JP2009214450A - Method for detecting residual amount of ink and inkjet recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recording apparatus capable of accurately judging the residual amount of ink in an ink tank by a relatively simple constitution, and to provide a method for detecting the residual amount of the ink. <P>SOLUTION: A specified energy is provided to a heater of an inkjet recording head, and before increase in temperature of the recording head before and after providing the energy is measured, a suction recovery operation to the inkjet recording head is executed. It becomes possible thereby to measure the increase in temperature after the temperature of the recording head is lowered to a stabilized value in a relatively short time even under a condition that the temperature of the recording head has been elevated by a recording operation performed just before. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an ink remaining amount detection method for determining whether or not sufficient ink remains in a recording head used in an inkjet recording apparatus so that normal recording operation can be continued. The ink remaining amount detection method of the present invention can be applied not only to an ink jet recording apparatus but also to a facsimile, a copying machine, a word processor, or a multifunction machine that employs the ink jet recording method.

  In a recording apparatus that employs an inkjet method, recording is performed by ejecting ink from a recording head toward a recording medium. At this time, the ink consumed in association with the recording operation is intermittently supplied from an ink tank that is integrated with the recording head or detachably connected to the recording head. . However, if the ink in the tank becomes small due to consumption of the ink and the ink is not smoothly supplied to the recording head, the ejection operation from the recording head tends to become unstable. Therefore, a general ink jet recording apparatus is provided with some means for detecting the remaining amount of ink in the ink tank, and when the remaining amount becomes small, the user is notified of this, and the recording head cartridge or ink tank To encourage replacement.

  Various proposals have already been made for methods for detecting the remaining amount of ink. For example, the number of times ink is ejected from the recording head or the number of times of performing a suction operation for forcibly sucking ink from the recording head is counted, and when the ink consumption estimated from the count value exceeds a predetermined threshold value A method of notifying the user has been proposed. Also proposed and implemented are a method for detecting the remaining amount of ink from changes in the electrical resistance value of the ink or ink holding member, and a method for detecting the remaining amount of ink by detecting the ink ejection state by optical means such as a photo interrupter. Has been.

  Patent Document 1 discloses a method of detecting the remaining amount of ink in an ink jet recording head provided with an electrothermal transducer (heater) based on the degree of temperature rise of the recording head during ink ejection. In an ink jet recording head provided with a heater, a heater is provided in an ink path communicating with each ejection port, and a film boiling occurs in the ink by applying a voltage pulse to the heater according to a recording signal. Then, a predetermined amount of ink is pushed out from the discharge port by the foaming pressure at this time, and the ink adheres to the recording medium to perform recording. At this time, in the heater board provided with a plurality of heaters, the temperature depends on the inflow of heat from the heater as a heat source and the outflow of heat to the ink and other components in contact with the heater board. That is, in a state where the ink path is sufficiently filled with ink, there is a temperature outflow due to the heat-absorbed ink being discharged to the outside, but in a state where the ink path is not sufficiently filled with ink, There is little outflow of temperature, and the heater board rises in temperature and becomes cheaper.

  FIG. 8 is a diagram for comparing the degree of increase in temperature detected by a temperature sensor provided on the heater board when continuous ejection operations are performed with the amount of ink remaining in the ink tank. . In the figure, the horizontal axis indicates the number of discharges at each discharge port. On the other hand, the vertical axis shows the temperature rise after the start of the discharge operation, that is, the value ΔT obtained by subtracting the temperature detected by the temperature sensor before starting the discharge operation from the temperature detected by the temperature sensor from time to time. Yes. In the figure, a curve 801 indicates a state where a small amount of ink remains in the ink tank, a curve 802 indicates a state where only a small amount remains, and a curve 803 indicates a state where sufficient ink remains in the ink tank. As can be seen from the figure, even if the ejection operation is performed the same number of times under the same conditions, the smaller the remaining amount of ink in the ink tank, the greater the value of ΔT (temperature rise) detected by the temperature sensor. For example, when 8000 discharge operations are performed, the temperature rise ΔT = 70 ° C. in the curve 801, the temperature rise ΔT = 60 ° C. in the curve 802, and the temperature rise ΔT = 45 ° C. in the curve 803.

  Patent Document 1 discloses a method for detecting the remaining amount of ink from the degree of temperature rise of the heater board when predetermined energy is applied to each heater by using such a tendency. For example, referring to FIG. 8, in a state where ink is sufficiently left in the ink tank (curve 803), the temperature rise PreΔT = 45 ° C. after the 8000 ejection operations are obtained in advance. After that, 8000 ejection operations are performed again at the timing of actually detecting the remaining amount of ink, and the temperature rise ΔT obtained at that time exceeds a predetermined amount (for example, 10 ° C. or more) over PreΔT = 45 ° C. When (ΔT> 55 ° C.), it is determined that the remaining amount of ink is small. The predetermined amount (10 ° C.) at this time can be adjusted according to “how much ink is consumed when the user is notified”.

  As described above, in order to detect the remaining amount of ink as disclosed in Patent Document 1, it is apparent that the ink is sufficiently supplied, and the heater board when the predetermined energy is applied is used. It is necessary to know the temperature rise (PreΔT) in advance. Hereinafter, such a process for acquiring PreΔT is referred to as a temperature rise characteristic acquisition process. However, the temperature rise actually detected when predetermined energy is applied varies depending on individual differences of the recording head and the recording apparatus.

  FIG. 9 is a diagram for explaining an error between the actual temperature of ink existing near the ejection port and the temperature detected by the temperature sensor mounted on the heater board. Here, when predetermined energy is applied (for example, 8000 ejection operations are executed), the actual temperature rise of the ink near the heater board is obtained from the temperature sensor mounted on the heater board on the horizontal axis. The elevated temperature ΔT is shown on the vertical axis. Even if the actual temperature and the detected temperature match before energy application, if a certain amount of energy is applied, an error occurs between the two as shown in the figure. Such an error is caused by a tolerance of the recording apparatus, a tolerance of the recording head, a variation in sensors, and the like. Therefore, when the remaining amount is detected as in Patent Document 1, it is preferable to measure PreΔT with individual recording heads or individual recording devices, and to eliminate variation factors due to individual differences.

  By the way, the remaining amount detection method described in Patent Document 1 can be used in combination with the other ink remaining amount detection methods described above. For example, based on the remaining amount of ink estimated from the counts of the number of ejections and the number of suctions of the recording head, the user finally notifies the user of the remaining amount of ink in advance, and finally determines whether there is a remaining amount. You may perform by the method currently disclosed by the said patent document 1. FIG.

  Hereinafter, a method for determining the final presence or absence of the remaining ink amount by adopting the method of Patent Document 1 while estimating a certain amount of remaining ink amount from the count values of the number of ejection times and the number of suction times will be concretely described. Explained.

  FIG. 11 is a flowchart for explaining an example of the temperature rise characteristic acquisition step performed by the recording apparatus. In this example, an example is shown in which a new or in-use recording head (or ink tank) is newly installed in the recording apparatus.

  When the recording head cartridge or ink tank is attached to the recording apparatus in step S1101, ink remaining amount information V of the attached ink tank is acquired in step S1102. The remaining amount information V at this time is information stored in advance by the above-described conventional method (for example, a method inferred from the count values of the discharge count and the suction count of the print head).

  In subsequent step S1103, the acquired remaining amount information V is compared with a predetermined threshold Low1. Here, “Low1” indicates a minimum ink remaining amount that is sufficient to perform a recording operation after a predetermined ejection operation for obtaining PreΔT. If V ≦ Low1 in step S1103, it is determined that the remaining amount of ink is not sufficient to acquire PreΔT, and this mode is terminated as it is, and the recording apparatus enters a standby state.

  On the other hand, if V> Low1 in step S1103, the process proceeds to the temperature increase acquisition mode in step S1104.

  FIG. 18 is a flowchart for explaining the process of the temperature increase acquisition mode. When the temperature rise acquisition mode is started, the temperature T1 of the heater board at that time is first acquired by the temperature sensor mounted on the recording head (step S1801). Subsequently, the recording head performs 8000 ejection operations from each of the ejection ports of the recording head toward the cap member or the like prepared in the recovery unit (step S1802).

  Thereafter, the temperature T2 of the discharged heater board after the above operation is acquired again by the temperature sensor (step S1803). In step S1804, the print head temperature rise ΔT = T2−T1 is calculated. With the above, the temperature rise characteristic mode ends, and the process returns to the original process.

  If the temperature increase acquisition mode is executed in the temperature increase characteristic acquisition step, the acquired temperature increase ΔT is PreΔT. Further, if it is executed in the remaining amount detection step, the acquired temperature increase ΔT is the temperature increase ΔT for comparison with PreΔT obtained in advance.

  Refer to FIG. 11 again. When PreΔT is acquired in the temperature increase acquisition mode in step S1104, the process proceeds to step S1105, where the acquired PreΔT is stored in the memory in the apparatus, and this mode ends.

  On the other hand, FIG. 12 is a flowchart illustrating an example in which the temperature rise characteristic acquisition step is executed after performing a normal recording operation. When the recording operation based on one job is completed in step S1201 and the recording medium of the last page is ejected, in step S1202, the current ink remaining amount information V of the ink tank is acquired. The remaining amount information V at this time is information stored in advance by the above-described conventional method (for example, a method inferred from the count values of the discharge count and the suction count of the print head).

  In the subsequent step S1203, the acquired remaining amount information V is compared with the threshold value Low1 described above. If V ≦ Low1 in step S1203, it is determined that the remaining amount of ink is not sufficient to acquire PreΔT, and this mode is terminated as it is, and the recording apparatus enters a standby state.

  On the other hand, if V> Low1 in step S1203, the process proceeds to step S1204 to execute the temperature increase acquisition mode described in FIG.

  Thereafter, the process proceeds to step S1205, where PreΔT acquired in the temperature increase acquisition mode is stored in the memory in the apparatus, and this mode is terminated.

  FIG. 10 is a flowchart for explaining an example of the remaining amount detection process performed by the recording apparatus when detecting the actual remaining ink amount. In this example, the ink remaining amount detection is performed immediately after executing the operation every time the recording apparatus receives the recording data.

  When the recording device receives the recording data (step S1001), it executes a series of recording operations according to the recording data (step S1002). At this time, the latest ink remaining amount information V is also obtained by counting the number of ejections of the recording head.

  When the recording medium is discharged and the recording operation is completed, the process proceeds to step S1003, and the acquired remaining amount information V is compared with a threshold value Low2. Here, Low2 indicates the remaining amount of ink that may not have sufficient ink remaining when a predetermined ejection operation such as a recording operation is performed thereafter. Low2 can be adjusted according to the setting of the ink amount of the cartridge. When V> Low2, it is determined that the remaining amount of ink is early at the timing of detecting the remaining amount of ink, this mode is terminated as it is, and the recording apparatus enters a standby state. On the other hand, if V ≦ Low2, the process proceeds to step S1004 to execute the temperature increase acquisition mode described with reference to FIG.

  In subsequent step S1005, ΔT obtained in step S1004 is compared with PreΔT acquired in advance and stored in the memory in the apparatus. Specifically, it is determined whether or not ΔT ≦ PreΔT + α. Here, the value of α can be set to about 10 ° C., for example, but this value can be adjusted by “how much ink is consumed and notified to the user”.

  In step S1005, if ΔT ≦ PreΔT + α, it is determined that there is remaining ink, the remaining amount detection step is terminated, and the recording apparatus enters a standby state. On the other hand, if ΔT> PreΔT + α, it is determined that there is no remaining ink, and the process advances to step S1006 to notify the user that the ink has run out and request replacement of the ink tank or recording head. In step S1007, the recording data received in step S1001, that is, the image data recorded immediately before the ink out state is stored in the memory in the apparatus. This is for making preparations that the printing operation can be performed again with the replaced ink tank even if the output image recorded in step S1002 has an adverse effect due to lack of ink. Thereafter, the recording apparatus enters a standby state.

  By performing the two-stage process as described above, that is, the process for obtaining the temperature rise characteristic shown in FIGS. 11 and 12, and the process for detecting the remaining quantity shown in FIG. Detection can be determined with a relatively simple configuration. Therefore, in an ink jet recording head using an electrothermal transducer, it is useful as a particularly effective method for detecting the remaining amount of ink.

Japanese Patent No. 3297465

  However, the temperature of the heater board at the time of acquiring the elevated temperature is affected not only by individual differences of the recording head and the recording apparatus but also by the immediately preceding recording operation. Specifically, when an image having a high density is recorded immediately before executing the temperature increase acquisition mode, the temperature of the heater board at the time of measuring the temperature increase is increased. On the other hand, when the recording operation is not performed immediately before measuring the temperature rise, the temperature of the heater board can be regarded as substantially equal to the ambient temperature. In such a case, even if the ink is sufficiently supplied to the recording head in the same manner, if the original temperature of the heater board is high, the values of PreΔT and ΔT are measured to be small, and originally When the temperature is low, it tends to be measured greatly. That is, with respect to the heater board temperature rise ΔT when detecting the remaining ink amount and PreΔT to be compared with this, the relative relationship becomes unstable due to the recording operation or the like immediately before the measurement of each temperature rise, and the detection with certainty There is a risk that results may not be obtained.

  In order to cope with such a problem, a method of waiting the recording apparatus for a predetermined time before acquiring PreΔT and ΔT may be considered in order to stabilize the temperature of the recording head that has been heated by the immediately preceding recording operation.

  FIG. 13 is a diagram illustrating a state in which the temperature of the heater board gradually decreases during the standby time immediately after the predetermined recording operation is performed. It can be seen that the temperature that has risen to 45 ° C. immediately after the recording operation is stabilized at a constant value in about 50 seconds. That is, when the temperature rise acquisition mode is executed, if a waiting time of 50 seconds is provided at the time when the immediately preceding recording operation or one job is completed, it is possible to obtain a temperature rise that is stabilized to some extent. However, it is known that when such a waiting time is secured, the supply of ink to the recording head is also promoted.

  FIG. 14 is a diagram showing how the temperature of the heater board rises for each waiting time when a printing operation is performed after waiting for a predetermined time in a state where the remaining amount of ink is small. According to the figure, it is understood that when the standby time of 60 seconds or more is provided, the value of the temperature increase ΔT is small even though the remaining amount of ink is small. That is, if a long standby time is provided, the temperature of the heater board is stabilized, but it becomes difficult to detect that the remaining amount of ink is small. Furthermore, the user's feeling of use with respect to the recording apparatus is also deteriorated by the long standby time itself.

  The present invention has been made to solve the above problems. Therefore, the object is to provide an ink jet recording apparatus capable of accurately determining the remaining amount of ink in the ink tank with a relatively simple configuration without providing an unnecessary standby time, and the ink remaining amount. It is to provide a quantity detection method.

  Therefore, in the present invention, there is provided a method for detecting an ink remaining amount of an ink jet recording apparatus that records an image using an ink jet recording head that discharges ink supplied from an ink tank using heat generated in a heater. A temperature increase characteristic acquisition step of applying predetermined energy to the heater at a timing when the ink remaining amount in the ink tank is sufficient, and measuring the temperature rise PreΔT of the recording head before and after the application, and the ink At the timing of detecting the remaining amount of ink in the tank, the predetermined energy is applied to the heater, the temperature rise ΔT of the recording head before and after the application is measured, and the result of comparing PreΔT and ΔT An ink remaining amount detecting step for determining the remaining amount of ink according to the temperature rising characteristic acquiring step and the ink remaining amount In at least one known process, and executes a suction recovery operation for said ink jet recording head before applying the predetermined energy to said heater.

  In addition, an ink jet recording head that discharges ink supplied from an ink tank by thermal energy of a heater generated by applying a voltage pulse, a temperature sensor that measures a temperature in the vicinity of the heater of the recording head, and the heater Obtained by the temperature rise acquisition means for applying a predetermined energy to the ink tank and measuring the temperature rise of the recording head before and after the application, and the temperature rise acquisition means at a timing for detecting the remaining amount of ink in the ink tank. Judgment means for judging the remaining amount of ink according to the result of comparing the raised temperature ΔT with the raised temperature PreΔT obtained by the raised temperature acquisition means at a timing when the remaining amount of ink in the ink tank is sufficient. And the determination means obtains at least one of the ΔT and the PreΔT when the predetermined value is obtained. Before granting Nerugi, characterized in that to perform the suction recovery operation for said ink jet recording head by said recovery means.

  According to the present invention, even in a situation where the recording head has been heated due to the previous recording operation or the like, the temperature of the recording head is decreased to a stable value in a relatively short time, and then the temperature rise Can be measured. As a result, the temperature rise temperature PreΔT when there is a sufficient amount of remaining ink and the value of the rise temperature ΔT compared to this are less likely to include temperature factors other than the temperature rise associated with the predetermined recording operation. By comparing these two values in a valid state, it is possible to execute remaining amount detection with high accuracy.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, a schematic configuration of an ink jet recording apparatus and a recording head that can be applied to all of the embodiments disclosed in this specification will be described, and then a plurality of embodiments will be specifically described.

  FIG. 2 is a schematic configuration diagram for explaining a main part of an ink jet recording apparatus applicable to the embodiment of the present invention. A chassis M3019 housed in an unillustrated exterior member is composed of a plurality of plate-like metal members having a predetermined rigidity, forms a skeleton of the recording apparatus, and holds each mechanism in the apparatus.

  The automatic feeding unit M3022 automatically feeds the recording medium (paper) into the apparatus main body. The transport unit M3029 guides the recording medium sent one by one from the automatic feeding unit M3022 to a predetermined recording position, and moves the recording medium from the recording position to the discharge unit M3030 in the arrow Y direction (sub-scanning direction). Transport. M3001 is an LF roller for directly contacting and transporting the recording medium, and M3006 is a bearing for the LF roller M3001. The sheet conveyed to the recording position is subjected to desired recording by a recording head mounted on the carriage M4001. M2015 is a paper interval adjusting lever for adjusting the distance between the recording head in the recording unit and the recording surface of the recording medium.

  The carriage M4001 is supported by a carriage shaft M4021 so as to be movable in the main scanning direction indicated by the arrow X. A recording head (not shown in FIG. 2) capable of ejecting ink is detachably mounted on the carriage M4001. The carriage M4001 is provided with a carriage cover M4002 and a head set lever M4007 for guiding and fixing the recording head H4001 at a predetermined position of the carriage M4001. The head set lever M4007 is provided so as to be rotatable with respect to a head set lever shaft located at the upper part of the carriage M4001, and a spring-biased head set plate (a spring-set head set plate ( (Not shown). When the recording head is mounted on the carriage M4007, the head set lever M4007 presses the recording head by its spring force and mounts the recording head at a predetermined position of the carriage cover M4002.

  A recording signal is transmitted to the recording head mounted on the carriage M4001 from the main board E0001 disposed on the back side of the chassis M3019 via the main body flexible cable E0012. By alternately repeating the recording main scan in which the carriage M4001 scans in the X direction in accordance with the ejection operation of the recording head according to the recording signal and the conveying operation of a predetermined amount of the recording medium by the conveying unit M3029, the recording medium Images are formed step by step.

  Recovery processing is appropriately performed on the recording head by the recovery unit M5000. The recovery unit M5000 includes a cap member for capping the ink discharge port surface provided in the recording head, a wiper member for wiping the ink discharge port surface, and the like. A suction pump capable of introducing a negative pressure is connected to the cap member. The ink in the recording head can be forcibly discharged from the ink discharge port by introducing a negative pressure into the cap member with a suction pump while the ink discharge port surface is capped. In this specification, such an operation is referred to as a suction recovery operation. Further, after ink that does not contribute to image recording is ejected from the ink ejection port toward the cap member, the ink stored in the cap member can be discharged to the waste ink tank by the pump means. As described above, a series of maintenance operations performed on the recording head in order to stabilize the ejection is generally referred to as a recording head recovery process.

  FIG. 3 is a schematic perspective view for explaining an example of a recording head cartridge applicable in the present invention. Here, an example is shown in which an ejection section H3002 for ejecting ink and an ink tank H3009 for supplying ink to the ejection section H3002 are integrally configured. In the case of such a configuration, the carriage M4001 has a configuration in which the recording head and the ink tank are mounted at the same time. A recording signal transmitted from the main board E0001 via the flexible cable E0012 is received by the electrical contact H3003 and transmitted to the ejection unit H3002 by a tab H3004 having electrical wiring. Here, a print head cartridge that stores one type (one color) of ink has been described. However, an actual carriage M4001 is mounted so that a plurality of colors of such a print head cartridge can be independently attached and detached. Is done.

  FIG. 4 is a schematic perspective view for explaining another form of the printhead cartridge applicable in the present embodiment. Here, a configuration example is shown in which a plurality of ink tanks H4900 containing different types of ink can be independently attached to a recording head including an ejection unit H4001 for ejecting ink. In such a case, an ink tank that needs to be replaced is appropriately attached to and detached from the carriage M4001 with the recording head attached. The electrical contacts and tabs are arranged on the back side of the figure, and transmit a recording signal to the discharge unit H4001.

  FIG. 5 is a plan view when observed from the ink ejection port side for explaining a partially enlarged configuration of the ejection section (H3002 or H4001) of the recording head explained in FIG. 3 or FIG. FIG. 6 is a schematic diagram showing a CC cross section of FIG. The ink supplied from the ink tank to the common liquid chamber 7 is guided to the ink bubbling chamber 6 through the individual ink introduction portions 9. A voltage pulse is applied to the electrothermal transducer (heater) disposed on the heater board 11 according to the recording signal, and the ink in the foaming chamber 6 is rapidly heated. This thermal energy causes film boiling in the ink in the foaming chamber 6, and a predetermined amount of ink is projected to the outside from the ink discharge ports 57 or 58 due to the growth of bubbles. In this example, 81 and 57 indicate a heater and an ink discharge port for discharging a 5 pl ink droplet, and 82 and 58 indicate a heater and an ink discharge port for discharging 1 pl of ink. The individual discharge ports and the heaters are arranged at a predetermined pitch in the Y direction so as to face each other in the respective foaming chambers, and this row is arranged on both sides of the common liquid chamber 7 so that ink for one color is discharged. The part is formed. By performing the ejection operation while moving the recording head having such a configuration in the X direction (main scanning direction) in the drawing, each pixel on the recording medium is expressed in gradation in two stages of 5 pl and 1 pl. I can do it.

  The temperature sensor 10 provided on the heater board 11 is composed of, for example, a diode sensor, and can appropriately detect the temperature of the heater board 11, that is, the temperature in the vicinity of the heater.

  The configuration of the recording head that ejects ink droplets of two sizes of 5 pl and 1 pl has been described above. However, the present invention and any of the embodiments described below are not limited to such a configuration. Even a recording head that discharges ink droplets of the same size, or even a recording head that can discharge a multi-level amount of ink, a heater that can cause the film boiling and discharge ink as droplets. If provided, the present invention and the following examples can be applied.

  FIG. 7 is a block diagram for explaining the control configuration of the inkjet recording apparatus described above.

  Reference numeral 100 denotes a CPU that controls the overall operation mechanism and data processing of the ink jet recording apparatus of the present embodiment. For example, the CPU 100 controls various mechanisms according to the image data received from the host device 200 and outputs an image.

  The ROM 101 is a memory area in which programs and parameters for processing executed by the CPU 100 are stored. The RAM 102 is a memory area used as a work area for the CPU 100 to execute processing.

  The CPU 100 processes the image data received from the host device 200 and generates print data that can be ejected by the ejection unit H3002 (H4001). Then, by supplying the recording data and the drive control signal (heat pulse signal) to the head driver H1001, the ejection unit H3002 (H4001) is caused to perform the ejection operation. Also, the detection values of the temperature sensor 10 provided in the discharge unit H3002 (H4001) and the environmental temperature sensor 12 for detecting the environmental temperature where the printing apparatus is placed are received, and various determinations and Execute control.

  The CPU 100 controls the carriage motor 103 for driving the carriage M001 in the main scanning direction via the motor driver 103A. Further, an LF motor 104 for rotating an LF roller that conveys the recording medium in the sub-scanning direction is controlled via a motor driver 104A. Further, the suction pump and the wiper blade of the recovery unit M5000 are controlled via the motor driver 105.

  A characteristic configuration of the present invention will be described below as a plurality of embodiments using the ink jet recording apparatus and the recording head cartridge described above.

  FIG. 1A is a flowchart for explaining the process for obtaining the temperature rise characteristic in the present embodiment in comparison with FIG.

  When the recording operation based on one job is completed in step S101 and the recording medium of the last page is discharged, the current ink remaining amount information V of the ink tank is acquired in step S102. The remaining amount information V at this time is information stored by the above-described conventional method (for example, a method inferred from the count values of the number of ejections of the print head and the number of suctions).

  In the subsequent step S103, the acquired remaining amount information V is compared with a threshold value Low. Here, as in the case of Low1 described in the section of the background art, “Low” means a minimum level that allows sufficient printing to be performed after that even if a predetermined operation for obtaining PreΔT is performed thereafter. Indicates the remaining amount of ink. However, as will be described later, the present embodiment is characterized in that the suction recovery operation is executed before the predetermined temperature increase acquisition mode is executed. Therefore, the value of Low in this embodiment is set to a value that allows for the amount of ink consumed by one suction recovery operation, rather than Low1 described in the background section. If V ≦ Low in step S103, it is determined that the remaining amount of ink is not sufficient to acquire PreΔT, this mode is terminated, and the recording apparatus enters a standby state.

  On the other hand, if V> Low in step S103, the process proceeds to step S104, and the recovery recovery process for the recording head by the recovery unit M5000 is executed. Specifically, the cap member is pressed against the surface of the ink discharge port, and a negative pressure is introduced into the cap member by a suction pump, whereby a predetermined amount of ink in the recording head is discharged from the ink discharge port. By this suction recovery operation, the ink whose temperature has been raised in the immediately preceding recording operation is removed from the recording head, and new ink stored in the ink tank is supplied near the heater board of the recording head. Therefore, the temperature of the heater board also drops to a stable value.

  FIG. 15 is a diagram illustrating a change in the temperature of the heater board when the suction operation is performed on the recording head whose temperature has been increased by the immediately preceding recording operation. Even in a state where the temperature has been raised to about 70 ° C., the temperature drops to about 30 ° C. in about 6 seconds after the suction recovery operation is started, and it can be seen that it is stable.

  Returning again to FIG. After the temperature of the recording head is returned to a stable value by the suction recovery operation in step S104, the process proceeds to step S105, and the temperature increase acquisition mode is executed. As the temperature increase acquisition mode at this time, the process described in FIG. That is, by applying predetermined energy to the heater, 8000 ejection operations are executed, and the temperature rise of the recording head before and after the ejection operation is measured.

  Further, the process proceeds to step S106, where PreΔT acquired in the temperature increase acquisition mode and the environmental temperature and time when the temperature increase acquisition mode is executed are stored in the memory in the apparatus, and this mode ends.

  FIG. 1B is a flowchart for explaining the steps for detecting the remaining amount of ink in this embodiment, comparing with FIG. In this embodiment, the ink remaining amount detection is performed immediately after the recording apparatus receives the recording data, and immediately after the operation is executed.

  When the recording device receives the recording data (step S108), it executes a series of recording operations according to the recording data (step S109). At this time, the latest ink remaining amount information V is also obtained by counting the number of ejections of the recording head.

  When the recording operation is finished and the recording medium is discharged, the process proceeds to step S110, and the obtained remaining amount information V is compared with the above-described threshold Low2, thereby determining whether or not the remaining ink amount can be detected. Here, Low2 indicates the remaining amount of ink that may not have sufficient ink remaining when a predetermined ejection operation such as a subsequent recording operation is performed. Low2 can be adjusted according to the setting of the ink amount of the cartridge. When V> Low2, it is determined that the remaining amount of ink is early at the timing of detecting the remaining amount of ink, this mode is terminated as it is, and the recording apparatus enters a standby state. On the other hand, if V ≦ Low2, the process proceeds to step S111, and the suction recovery process for the recording head by the recovery unit M5000 is executed as in step S104 of FIG. By this suction recovery operation, the ink whose temperature has been increased in the immediately preceding recording operation is eliminated, and the temperature of the heater board is also lowered to a stable value in substantially the same manner as when PreΔT was acquired. Then, it progresses to step S112 and performs the temperature rising acquisition mode demonstrated in FIG.

  In subsequent step S113, ΔT obtained in step S112 is compared with PreΔT stored in the memory in advance by the temperature rise characteristic obtaining step described in FIG. Specifically, it is determined whether or not ΔT ≦ PreΔT + α. Here, the value of α can be set to about 10 ° C., for example, but this value can be adjusted by “how much ink is consumed and notified to the user”.

  In step S113, if ΔT ≦ PreΔT + α, it is determined that there is remaining ink, the remaining amount detection step is terminated, and the recording apparatus enters a standby state. On the other hand, if ΔT> PreΔT + α, it is determined that there is no remaining ink, and the process proceeds to step S114 to notify the user that the ink has run out and request replacement of the ink tank or the recording head. In step S115, the recording data received in step S108, that is, the image data recorded immediately before the ink out state is stored in the memory in the apparatus. This is to prepare for the recording operation to be performed again with the replaced ink tank even if the output image recorded in step S109 has an adverse effect due to lack of ink. Thereafter, the recording apparatus enters a standby state.

  As described above, in this embodiment, in the temperature rise characteristic detection step and the remaining amount detection step, the suction recovery operation for the recording head is executed as a pre-step of the temperature rise acquisition mode executed in these steps. As a result, even in a situation where the recording head has been heated due to the previous recording operation, etc., the temperature rise is measured after the temperature of the recording head has dropped to a stable value in a relatively short time. Can be done. As a result, the temperature rise temperature PreΔT when there is a sufficient amount of remaining ink and the value of the rise temperature ΔT compared to this are less likely to include temperature factors other than the temperature rise associated with the predetermined recording operation. By comparing these two values in a valid state, it is possible to execute remaining amount detection with high accuracy.

  In the first embodiment described above, the contents of performing the suction recovery operation immediately before executing the temperature increase acquisition mode in both the temperature increase characteristic acquisition step and the ink remaining amount detection step have been described. It is not limited to such a configuration. The effect of the present invention can be obtained even in a configuration in which the suction recovery operation is executed immediately before the temperature rise acquisition mode is executed only in either the temperature rise characteristic acquisition step or the ink remaining amount detection step. . For example, in the case of executing a temperature rise characteristic acquisition step in which more accurate temperature rise detection is desired, a step that incorporates a suction recovery operation is used (FIG. 1A), and there is a concern that ink will be consumed more frequently. In the remaining amount detection step, the step shown in FIG.

  FIGS. 16A and 16B illustrate the process of acquiring the temperature rise characteristic and the process of detecting the ink remaining amount in Example 2 while comparing with FIGS. 12 and 1A and 1B. It is a flowchart for doing.

  In this embodiment, as a stage before executing the suction recovery operation for the recording head, the temperature of the recording head detected by the temperature sensor 10 provided on the heater board and the temperature sensor 12 provided in the recording apparatus main body detect. Get environmental temperature and. Then, the two detected temperatures are compared, and it is determined whether or not the difference between them is 15 ° C. or more (step S1604 or step S2003).

  When it is determined in step S1604 or step S2003 that the detected temperature difference is 15 ° C. or more, the process proceeds to step S1605 or step S2004, and the suction recovery operation is executed. Thereafter, PreΔT or ΔT is acquired in the temperature rise acquisition mode in step S1606 or step S2005. On the other hand, if it is determined in step S1604 or step S2003 that the detected temperature difference is less than 15 degrees, it is determined that the suction recovery operation is not necessary, and the process proceeds to step S1606 or step S2005. Then, the temperature increase acquisition mode is executed without performing the suction recovery operation, and PreΔT or ΔT is acquired.

  An object of the present invention is to eliminate a problem in the case where the temperature of a recording head is increased and becomes unstable due to a recording operation immediately before obtaining PreΔT or ΔT. For this purpose, the temperature environment of the recording head is stabilized by performing a suction recovery operation. However, even when the recording operation is performed immediately before, the temperature of the recording head does not rise so much and the temperature is relatively stable, it is preferable to perform the suction recovery operation more than necessary and consume ink. Absent.

  According to the present embodiment, by providing a step of determining whether or not the suction operation is necessary as in step S1604 and step S2003, it is possible to acquire a reliable temperature rise characteristic while suppressing ink consumption as much as possible. It becomes. As a result, it is possible to accurately determine the presence or absence of the remaining amount of ink for subsequent detection of the remaining amount of ink.

  However, such a step of determining whether or not the suction recovery operation is necessary does not necessarily include both the temperature rise characteristic acquisition step and the remaining amount detection step. In the temperature rise characteristic acquisition step where a more accurate temperature rise value is desired, the suction recovery operation is always performed, but only in the remaining amount detection step that is more frequently performed and the ink consumption is a concern, FIG. The remaining amount may be detected according to the flowchart described in (1). The opposite is also possible.

  In this embodiment, whether the difference between the temperature of the recording head detected by the temperature sensor 10 provided on the heater board and the environmental temperature detected by the temperature sensor 12 provided in the apparatus main body is 15 ° C. or more. Although it is determined whether or not, the value of the temperature difference is not limited to this. This value may be determined appropriately depending on the characteristics of the ink jet recording head and the recording apparatus to be used.

  FIG. 17 is a flowchart for explaining the process of acquiring the temperature rise characteristic in the present embodiment while comparing it with FIG. This embodiment shows an example in which the temperature rise characteristic is executed when a new or in-use recording head cartridge (or ink tank) is newly installed in the recording apparatus.

  When the recording head cartridge or ink tank is attached to the recording apparatus in step S1701, ink remaining amount information V of the attached ink tank is acquired in step S1702. The remaining amount information V at this time is acquired in advance by the above-described conventional method (for example, a method inferred from the count values of the number of ejections and the number of suctions of the recording head), and is stored in the storage unit of the recording head cartridge or the ink tank. Information.

  In the subsequent step S1703, the acquired remaining amount information V is compared with the threshold value Low1 described above. When V ≦ Low1, it is determined that the ink remaining amount in the head cartridge or ink tank is not sufficient to obtain PreΔT. Then, the process proceeds to step S 1711 to set that PreΔT acquisition is impossible and that the temperature increase acquisition mode at the time of ink remaining amount detection cannot be executed. In step S1712, the ink jet recording apparatus or the PC displays that the remaining amount is unknown and notifies the user, and the recording apparatus enters a standby state.

  On the other hand, if V> Low1 in step S1703, the process proceeds to step S1704, and the recovery recovery process for the recording head by the recovery unit M5000 is executed. Specifically, the cap member is pressed against the surface of the ink discharge port, and a negative pressure is introduced into the cap member by a suction pump, whereby a predetermined amount of ink in the recording head is discharged from the ink discharge port.

  By the suction recovery operation step in step S1704, the temperature of the recording head becomes substantially equal to the ink stored in the ink tank attached in step S1701. In this state, the process proceeds to step S1705, and the temperature (initial temperature ST) of the print head at this stage is acquired by the temperature sensor 10 and stored in a predetermined area.

  Thereafter, the process proceeds to step S1706, and the temperature increase acquisition mode described with reference to FIG. 18 is executed to acquire PreΔT. In step S1707, the PreΔT and the environmental temperature and time when the temperature rise acquisition mode in step S1706 is executed are stored in the memory in the apparatus.

  In the subsequent step S1708, the initial temperature ST acquired in step S1705 is compared with the environmental temperature ET detected by the temperature sensor 12 attached to the main body of the recording apparatus, and whether the difference between these two temperatures is 10 ° C. or more. Judge whether or not. If the temperature is less than 10 ° C., the value of PreΔT stored in step S1707 is considered to be reliable, and the process jumps to step S1710 to end this mode.

  On the other hand, if it is determined in step S1708 that the difference between the environmental temperature ET and the initial temperature ST is 10 ° C. or more, the temperature of the recording head is not familiar with the environmental temperature. The value is judged to be unreliable. Therefore, in step S1709, a flag indicating that it is necessary to newly acquire PreΔT is set, and this mode is ended.

  When the difference between the environmental temperature and the ink temperature is large at the time when the recording head cartridge or the ink tank is replaced, the ink temperature tends to gradually change so as to be adapted to the environmental temperature. In such a case, it is possible to acquire PreΔT, but there is a concern that the value at this time does not function effectively at the timing of actually detecting the remaining amount of ink later. Even in such a case, in this embodiment, by setting a flag in step S1709, execution of the temperature rise characteristic acquisition mode as described in the first embodiment is performed on the occasion of executing the next recording operation. Can be encouraged. In order to actually detect the remaining amount of ink, it is possible to acquire PreΔT with higher reliability at the next opportunity.

  In the embodiment described above, when PreΔT is measured in the temperature rise characteristic obtaining step, the environmental temperature and time at that time, together with the value of PreΔT, are stored in the memory of the recording apparatus. In this embodiment, the temperature rise characteristic acquisition process as described above is performed a plurality of times, and the data acquired each time is stored in different areas of the recording device, and when actually detecting the remaining amount, the plurality of information The most appropriate one can be selected.

  FIG. 19 is a flowchart for explaining the process for detecting the remaining ink amount in this embodiment while comparing it with FIG. 10 or FIG. When the recording device receives the recording data (step S1900), it executes a series of recording operations according to the recording data (step S1901). At this time, the latest ink remaining amount information V is also obtained by counting the number of ejections of the recording head.

  When the recording operation is finished and the recording medium is discharged, the process proceeds to step S1902, and the acquired remaining amount information V is compared with the above-described threshold Low2. When V> Low2, it is determined that the remaining amount of ink is early at the timing of detecting the remaining amount of ink, this mode is terminated as it is, and the recording apparatus enters a standby state. On the other hand, if V ≦ Low2, the process proceeds to step S1903, and the suction recovery process for the recording head by the recovery unit M5000 is executed as in the above-described embodiment. By this suction recovery operation, the ink whose temperature has been increased in the immediately preceding recording operation is removed, and the temperature of the heater board also drops to a stable value. Then, it progresses to step S1904 and performs the raise temperature acquisition mode demonstrated in FIG.

  In a succeeding step S1905, it is confirmed whether or not a plurality of PreΔT is stored in the memory in the apparatus. If it is determined that there is only one value of PreΔT, the process jumps to step S1909. On the other hand, if it is determined that there are a plurality of values of PreΔT, the process proceeds to step S1906, and the variation of these values is checked. Specifically, it is determined whether or not the variations in the values of the plurality of PreΔT are within a range of 15 ° C.

  If it is determined that these variations are within 15 ° C., the process proceeds to step S1907, and the value of PreΔT that is closest to the current time when PreΔT is acquired is used when performing the remaining amount detection this time. PreΔT to be determined.

  On the other hand, if it is determined in step S1906 that the variation in the plurality of PreΔT values is not within 15 ° C., the process proceeds to step S1908. Then, the value of PreΔT at which the environmental temperature at the time of obtaining PreΔT is the closest to the current environmental temperature is determined as PreΔT used when the current remaining amount detection is executed.

  In subsequent step S1909, ΔT obtained in step S1904 is compared with PreΔT determined in step S1907 or step S1908. Specifically, it is determined whether or not ΔT ≦ PreΔT + α. Here, the value of α can be set to about 10 ° C., for example, but this value can be adjusted by “how much ink is consumed and notified to the user”.

  If ΔT ≦ PreΔT + α in step S1909, it is determined that there is remaining ink, the remaining amount detection step is terminated, and the recording apparatus is in a standby state. On the other hand, if ΔT> PreΔT + α, it is determined that there is no remaining ink, and the process advances to step S1910 to notify the user that the ink has run out and request replacement of the ink tank or recording head. In step S 1911, the recording data received in step S 1900, that is, the image data recorded immediately before the ink out state is stored in the memory in the apparatus. This is to prepare for the recording operation to be performed again with the replaced ink tank even if the output image recorded in step S1901 has a problem due to lack of ink. Thereafter, the recording apparatus enters a standby state.

  As described above, in the present embodiment, when the remaining amount is actually detected while executing the temperature rise characteristic acquisition mode a plurality of times in advance and preparing a plurality of types of PreΔT, It becomes possible to select PreΔT measured in an environment that seems to be close. As a result, it is possible to compare temperature factors other than the temperature rise associated with the predetermined recording operation in a state where PreΔT and ΔT are aligned as much as possible, and it is possible to perform remaining amount detection with high accuracy.

(A) And (b) is a flowchart explaining the process for acquiring the temperature rising characteristic in an Example, and the ink remaining amount detection process. 1 is a schematic configuration diagram for explaining a main part of an ink jet recording apparatus applicable to an embodiment of the present invention. FIG. 3 is a schematic perspective view for explaining an example of a recording head cartridge applicable in the present invention. FIG. 5 is a schematic perspective view for explaining another form of a recording head cartridge applicable in the present invention. FIG. 6 is a plan view when observed from the ink ejection port side for explaining a partially enlarged configuration of the ejection unit of the recording head. It is a schematic diagram which shows the CC cross section of FIG. It is a block diagram for demonstrating the structure of control of the inkjet recording device applicable to this invention. FIG. 6 is a diagram for comparing the degree of increase in temperature detected by a temperature sensor provided on a heater board when performing a continuous ejection operation with the amount of ink remaining in an ink tank. It is a figure for demonstrating the error of the temperature which the actual temperature of the ink which exists in the ejection opening vicinity, and the temperature sensor mounted on a heater board detect. 10 is a flowchart for explaining an example of a remaining amount detection process performed by the recording apparatus when detecting an actual remaining ink amount. It is a flowchart for demonstrating an example of the conventional temperature rising characteristic acquisition process which a recording device performs. It is a flowchart which shows the conventional example which performs a temperature rising characteristic acquisition process, after performing normal recording operation | movement. It is the figure which showed a mode that the temperature of a heater board fell gradually in the standby | waiting time immediately after performing predetermined | prescribed recording operation | movement. FIG. 10 is a diagram showing a state of temperature rise of the heater board for each waiting time when a recording operation is performed after waiting for a predetermined time in a state where the remaining amount of ink is small. It is a figure which shows a mode that the temperature of a heater board changes at the time of performing said attraction | suction operation | movement with respect to the recording head heated up by the last recording operation. (A) And (b) is a flowchart for demonstrating the process of acquiring the temperature rising characteristic in Example 2, and the process of performing remaining ink amount detection. 10 is a flowchart for explaining a process of acquiring a temperature rise characteristic in Example 3. It is a flowchart for demonstrating the process of temperature rising acquisition mode. 10 is a flowchart for explaining a process when detecting a remaining amount of ink in Embodiment 4.

Explanation of symbols

6 Foaming chamber
7 Common liquid chamber
9 Ink introduction part
10 Temperature sensor (diode sensor)
11 Heater board
12 Temperature sensor
57, 58 Ink outlet
81, 82 Electrothermal converter (heater)
100 CPU
101 ROM
102 RAM
103 Carriage motor
103A motor driver
104 LF motor
104A motor driver
105 Motor driver
H3002 Discharge part
H3003 Electrical contact
H3004 tab
H3009 Ink tank
H4001 Discharge part
H4900 ink tank

Claims (11)

A method of detecting an ink remaining amount of an ink jet recording apparatus that records an image using an ink jet recording head that discharges ink supplied from an ink tank using heat generated in a heater,
A temperature rise characteristic acquisition step of applying predetermined energy to the heater at a timing when the remaining amount of ink in the ink tank is sufficient, and measuring the temperature rise PreΔT of the recording head before and after the application;
At the timing of detecting the remaining amount of ink in the ink tank, the predetermined energy is applied to the heater, the temperature rise ΔT of the recording head before and after the application is measured, and the PreΔT and the ΔT are compared. An ink remaining amount detecting step for determining the remaining amount of ink according to a result,
In at least one of the temperature rise characteristic acquisition step and the ink remaining amount detection step, a suction recovery operation is performed on the ink jet recording head before applying the predetermined energy to the heater. Detection method.   The method for detecting the remaining amount of ink according to claim 1, wherein the suction recovery operation is executed in both the temperature rise characteristic acquisition step and the remaining ink amount detection step.   In at least one of the temperature rise characteristic acquisition step and the ink remaining amount detection step, the method further includes a step for determining whether or not the suction recovery operation step is necessary based on a temperature difference between the recording head and the environmental temperature. The method for detecting the remaining amount of ink according to claim 1 or 2.   A step of determining whether or not the temperature rise measurement is possible in the temperature rise characteristic acquisition step or the ink remaining amount detection step based on ink remaining amount information obtained from count values of the number of ejections and the number of suctions of the recording head A method for detecting a remaining amount of ink according to any one of claims 1 to 3, further comprising:   The method for detecting the remaining amount of ink according to any one of claims 1 to 4, wherein the temperature rise characteristic obtaining step is executed at a timing when the ink tank is mounted on the inkjet recording apparatus.   5. The ink remaining amount detection method according to claim 1, wherein the temperature rise characteristic acquisition step is performed at a timing when a recording operation by the ink jet recording apparatus is completed.   7. The method according to claim 1, further comprising a step of urging the execution of the temperature rising characteristic acquisition step based on a temperature difference between the recording head and the environmental temperature in the temperature rising characteristic acquisition step. Ink level detection method. Storing the plurality of PreΔT acquired in the plurality of temperature rise characteristic acquisition steps and the environmental temperature and time when each PreΔT is acquired;
Determining whether or not a plurality of stored variations of PreΔT fall within a predetermined range in the ink remaining amount detecting step;
When the variation falls within the predetermined range, a step of determining PreΔT acquired at a time closest to a time of executing the ink remaining amount detection step as PreΔT for comparing with the ΔT;
If the variation does not fall within the predetermined range, a step of determining PreΔT acquired at an environmental temperature closest to the environmental temperature at the time of executing the ink remaining amount detection step as PreΔT for comparing with the ΔT; The ink remaining amount detection method according to claim 1, further comprising: An ink jet recording head for discharging ink supplied from an ink tank by heat energy of a heater generated by applying a voltage pulse;
A temperature sensor for measuring the temperature in the vicinity of the heater of the recording head;
Applying a predetermined energy to the heater and measuring a temperature rise of the recording head before and after the application;
The temperature rise ΔT obtained by the temperature rise acquisition means at the timing of detecting the ink remaining amount in the ink tank is obtained by the temperature rise acquisition means at a time when the ink remaining amount in the ink tank is sufficient. Determination means for determining the remaining amount of ink according to the result of comparison with the raised temperature PreΔT,
The determination unit causes the recovery unit to perform a suction recovery operation on the inkjet recording head before applying the predetermined energy when acquiring at least one of the ΔT and the PreΔT. Recording device.   The ink jet recording apparatus according to claim 9, wherein the recording head and the ink tank are integrally formed.   The inkjet recording apparatus according to claim 9, wherein the ink tank is configured to be detachable from the recording head.

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