JP2019018483A - Ink jet recording apparatus and ink jet recording method - Google Patents

Abstract

To provide an ink jet recording apparatus and an ink jet recording method that are able to detect a defective nozzle without requiring much time.SOLUTION: An ink jet recording apparatus comprises: a recording head with a nozzle array formed by arranging a plurality of nozzles capable of ejecting ink; detecting means that is able to detect vibration that may occur as a result of ink ejection; and determining means that determines whether a defective nozzle in which ink ejection is defective has occurred or not on the basis of the waveform of a vibration detected by the detecting means during a recording operation in which ink is emitted from the nozzles on the basis of recorded data or during a recovery operation in which ink that is not involved in image recording is ejected from the nozzles.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an ink jet recording apparatus and an ink jet recording method for ejecting ink onto a recording medium.

  Techniques disclosed in Patent Document 1 and Patent Document 2 are known as techniques for detecting an ejection failure state of a nozzle that cannot properly eject ink. That is, in Patent Document 1, it is determined whether or not ink is normally ejected based on the sound generated by the cavitation phenomenon in a recording head that ejects ink by a thermal method using an electrothermal conversion element as an ejection energy generating element. doing. Further, in Patent Document 2, in a recording head that ejects ink by a piezo method using a piezo element as an ejection energy generating element, based on the vibration of the residual vibration of a diaphragm that is displaced by driving of an actuator when ejecting ink. Nozzle discharge abnormality is detected.

JP 2004-167773 A JP 2004-276367 A

  However, the techniques disclosed in Patent Document 1 and Patent Document 2 are provided in the recording head in order to detect nozzles that are defective in ink ejection (hereinafter referred to as “defective nozzles” as appropriate). A process is performed to determine whether or not each nozzle is a defective nozzle. For this reason, a lot of time is required for the defective nozzle detection process.

  The present invention has been made in view of the above problems, and an object thereof is to provide an ink jet recording apparatus and an ink jet recording method capable of detecting a defective nozzle without requiring much time.

  In order to achieve the above object, an ink jet recording apparatus according to the present invention detects a recording head including a nozzle array formed by arranging a plurality of nozzles capable of ejecting ink, and vibrations generated as ink is ejected. And a vibration waveform detected by the detection means during a recording operation in which ink is ejected from the nozzles based on recording data, or during a recovery operation in which ink that does not contribute to image recording is ejected from the nozzles And determining means for determining whether or not a defective nozzle having a defective ink discharge state has occurred.

  According to the present invention, it does not take much time to detect a defective nozzle.

FIG. 2 is a schematic configuration plan view of a recording apparatus. FIG. 3 is an explanatory diagram showing the arrangement position of a vibration detection element in a recording head. FIG. 3 is a block diagram illustrating a hardware configuration of a control system of the recording apparatus. FIG. 3 is a block diagram showing a functional configuration of a control unit in the recording apparatus according to the first embodiment. Explanatory drawing explaining the vibration waveform detected with a vibration detection element. Explanatory drawing explaining an example of the vibration waveform when ink is not discharged from some nozzles. Explanatory drawing explaining an example of the vibration waveform when a defective nozzle is detected. The flowchart which shows the processing content of a 1st detection process. FIG. 6 is a block diagram illustrating a functional configuration of a control unit in a recording apparatus according to a second embodiment. The flowchart which shows the processing content of a 2nd detection process. Explanatory drawing which shows the modification of a vibration detection element. Explanatory drawing which shows the modification of the arrangement position of a vibration detection element.

  Hereinafter, an example of an ink jet recording apparatus and an ink jet recording method according to the present invention will be described in detail with reference to the accompanying drawings. In the following description, an example of an ink jet recording apparatus provided with a recording head that discharges ink (liquid) by an ink jet method will be described.

(First embodiment)
First, the first embodiment of the ink jet recording apparatus according to the present invention will be described with reference to FIGS. Here, FIG. 1 shows a schematic plan view of a recording apparatus which is an ink jet recording apparatus according to the present invention. The recording apparatus 10 shown in FIG. 1 performs recording by ejecting ink from a recording head 16 that scans a recording medium M to be transported in a direction that intersects the transport direction (orthogonal in the present embodiment). This is a serial scan type ink jet recording apparatus.

  That is, the recording apparatus 10 is detachably mounted on a carriage 14 that is movably disposed along a guide shaft 12 that extends in a main scanning direction that intersects the conveyance direction of the recording medium M. And a recording head 16. Further, the platen 18 that supports the recording medium M that is conveyed in the sub-scanning direction, which is the conveyance direction, by a conveyance roller (not shown), the paper feeding unit 20 that feeds the conveyance roller, and the recorded recording medium M is discharged. The paper discharge unit 22 is provided. Furthermore, a recovery unit 24 for maintaining and recovering the state of nozzles (not shown) for ejecting ink in the recording head 16 is provided on one end side in the main scanning direction in which the carriage 14 is movable. . The overall operation of the recording apparatus 10 is controlled by the control unit 100 described later.

  More specifically, the carriage 14 is connected to a belt (not shown) driven by a motor (not shown), and reciprocates in the main scanning direction along the guide shaft 12 by driving the belt. An ink cartridge (not shown) is detachably disposed on the carriage 14, and ink is supplied from the ink cartridge to the recording head 16. Note that the recording head 16 may be configured such that ink is supplied from an ink tank fixedly provided at a predetermined position of the recording apparatus 10 via an ink tube.

  The recording head 16 is mounted on the carriage 14 such that a plurality of nozzles that can eject ink face the platen 18. The recording head 16 includes an electrothermal conversion element (heater) as an ejection energy generating element. Thus, in the recording head 16, by driving a heater (not shown), the ink from the nozzle is utilized by utilizing the pressure change caused by the bubble growth and contraction (cavitation phenomenon) due to the film boiling of the ink stored in the nozzle. Will be discharged.

  Further, as shown in FIG. 2, the recording head 16 has a nozzle row 26 in which a plurality of nozzles are arranged in the sub-scanning direction, and each nozzle row 26 ejects ink of different colors. In the present embodiment, a case where six nozzle rows 26 are formed side by side along the main scanning direction will be described, but the number of nozzle rows 26 is not limited to six. In the recording head 16, vibration detection elements 28 a and 28 b (detection means) that detect vibrations from the nozzles and output signals based on the detected vibrations are arranged in the vicinity of both ends in the extending direction of each nozzle row 26. It is installed. The vibration detecting element 28a is arranged with a gap G from one end portion 26a of the nozzle row 26, and the vibration detecting element 28b is arranged with a gap G from the other end portion 26b of the nozzle row 26. Yes. The vibration detection elements 28a and 28b detect vibration from the nozzle, that is, vibration generated by a cavitation phenomenon caused by driving the heater.

  The vibration detection elements 28a and 28b detect vibrations from the nozzles in the nozzle row 26 located near both ends, and do not detect vibrations from the nozzles in the other nozzle rows 26. . For example, the nozzle row 26 including the vibration detection elements 28a and 28b is disposed between the adjacent nozzle row 26 and an absorption unit (not shown) that absorbs vibration from the nozzles. That is, in a predetermined nozzle row 26, vibrations between the nozzle rows 26 are prevented so that vibrations from the nozzles in the adjacent nozzle rows 26 are not detected by the vibration detection elements 28a and 28b located near both ends of the nozzle row 26. An absorption part that absorbs water is disposed.

  The recovery unit 24 is used when performing a recovery process (at the time of a recovery operation) for maintaining a good ink discharge state from each nozzle in the recording head 16. The recovery unit 24 includes, for example, a cap (not shown) that can cap each nozzle row 26 and depressurize the internal space in the capped state. Further, a wiper (not shown) for wiping the ejection surface 30 including the nozzle row 26 in the recording head 16 is provided. As recovery processing, preliminary ejection processing for ejecting ink into the cap from nozzles that eject ink that does not contribute to image recording, pressurization for forcibly ejecting ink from the nozzles into the cap by pressurizing the interior of the recording head 16 Perform recovery processing. In the capped state, a suction recovery process for forcibly sucking ink by reducing the pressure in the cap and a wiping process for wiping the ejection surface 30 are performed.

  The recording head 16 ejects ink to the recording medium M conveyed in the sub-scanning direction while moving in the main scanning direction via the carriage 14 to record a predetermined image on the recording medium M. That is, first, when the recording head 16 moves in the main scanning direction via the carriage 14, ink is ejected from the nozzles to the recording medium M supported by the platen 18, and one recording scanning is performed on the recording medium M. Record images. Next, the recording medium M is conveyed by a predetermined amount in the sub-scanning direction, and an area where nothing has been recorded is positioned at a position facing the recording head 16 on the recording medium M. Thereafter, when the recording head 16 moves in the main scanning direction via the carriage 14, ink is ejected from the nozzles to perform recording on the area. By repeating such a series of operations, an image is recorded on the recording medium M.

  The overall operation of the recording apparatus 10 is controlled by the control unit 100. As shown in FIG. 3, the control unit 100 includes a central processing unit (CPU) 102, a ROM 104, and a RAM 106. In the CPU 102, control processing for various operations of the recording apparatus 10 is executed. Connected to the CPU 102 are a ROM 104 storing a predetermined program for executing the entire operation and various processes, and a RAM 106 as a working area in which various registers necessary for executing the program by the CPU 102 are set. Yes.

  Also, various interfaces (I / F) 108 are connected to the CPU 102, and are connected via the I / F 108 to a host computer (not shown) capable of inputting / outputting various information. The I / F 108 includes, for example, a communication IC, a wireless LAN, a wired LAN, and an external memory slot. Furthermore, a display unit 110 such as an LCD and an operation unit 112 such as a switch or a touch panel are connected to the CPU 102. Furthermore, the CPU 102 is in contact with a sensor unit 114 including various sensors such as vibration detection elements 28a and 28b that can detect vibration during ink ejection. The CPU 102 is connected to a driving unit 116 that controls the movement of the carriage 14 and the driving of the conveyance roller, and a head driving unit 118 that controls the driving of the recording head 16.

  Here, the functional configuration of the control unit 100 will be described with reference to FIG. In addition to a known configuration such as a control unit that controls various operations of the constituent members, the control unit 100 performs a first determination to determine whether or not a signal based on vibration has been detected in the vibration detection elements 28a and 28b. Part 120 is provided. Further, a second determination unit 122 that determines whether or not the signals detected by the vibration detection elements 28a and 28b are normal is provided. Furthermore, a position specifying unit 124 is provided for specifying the position of the nozzle in the nozzle row 26 in the undischarge failure state based on the signals based on the two vibrations detected by the vibration detection elements 28a and 28b. Furthermore, a notification unit 126 that notifies the user of information to be notified to the user, such as detection of a defective nozzle having a defective ink ejection state, is provided.

  The first determination unit 120 determines whether or not a signal based on vibration detected by the vibration detection elements 28a and 28b is input. When signals from the vibration detection elements 28 a and 28 b are input to the control unit 100, it is determined that a signal based on vibration is detected, and signals from the vibration detection elements 28 a and 28 b are not input to the control unit 100. It is determined that a signal based on vibration is not detected.

  The second determination unit 122 determines whether the amplitude and frequency of a signal pattern based on vibration detected by the vibration detection elements 28a and 28b match a reference value stored in advance. In the following description, a signal pattern based on vibration is appropriately referred to as “vibration waveform”.

  By the way, in the present embodiment, defective nozzles are detected during a normal recording operation. For this reason, in each nozzle row 26, the position and the number of nozzles from which ink is ejected change. For example, as shown in FIG. 5A, it is assumed that the vibration detection element, the first nozzle, the second nozzle, the third nozzle, the fourth nozzle, and the fifth nozzle are arranged in this order. When ink is ejected appropriately and simultaneously from all the nozzles, the vibration waveform detected by the vibration detection element is as shown in FIG. In this case, the vibration reaching each vibration detection element from each nozzle is sufficiently attenuated by about three nozzles. That is, when the vibration of the fourth nozzle reaches the vibration detecting element, the vibration of the first nozzle is attenuated and can be ignored.

  In FIG. 5B, the vibration of the first period of the first nozzle (see FIG. 5C) is detected in the first period. Further, in the second period, vibration in which the vibration of the second period of the first nozzle (see FIG. 5C) and the vibration of the second nozzle of the first period (see FIG. 5D) are superimposed is detected. Has been. In the third period, the vibration of the third period of the first nozzle (see FIG. 5C), the vibration of the second nozzle of the second period (see FIG. 5D), and the third nozzle Vibration in which one cycle (see FIG. 5E) is superimposed is detected. Further, in the fourth period, the vibration of the second nozzle in the third period (see FIG. 5D), the vibration of the third nozzle in the second period (see FIG. 5E), and the fourth nozzle in the fourth period. Vibration in which one cycle (see FIG. 5 (f)) is superimposed is detected. In the fifth cycle, the vibration of the third nozzle (see FIG. 5E), the vibration of the fourth nozzle in the second cycle (see FIG. 5F), and the fifth nozzle Vibration in which one cycle (see FIG. 5G) is superimposed is detected.

  Therefore, for example, when ink is appropriately ejected from the first nozzle and the fifth nozzle and ink is not ejected from the second nozzle, the third nozzle, and the fourth nozzle, the vibration waveform detected by the vibration detection element is as shown in FIG. As shown in (a). For example, when ink is appropriately ejected from the first nozzle, the second nozzle, and the third nozzle and ink is not ejected from the fourth nozzle and the fifth nozzle, the vibration waveform detected by the vibration detection element is as shown in FIG. )become that way. Thus, the amplitude and frequency of the vibration waveform differ depending on whether or not the nozzle is ejected.

  Therefore, in the present embodiment, for each nozzle row, the amplitude of the vibration waveform detected by the vibration detection elements 28a and 28b when ink is ejected from normal nozzles based on the combination of ejection / non-ejection of ink from the nozzles. The reference value of the frequency is stored.

  For example, when the vibration detection element, the first nozzle, the second nozzle, and the third nozzle are arranged in this order, the combination of ejection / non-ejection from each nozzle is the first nozzle, the second nozzle, the second nozzle, The order of the three nozzles is as follows. (Discharge, discharge, discharge), (discharge, discharge, non-discharge), (discharge, non-discharge, discharge), (non-discharge, discharge, discharge), (discharge, non-discharge, non-discharge), (non-discharge, non-discharge) Ejection, ejection), (non-ejection, ejection, non-ejection), and (non-ejection, non-ejection, non-ejection). Therefore, in this case, when ink is ejected in each combination described above, the amplitude and frequency in the vibration waveform detected by the vibration detection element are acquired, and the acquired amplitude and frequency are used to determine whether the vibration waveform is normal. It is stored as a reference value for judgment. In addition, about an amplitude, a reference value will be acquired for every period.

  Then, the second determination unit 122 acquires discharge nozzle information indicating from which nozzle ink is discharged when the detected vibration is generated based on the recording data, and based on the discharge nozzle information. The stored reference value is acquired. Thereafter, it is determined whether or not the acquired amplitude and frequency reference values match the amplitude and frequency of the vibration waveforms detected by the vibration detection elements 28a and 28b.

  For example, the vibration detection element and the five nozzles are arranged as shown in FIG. 5A and controlled to eject ink from all the nozzles, but the third nozzle is in a non-ejection state where ink is not ejected. Sometimes, it becomes as shown in FIG. In FIG. 7A, it is assumed that the third nozzle does not vibrate due to the non-discharge state. In this case, in the third period, a vibration in which the vibration of the third period of the first nozzle and the vibration of the second period of the second nozzle are superimposed is detected, and is in a normal state (see FIG. 5B). The amplitude is smaller than that. Further, when the ink of the third nozzle is in an ejection failure state due to thickening, the state is as shown in FIG. In this case, in the third period, the waveform is shifted in the time direction due to the thickening of the ink, and therefore the frequency is different from that in the normal state. In the fourth period and the fifth period, since the influence of the defective ejection state of the third nozzle is reduced, the difference from the normal frequency is also reduced.

  When the second determination unit 122 (determination means) determines that the amplitude and frequency of the vibration waveform match the reference values, it is determined that the vibration waveform is normal, that is, no defective nozzle is detected. The If it is determined that the amplitude and frequency of the vibration waveform do not match the reference values, it is determined that the vibration waveform is abnormal, that is, a defective nozzle has been detected. The fact that the amplitude and frequency of the vibration waveform match the reference value is not limited to the case where they completely match, and the amplitude and frequency of the vibration waveform may be within a predetermined range centered on the reference value. Shall be included.

  The second determination unit 122 may make a determination based on the vibration waveform detected by both the vibration detection elements 28a and 28b, or the vibration waveform detected by one of the vibration detection elements 28a and 28b. You may make it judge based on. In the present embodiment, a case will be described in which a determination is made based on a vibration waveform detected by the vibration detection element 28a.

  The position specifying unit 124 (first specifying means) specifies the position of the defective nozzle based on the two vibration waveforms detected by the vibration detection elements 28a and 28b. The vibration waveform for specifying the position of the defective nozzle is detected by the vibration detection element that is determined to be abnormal by the second determination unit 122 or the vibration detection element that forms a pair with the vibration detection element that detects the vibration waveform. The vibration waveform is used. That is, when the second determination unit 122 determines the vibration waveforms of both the vibration detection elements 28a and 28b, these two vibration waveforms are used. When the second determination unit 122 determines the vibration waveform of one of the vibration detection elements 28a and 28b, the vibration detection element (a vibration detection element that forms a pair with the vibration detection element that detects the vibration waveform) That is, the vibration waveform detected at the end of the same nozzle row 26 is used.

  That is, the position specifying unit 124 detects the vibration waveform determined to be abnormal by the second determination unit 122 and the vibration disposed at the end of the nozzle row 26 that is the same as the vibration detection element 28a that has detected the vibration waveform. The vibration waveform detected by the detection element 28b is used. Specifically, in these two vibration waveforms, the position of the defective nozzle is specified based on the time when the abnormal vibration generated in the defective nozzle is detected. For example, if the defective nozzle is located closer to the vibration detection element 28a than the vibration detection element 28b, the abnormal vibration reaches the vibration detection element 28a earlier than the vibration detection element 28b. Therefore, the position of the defective nozzle can be specified from the detection time of the abnormal vibration and the position information of the vibration detection elements 28a and 28b. That is, in the present embodiment, the position of the defective nozzle is specified using the difference in arrival time of vibration based on the distance between the vibration detection elements 28a and 28b and each nozzle row. For example, the position of the defective nozzle can be specified by the difference between the detection times of abnormal vibrations of the two vibration waveforms and the distance between the vibration detection elements 28a and 28b. The abnormal vibration detection time is, for example, the peak position of a waveform that is determined to be abnormal vibration.

  The notification unit 126 outputs information to be notified to the user to the display unit 110. For example, in the detection process described later, when a defective nozzle is detected, a message to that effect is displayed and the position of the specified defective nozzle is displayed.

  In the above configuration, when the printing operation is started, the printing apparatus 10 starts the first detection process for detecting a defective nozzle. Here, FIG. 8 shows a flowchart showing the detailed processing contents of the first detection processing. When the first detection process is started, it is determined whether or not vibration is detected by the vibration detection elements 28a and 28b (step S802). That is, in step S <b> 802, the first determination unit 120 determines whether signals from the vibration detection elements 28 a and 28 b are input to the control unit 100.

  If it is determined in step S802 that no vibration has been detected, that is, signals from the vibration detection elements 28a and 28b have not been input to the control unit 100, it is determined whether or not a predetermined time has elapsed (step S802). S804). That is, in step S804, it is determined whether or not a predetermined time set in advance has elapsed since the start of the first detection process. Note that the predetermined time is a time when it is determined that a problem has occurred in the recording operation because ink is not ejected from the recording head 16 even though the recording operation is started.

  If it is determined in step S804 that the predetermined time has not elapsed, the process returns to step S802 to perform the subsequent processing. That is, in this first detection process, if no vibration is detected by the vibration detection elements 28a and 28b, the process of step S802 is executed until a predetermined time elapses. If it is determined in step S804 that the predetermined time has elapsed, it is determined that recording cannot be performed because ink is not ejected from the recording head 16, and the first detection process is terminated. At this time, the notification unit 126 may display on the display unit 110 a notification that recording cannot be performed because ink has not been ejected.

  If it is determined in step S802 that vibration has been detected, it is next determined whether or not the vibration waveforms detected by the vibration detection elements 28a and 28b are normal (step S806). That is, in step S806, the reference value of the amplitude and frequency is acquired from the ejection nozzle information in the second determination unit, and the amplitude and frequency of the vibration waveform detected by the vibration detection elements 28a and 28b respectively match the reference value. It will be judged whether or not.

  If it is determined in step S806 that the vibration waveform is normal, that is, if the amplitude and frequency of the vibration waveform match the reference values, it is determined that no defective nozzle has been detected, and whether or not the recording operation has ended. Is determined (step S808). If it is determined in step S808 that the recording operation has ended, the first detection process ends. If it is determined in step S808 that the recording operation has not ended, the process returns to step S802 to perform the subsequent processing.

  If it is determined in step S806 that the vibration waveform is not normal, that is, the amplitude and frequency of the vibration waveform do not match the reference values, it is determined that a defective nozzle has been detected, and the position of the defective nozzle is specified (step S810). ). That is, in step S810, the position specifying unit 124 specifies the position of the defective nozzle using the two vibration waveforms detected by the vibration detection elements 28a and 28b. Thereafter, the position of the specified defective nozzle is notified (step S812), and the first detection process is terminated. That is, in step S812, the notification unit 126 notifies the position of the defective nozzle via the display unit 110.

  As described above, in the recording apparatus 10, the vibration detection elements 28 a and 28 b are disposed in the vicinity of both ends in the extending direction of the nozzle row 26 of the recording head 16. Then, a first detection process for detecting a defective nozzle is performed during a recording operation for recording an arbitrary image. In this first detection process, it is determined whether or not the vibration waveform detected by the vibration detection element 28a during the recording operation is normal, and if it is determined to be abnormal, it is determined that a defective nozzle has occurred. From the vibration waveform determined to be abnormal and the vibration waveform detected by the vibration detection element 28b located near the end of the same nozzle row 26 as the vibration detection element 28a that detected the vibration waveform, the defective nozzle The position of was to be specified.

  As described above, since the recording apparatus 10 detects the occurrence of defective nozzles in parallel with the recording operation for recording an arbitrary image, the process for detecting the occurrence of defective nozzles is performed independently. There is no need. Further, since defective nozzles are specified when ink is ejected from a plurality of nozzles, detection of defective nozzles can be completed in a short time. As a result, the working time can be greatly shortened as compared with the techniques disclosed in Patent Documents 1 and 2 in which the defective ejection state is confirmed for each nozzle.

(Second Embodiment)
Next, a second embodiment of the ink jet recording apparatus according to the present invention will be described with reference to FIGS. In the following description, the same or corresponding components as those of the recording apparatus 10 described above are denoted by the same reference numerals, and detailed description thereof is omitted as appropriate.

  The printing apparatus 200 according to the second embodiment is different from the printing apparatus 10 described above in that the cause of defective nozzles is specified and recovery processing is performed based on the specified cause of occurrence. That is, in the printing apparatus 200, as shown in FIG. 9, the control unit 100 specifies a specifying unit 128 (second specifying unit) for specifying the cause of the defective nozzle, and a recovery according to the generating cause specified by the specifying unit 128. And a determination unit 130 for determining processing.

  More specifically, the specifying unit 128 determines that the reference range when the amplitude and frequency of the vibration waveform determined to be abnormal by the second determination unit 122 are within the pre-stored amplitude and frequency reference range. The cause of the defective nozzle is identified based on the information associated with. That is, the specifying unit 128 (or a storage unit not shown) stores a reference range of amplitude and frequency set for each cause of defective nozzles, and information on the cause of defective nozzles is stored in each reference range. Is associated. Therefore, the specifying unit 128 specifies the cause of the defective nozzle based on the information regarding the cause of the defective nozzle associated with the reference range.

  For example, as the ink thickens, the frequency of the vibration waveform decreases. Therefore, when the cause of defective nozzles is ink thickening, the frequency reference range is smaller than the frequency of the normal vibration waveform. In addition, when ink cannot be ejected from the nozzle due to adhesion of ink or adhesion of foreign matter, vibration due to the cavitation phenomenon does not occur, and the frequency of the vibration waveform is less, or vibration is not detected. Therefore, when the nozzle is not ejected due to ink sticking or foreign matter adhering, the reference range of the frequency becomes a smaller value than the case of ink thickening. Further, when bubbles are mixed in the nozzle, more vibration is generated by the bubbles having a lighter mass than the ink. Accordingly, when the cause of the defective nozzle is the mixing of bubbles, the frequency reference range is a value larger than the frequency of the normal vibration waveform.

  The determining unit 130 determines a recovery process to be executed based on the cause of the defective nozzle identified by the identifying unit 128. For example, when the specifying unit 128 specifies that the ink thickening is the cause of the defective nozzle, it is determined to perform the preliminary discharge process as the recovery process. If it is determined that ink sticking is the cause of defective nozzles, it is determined to perform suction recovery processing or pressure recovery processing as recovery processing. Furthermore, when it is determined that the adhesion of foreign matter is the cause of defective nozzles, it is determined to perform a wiping process as a recovery process. Furthermore, when it is determined that the mixing of bubbles is the cause of the defective nozzle, it is determined to perform the suction recovery process as the recovery process. However, the recovery process for the cause of the defective nozzle is not limited to the above. The user may set appropriately, or a plurality of recovery processes may be combined.

  In the above configuration, when the printing operation starts, the printing apparatus 200 discloses a second detection process for detecting a defective nozzle. Here, FIG. 10 shows a flowchart showing the detailed processing contents of the second detection processing. When the second detection process is started, the number n of defective nozzles identified for each nozzle is initialized, and it is determined whether vibration is detected by the vibration detection elements 28a and 28b (step S1002). Note that the specific processing contents from step S1004 to step S1010 correspond to the processing from step S504 to step S510 of the first detection processing, respectively, and thus detailed description thereof is omitted.

  That is, if it is determined in step S1002 that no vibration has been detected, it is determined whether or not a predetermined time has elapsed (step S1004). If it is determined that the predetermined time has not elapsed, the process proceeds to step S1002. Return. When it is determined that the predetermined time has elapsed, the second detection process is terminated. If it is determined in step S1002 that vibration has been detected, it is determined whether the detected vibration waveform is normal (step S1006). If it is determined normal, it is determined whether the recording operation has ended. (Step S1008). If it is determined that the recording operation has been completed, the second detection process is terminated. If it is determined that the recording operation has not been completed, the process returns to step S1002. If it is not determined to be normal in step S1006, the position of the defective nozzle is specified (step S1010). In step S1010, the number of times “n” specified as a defective nozzle is incremented for the nozzle specified as a defective nozzle.

  Thereafter, for the nozzle identified as a defective nozzle, a field determination is made as to whether or not the number of times identified as a defective nozzle has reached a predetermined number (step S1012). That is, in step S1012, it is determined whether or not the number of times “n” identified as a defective nozzle has reached a predetermined number of times set in advance. Note that the counting of the number of times identified as a defective nozzle is performed in a counting unit (not shown) provided in the control unit 100. In this step S1012, when it is determined that the number of times of being identified as a defective nozzle has reached a predetermined number, the notification unit 126 notifies the display unit 110 that there is a defective nozzle that cannot be recovered by the recovery process. (Step S1014), the second detection process is terminated.

  If it is determined in step S1012 that the number of defective nozzles has not reached the predetermined number, the cause of the defective nozzle is identified (step S1016). That is, in step S1016, the specifying unit 128 acquires a reference range including the amplitude and frequency of the vibration waveform determined to be abnormal in step S1006, and specifies the cause of the defective nozzle from the information associated with the reference range. .

  Thereafter, a recovery process for eliminating the defective ejection state of the defective nozzle is determined (step S1018), and the determined recovery process is executed (step S1020). That is, in step S1018, the determination unit 130 determines an appropriate recovery process based on the cause of the defective nozzle identified in step S1016. In step S1020, the recording operation is temporarily stopped, and the recovery process determined in step S1018 is executed. When the recovery process is completed, the recording operation is resumed, and the process proceeds to step S1008 to execute the subsequent processes.

  In the second detection process, after the cause of the defective nozzle is identified, the recovery process for eliminating the defective discharge state of the defective nozzle is determined and executed, but the process related to the recovery process is omitted. You may do it. In this case, after specifying the cause of the defective nozzle, the notification unit 126 displays the cause of the defective nozzle on the display unit 110 together with the position of the defective nozzle. In this case, the count of the number of times identified as a defective nozzle, the processing in step S1012, and the like are omitted.

  As described above, in the recording apparatus 200, the second detection process for detecting a defective nozzle is performed during a recording operation for recording an arbitrary image. In this second detection process, the position of the defective nozzle is specified, and the cause of the defective nozzle is specified from the vibration waveform determined to be abnormal and the reference range of the amplitude and frequency stored in advance. . As a result, the printing apparatus 200 has the same effects as the printing apparatus 10 and can perform the recovery process based on the identified cause of the defective nozzle, thereby executing the recovery process more smoothly. it can.

(Other embodiments)
The above embodiment may be modified as shown in the following (1) to (6).

  (1) In the above embodiment, the heater is used as the ejection energy generating element placed on the recording head 16, but the present invention is not limited to this. That is, a piezo element may be used as the ejection energy generating element. In this case, the vibration detection elements 28a and 28b detect vibration from the piezo element as the ejection energy generating element. As described above, the recording apparatuses 10 and 200 according to the present invention can support both the thermal method and the piezo method.

  When a piezo element is used as the ejection energy generation element, vibration from the nozzle that ejects ink is detected by the piezo element that is disposed in the nozzle that does not eject ink without providing the vibration detection elements 28a and 28b. You may make it do. For example, as shown in FIG. 11, when ink is ejected from a plurality of nozzles located in the center of the nozzle row 26, the nozzle row 26 is arranged in a nozzle that does not eject ink adjacent to the nozzle that ejects ink. Two piezoelectric elements are used as vibration detection elements. Note that the two piezo elements serving as the vibration detection elements are not limited to being disposed in nozzles that do not eject ink adjacent to the nozzles that eject ink. In other words, the two piezo elements that serve as vibration detection elements are located between the nozzles that eject ink, and are piezo elements that are disposed at any position as long as the nozzles are not ejecting ink. May be.

  This shortens the time (that is, the time to detect) that the vibration generated by the nozzle that ejected ink reaches the vibration detection element. For this reason, when ink is continuously ejected, the detection time in the vibration detection element is shortened, and a defective nozzle can be detected in a shorter time. Further, it is not necessary to newly provide a vibration detecting element in the recording head 16, and the configuration of the recording head 16 is simplified.

  (2) In the above embodiment, the detection process (first detection process, second detection process) is performed during the recording operation of an arbitrary image. However, the present invention is not limited to this. That is, the detection process may be performed during the recording operation of the check pattern for detecting the nozzle state. The timing of the detection process is not limited to the recording operation in which ink is ejected from the nozzles based on the recording data, but is in the recovery operation for ejecting ink that does not contribute to image recording from the nozzles (for example, preliminary ejection). Detection process). Further, the defective nozzle can be detected with higher accuracy by performing the detection process using the check pattern during the recovery operation.

  (3) In the above-described embodiment, the vibration detection elements 28a and 28b are disposed in the vicinity of both ends in the extending direction in each nozzle row 26. However, the present invention is not limited to this. That is, as shown in FIG. 12A, an element array 38 formed of a plurality of vibration detection elements may be provided so as to be adjacent to the nozzle array 26. That is, the element row 38 is formed of a plurality of vibration detection elements arranged along the extending direction of the nozzle row 26. Each vibration detection element of the element array 38 may be disposed in a one-to-one relationship with each nozzle forming the nozzle array, or may be disposed in a one-to-many relationship. Good. By arranging the vibration detecting element in the vicinity of each nozzle of the nozzle row 26, the time required for detecting the defective nozzle is shortened and the detection accuracy is improved.

  Further, as shown in FIG. 11B, vibration detection elements 48 may be arranged at the four corners of the ejection surface 30 of the recording head 16 where the nozzle row 26 is formed. In this case, the position specifying unit 124 specifies the position of the defective nozzle from the abnormal vibration detection time and the position information of each vibration detection element 48 from the vibration waveforms detected by the four vibration detection elements 48. Thereby, the number of vibration detecting elements provided in the recording head 16 is reduced, and the configuration can be simplified.

  (4) Although not specifically described in the above embodiment, in step S506 of the detection process, FFT analysis processing is performed on the vibration waveform, and the nozzle vibration waveform is extracted to determine whether it is normal or defective. The position of the nozzle may be specified. That is, an FFT analysis process is performed to separate a vibration waveform caused by nozzle vibration and a vibration waveform caused by vibration from a motor or the like. As a result, the peak of noise (vibration from a motor or the like) is detected, inversely converted, and the difference from the original vibration waveform is taken to extract only the vibration waveform of the nozzle. Thereby, noise in the vibration waveform can be removed, and the defective nozzle can be detected more accurately.

  (5) In the above embodiment, the position of the defective nozzle is specified using the difference in arrival time of vibration based on the distance between the vibration detection elements 28a, 28b and each nozzle. However, the present invention is not limited to this. Absent. That is, the position of the defective nozzle may be specified by using a difference in vibration attenuation based on the distance between the vibration detection elements 28a and 28b and each nozzle.

  (6) In the above embodiment, the recording head 16 is provided with the six nozzle rows 26. However, the present invention is not limited to this, and the recording head 16 is provided with one to five nozzle rows or seven or more nozzle rows. Also good. In the above embodiment, the serial type recording head has been described. However, the present invention may be applied to a full line type recording head. Furthermore, in the above-described embodiment, the recording apparatus including the recording head that discharges ink has been described. However, the present invention can be applied to a liquid discharging apparatus including a liquid discharging head that discharges various liquids.

10, 200 Recording device 120 First determination unit 122 Second determination unit 124 Position specifying unit 126 Notification unit

Claims (12)

A recording head provided with a nozzle array formed by arranging a plurality of nozzles capable of ejecting ink; and
Detection means capable of detecting vibrations generated with ink ejection;
Based on the vibration detected by the detection means during a recording operation for ejecting ink from the nozzles based on recording data, or during a recovery operation for ejecting ink that does not contribute to image recording from the nozzles, an ink ejection state An ink jet recording apparatus comprising: a determination unit that determines whether a defective nozzle having a defect is generated.   The inkjet recording apparatus according to claim 1, wherein the detection unit detects vibration generated when ink is simultaneously ejected from a plurality of nozzles.   3. The apparatus according to claim 2, further comprising a first specifying unit that specifies a position of the defective nozzle by using a difference in arrival time of vibration corresponding to a distance between the plurality of detection units and each nozzle. Inkjet recording apparatus.   3. The apparatus according to claim 2, further comprising: a first specifying unit that specifies a position of the defective nozzle using a difference in vibration attenuation based on a distance between the plurality of detection units and each nozzle. The ink jet recording apparatus described.   5. The inkjet recording apparatus according to claim 3, further comprising a second specifying unit that specifies a cause of occurrence of the defective nozzle based on a vibration waveform detected by the detecting unit.   The inkjet recording apparatus according to claim 2, wherein the detection unit is disposed in the vicinity of both end portions in the extending direction of the nozzle row.   6. The ink jet recording apparatus according to claim 2, wherein the detection unit is disposed at four corners of an ejection surface of the recording head in which the nozzle row is formed.   The inkjet recording apparatus according to claim 1, wherein the detection unit is arranged along an extending direction of the nozzle row so as to be adjacent to the nozzle row.   The inkjet recording apparatus according to claim 1, wherein each nozzle in the nozzle row uses an electrothermal conversion element as an ejection energy generating element.   The inkjet recording apparatus according to claim 1, wherein each nozzle in the nozzle row uses a piezo element as an ejection energy generating element.   The inkjet recording apparatus according to claim 10, wherein the piezoelectric element has a function as the detection unit. An ink jet recording method for performing recording using a recording head including a nozzle row formed by arranging a plurality of nozzles capable of ejecting ink,
A detection process for detecting vibrations generated with ink ejection;
Based on the vibration detected in the detection step, during the recording operation for ejecting ink from the nozzle based on the recording data, or during the recovery operation for ejecting ink that does not contribute to image recording from the nozzle, the ink ejection state And a determination step of determining whether or not a defective nozzle having a defect is generated.

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