-volatile information, thereby updating the sensor-to-sensor dot count (recovery) 706.

[0041] Fig. 10 is a flowchart of a series of processes for correcting estimated ink usage. For example, this is realized by the CPU 101 shown in Fig. 1 reading a program stored in ROM 102 into RAM 103 and executing it. This process is performed after the process of estimating ink usage in the recording device 100 (S804 in Fig. 8).

[0042] In S1001, it is determined whether correction values ​​are stored in the estimated ink usage amount correction value (printing) 708 and the estimated ink usage amount correction value (recovery) 709 of the non-volatile information 701. If correction values ​​are stored in the estimated ink usage amount correction value (printing) 708 and the estimated ink usage amount correction value (recovery) 709 (correction values ​​present in S1001), the process proceeds to S1002. If correction values ​​are not stored in the estimated ink usage amount correction value (printing) 708 and the estimated ink usage amount correction value (recovery) 709 (no correction values ​​present in S1001), the process proceeds to S1003.

[0043] In S1002, the purpose for which ink is to be used is determined. If the purpose for which ink is to be used is printing (printing in S1002), the process proceeds to S1004, and if the purpose for which ink is to be used is recovery processing (recovery in S1002), the process proceeds to S1005.

[0044] In S1004, the estimated ink usage amount is corrected by applying the estimated ink usage amount correction value (printing) 708 to the estimated ink usage amount (estimated usage amount) estimated in the ink usage amount estimation process. Specifically, the estimated ink usage amount is corrected by multiplying the estimated ink usage amount by the estimated ink usage amount correction value (printing) 708. For example, if the estimated ink usage amount is 10 ml and the estimated ink usage amount correction value (printing) is 0.9, the estimated ink usage amount is corrected to 9 ml.

[0045] In S1005, the estimated ink usage amount estimated in the ink usage amount estimation process is corrected by applying the estimated ink usage amount correction value (recovery) 709. Specifically, the estimated ink usage amount is corrected by multiplying the estimated ink usage amount by the estimated ink usage amount correction value (recovery) 709. For example, if the estimated ink usage amount is 10 ml and the estimated ink amount correction value (printing) is 0.8, the estimated ink usage amount is corrected to 8 ml.

[0046] In S1003, it is determined whether a correction value is stored in the estimated ink usage correction value (total) 707 in the non-volatile information 701. If a correction value is stored in the estimated ink usage correction value (total) 707 (correction value present in S1003), the process proceeds to S1006. If a correction value is not stored in the estimated ink usage correction value (total) 707 (no correction value present in S1003), the process ends without executing the correction process.

[0047] In S1005, the estimated ink usage amount estimated in the ink usage amount estimation process is corrected by applying the estimated ink usage amount correction value (total) 707. Specifically, the estimated ink usage amount is corrected by multiplying the estimated ink usage amount by the estimated ink usage amount correction value (total) 707. For example, if the estimated ink usage amount is 20 ml and the estimated ink usage amount correction value (total) is 0.85, the estimated ink usage amount is corrected to 17 ml.

[0048] 11 is a flowchart of a series of processes executed when the ink detection sensor 409 detects that there is no ink in the recording apparatus 100 of this embodiment. Each process in FIG. 11 is realized, for example, by the CPU 101 shown in FIG. 1 reading a program stored in the ROM 102 into the RAM 103 and executing it.

[0049] In S1101, the remaining ink amount displayed on the display unit 106 of the recording apparatus 100 is updated. At the start of this process, the amount of ink stored in the ink tank unit 110 is slightly below the ink amount 501. Therefore, the process starts when the ink detection sensor 409 switches from a state in which ink is present, i.e., the ink amount is equal to or greater than the ink amount 501, to a state in which ink is absent, i.e., the ink amount is less than the ink amount 502. At this time, because the ink detection sensor 409 has detected that there is no ink, the ink amount display shows the remaining amount 606. In S1102, information related to the ink dot count in the non-volatile information is cleared. Specifically, 0 is written to the inter-sensor dot count (total) 704, inter-sensor dot count (printing) 705, and inter-sensor dot count (recovery) 706.

[0050] In S1102, in order to start the measurement process of the dot count between the sensors, the dot count tally flag 703 in the non-volatile information is changed to indicate that dot count tally is required.

[0051] Fig. 12 is a flowchart of a series of processes executed when the ink detection sensor 410 detects the absence of ink. Each process in Fig. 12 is executed, for example, by the CPU 101 shown in Fig. 1 reading a program stored in the ROM 102 into the RAM 103.

[0052] In S1201, the ink amount displayed on the display unit 106 of the recording apparatus 100 is updated. At the start of this process, the amount of ink stored in the ink tank unit 110 is slightly below the ink amount 502. Therefore, the process starts when the ink detection sensor 410 switches from a state in which ink is present, i.e., the ink amount is equal to or greater than the ink amount 502, to a state in which ink is absent, i.e., the ink amount is less than the ink amount 502. Because the ink detection sensor 410 has detected that there is no ink, the ink amount display shows the remaining amount 608. In S1202, in order to end the measurement process of the sensor-to-sensor dot count, the dot count tally flag 703 in the non-volatile information is changed to indicate that dot count tally is not required.

[0053] In S1203, an estimated ink usage correction value (total) is calculated based on the aggregated inter-sensor dot count (total) 704. Details of the calculation process for the estimated ink usage correction value (total) will be described later with reference to FIG. 13. In S1204, an estimated ink usage correction value (printing) and an estimated ink usage correction value (recovery) are calculated based on the aggregated inter-sensor dot count (printing) 705 and inter-sensor dot count (recovery) 706. Details of the calculation process for the estimated ink usage correction value (printing) and estimated ink usage correction value (recovery) will be described later with reference to FIG. 14.

[0054] Fig. 13 is a flowchart of a series of processes for calculating the estimated ink usage amount correction value (overall). Each process in Fig. 13 is realized, for example, by the CPU 101 shown in Fig. 1 reading a program stored in the ROM 102 into the RAM 103 and executing it.

[0055] In S1301, the amount of ink used between the sensors is estimated based on the total inter-sensor dot count (total) value. Similar to S804 in Fig. 8, the estimated inter-sensor ink use amount is calculated based on the dot count value and the mass per ink dot.

[0056] In S1302, the estimated ink usage amount between sensors calculated in S1301 is compared with the ink usage amount between sensors 503 to calculate the difference (ink usage amount difference) between the estimated ink usage amount and the ink usage amount between sensors 503. For example, if the ink usage amount between sensors 503 is 100 ml and the estimated ink usage amount between sensors is 110 ml, the ink usage amount difference is 10 ml.

[0057] In S1303, it is determined whether the ink usage difference calculated in S1302 exceeds a predetermined difference threshold. The difference threshold is determined for each ink color depending on the ink components, print head design, etc. If the ink usage difference calculated in S1302 is within the difference threshold (YES in S1303), the process proceeds to S1304. If the ink usage difference is not within the difference threshold (NO in S1303), it is determined that an event has occurred, such as ink being injected into the ink tank unit 110 or the print head 401 being replaced, and the process ends without calculating the estimated ink usage correction value (total).

[0058] In S1304, an estimated ink usage correction value (total) is calculated to correct the ink usage difference calculated in S1302. For example, if the ink amount between ink detection sensors 503 is 100 ml and the estimated ink usage between the sensors is 110 ml, the estimated ink usage correction value (total) is calculated as 100 / 110, or 0.909.

[0059] In S1305, the estimated ink usage amount correction value (total) calculated in S1304 is saved in the estimated ink usage amount correction value (total) 707 of the non-volatile information 701.

[0060] Fig. 14 is a flowchart of a series of processes for calculating the estimated ink usage correction value (printing) and the estimated ink usage correction value (recovery). Each process in Fig. 14 is realized, for example, by the CPU 101 shown in Fig. 1 reading a program stored in the ROM 102 into the RAM 103 and executing it. This process is performed as part of the process (Fig. 12) that is performed when the ink detection sensor 410 detects that there is no ink in each ink tank.

[0061] In S1401, the amount of ink used in the printing process between the sensors is estimated using the dot count (printing) between the sensors, which is stored in non-volatile information. The estimated amount of ink used is calculated based on the dot count value and the mass per dot of ink, similar to S804 in Figure 8.

[0062] In S1402, the amount of ink used in the recovery process between the sensors is estimated using the sensor-to-sensor dot count (recovery) stored in the non-volatile information. The estimated amount of ink used is calculated based on the dot count value and the mass per dot of ink, similar to S804 in Figure 8.

[0063] In S1403, as in S1303, it is determined whether the difference between the total estimated ink usage amount between the ink sensors used in the printing process and recovery process calculated in S1401 and S1402 and the ink amount between sensors 503 (ink usage amount difference) exceeds the difference threshold. If the ink usage amount difference is within the difference threshold (YES in S1403), the process proceeds to S1404. If the ink usage amount difference is not within the difference threshold (NO in S1403), it is determined that ink has been injected into the ink tank unit 110 or the print head 401 has been replaced during the process, and the process ends without proceeding to S1404.

[0064] In S1404, it is checked whether dot count information is stored in the non-volatile information Previous Inter-Sensor Dot Count (Print) 710 and Previous Inter-Sensor Dot Count (Recovery) 711. If the dot count information is stored (YES in S1404), the process proceeds to S1405, and if the dot count information is not stored (NO in S1404), the process proceeds to S1410.

[0065] In S1405, the previous estimated ink usage (printing) and previous estimated ink usage (recovery) are calculated using the previous sensor-to-sensor dot count (printing) and previous sensor-to-sensor dot count (recovery) stored in non-volatile information. The estimated ink usage is calculated based on the dot count value and the mass per dot of ink, similar to S804 in Figure 8.

[0066] In S1406, the estimated ink usage amount (current) calculated in S1402 and the estimated ink usage amount (previous) calculated in S1405 are used to generate an estimated ink usage amount correction value (printing) and an estimated ink usage amount correction value (recovery). The estimated ink usage amount correction value is generated by solving simultaneous equations using the estimated ink usage amount (current), estimated ink usage amount (previous), and the ink amount between sensors. For example, if the estimated ink usage amount (printing) this time is 88.9 ml, the estimated ink usage amount (recovery) this time is 25.0 ml, the previous estimated ink usage amount (printing) was 66.7 ml, the estimated ink usage amount (recovery) this time is 50.0 ml, and the ink amount between sensors 503 is 100 ml, then 88.9x+25.0y=100 66.7x+50.0y=100 This solves the simultaneous equations above. This generates the estimated ink usage correction value (printing): x and the estimated ink usage correction value (recovery): y. In this example, the estimated ink usage correction values ​​generated are x=0.899 and y=0.799.

[0067] In S1407, it is determined whether the calculation of the correction value in S1406 was successful. For example, if a negative number is calculated as the correction value, or if a correction value greater than a predetermined threshold value is calculated, it is determined that the calculation of the correction value failed (NO in S1407). If ink is injected into the ink tank unit 110 during the dot count measurement process, or if the print head 401 is replaced during the dot count measurement process, the tendency of variation in the calculation of the estimated ink usage amount will change midway. This may result in an inability to calculate the correct correction value. If the correction value was calculated in S1406 (YES in S1407), proceed to S1408; if the correction value was not calculated (NO in S1407), proceed to S1409.

[0068] In S1408, the estimated ink usage correction value (printing) and estimated ink usage correction value (recovery) in the non-volatile information are updated with the values ​​calculated in S1406.

[0069] In S1409, the previous sensor-to-sensor dot count (printing) and previous sensor-to-sensor dot count (recovery) are updated based on the sensor-to-sensor dot count (printing) and sensor-to-sensor dot count (recovery) values. The saved dot count values ​​are used in the next correction value calculation. Note that in this embodiment, the process is divided into two processes using two types of ink, printing and recovery, and a correction value is calculated for each of them, but if there are three or more types of processes using ink, a correction value corresponding to each of the processes may also be calculated. In that case, the dot count values ​​are saved and calculated a number of times according to the number of types of processes using ink.

[0070] FIG. 15 is a flowchart of a series of processes when non-volatile information is cleared in the recording device 100. Each process in FIG. 15 is realized, for example, by the CPU 101 shown in FIG. 1 reading a program stored in ROM 102 into RAM 103 and executing it. This process is performed when the printhead 401 is replaced. In this embodiment, the printhead 401 is detachably mounted on the carriage 402, allowing the user to replace the printhead 401 at any time. The printhead 401 is equipped with a chip (not shown) that stores printhead usage information, and a reading unit (not shown) provided on the carriage 402 reads the information on the chip in the printhead 401 to detect that the printhead 401 has been replaced.

[0071] In S1501, the non-volatile information is erased, which needs to be reset when the print head 401 is replaced. In this embodiment, the following information is erased for all ink colors: dot count tally flag, inter-sensor dot count (overall), inter-sensor dot count (printing), inter-sensor dot count (recovery), estimated ink usage correction value (overall), estimated ink usage correction value (printing), estimated ink usage correction value (recovery), previous inter-sensor dot count (printing), and previous inter-sensor dot count (recovery).

[0072] With the above configuration, the estimated ink usage amount can be corrected by calculating the difference between the ink amount between the ink detection sensors 409, 410 measured between the sensors 503 and the ink usage amount estimated by dot counting. This makes it possible to correct for variations in the amount of ink ejected from the print head, improving the accuracy of detecting the amount of liquid in the liquid storage section.

[0073] The present invention can also have the following configuration.

[0074] (1) a liquid ejection head that ejects liquid; a liquid storage section that stores the liquid to be supplied to the liquid ejection head; a first detection means for detecting whether the amount of liquid stored in the liquid storage section is equal to or greater than a first amount or less than a first amount; a second detection means for detecting whether the amount of liquid stored in the liquid storage section is equal to or greater than a second amount that is smaller than the first amount; an estimation means for estimating, as an estimated usage amount, the amount of liquid ejected by the recording head during the period from when the first detection means detects that the amount of liquid stored in the liquid storage section has changed from a state where it is equal to or greater than the first amount to a state where it is less than the first amount to when the second detection means detects that the amount of liquid stored in the liquid storage section has changed from a state where it is equal to or greater than the second amount to a state where it is less than the second amount, The liquid ejection device is characterized in that the estimation means calculates a first correction value for correcting the estimated usage amount based on a first difference that is the difference between the first amount and the second amount, the estimated usage amount, and a second difference that is the difference between the first difference and the estimated usage amount, and then corrects the estimated usage amount based on the correction value.

[0075] (2) The liquid ejection device according to (1), wherein when the second difference is greater than a threshold value, the estimation means does not calculate the first correction value.

[0076] (3) the liquid ejection device includes a recovery unit that recovers the ejection performance of the liquid ejection head, the liquid ejection head performs a printing process of ejecting liquid onto a recording medium and a recovery process of ejecting liquid onto the recovery means; The liquid ejection device described in (1) or (2) is characterized in that the estimation means estimates a first liquid amount, which is the amount of liquid ejected by the recording head in the printing process, and a second liquid amount, which is the amount of liquid ejected by the recording head in the recovery process, and calculates a second correction value for correcting the first liquid amount and a third correction value for correcting the second liquid amount based on the difference between the estimated liquid amounts and the first amount.

[0077] (4) the liquid ejection head is capable of ejecting a first liquid and a second liquid having a color different from that of the first liquid; the liquid ejection device includes, as the liquid storage section, a first liquid storage section that stores the first liquid and a second liquid storage section that stores the second liquid; The liquid ejection device described in any one of (1) to (3), characterized in that the estimation means calculates a correction value for correcting the estimated usage amount of the first liquid and a correction value for correcting the estimated usage amount of the second liquid.

[0078] (5) The liquid ejection device according to any one of (1) to (4), wherein the liquid storage section includes an inlet for injecting liquid into the liquid storage section.

[0079] (6) The liquid ejection device described in any one of (1) to (5) is characterized in that the liquid ejection head is configured to be detachable from the liquid ejection device, and the correction value is erased when the liquid ejection head is replaced. [Explanation of symbols]

[0080] 100 Recording device 101 CPU 110 Ink tank section 401 Recording head 409, 410 Ink detection sensor

Claims

1. a liquid ejection head that ejects liquid; a liquid storage section that stores the liquid to be supplied to the liquid ejection head; a first detection means for detecting whether the amount of liquid stored in the liquid storage section is equal to or greater than a first amount or less than a first amount; a second detection means for detecting whether the amount of liquid stored in the liquid storage section is equal to or greater than a second amount that is smaller than the first amount; an estimation unit that estimates a first amount of liquid ejected by the liquid ejection head onto a recording medium and a second amount of liquid discharged from the liquid ejection head to recover the ejection performance of the liquid ejection head during a period from when the first detection unit detects that the amount of liquid stored in the liquid storage unit has changed from a state where it is equal to or greater than the first amount to a state where it is less than the first amount to when the second detection unit detects that the amount of liquid stored in the liquid storage unit has changed from a state where it is equal to or greater than the second amount to a state where it is less than the second amount, The liquid ejection device is characterized in that the estimation means calculates a first difference, which is the difference between the first amount and the second amount, a printing correction value that corrects the first amount of liquid based on the first amount of liquid, and a recovery correction value that corrects the second amount of liquid based on the first difference and the second amount of liquid.

2. A liquid ejection device as described in Claim 1, characterized in that when the difference between the total value of the first liquid amount and the second liquid amount and the first difference is greater than a threshold value, the estimation means does not calculate the printing correction value and the recovery correction value.

3. the liquid ejection head is capable of ejecting a first liquid and a second liquid having a color different from that of the first liquid; the liquid storage section includes a first liquid storage section that stores the first liquid and a second liquid storage section that stores the second liquid, 2. The liquid ejection apparatus according to claim 1, wherein the estimation unit calculates the print correction value and the recovery correction value for each of the first liquid and the second liquid.

4. The liquid ejection device according to claim 1 , wherein the liquid storage section has an inlet through which liquid can be injected into the liquid storage section.

5. A storage means for storing the print correction value and the recovery correction value, The liquid ejection device according to claim 1, wherein the liquid ejection head is configured to be detachable from the liquid ejection device, and when the liquid ejection head is replaced, the liquid ejection device erases the printing correction value and the recovery correction value stored in the memory means.

6. A cap is provided to cap an ejection surface on which an ejection port of the liquid ejection head is formed, 2. The liquid ejection apparatus according to claim 1, wherein the liquid ejection head ejects liquid onto the cap.

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