System and method for analyzing operation of an ink jet head
First Claim
1. A system for analyzing operation of an ink jet head from which ink is ejected due to pressure within said head, said system comprising:
- sensing means for sensing the pressure characteristic in the ink jet head during a predetermined pressure change period; and
determining means connected with said sensing means for determining pressure build-up within said ink jet head to thereby detect faults in performance of said ink jet head based upon said pressure characteristics sensed by said sensing means.
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Abstract
A system and method are disclosed for analyzing operation of an ink jet head. Initiation of start-up is sensed, as is the pressure build-up in the ink jet head as ink is supplied thereto. The time lapse between initiation of start-up and the commencement of pressure build-up is determined, as is the time required for the pressure within the ink jet head to build to an operational level, and outputs indicative thereof are utilized for determination of fault occurrence and indication of faults or initiation of fault correction in response thereto. The system includes a pair of counters controlled by start-up initiation and the outputs from a pair of comparators which receive predetermined reference signals and signals indicative of pressure build-up at the ink jet head, with the outputs from the counters being coupled to a microcomputer for determination of faults.
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Citations
80 Claims
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1. A system for analyzing operation of an ink jet head from which ink is ejected due to pressure within said head, said system comprising:
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sensing means for sensing the pressure characteristic in the ink jet head during a predetermined pressure change period; and determining means connected with said sensing means for determining pressure build-up within said ink jet head to thereby detect faults in performance of said ink jet head based upon said pressure characteristics sensed by said sensing means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A system for analyzing operation of an ink jet head, said system comprising:
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a piezoelectric crystal for sensing the pressure at an ink jet head and providing an electrical output signal proportional to the pressure sensed; a first comparator for comparing the pressure sensed by said piezoelectric crystal and a first reference level, said first comparator providing an output when said pressure sensed by said piezoelectric crystal exceeds said first reference level; a second comparator for comparing the pressure sensed by said piezoelectric crystal and a second reference level, said second comparator providing an output when said pressure sensed by said piezoelectric crystal exceeds said second reference level; a first counter connected with said first comparator for counting from initiation of start-up until said first pressure level is exceeded at said ink jet head; a second counter connected with said first and second comparators for counting from the time that said first pressure level is exceeded until said second reference level exceeds at said ink jet head; and a microcomputer connected with said first and second counters for initiating at least one of indication and correction when said count on said counters indicates a fault in operation of said ink jet head. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28, 29)
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30. A system for analyzing operation of a device having a material flow initiating unit and a pressure drive for expelling material from said device, said system comprising:
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sensing means connected with said material flow initiating unit for sensing initiation of material flow and providing an output indicative thereof; transducer means for vibrating said flow during normal operation of said transducer means and also sensing pressure build-up in said device following initiation of material flow and providing an output indicative of said pressure build-up; and determining means connected with said sensing means and said transducer means to receive said outputs therefrom and responsive thereto determining the time lapse between initiation of material flow and pressure build-up. - View Dependent Claims (31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41)
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42. A system for analyzing operation of an ink jet head receiving ink from an ink supply through a valve controlled by a valve control unit so that ink received at said ink jet head is ejected under pressure therefrom, said system comprising:
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first sensing means for sensing actuation of said valve control unit to open said valve and providing an output indicative thereof; second sensing means for sensing pressure build-up in said ink jet head and producing an output indicative thereof; and time lapse determining means for receiving said output from said first and second sensing means and responsive thereto producing an output indicative of the time lapse between said actuation of said valve and said pressure build-up in said ink jet head. - View Dependent Claims (43, 44, 45, 46, 47, 48, 49, 50)
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51. A system for analyzing operation of a material inking unit having ink flow from an ink supply to an ink jet head through a valve controlled by an electrical valve control unit with the ink being ejected under pressure from the ink jet head, said system comprising:
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a first gate connected to receive a clock input at a predetermined frequency and the electrical output signal from said electrical valve control unit indicative of initiation of inking in said inking unit, said first gate providing an output at said clock frequency upon receipt of said electrical output signal indicative of initiation of inking; a delay counter connected to said first gate to receive said output therefrom to cause said delay counter to count at said clock frequency; a piezoelectrical crystal at said ink jet head to sense the pressure thereat and providing an output signal indicative thereof; a first comparator connected to receive a reference input signal at a predetermined level and said output signal from said piezoelectric crystal, said first comparator providing an output to said delay counter to terminate the count thereat when said output signal from piezoelectric crystal exceeds the level of said first reference input signal; a second gate connected to receive said clock input and the output from said first comparator, said second gate providing an output at said clock frequency upon receipt of said output from said first comparator; a rise time counter connected to said second gate to receive said output therefrom to cause said rise time counter to count at said clock frequency; a second comparator connect to receive a reference input signal at a predetermined level greater than said first predetermined level and said output signal from said piezoelectric crystal, said second comparator providing an output to said rise time counter to terminate the count thereat when said output signal from said piezoelectric crystal exceeds the level of said second reference input signal; a microcomputer having a delay register and a rise time register; coupling means including first and second logic gates connected with said delay counter and said rise time counter, respectively, with said first and second gates being connected with said delay register and said rise time register, respectively, through a data bus; and address decode means connected with said microcomputer and said first and second gates for controlling passage of the counts on said counters to said registers of said microcomputer. - View Dependent Claims (52)
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53. A method for analyzing operation of an ink jet head from which ink is ejected due to pressure within said head, said method comprising:
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sensing the pressure characteristic in an ink jet head during a predetermined pressure change period; and determining pressure build-up within said ink jet head to thereby detect faults in performance of said ink jet head based upon said sensed pressure characteristic. - View Dependent Claims (54, 55, 56, 57, 58, 59, 60)
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61. A method for monitoring operation of a device having a material flow initiating unit and a pressure drive for expelling material from said device, said method comprising:
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sensing initiation of material flow in said device; utilizing a transducer to vibrate the flow during normal operation and utilizing the same transducer to sense pressure build-up in said device following initiation of material flow; and determining the time lapse between sensed initiation of material flow and pressure build-up as sensed by the transducer for monitoring operation of said device. - View Dependent Claims (62, 63, 64, 65)
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66. A method for analyzing operation of an ink jet head, said method comprising:
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sensing initiation of start-up of the ink jet head; sensing pressure build-up in said ink jet head to a predetermined level; and determining the time lapse between said sensed initiation of start-up and said pressure build-up for analyzing operation said ink jet head. - View Dependent Claims (67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80)
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Specification