Abstract: The liquid supply system includes: a buffer tank (12) in which a liquid to be supplied to a liquid supply target device (15) is stored; a liquid level varying device (78, 82) that changes a liquid level height in the buffer tank; a liquid flow passage (16, 18) through which the liquid supply target device and the buffer tank communicate with each other; a pump (98A) provided in the liquid flow passage; and a valve (97A) for opening and closing the liquid flow passage, in which in a case in which the liquid supply target device is not in operation, the liquid is discharged from the buffer tank to lower the liquid level height in the buffer tank; and the pump and the valve are controlled to allow the liquid to flow into the buffer tank from the liquid flow passage.

Abstract: A sequence that includes first processing of generating a positive flow in a first direction in a liquid in a first flow passage including at least a part of a circulation flow passage through which the liquid is supplied from a liquid tank to the liquid jetting head and the liquid is collected from the liquid jetting head to the liquid tank and second processing of generating a negative flow in an opposite direction to the first direction in the liquid in the first flow passage, is executed. In the first flow passage, a filter that removes a foreign substance in the liquid is disposed between the liquid tank and the liquid jetting head in the positive flow. A flow rate of the liquid of the positive flow is higher than a flow rate of the liquid of the negative flow. The negative flow has a steady flow state.

Abstract: An inkjet head ejection performance evaluation method includes: printing a test pattern for examining an ejection condition for each nozzle by an inkjet head and reading the test pattern by an image reading device; measuring a first depositing position for each nozzle from a read image to calculate an angle deviation amount of the inkjet head based on the first depositing position and pattern information; calculating at least one of a second depositing position and second deposit displacement amount in which an influence due to angle deviation caused is eliminated; calculating a moving amount caused by rotation of the angle deviation amount from a reference position of the nozzle at a reference attaching angle up to a current nozzle position; and calculating, by using these calculation results, at least one of a distance between the adjacent pixels and a third deposit displacement amount including the influence.

Abstract: Provided are an image recording apparatus that efficiently detects defective recording elements causing image defects in a plurality of recording heads and a method of detecting the defective recording elements. An image recording apparatus including: a plurality of recording heads; an indicator acquisition unit for acquiring an indicator which relatively indicates how easily image defects are visually perceived for each color, an appearance ratio setting unit for setting an appearance ratio of a test pattern as a higher value as the indicator of each color becomes higher; a recording unit for recording the test pattern of each color on a recording medium at the appearance ratio; an imaging unit for capturing an image of the test pattern which is recorded on the recording medium; and an analysis unit for analyzing the captured test pattern and detecting a defect of a recording element in the recording head.

Abstract: A liquid ejection device includes a head driving unit that generates a first driving voltage and a second driving voltage in which whether or not there is ejection of liquid from a first ejection element in a case where the first driving voltage alone is applied to the first ejection element that is a detection target of a short circuit between ejection elements is different from whether or not there is ejection of liquid from the first ejection element in a case where the first driving voltage and the second driving voltage are applied to the first ejection element, supplies the first driving voltage to the first ejection element, and supplies the second driving voltage to the second ejection element suspected of a short circuit with the first ejection element.

Abstract: A pattern formation device, a liquid ejection device, and an electrical fault detection method capable of detecting electrical fault of a liquid ejection head on the basis of an analysis result of an electrical fault detection pattern are provided. An electrical fault detection pattern having an arrangement of dot arrays satisfying an arrangement condition with an arrangement of a plurality of ejection elements in a liquid ejection head is formed by ejecting liquid from a liquid ejection head in which M rows of ejection element groups in which a plurality of ejection elements are arranged in a first direction are arranged in a second direction intersecting the first direction, and M is an integer equal to or greater than 2.

Abstract: A pattern formation device, a liquid ejection device, and an electrical fault detection method capable of detecting electrical fault of a liquid ejection head on the basis of an analysis result of an electrical fault detection pattern are provided. An electrical fault detection pattern having an arrangement of dot arrays satisfying an arrangement condition with an arrangement of a plurality of ejection elements in a liquid ejection head is formed by ejecting liquid from a liquid ejection head in which M rows of ejection element groups in which a plurality of ejection elements are arranged in a first direction are arranged in a second direction intersecting the first direction, and M is an integer equal to or greater than 2.

Abstract: A liquid ejection device includes a head driving unit that generates a first driving voltage and a second driving voltage in which whether or not there is ejection of liquid from a first ejection element in a case where the first driving voltage alone is applied to the first ejection element that is a detection target of a short circuit between ejection elements is different from whether or not there is ejection of liquid from the first ejection element in a case where the first driving voltage and the second driving voltage are applied to the first ejection element, supplies the first driving voltage to the first ejection element, and supplies the second driving voltage to the second ejection element suspected of a short circuit with the first ejection element.

Abstract: The inkjet head ejection performance evaluation method includes: printing a test pattern for examining an ejection condition for each nozzle by an inkjet head having a plurality of nozzles arrayed in a matrix and is read by an image reading device; and measuring a depositing position for each nozzle from the read image to calculate a deposit displacement amount based on the depositing position and pattern information, wherein a position of a center of gravity in a Y direction of nozzles used for calculation for calculating the deposit displacement amount of the nozzle number n is equal to a position of a center of gravity in the Y direction of all nozzles existing in the nozzle range of the nozzles used for calculation, where a direction of relative movement between the inkjet head and a recording medium is the Y direction.

Abstract: The liquid ejection head has a structure in which three or more head modules including a plurality of ejection elements are arranged along a single direction, and the liquid ejection head includes a first head module, a second head module and a third head module which are arranged in ascending order of slope of ejection volume distribution in the single direction or are arranged in descending order of the slope of the ejection volume distribution in the single direction, the slope of the ejection volume distribution in the single direction being evaluated by subtracting an ejection volume at one end part in the single direction from an ejection volume at the other end part in the single direction.

Abstract: The production method for a liquid ejection head is provided, in which a first head module is set, a second candidate head module is selected, a first representative value of the first head module is acquired, a second representative value of the second candidate head module is acquired, an average value of the first representative value and the second representative value is derived, and the second candidate head module by which the derived average value is 0.76-fold or more and 1.24-fold or less of an average ejection volume target value is set as a second head module.

Abstract: A plurality of recording elements included in a printed head are grouped into a plurality of groups, a test order is set in units of groups, and a test of the recording elements is periodically performed in units of groups in the set test order. In a case where an abnormality is detected in the recording element as a result of the test, the recording element in which an abnormality is detected is recognized as a retest target, an order of tests is changed through interruption, and a retest of a group including the recording element recognized as a retest target is performed. In a case where an abnormality is detected again in the recording element that is a retest target as a result of the retest, the recording element that is a retest target is recognized as an abnormal recording element.

Abstract: The inkjet head ejection performance evaluation method includes: printing a test pattern for examining an ejection condition for each nozzle by an inkjet head having a plurality of nozzles arrayed in a matrix and is read by an image reading device; and measuring a depositing position for each nozzle from the read image to calculate a deposit displacement amount based on the depositing position and pattern information, wherein a position of a center of gravity in a Y direction of nozzles used for calculation for calculating the deposit displacement amount of the nozzle number n is equal to a position of a center of gravity in the Y direction of all nozzles existing in the nozzle range of the nozzles used for calculation, where a direction of relative movement between the inkjet head and a recording medium is the Y direction.

Abstract: An inkjet head ejection performance evaluation method includes: printing a test pattern for examining an ejection condition for each nozzle by an inkjet head and reading the test pattern by an image reading device; measuring a first depositing position for each nozzle from a read image to calculate an angle deviation amount of the inkjet head based on the first depositing position and pattern information; calculating at least one of a second depositing position and second deposit displacement amount in which an influence due to angle deviation caused is eliminated; calculating a moving amount caused by rotation of the angle deviation amount from a reference position of the nozzle at a reference attaching angle up to a current nozzle position; and calculating, by using these calculation results, at least one of a distance between the adjacent pixels and a third deposit displacement amount including the influence.

Abstract: A printing device includes a jetting section that jets out ink, a storage section that stores the ink, a supply channel through which the ink flows from the storage section toward the jetting section, a recovery channel through which the ink flows from the jetting section toward the storage section, a filter provided on at least one of the supply channel and the recovery channel, a pump provided on at least one of the supply channel and the recovery channel, and a control section. The control section applies control to the pump to make a flow speed of the ink in a non-printing period smaller than a flow speed of the ink in a printing period, the printing period including a period from a printing start time to a printing completion time, and the non-printing period being outside the printing period.

Abstract: Provided are an image recording apparatus that efficiently detects defective recording elements causing image defects in a plurality of recording heads and a method of detecting the defective recording elements. An image recording apparatus including: a plurality of recording heads; an indicator acquisition unit for acquiring an indicator which relatively indicates how easily image defects are visually perceived for each color, an appearance ratio setting unit for setting an appearance ratio of a test pattern as a higher value as the indicator of each color becomes higher; a recording unit for recording the test pattern of each color on a recording medium at the appearance ratio; an imaging unit for capturing an image of the test pattern which is recorded on the recording medium; and an analysis unit for analyzing the captured test pattern and detecting a defect of a recording element in the recording head.

Abstract: Provided are an ink jet recording apparatus and an abnormality detection method of an ejector which are capable of performing high-accuracy abnormality detection and suppressing the generation of excessive abnormality detection with respect to a required image quality. An ink jet recording apparatus (10) includes an ink jet head (20C, 20M, 20Y, 20K) having a plurality of ejectors, a medium transport unit (22), a calculation unit (34) that calculates an index value relevant to a droplet ejection amount for each ejector on the basis of printing data, a threshold determination unit (40) that determines a threshold for ejection abnormality determination for each ejector in accordance with the index value, a threshold storage unit (44) that stores the threshold determined for each ejector, and an abnormality determination unit (54) that determines the presence or absence of ejection abnormality by comparing the threshold with a measurement amount for each ejector.

Abstract: The production method for a liquid ejection head is provided, in which a first head module is set, a second candidate head module is selected, a first representative value of the first head module is acquired, a second representative value of the second candidate head module is acquired, an average value of the first representative value and the second representative value is derived, and the second candidate head module by which the derived average value is 0.76-fold or more and 1.24-fold or less of an average ejection volume target value is set as a second head module.

Abstract: The liquid ejection head has a structure in which three or more head modules including a plurality of ejection elements are arranged along a single direction, and the liquid ejection head includes a first head module, a second head module and a third head module which are arranged in ascending order of slope of ejection volume distribution in the single direction or are arranged in descending order of the slope of the ejection volume distribution in the single direction, the slope of the ejection volume distribution in the single direction being evaluated by subtracting an ejection volume at one end part in the single direction from an ejection volume at the other end part in the single direction.

Abstract: A plurality of recording elements included in a printed head are grouped into a plurality of groups, a test order is set in units of groups, and a test of the recording elements is periodically performed in units of groups in the set test order. In a case where an abnormality is detected in the recording element as a result of the test, the recording element in which an abnormality is detected is recognized as a retest target, an order of tests is changed through interruption, and a retest of a group including the recording element recognized as a retest target is performed. In a case where an abnormality is detected again in the recording element that is a retest target as a result of the retest, the recording element that is a retest target is recognized as an abnormal recording element.